Brushless String Trimmer Shootout! DeWALT, Toro, STIHL, Troy-Bilt. Brushless weed eater
Brushless String Trimmer Shootout! DeWALT, Toro, STIHL, Troy-Bilt
This article is a review of four of the best cordless string trimmers available right now. The Toro Power Plex, STIHL FSA 90 R, Troy-Bilt C.O.R.E., DeWALT Flex-Volt. I also talk about the new EGO carbon fiber shaft trimmer.
I’ll admit it – I’m one of the people who would love to see all small lawn garden gas engines disappear. In particular the cheap homeowner string trimmers, blowers, hedge trimmers and even chainsaws. I’ve owned way to many of them over the years and they have always been notoriously hard to start, noisy and don’t last long. In the last 15 years even if you do find one that is better than most – the engines have been regulated to the point where they have no power for all but basic tasks. Because of that, I’ve spent the last five years watching the cordless, battery-powered string trimmer market come of age. As homeowners, we are finally getting quality trimmers, blowers, hedge trimmers and other equipment for our normal suburban lawns that will do the job better than the small gas engines. In my opinion, there are now a few on the market that will tackle any of your tasks and last for years.
Right to left: STIHL, Toro, Troy-Bilt, DeWALT, Husqvarna Gas for comparison.
I purchased these brushless trimmers myself. I’m not sponsored by any of the brands so it helps me to stay completely objective in my reviews.
There are well over 75 different cordless string trimmers on the market right now and after reading all the specifications and reviews I purchased 4 models for this article. The models I purchased are the Toro Power Plex, STIHL FSA 90 R, Troy-Bilt C.O.R.E., DeWALT Flex-Volt. All of these are designed to replace your gas trimmer. All use the latest high tech brushless motors to give you the most power and battery efficiency. I’ll keep this article simple and only go over what I like and don’t like about these trimmers.
Most of the links in this article will take you to Amazon. My readers and I have been having just the best luck buying cordless string trimmers from Amazon. If a model is available directly from Amazon or a reputable seller on Amazon I will offer you a buy link. Amazon literally is the best place to buy anything online. The delivery is swift, and if there are any issues with the shipping or the item Amazon takes care of it immediately. Buy at Amazon
By the way, Just assume that if I send you to a website to “read more and buy” I’ll make a small commission from the sale. (That’s how I make the money to operate this site)
The Best Trimmer Line? I like this trimmer line for all string trimmers:
If you don’t have a lot of experience using string trimmers or you have weak wrists I suggest buying the round line. I use round line myself.
The trimmer line below is edged and cuts the best but the edges can “catch” and cause your trimmer to stray into areas you don’t want to be trimmed.
Number One – Toro PowerPlex Brushless String Trimmer Review
Buy Here: Toro PowerPlex 51482 Brushless 40V Lithium-Ion 14″ Cordless String Trimmer, 2.5 Ah Battery Charger Included
Of the 4 trimmers, I bought the Toro is the one I grab the most often.
Toro has been fairly slow to come out with a competitive cordless string trimmer. Why? Because they never jump on the latest trend without spending hundreds of hours researching and testing their prototypes. You can be assured that the item they offer is good, reliable and ready to last you a long, long time.
The Toro 14 inch brushless is different from the rest. It’s designed for a suburban homeowner who needs a well built, easy to operate, lightweight trimmer. Many homeowners just want a good trimmer that is very easy to use, is lightweight, trims their lawn well and can cut down the occasional 3-foot weed they missed. With the battery, it is less than 9 lbs. They don’t need a 14 lb monster trimmer to go out in the back 40 and knock down an acre of horseweeds.
What I really like about the Toro
- Extremely efficient brushless motor. The speed is controlled with a trigger just like your older gas powered trimmer so you can trim around delicate areas. This trimmer is very quiet.
- Lighter than all the other trimmers I handled. The quick adjust handle will let both short and tall people use this trimmer any time. You will not need to use a carry strap for extended use. It is balanced very well with just enough weight in the head so it’s very easy to trim accurately around delicate plants and landscaping.
- Heavy duty dual line head for efficient cutting. It uses the standard.080 line and can accept the rounded, twisted and edged varieties. You can wind your own or buy pre-wound spools.
- Excellent quality. Toro has engineered every part of this trimmer to last.
- Foldable for transport in your car trunk. The only straight shaft trimmer on the market that easily folds up.
- At least 45 minutes run time. I can trim my entire one acre landscaped yard twice on one charge. Included T90 battery charges in just an hour.
- This trimmer is part of a system that includes a 480 CFM 150 MPH leaf blower, 24-inch hedge trimmer, 13-inch single line trimmer, 14-inch chainsaw, and double capacity T180 battery.
The Elephant In The Room: Toro’s Battery Size.
From Justin: I am concerned about battery life which is my only hesitation the Toro’s low watt-hour T90 battery.
My Answer: The Toro is very efficient and I can get 40 minutes or more of run time out of the T90 battery. Remember you don’t need to leave it running like you do with a gas model when you walk from one area to the next to trim. It also trims very well at half-throttle so the battery can last even longer.
COMPARING MILWAUKEE M18 BRUSHLESS STRING TRIMMER TO FUEL QUIK-LOK // MILWAUKEE TRIMMER CHALLENGE!
If it takes you longer than that to trim just slap the battery on the charger and have a cup of coffee. You don’t have to charge the lithium battery fully each time you use it. Plus when you are done you can leave the battery on the charger. It won’t hurt the battery at all.
Justin: You know, I hadn’t considered that the unit is not running at all times. You have completely changed my view on what 40 minutes of battery life actually means!
- So, the T90 battery is great for a string trimmer and hedge trimmer but the T180 (5 AH) is a better choice for the leaf blower and chainsaw. I would like to see a purchase option for the blower and chainsaw with the T180 Battery.
Batteries: DeWALT FlexVolt, Troy-Bilt 40v, Toro Power Plex, STIHL AP300
Number Two – STIHL FSA 90 R Brushless String Trimmer Review
STIHL makes four cordless string trimmers with removable batteries. In addition, they make two separate battery series. The AK series is designed for homeowners. The AP series is designed for large acreages and commercial operators. The FSA 90 R I choose for this test is the top-of-the-line commercial version. I purchased it with the AP300 battery/charger.
Why? Because I needed one “standard” to judge all the others by. In addition, I’ve used the commercial gas series STIHL trimmers for years and think I the trimmer head they use is one of the best on the market.
What I really like about the STIHL
- With the AP100 battery, it weighs just a few ounces more than the Toro PowerPlex.
- Has many battery options ranging from a 100 WH for homeowners to a huge backpack battery for all-day commercial use.
- Uses the same commercial trimmer head the gas engine models use. It will last the life of the trimmer and then some.
- It has a speed limiter dial on the handle. You can dial down the top speed and it will trim your weekly work well and the battery will last all day. Most reviewers don’t get the dial is for economy and/or speed control around delicate plants.
