Weed Eater Powered Scooter




Introduction: Weed Eater Powered Scooter

Sometimes I find that my projects are defined by the things that I find.... Please read next.

This project was also inspired by something I wanted to learn. I always wanted to learn to weld and this potential project was further motivation. I picked up a wire feed welder off Craigslist last year after searching a while. I chose to go the practical application route rather then spend $ on classes and books to learn the technical background of how it works. As the saying goes: You listen, you hear, you look you see, you do, you understand"... or something like that. So after practicing a bit on some random scraps, and getting some hands on pointers from some people who knew what they were doing I dove right in with my first welding project.

Step 1: Pieces and Parts

Found this scooter in our garage (actually I found it at a garage sale a couple years ago, cheap)

Found this bicycle rear wheel in a dumpster

Found this string trimmer at a garage sale.

Found out that inside this $2 chair (from a surplus store) there are lengths of 7/8" dia. 1/8" wall thickness tube steel reinforcing inside the 1" tube steel frame.

Found I couldn't stop thinking about mounting the weed eater engine to the scooter.

Step 2: Tools

Welder: Just got this last fall and still learning to use it so forgive the quality of my welds.

Metal Chop saw: for cutting angles.

Angle grinder: with cutting and sanding wheels.

A bevy of hand tools, to numerous to explain. This was a figure it out as you go along project the number of tools only exceeded by the number of failed strategies.

Step 3: The Challenges and First Steps (Freewheel Hub)

I looked for other designs online most involved attaching a spindle to the motor and having it friction drive the rear wheel. This would have been much easier than the strategy I employed. I wanted the scooter to have a chain drive. This meant the engine had to have a clutch so it could be started in idle and the rear wheel needed to be able to coast when not accelerating (freewheel)

There were probably easier ways of doing it but I went the free and cheap route. If a project is to be judged based on what you learn in the process then this one was way up there for me. Hindsight being 20/20 I would have done many things differently but this project represents the forging ahead.

I needed a big sprocket on the tire and a small one on the engine. I did the math and was afraid a 6,000 rpm weed engine would translate to a very fast scooter (it didn't by the way and I will be upgrading in the future)

the large sprocket came from a used crank from a bicycle shop.

I got the freewheel hub out of a rear bicycle wheel.

the wheel was the existing wheel from the back of the scooter.

had a couple discs made so I could weld sprockets from the salvaged cassette to the disks and bold the discs to the large sprocket. i used a combination of existing spacers that came from the cassette and acrylic disks I cut out to locate the sprocket and mount it to the freewheel hub

Step 4: Attaching Hub to Tire

I drilled, cut, filed and sanded the existing tire hub and JB welded the new hub to the exiting tire.

Step 5: Attaching Sprocket to Drive

Note: some string trimmers have a centripetal clutch, some do not. my first efforts were involved trying to figure out how to put a chainsaw clutch on a trimmer without a clutch (big challenge) and then I found a trimmer with a clutch at a garage sale for $15.... problem solved.

I cut a length of black pipe that fit snugly over the drive shaft (and clutch cover) added a washer as a spacer and to center the small sprocket and welded it all together (a couple times)

Step 6: Measurements and Design

Turns out that the mounting width of new rear tire is a couple inches wider than the mounts on the scooter.

So I built a temporary framework to get measurements and lay out the design, then drafted it to get the cut angles and dimensions of the frame.

Step 7: Marking and Cutting the Tube Steel

Then using the tube steel salvaged from inside the base of the $2 chair I cut the pieces to length.

I struggled a bit to figure out how to make parallel angle cuts on tube steel. the technique I came up with involved cutting the angles on a square pieces of wood, holding the tube steel tight against the angle then finding the high point by placing the tube between two adjacent then running a file across the three to find the high point. I then marked down the center line with a sharpie and piece of angle. I am sure there is someone out there that has a better way of doing this. If you are them and you have read this far please explain in the comments section.

Step 8: Learning to Weld

Then the welding started. I picked up a 120v Hobart 140 last fall because I always wanted one. This was my first legitimate effort to put something together with it, as is obvious looking at the quality of the welds. but they are getting better and I am excited about the future possibilities in working with steel.

I cut the axle mounts out of a piece of 1/8" flat stock with and angle grinder and cutting disk and sloppily welded that to the frame.

I cut out the motor mounting plat and welded that the the frame. (sorry missed taking a pic of the mount welded to the frame.

Step 9: Attaching the Tail End

The front and back were aligned, clamped together and welded.

Step 10: Cleaning Up the Mess

I ground off the major chunks of my crappy weld job then cheated with a little hastily applied Bondo.

After a coat of closely matching paint it didn't look half bad.

I cut the foot board and backstop out of 1/2" plywood and painted it. This scooter has a foot board about 6" longer than the original so an adult or large child or adult that acts like a large child can stand on it.

Step 11: Motor and Throttle

I JB welded the eyelet to the motor casing as the other half of the casing has been removed.

the thumb shift button and derailleur cable was salvaged off an old scrap bike, withe the derailleur cable bolt modified with a couple bored out washers was used to tie the new cable and the motor throttle cable together. I zipped tied the cables to the bike frame.

Step 12: Finished!

Well it wasn't as simple as all that, it was a lot of trial and error; and it took about 4 times longer that i thought it would and i didn't describe all the FAILs. As it took longer than I thought it would and today is the deadline for the make it move challenge contest the instructions are a bit less detailed than I would like them. But I learned a tremendous amount by making it and if success were based on how much I learned I would have to call the project very, very successful. It doesn't go nearly as fast as I thought it would (faster than a jog, slower than a sprint) which is ok I guess and I am still having some challenges with the chain and sprocket alignment. I plan to reduce the size of the sprocket on the wheel by using the large sprocket from the original cassette and some the acrylic spacers. Also plan to add some clips to hold the axle square when tightening the nuts. this should speed things up and refine the sprocket to sprocket alignment a little better. But that is for next week.

Step 13:

Well that clutch didn't last last long, probably should have known better note the blue (burnt up clutch) color.

Went back to the chainsaw clutch and thought a axle for the clutch would be a good idea.

After the existing clutch was removed a 3/8"-24 thread on the motor spindle was revealed.

Used a 3/8"-24 threaded coupling and a couple 3/8"-24 bolts,

Took the plunge and dremmled off the small end of the shaft. Can't ever go back to the original clutch and drum now!

Had to grind the coupling down it was a bit to long.

Had the left over end of the scooter thought that would make a good support for the other side of the axle. marked it and cut it,

3/8"-24 all thread turned out to be unobtainium. had to weld to bolts together to get the length. ground it smooth.

Once the axle was added found that it was a bit easier to square the motor to the wheel (hmm hadn't thought of that earlier)

Welded the clutch shoe to the axle, then had an "oh crap" moment as the weld did not allow the clutch and drum to fit together properly. put it the drill press and filed and sand clothed it till it fit pretty good and spun smoothly.

Welded the sprocket to the drum cassette (that the chainsaw chain usually fits in) wrapped tape around it to get it centered in the sprocket. unconventional probably but it worked.

Then it started to rain, then thunder then lightning. Wont get to test it tonight.

Put bearings and the appropriate bushings on the other end of the axle collar lock on one side and nut on the other side. Last pic is how it all goes together. hope it works but its storming outside and I wanted to get this posted by the deadline.

Make it Move Contest 2016

Second Prize in the
Make it Move Contest 2016

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    Tip 1 year ago

    Awesome freakin' scoot dude! Word of advice from someone with 19 years under