- Tremendous cutting power. Even when cutting 8-foot prairie grass I could not get this trimmer to slow down. It also does an excellent job of not wrapping around the head when cutting tall grass.
- This trimmer is part of a system that includes other trimmers, chainsaws, blowers, hedge trimmers and steel-deck walk-behind mowers.
No, this is not a “quick load” head. You will have to read the instructions to load new line on it the first time. Take your time to learn how to load it and it will be easy after that. BUT! It always works and never acts up. Remember, this head is their commercial head and even in the worst conditions and abuse, it will last.
Here is a video showing you how to load the head. FYI – you don’t need a screwdriver to push in the buttons. The buttons are designed for your thumbs.
What I don’t like about the STIHL
- Most expensive cordless trimmer on the market.
- You must go to a local dealer to purchase.
- There is no suggested pricing online so you don’t know if you are getting a good deal from your local store. STIHL MAKES you shop different dealers to make sure you are getting a fair price.
Intermission: Is a brushless string trimmer right for you?
Before I discuss the remaining trimmers I want to say: The best brushless string trimmer right now for most people is the Toro Power Plex and the best brushless string trimmer on the market is the STIHL FSA 90 R but it may not be the best trimmer for you.
If you just need a trimmer for weekly mowing tasks I actually suggest getting a trimmer to match your cordless drill batteries. For about 100-150 you can get a bare tool DeWALT 20 volt, Ryobi 18 volt, or Milwaukee 18 volt. These are all quality, brushless motor string trimmers and they will do the job well for you. Don’t fall for the hype of having to have a separate high voltage battery for your yard tools.
Number Three – EGO Power Carbon Fiber Shaft Trimmer
What about EGO Power ? I’m going to go through the EGO in the video below. EGO gave everyone on YouTube with a thousand subscribers or more a free one over the last three years so the older models have been covered to death. For 2018 they have introduced two completely new lines of trimmers …again… and I just finished this video on the new EGO carbon fiber shaft trimmer.
The EGO is not my first choice for most homeowners but if you want a complete system – walk-behind, trimmer, blower, chainsaw, edger, etc they are worth comparing to the other models in this article. EGO Power at The Home Depot
Number Four – DeWALT Flex-Volt Brushless String Trimmer Review
DeWALT currently makes 3 string trimmers. a 20-volt MAX, 40 volt commercial and 60 volt. I’ve used all three and I decided the 60 volt Flex-Volt was the one I should buy for this test.
What I really like about the DeWALT Flex-Volt
- I like that it uses the same batteries as the FlexVolt tools. If you already have the batteries you can save 100 and just buy the bare tool.
- It has the most power of the three DeWALT string trimmers. power than the Toro PowerPlex and a little less power than the STIHL FSA 90 R. It has plenty of power to cut down tall weeds.
- Conventional – dual line head.
- It’s balanced well. It’s about 4 lbs heavier than the Toro PowerPlex but for most people, you can trim your entire lawn without it getting too tiring to use.
- The head accepts both.080 and.095
- This trimmer is part of a system that uses the same Flex-Volt battery for both hand tools and lawn tools. At this time it does NOT include a walk-behind mower.
What I don’t like about the DeWALT Flex-Volt
- It’s noisy. DeWALT has chosen to use a brushless motor and a gear reducer. The gears are noisy compared to the other brushless trimmers I tested here.
- The trimmer head works very well but winding new line takes practice. Sticking the line through the holes in the housing can be a pain. I wish it had the drop in slots like the STIHL.
- All the other brands use a sealed aluminum housing for the motor on the trimmer head. The aluminum dissipates the heat during use, The aluminum design is very rugged and you can use it under any conditions. For some unknown reason, DeWALT decided to use a steel housing and use air vents to cool the motor. Yes, that’s how they make all their hand tools but what made them think that was a good idea on a string trimmer! What. I know DeWALT uses vents and fans on all their hand tools to cool the motor. But this really doesn’t make sense on a string trimmer. You have to clean air vents on the trimmer head every time you use it and DeWALT also states “Do Not Get the Head Wet!”
Number Five – Troy-Bilt C.O.R.E Brushless String Trimmer Review
I am a big fan of the CORE Technology electric motor so when MTD purchased the company a few years ago I was hoping they would take it to the next level and design a complete line of cordless tools around the motor.
C.O.R.E. is an actual technology not just some advertising lingo that sounds good.
- The battery life is phenomenal. The CORE uses load sensing electronics to keep the trimmer running at an optimum speed. When you are trimming weekly growth it uses very little power but get into the high weeds and it automatically senses the extra load and supplies more current to the motor.
- It’s heavier than the Toro PowerPlex or STIHL FAS 90 R, but comes with a built-in snap ring for a harness.
- The trimmer head is built very strong. I’d guess that it’s the toughest residential head on the market. It is an easy load head (more on that later)
- This trimmer is part of a system that includes a self-propelled steel deck mower, blower, and hedge trimmer.
- I personally didn’t get along with the trimmer head. It’s a quick load head but for some reason, I could not get it wound correctly and I always ended up with a bird’s nest. I don’t see any reviews with the same problem though – maybe it’s just me.
- With great power – comes greater weight. This trimmer was the heaviest of the bunch but it also has the longest run times and the battery can also power a self-propelled walk-behind motor. No need to buy additional higher capacity batteries for the mower.
- It’s balanced like a gas trimmer. There is more weight on the rear than on the head. so when you are walking from one landscape bed to another using one hand the head pops up. Although it’s like your gas trimmer it’s not as efficient because you have to push the head down each time you start to use it. Is that really a problem? Maybe it’s just me….
The trimmer head and I didn’t always get along
Load sensing panel with the boost button
As expected the entire cordless trimmer market is a mess and full of advertising hype and misinformation. Many of the reviewers don’t understand the terminology of battery tech so they are mistakenly using max voltage or amps as their deciding factor in which models to promote. It’s not volts or amps – it’s Watt-Hours.
Other reviewers are sponsored by a brand or getting free stuff to review and that is skewing the results. Here are two articles that explain what is important to know about the batteries.
Gas-Powered vs. Battery-Powered Weed Eaters
Do the loud noises from neighborhood lawn equipment ruin your quiet Saturday? Or are you more, “Give me power at any cost?” These are things you’ll need to consider when choosing between gas vs. battery-powered weed eaters.
Battery-powered and gas-powered weed eaters do the same job, so you may wonder, “What’s the difference?” Actually, power sources mean big differences in the use and performance of machines. Before you buy a weed eater, you want to know what type of machine will serve your lawn most efficiently and whether or not the noise or gas smell will bother you.
We’ll discuss the pros and cons of gas-powered vs. battery-powered weed eaters to help you decide which is best for your lawn.
- Why do I need a weed eater?
- Essential weed eater terms
- Pros and cons of gas-powered weed eaters
- Pros and cons of battery-powered weed eaters
- Which is the best weed eater for me?
- FAQ about weed eaters
Why do I need a weed eater?
Weed eaters are an indispensable power tool in the DIY lawn maintenance tool kit. These handy machines help homeowners and lawn pros cut down grass and weeds in areas that a lawn mower just won’t reach.
If you have a drain ditch in your lawn or a steep slope, a weed eater will keep the grass looking nice and neat. These machines also create that professional, finished look when you use them to create clean lines around the edge of your lawn and flower beds.
Believe it or not, battery- and gas-powered machines aren’t the only types of weed eaters on the market. You’ll also see electric string trimmers (AKA corded models that require an extension cord) and even propane weed eaters.
Electric models are popular in very small, “postage stamp” lawns, and propane models perform as well as gas. While it’s good to know there are other options, we’ll FOCUS on the more popular gas-powered and cordless models in this article.
Not only do weed eaters accomplish many lawn tasks, but they also have many names:
- Weed whacker (or weed wacker)
- Whipper snipper
- Weed trimmer
- String trimmer
- Weed whipper
- Line trimmer
- Grass trimmer
They all mean the same thing and do the same job. Here are a few brands you’re probably familiar with:
Essential weed eater terms
If you’re a weed eater novice, here are a few terms and components to familiarize yourself with as you do your research:
Gas models rely on gas and oil to power the engine. Battery-powered models rely on batteries — usually a lithium-ion battery. Both types offer brushless motors as well. Brushless motors are more efficient and less noisy than brushed motors. If you’re concerned about cost, though, know that the brushless motors are more expensive.
When you look at these power sources, gas models will label motor power in cubic centimeters (cc) and battery models will label it in volts (24V). The higher the number, the more power they offer.
Battery-powered models work well on lawns up to an acre, depending on your level of power. Use a machine with 20-40 volts for up to ½ acre, or from 40-80 volts for up to an acre. If your lawn is over an acre, you may want to consider a gas-powered machine.
Also, pay attention to rpm (revolutions per minute). Some will have a variable speed option as well (3,500 rpm, 5,300 rpm, 6,500 rpm) to save battery power. The higher rpm, the better the line will cut through thicker material.
There are four types of feed systems: bump feed, auto-feed, command feed, and fixed-line feed. The purpose of the feed system is to release more line when you’re running low.
- Bump feed: Tap the machine on the ground a few times while it’s running to get a longer string. This system is quick and easy and, if you’ve removed the guard, it gives you control over the length of your line.
- Auto-feed: The trimmer uses its own “brain” to release more line when the line is too short. This system is convenient but gives the operator less control over the length of the line.
- Command feed: When you run low on line, simply push a button or turn a dial, and the feed mechanism will release more line. This is similar to the bump feed because you can make your line as short or long as you wish.
- Fixed-line system: Buy pre-measured segments of line to load into the feed mechanism when your line runs low. This system works with fixed-line heads to load a pre-cut length of line into the machine. These heads are often ideal for heavy-duty trimmers that require thicker string.
Trimmer line (or blade)
Different trimmers will accept different trimmer line widths. (Trimmer line is the string that does all of the cutting.) Some battery-powered models accept slightly thinner line widths than gas models. Some trimmers come with the option to buy blades for tougher jobs.
You can choose from two main types of handles: loop handles or bicycle (AKA “bullhorn”) handles. Loop handles are most common on residential weed eaters. Bicycle handles may be more comfortable for larger, longer, brush clearing jobs. Try both types to see which feels more comfortable for you.
Weed eaters come with curved shafts or straight shafts. Curved shafts are for light use on a residential property, and they are great for beginners. Straight shafts are for more strenuous commercial work and sometimes come with the option to buy a blade or other accessories. Straight shaft trimmers are also easier to get under bushes. Curved-shaft models are less expensive overall.
If you have lots of brush or rocks in your lawn, pay attention to the size of your debris guard on the back of the head. Some are larger than others. You’ll want to invest in a model with a larger deflector (or purchase a kit) if this is a concern for you. Some models also come with a flip-down edge guard in the front that ensures you don’t get too close to trees and other plants.
After you’ve started the engine, you may wonder, “How do I spin the line?” There are often two control buttons above the handle. Why are there two? One acts as a safety. For example, if you mistakenly press one while you are holding the machine, the line won’t run (and you’ll be less likely to cut something unintentionally). So, when you’re ready to start weed eating, press both control buttons to spin the line.
Pros and cons of gas-powered weed eaters
Gas-powered string trimmers are the “old guard” of the string trimmer world. They’ve been around much longer than battery or electric weed eaters and have a good track record of reliable performance. Here are some pros and cons of these machines.
✓ Delivers commercial-level, all-day performance✓ Sufficient power for large properties or many properties✓ Handles tall grass and overgrowth with ease✓ Preferred choice of pros✓ Can be repaired ✓ Consistent power throughout use✓ Easy to carry gasoline with you
✗ Gas engine requires maintenance✗ Exhaust emissions may have adverse effects on people and air quality✗ Noisy to operate✗ Engine can become gummed up with old fuel or fuel without proper stabilizer ✗ Pull starters can be difficult for some homeowners✗ Gas and oil can be messy to work with
Pros and cons of battery-powered weed eaters
Battery-powered weed eaters (AKA cordless weed eaters) are the (relatively) new kid on the weed whacking block, but they’ve made quite an impression on many homeowners. Many residential customers enjoy their quiet, emission-free operation and sufficient run time.
✓ Does a sufficient job for a small property or a single property✓ No engine to maintain✓ Batteries swap out easily if you run out of power✓ Very low noise✓ No gas or oil to replace✓ Easier to start — no pull cord✓ No fumes✓ Can use batteries from other machines from the same brand✓ No emissions
✗ Battery power dilemma — Need a recharging station if you want to weed eat all day (or have tons of batteries)
✗ Battery run time✗ Battery recharge time✗ Hard to find someone to repair✗ Power fades as battery life fades✗ Rechargeable batteries and charger may not come with the unit
Which is the best weed eater for me?
Here are a few questions to ask yourself to help you make a decision:
What size property do you have? Smaller residential properties are ideal for battery-powered weed eaters. Larger properties not only have more space but are likely to have taller grass and brush, so gas-powered trimmers may be a better fit.
How do you plan to use the weed eater? Unless you’ve built your lawn care business around being an all-electric provider, you’ll need at least one gas weed eater in your arsenal. If the machine will only be for you as a homeowner, a battery-powered model has plenty of power.
What level of engine care are you willing to do? Gas-powered models require you to get your hands dirty. You’ll need a constant supply of gas and oil, and you’ll need to winterize it before you put it away for the off-season. If you’re not willing to do this, go with a battery-powered model.
What kind of attachments do you need? Before you make a purchase, look into which attachments (if any) your top pick offers. Common attachments include hedge trimmers, pole saws, edgers, and cultivators. Attachments save space and money and are a good investment for many customers.
Both gas string trimmers and cordless string trimmers come with a few models that are dual brush cutter/trimmers. This gives you many more options for ways to use your trimmer.
Physical considerations: As you’re shopping around, pay attention to the weight of the machine. If you don’t like to carry around heavy machinery for a long time, consider that as you shop. Gas-powered machines are generally a little heavier than battery-powered models.
See if it has other ergonomic features for ease of use or for jobs that will require more than a quick walk around the lawn. Sometimes straps and slings are helpful for those larger cleanup jobs. Straps and slings distribute the weight across your shoulders and give your arms and back a break.
Finally, consider the length of the shaft. Although some shafts have an adjustable-length feature, other machines only have one length, which could be problematic for some buyers. If you’re concerned about getting a machine that works well for your stature, go inside the store and hold several different machines to gauge weight, ergonomics, and length.
Extras: Not all battery-powered models include the battery and/or charger. In addition, you’ll probably want to buy a backup battery upfront so you can have an extra battery on days when you want to stay out in the lawn longer than one battery will allow.
Cutting width: If you prefer a wide cutting width (diameter), check this before you buy. If you’re used to a 17-inch cutting path, for example, you might be disappointed if you get home and find that yours only has a 13-inch reach.
Warranty: If this is important to you, check to see what warranty is offered. With battery-powered equipment, battery warranties may be separate. If you don’t see a separate warranty for the battery, check to see whether or not that is included.
FAQ about weed eaters
Which is the best weed eater for seniors?
For seniors or for anyone who isn’t as strong as Joe Lumberjack, there are a few considerations to keep in mind:
—Weight: Look at the tool weight. Also, consider that a battery or tank of gas will add to that. —Pull start vs. battery start: With a gas model, the pull start may be an issue for some seniors. You have to put the weed eater on the ground and quickly pull up on the string. A spring-assist pull start may make starting the machine easier if you prefer a gas weeder. However, if you’re considering a battery-powered model, push a button, squeeze the trigger, and you’re good to go. —Ergonomics: You may want to invest in a special handle or shoulder strap. Even though this tool may only see residential use, these components may make even a small job that much easier. —Cost: If you don’t have a lot of extra money to spend, curved-shaft models are usually less expensive. Also, look for refurbished models or seasonal sales. Generally, stores offer both great and great selection s on lawn equipment on the three summer holidays (Memorial Day, Independence Day, and Labor Day). Fall sales starting in September offer great deals (end-of-season), but selection may be more limited.
Which is the best brand of weed eater?
What brand of lawn equipment have you enjoyed using in the past? Or, what brand does your neighbor recommend? Personal experience and the recommendations of friends go a long way.
You may even ask the lawn workers in your neighborhood to see what type of equipment they use. If someone works with a tool day in and day out, they probably have a favorite brand to recommend.
Pro Tip: If neighbors or lawn crews are in short supply, call your local small engine shop. They’ve got the inside scoop on which brands they never see, and which ones come in all the time for repairs.
Which is the best residential weed eater?
Heavy-duty vs. light-duty use: If you have a small, postage-stamp-sized lawn, don’t go all out. A simple, lightweight machine will do fine. If, on the other hand, you have a standard yard, a large yard, or a backyard that looks like a jungle if you let it go, you may want to opt for a more powerful model.
Quality: High-quality machines usually cost more. If you don’t have experience with a particular brand or model, read helpful online “Best Weed Eater” guides, talk to neighbors, and read reviews.
Cost: This is a defining factor for many homeowners. Lighter use means a lower cost and vice versa. Shop sales, and do your research for a model that will do what you need at a price you can afford.
If weed-eating is not your favorite way to relax after a long week, let our local lawn care pros take the guesswork out of “Who’s going to mow my lawn?” Our reliable crews give your lawn a professional cut and edge every time.
Main Photo Credit: StrangeApparition2011 | Wikimedia Commons | CC BY-SA 4.0
The 10 Best Weed Eaters of 2023
Michelle Ullman is a home decor expert and product reviewer for home and garden products. She has been writing about home decor for over 10 years for publications like BobVila.com and Better Homes Gardens, among others.
Mary Marlowe Leverette is one of the industry’s most highly-regarded housekeeping and fabric care experts, sharing her knowledge on efficient housekeeping, laundry, and textile conservation. She is also a Master Gardener with over 40 years of experience and 20 years of writing experience. Mary is also a member of The Spruce Gardening and Plant Care Review Board.
Emily Estep is a plant biologist and journalist who has worked for a variety of online news and media outlets, writing about and editing topics including environmental science and houseplants.
Whether you call it a “weed eater,” “weed whacker,” or “string trimmer,” these landscaping tools are ideal for trimming grass and weeds along the edge of a flowerbed, around a tree trunk, underneath a deck, and in other hard-to-reach places.
Jeremy Yamaguchi, the CEO of Lawn Love, says, “A weed whacker can quickly and effectively trim grass, weeds, and other unwanted plant growth in areas difficult to reach with a mower or shears. When choosing one, the most important thing to look for is the power it offers, as well as the size and weight of the tool. Gas weed eaters are the most powerful, but electric models are best for most homeowners.”
He cautions, “To ensure safe use of a weed whacker, always wear the appropriate protective gear, including goggles and gloves, stand with your feet apart for balance, hold the tool’s handle firmly but comfortably with both hands, and never operate the weed whacker without its guard attached.”
Ryobi 40-Volt Lithium-Ion Brushless Electric Cordless String Trimmer
If you want the power of a gas weed eater but the convenience of a battery-powered tool, then this 40-volt offering from Ryobi is the answer. Our top choice of string trimmer is loaded with great features, including a brushless motor for longer life with less required maintenance and an adjustable handle so you can position it comfortably for your height. We also appreciate its two-speed trigger with variable speed control, so you can go faster when you need extra power for tough weeds or brush, and slow the tool down to extend the battery run-time when merely cutting small weeds and grass. Plus, it has an adjustable cutting width, with a minimum of 13 inches and a maximum of 15 inches.
This string trimmer comes with 0.085-inch string, which is good for trimming grass and weeds, but you can also load it with 0.095-inch string if desired for tackling tougher weeds, light brush, or thick grass. Either way, the weed whacker is very easy to reload, thanks to the REEL EASY head, which can be rewound in under 60 seconds. When you want to let out more string, a gentle bump of the tool against the ground advances just the right amount so you can keep working without having to stop and let out line by hand. The tool also comes with a set of serrated plastic blades, which can be fitted into the tool’s head in place of string. Use the blades for cutting tougher brush and weeds. While not nearly as strong as metal blades, these do a good job on softer weeds and grasses, but they aren’t sturdy enough for woody weeds.
This versatile weed eater works with the Ryobi line of Expand-It accessories, sold separately, which can turn your string trimmer into a pole saw, electric hedge trimmer, soil cultivator, snow thrower, blower, and more quickly and easily. The weed whacker comes with one Ryobi lithium-ion 40-volt battery and charger, which are compatible with any other Ryobi tool using a 40-volt battery. Depending on conditions, you can get up to one hour and 10 minutes of run-time from the battery before needing to recharge.
Price at time of publish: 213
Type: Cordless electric | Weight: 11.3 pounds | Engine/Battery Power: 40 volts | Shaft Type: Straight | Maximum Cutting Width: 15 inches
Greenworks 5.5 Amp 15-Inch Corded Electric String Trimmer
Just because a weed whacker comes at a budget price, that doesn’t mean you have to forgo great features, as this corded electric offering from Greenworks proves. Plug the tool into an outdoor-rated extension cord up to 100 feet in length; no smelly gasoline fumes or worrying about a battery running down before you finish. Suited to a small-to-medium yard, this string trimmer’s head easily pivots for use as a trimmer or an edger, doubling its versatility. It has a 15-inch cutting swath and uses 0.065-inch string, which automatically advances as the exposed string wears down. When you need to reload the string, you can use pre-filled spools or rewind bulk string onto the spool that comes with the tool. However, you cannot use heavy-weight string with this weed eater, and if you choose to rewind the spool, rather than replace it, it can be a bit tricky to do correctly.
The handle telescopes from 40 inches to 50 inches, and the grip is also adjustable, so you can set the weed whacker to fit your own height, making it comfortable to use for lengthy gardening sessions. Its 5.5-amp motor runs smoothly and quietly and has enough power to quickly cut through grass and non-woody weeds. At only seven pounds, this is a reasonably lightweight string trimmer, so it won’t wear you down before the job is through.
Price at time of publish: 90
Type: Corded electric | Weight: 7 pounds | Engine/Battery Power: 5.5 amp | Shaft Type: Straight | Maximum Cutting Width: 15 inches
Echo 25.4 cc Gas 2-Stroke Straight Shaft Trimmer
If you have a large area of brush, overgrown grass, or woody weeds to clear, then you’ll appreciate the extra power of a gas weed eater like this offering from Echo, which runs on a 25.4 cc, professional-grade two-stroke engine. Like other gas-powered weed eaters, you’ll need to fill the gas tank with a 50:1 ratio of fuel to oil mix. Echo’s i-30 starting system makes it much easier to start up this weed eater than most others, and once powered on, this sturdy beast chews steadily through just about anything you ask it to. The handles are padded and ergonomically shaped for comfort and are also designed to greatly reduce the amount of vibration that reaches your hands and arms.
The 0.095-inch heavy-duty string advances with a bump of the tool against the ground. When the string runs out, the Echo Speed-Feed system requires no tools and takes only seconds to reload; no frustrating fuss or bother. With a 17-inch cutting swath, you can work your way across the lawn quickly. Should you need even more powerful cutting action, Echo sells a separate conversion kit that lets you swap out the string head for a metal-bladed head that easily cuts through thick underbrush and overgrown weeds. Be aware that this weed eater is quite loud and does emit gas fumes, as is typical for gas-powered tools.
Price at time of publish: 329
Type: Gas | Weight: 13.4 pounds | Engine/Battery Power: 25.4 cc | Shaft Type: Straight | Maximum Cutting Width: 17 inches
Ryobi ONE 18-Volt Cordless Battery String Trimmer
Go cordless with this lightweight string trimmer that’s designed to take care of small-to-medium yards. The curved shaft makes it easy to maneuver around shrubs, rocks, and tree trunks, and the handle is ergonomically designed for a comfortable grip. Plus, weighing a mere four pounds, this is a weed eater that shouldn’t tire you out. It’s powered by an 18-volt battery that recharges in an hour and runs for anywhere from 8 to 15 minutes per charge, depending on how you use it. And with a simple push of a button, you can switch the head’s orientation: use it horizontally for trimming and vertically for edging.
The cutting swath of this tool is 10 inches, which is on the small side but can be a good thing if you are edging a flowerbed or other area with many obstacles to work around. It can only use 0.065-inch string and automatically feeds out more string as required. It’s not too difficult to reload once the string runs out. The weed whacker comes with an 18-volt battery that can be used in other 18V Ryobi tools, as well as a charger. Note that it is not compatible with Ryobi’s Expand-It attachments, however.
Price at time of publish: 69
Type: Cordless electric | Weight: 4 pounds | Engine/Battery Power: 18-volt | Shaft Type: Curved | Maximum Cutting Width: 10 inches
Best Corded Electric
Ryobi 10-Amp Attachment-Capable Corded String Trimmer
As long as you have an outdoor-rated extension cord up to 100 feet, and you don’t need to trim beyond that point, a corded electric weed eater is a great option. You get a lot of power, like you would from a gas-powered tool, but you also get the benefits of a cordless tool, including no smelly fumes, no need to keep gasoline on hand, and an easy start at the push of a button. Plus, there’s no need to worry about your battery running out too soon. This corded weed whacker from Ryobi is loaded with great options beyond the above: It has a 10-amp motor for maximum performance, it cuts an impressive 18-inch path, and it is designed to reduce vibrations through the handle, so it’s easy on your hands, although it is relatively heavy for this type of tool.
The tool comes with 0.080-inch string, but can also use 0.095-inch string if you need something even more heavy-duty. String advances with a bump of the tool to the ground, and when it’s time to replace the reel, it’s very easy to install a new one or simply rewind bulk string around the reel. Best of all, this string trimmer is compatible with Ryobi’s extensive line of Expand-It attachments, meaning you can purchase a wide variety of optional attachments to turn the weed whacker into a brush cutter, hedge trimmer, pole saw, snow thrower, and more. However, its head does not pivot for use as an edger, as do many other weed eaters.
Price at time of publish: 90
Type: Corded electric | Weight: 11 pounds | Engine/Battery Power: 10 amp | Shaft Type: Straight | Maximum Cutting Width: 18 inches
Best Under 200
BLACKDECKER 20V 12 Inch Lithium Ion Cordless 2-in-1 Trimmer/Edger
Here’s a reasonably priced tool that effectively whacks weeds with the head in a horizontal position and then serves as an edger when you rotate the head into a vertical orientation. This battery-powered, 20-volt string trimmer from BLACKDECKER is perfect for small-to-medium-sized lawns and has enough power to chew through typical grass and weeds (although this isn’t the tool for tough brush or heavily overgrown lawns). You can adjust the handle up or down to suit your height. The cutting width of this weed eater is set at 12 inches, which is somewhat narrow but sufficient for small yards.
The weed eater comes with 0.065-inch line, which is suited to light use on grass and small weeds. Note that you cannot refill it with heavier line. The line advances automatically as it wears down with use, so you don’t need to carry the task out manually or bump the tool on the ground. The weed whacker comes with the 20-volt battery and charger, which are compatible with other BLACKDECKER cordless tools. Run-time before needing to recharge the battery varies greatly, depending on yard conditions, but you will typically get anywhere from 15 minutes to 30 minutes on a single charge, which is enough to finish trimming or edging a small lawn.
Price at time of publish: 89
Type: Cordless electric | Weight: 7.1 pounds | Engine/Battery Power: 20 volts | Shaft Type: Straight | Maximum Cutting Width: 12 inches
WORX WG163 GT 20V Power Share Cordless String Trimmer Edger
The WORX Power Share cordless weed eater just keeps racking up high ratings; this weed whacker has more than 20,000 customer ratings and an average of 4.5 stars. But that’s not really surprising, considering that this 20-volt tool comes with two batteries, so you can have one charging and one in use, doubling your working time. The batteries and charger are compatible with any other 20-volt WORX tool. You can easily pivot the head on the weed eater to turn it from trimmer to edger, and it’s easy to angle it for use on a slope or when reaching into awkward spots between plants or around obstacles. When using it as an edger, its rubber wheels help you stay in a steady line.
This weed whacker uses 0.065-inch string, which is easy to advance at the push of a button, thanks to the Command Feed spool system. But most amazing of all, WORX will send you free refill spools of string for the life of the tool; you just pay for shipping. This will come in handy, since the string can run out quickly. It also has a 12-inch cutting diameter, which isn’t the highest but is quite sufficient for average-sized lawns and yards. And at only 5.3 pounds, this is a lightweight string trimmer that’s easy to use even when your gardening sessions stretch out long.
Price at time of publish: 140
Type: Cordless electric | Weight: 5.3 pounds | Engine/Battery Power: 20 volts | Shaft Type: Straight | Maximum Cutting Width: 12 inches
DeWALT 60-Volt Cordless Attachment-Capable String Trimmer Kit
If you use your string trimmer frequently and want lots of power as well as useful features, then you’ll appreciate the DeWALT weed whacker, which is a cordless model running off a 60-volt battery; that’s a lot of power, although it does add to the overall weight of the product. The high-efficiency brushless motor requires no maintenance to keep on running smoothly and fairly silently. There’s a two-speed, variable control trigger, so you can turn it up high when you need maximum power for chewing through brush or tall grass, or turn it down low to extend the battery run-time. You can even adjust the cutting width between 15 and 17 inches.
The weed whacker comes with 0.080-inch string, but the tool can also use 0.095-inch string if you need something even more heavyweight. To advance more string, just bump the weed eater lightly against the ground. The quick-load spool makes it easy to refill the string once you run out. If you want even more versatility from this weed eater, you’ll like its universal-attachment capability, which means you can purchase a wide variety of attachments from DeWALT or other companies to transform the weed whacker into a brush cutter, hedge trimmer, pole saw, blower, tiller, and more. It comes with a 60-volt DeWALT battery that is compatible with other tools from this company, as well as a charger.
Price at time of publish: 301
Type: Cordless electric | Weight: 15 pounds | Engine/Battery Power: 60 volts | Shaft Type: Straight | Maximum Cutting Width: 17 inches
Best with Attachments
BLACKDECKER Corded String Trimmer With Lawn Mower Attachment
With most models of string trimmers, you have to purchase attachments separately. However, this 6.5-amp corded electric weed whacker from BLACKDECKER comes with a lawnmower attachment, making this a highly versatile tool for small backyards. In fact, it’s three tools in one: edger, string trimmer, and lawnmower. It’s especially good for mowing on slopes or hills where a traditional lawnmower can be hard to maneuver. And it can be used with an outdoor-rated extension cord up to 150 feet in length, so you can work your way around most small yards. Since there is no way to add a clipping bag to the tool, you can leave the grass clippings in place on the lawn to decompose into mulch or rake them up once you are finished mowing.
The string trimmer uses 0.065-inch string. There’s an automatic string feed, so you don’t have to stop and reel string out yourself or worry about bumping it against the ground while mowing. As a weed eater, the cutting swath is 12 inches. It pivots easily into edger mode. For use as a mower, the trimmer simply snaps into the mower base. You can adjust the mower’s cutting height from 1.6 inches to 2.4 inches; the mower does not have blades, but simply uses the spinning string to cut the grass, and it does a great job on most lawn types. You can even adjust the height of this tool’s handle between 33 inches and 43 inches to make it comfortable for your height.
Price at time of publish: 119
Type: Corded electric | Weight: 9.9 pounds | Engine/Battery Power: 6.5 amps | Shaft Type: Straight | Maximum Cutting Width: 12 inches
Milwaukee M18 FUEL Cordless Quik-Lok String Trimmer
This professional-quality cordless string trimmer has the kind of power and run-time you’d expect from a gas weed eater, thanks to its M18 8.0-Ah lithium-ion battery. This sturdy weed whacker consists of two parts: a Milwaukee M18 FUEL power head with Quik-Lok and a Milwaukee M18 FUEL Quik-Lok string trimmer attachment. You can use any of Milwaukee’s other compatible attachments with the fuel head, making this a very versatile tool that can carry out a wide range of landscaping tasks. It has enough power to clear through thick brush, overgrown grass, and heavy weeds, reaching full throttle in less than a second and maintaining power without bogging down. The tool is designed for good balance, making it easy to carry and comfortable to use, even on lengthy yard tasks.
A variable-speed trigger lets you go faster when you need more power, or slow things down when you want to extend battery run-time as much as possible. The cutting width of the weed whacker adjusts from 14 to 16 inches. The string that comes with the tool is 0.080 inches, but you can also use it with heavier 0.095-inch line. Either way, you can reload the string reel in just a few seconds. When the string gets short during use, just bump the trimmer against the ground to advance more string. Not everyone needs a weed eater with this kind of power and at this price point, but for those who do, it’s hard to beat this offering from Milwaukee.
Price at time of publish: 349
Type: Cordless electric | Weight: 12.3 pounds | Engine/Battery Power: 18 volts | Shaft Type: Straight | Maximum Cutting Width: 16 inches
If you’re looking for a cordless electric weed eater that not only has plenty of power but is also loaded with great features like an adjustable cutting swath, variable speed control, and compatibility with numerous attachments for other landscaping purposes, then it’s hard to go wrong with the Ryobi 40-Volt Brushless Electric String Trimmer. But if you need the kind of power that only a gas tool can deliver, then the Echo 25.4 cc Gas 2-Stroke Straight-Shaft Trimmer is our recommendation. It has a 17-inch cutting swath and can be converted for use with metal blades instead of string.
What to Look for in a Weed Eater
There are three basic types of weed eaters, based on their power source.
Gas-powered weed whackers like the Echo 25.4 cc Gas 2-Stroke Straight Shaft Trimmer are the most powerful type, making them the best suited for large properties or for chewing through heavy brush. On the downside, they are much louder than electric models and can be heavier and more difficult to start. Plus, they require you to have a supply of gasoline on hand, and in many areas, they are being phased out due to their emissions.
Corded electric string trimmers are not as popular as they once were, but are still a fine choice if you are looking for a low-priced weed eater, you don’t have a very large lawn or garden to maintain, and you have access to an outdoor electrical outlet and an outdoor-rated extension cord of 50 feet or more. The Ryobi 10-Amp Attachment-Capable Corded String Trimmer has an 18-inch cutting swath and great power.
Cordless or battery-powered weed eaters are now the most popular type—the WORX Power Share WG163 is an especially highly rated option—particularly in areas where gas-powered models are restricted. Today’s cordless weed whackers have good power, although not as much as a gas-powered model. Still, they have more than enough oomph to maintain a small to medium-sized lawn. As a rough guideline, you’ll generally get half an hour or so of runtime before you need to recharge the battery. For many people, that’s all that’s needed to get the job done. If you have a big lawn, then it’s convenient to keep two batteries on hand so one can recharge while the other is in use. Other benefits of cordless weed whackers include a lack of smelly emissions, immediate starting at the press of a button, reduced vibrations, and quiet operation.
A string trimmer’s cutting swath or cutting width is the width of the tool’s cutting capacity, indicating how much you’ll be able to trim in one pass. There are weed whackers with cutting swaths as small as 10 inches, and weed eaters with large 20-inch cutting widths, but most are between 12 and 16 inches. If you have a large lawn, a string trimmer with a wide cutting swath will help you trim more quickly. But if you need a tool that can squeeze between shrubs, rocks, or other obstacles, then you’ll find that a weed wacker with a smaller cutting swath can maneuver a bit more easily.
Some higher-end weed eaters have adjustable cutting swaths that let you go up or down a couple of inches. Our top choice, the Ryobi 40-Volt Brushless Electric String Trimmer, can be adjusted for cutting widths between 13 and 15 inches.
Noise Level and Vibrations
Generally, cordless string trimmers are fairly quiet; you’ll mostly hear the whirl of the string and the sound of grass or weeds giving way. However, gas-powered weed whackers are loud enough to require ear protection during use, and corded electric models may or may not be loud enough to make you want to cover your ears, depending on the brand and model. However, you should wear eye protection when using any type of weed eater, as there is always a danger of stones or debris being tossed up into your face.
Vibration can be an issue with many weed eaters, especially gas-powered models. This can be tiring if you are using the tool for an extended session of trimming or chewing through brush. Some brands now build anti-vibration technology into their string trimmers, usually in the form of a handle that helps reduce some of the vibration. You can cut down even further on unpleasant hand numbness or fatigue by wearing a good pair of thick work gloves while you use your weed eater.
Since you’ll be holding your weed eater the entire time you are working, its weight can become an issue. You don’t want to be tired out before you finish your edging or trimming. As a general rule, electric weed eaters are quite a bit lighter than gas-powered models. The Ryobi ONE 18V Cordless Electric String Trimmer weighs a mere four pounds.
Most electric weed eaters weigh 12 pounds or less, although battery-powered models are usually heavier than those with a cord. Gas weed whackers generally weigh between 12 and 18 pounds.
Any weed eater should have a protective guard over the string to help keep rocks and other debris from flying toward you. However, you should always wear closed shoes, long pants, and eye protection when using these tools. Most weed whackers have the power switch placed so you can easily shut the tool off immediately should there be an emergency.
Straight or Curved Shaft
There are two basic styles of weed eater shafts: straight and curved. Curved shafts are generally easier to maneuver around rocks and other obstacles and are less tiring to the user’s back during long work sessions. However, straight shafts give you more reach and can be extended underneath shrubs or fences. Weed eaters with straight shafts often have a little more power, and battery run-time tends to be a little longer on these tools as well, but the choice between the two mostly comes down to personal preference.
Weed whackers work by spinning a thin plastic string-like cord very rapidly, which creates enough force to slice through grass, weeds, and brush. Most weed eaters have a roll of string within the base of the tool, so you can reel out more as the cord wears down, which can happen fairly quickly when working on thick brush or grass. There are three basic methods for reeling out more cord:
- Automatic feed senses when the cord is getting short and reels out more without you needing to do anything. The Greenworks 5.5 Amp 15-Inch Corded Electric String Trimmer is an auto-feed weed whacker.
- Push-button feed requires you to push a button on the weed eater’s handle to reel out more string.
- Bump-feed weed eaters reel out more cord when the trimmer is bumped against the ground.
Once the reel of string is empty, you’ll need to refill it. This is a fairly simple process for most weed eaters, but be sure to read the instructions before attempting it for the first time.
Note that there are also different thicknesses of string-trimmer lines or strings: as a general rule, 0.065-inch to 0.085-inch string is for light-to-moderate trimming of grass and weeds. For heavier weeds, brush, or tough grass, string that’s between 0.085-inches and 0.110-inches is required. Many string trimmers can use different sizes of line so you can switch them out if necessary.
Most string trimmers have just one set speed. Some higher-end models, including the Milwaukee M18 FUEL Cordless String Trimmer, however, let you adjust the speed with either a two-speed setting or variable control. This allows you to speed up the tool for more power while tackling thicker growth or tougher brush, or slow the speed down to extend battery run-time when working on small weeds or grass.
Some string trimmers have heads that can be adjusted from a horizontal position to a vertical orientation, which allows them to be used as an edger as well as a trimmer. Others, including the DeWALT 60-Volt Cordless Attachment-Capable String Trimmer Kit, allow you to attach a variety of separately purchased heads for other landscaping tasks such as cultivating soil, shearing hedges, mowing grass, or blowing leaves.
The vast majority of weed eaters are stringed tools, using a thin plastic cord that spins very rapidly to cut through grass and weeds. There are more powerful, but similar tools often called “brush cutters,” that use metal blades instead of plastic cord to chop through thick brush, tough weeds, and highly overgrown grass. Some weed eaters can be converted for use with blades as well as with plastic cord. Typically, only a gas weed eater has the power to convert to metal blades for cutting thick brush. The electric corded or cordless models that can cut with blades, as well as cord, typically can only handle plastic blades. These can cut light brush but can’t handle thick, woody stems as a metal-bladed brush cutter can. Neither a string nor blade weed eater is necessarily better; the best choice depends on your specific needs and the condition of your property.
Both gas and electric weed eaters have their pros and cons. Gas-powered weed eaters are stronger and aren’t tethered to an electrical outlet. However, gas weed eaters require filling with gas and oil and create smelly fumes. They are generally much louder than electric models and vibrate more during use. They are also heavier and more costly than electric models. However, for maintaining a large property or tackling thick brush or very overgrown weeds, a gas weed eater can be the better choice. For most yard cleanup, however, an electric weed eater, whether corded or cordless, is sufficient to handle grass, weeds, and light brush that isn’t too woody. Electric weed eaters don’t create smelly fumes and don’t require you to keep gasoline on hand. They generally are much quieter than gas-powered models and don’t vibrate as heavily during use, which makes them easier on your hands and arms.
There are pros and cons to both two-stroke and four-stroke (also called “two-cycle” and “four-cycle”) gas-powered weed eaters. Fewer moving parts means that two-stroke weed eaters are lighter in weight and easier to maintain than four-stroke models. They generally also have quite a bit more power. However, you will need to mix the gas with oil for two-stroke trimmers. If you’re looking for a quieter model that produces lower emissions, a four-stroke gas trimmer is the way to go. Another benefit: with four-stroke models, no mixing of gas and oil is required. Keep in mind, these models are pricier and generally weigh more than two-stroke weed eaters.
There are gas weed eaters for home use with 20 cc engines and professional models with as much as 50 cc engines, but the majority of gas-powered weed eaters used by the average homeowner have 22 cc to 28 cc engines, which provide plenty of power for tackling overgrown weeds, grass, and brush. When it comes to electric weed eaters, corded models for very light use might have as little motor power as 3 amps or as much as 10 amps, but for typical home use, a motor in the middle of that range is more than sufficient. Cordless weed eaters can use batteries between 18 volts and 80 volts, but again, the middle of that range is generally powerful enough for regular home use.
Why Trust The Spruce?
This article was researched and written by Michelle Ullman, who specializesin home and garden products. She has been writing for The Spruce since 2020, covering a wide range of home improvement products including power and hand tools, painting supplies, landscaping tools, and tool organizers. To choose the best weed eaters for this article, she consulted dozens of customer and third-party reviews, considering each product’s power source, performance, ease of use, versatility, and price point. She received additional input from Jeremy Yamaguchi, the CEO of Lawn Love.
The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Introduction: Weed Trimmer Motor Replaced With Brushless RC Truck Motor and Uses an Arduino Control Board
For years I have been using my trimmer with upgraded LiPo batteries, kind of like the ones used in an RC car. LiPo batteries have worked well and provided much more trimmer use time at quite a bit less weight. The problem was the motor finally gave out the other day. The trimmer overall performance was OK but it lacked power. I figured it is time to make use of more powerful RC truck brushless motors I had laying around. Using an RC motor means I can use RC LiPo batteries as well which are lighter and have plenty of capacity to far exceed trimming time of any battery operated electric trimmer on the market today.
This project is a little more advance because of the use of an Arduino board. This was because I needed some way to turn the trigger into a controller to tell the RC truck Electronic Speed Controller (ESC) to start. There may be other ways to do this and I would be curious to hear other ideas, meanwhile an Arduino will have to do. You will also have to have the ability to solder wires to the Arduino as well.
CompatibilityIt is important that the weed trimmer is compatible to the brushless motor you plan on using. Turns out that the trimmer original motor had a 5mm shaft just like the larger 1/8 scale RC truck motors use. Note that if your trimmer has a 4mm shaft than look for a 1/10 RC truck motor for your swap.
Parts OverviewYou will need the following:
Step 1: Install the Motor
Picking the right motor is important. Brushless motors have a KV rating to help pick the right motor for the job, the lower the rating the slower the top RPM but the more torque it has. I suggest using a 2100kv or less. In the end I set the Arduino code to about 80% throttle to replicate the original motor speed. In my opinion more RPMs is not good, you want more torque.
I purchase this Hobbyking 2100kv motor and ESC for 95 combo, though its not top quality for RC trucks it has plenty of power for this application. The plastic plate was a good fit for the new motor, I did have to drill two new holes as the original screw holes didn’t line up, this was a minor modification.
Next I placed the spool on the end of the motor. Though it was pressed on the original motor but wasn’t a snug enough fit on the new motor. I had to drill a small hole and insert a screw to securely connect it to the new motor. you have to look closely at the picture for the little screw. This is common practice in the RC world as shafts on RC motors have a flat spot ending in a shape like a ‘D’. A set screw is used to hold gears onto the shaft, it doesn’t have to be fancy. My trimmer spool had a soft metal lead like base that was easy to drill. I let the screw do the tapping and added loctite. Turned out to be simpler than I expect.
Step 2: Connect the Esc and Battery
You will need a RC truck battery, really you need two to last for most larger yards,something in the 5000mAh 7.4v range.
In my case I had an existing battery and ESC setup so no wiring was needed. Of course you may have to buy connectors to finish your assembly if you are building from new parts. I have to assume you know how to wire and use a RC ESC and battery.
Step 3: Add an Arduino to the Mix
I needed some sort of way to recognize when I press the button on the weed trimmer and send a PWM of full throttle. the trick is that it has to ramp up or the ESC may burn out. I did this using a Arduino Pro Mini but a nano would do the trick. You should be able to get one for less than 10 online.
Next I wired the ESC pulse to the Analog pin0 and routed power from the ESC to the Arduino board power pin. and of course connect ground as well.
I’m Never Using Gas Again!. DeWalt DCM571 Review
I think for the most part all weed trimmers have a switch at inside the trigger in series with the battery and motor at the bottom. I shorted the battery terminal at the top since I will no longer be using it. As a result the two wires that would originally plug into the motor function as my switch/trigger connection. This was soldered between the Arduino power and digital pin2. I wired a 10k resistor to ground then to the switch on digital pin2 like shown in this example instructions here.
The trick is the code, the code must ramp up the motor. Here it is in raw form:
#include int switchState = 0; int switchPin = 2; int servoPin = 14; int ledPin = 13; int servoPwm = 1500; Servo servo; void setup pinMode(servoPin,OUTPUT); pinMode(switchPin, INPUT); servo.attach(servoPin); digitalWrite(ledPin, LOW); servo.writeMicroseconds(servoPwm); delay (7000); // wait for ESC to startup void loop switchState = digitalRead(switchPin); if (switchState HIGH servoPwm 1500) digitalWrite(ledPin, HIGH); servo.writeMicroseconds(1550); delay(100); servo.writeMicroseconds(1600); delay(100); servo.writeMicroseconds(1650); delay(100); servo.writeMicroseconds(1700); delay(100); servo.writeMicroseconds(1750); delay(100); servo.writeMicroseconds(1800); servoPwm = 1800; if (switchState LOW) servoPwm = 1500; servo.writeMicroseconds(servoPwm); digitalWrite(ledPin, LOW); delay(100); // waits for the servo to get there
Step 4: Get Creative and Button Things Up
You will have to get creative to finish things up. I ran an extra long wire so I could carry the RC car battery in my As I mentioned earlier I use two. If you are going to use LiPo batteries make sure the ESC you are using is compatible. The ESC should cut the throttle if the battery gets too low which in turn prevents you from damaging the battery. just like with a typical RC car.
Thought this is not a baby step type of instruction you have to admit it is a creative setup and a great way to revive that old weed trimmer. I always thought that this type of upgrade would be perfect for commercial use. This trimmer will keep up with any gas one out there in addition to reducing pollution, noise, and cost of gas. If you are interested in making a conversion but need me to build you an Arduino I would be happy to do so for a fee. Send me a message and I will give you a quote.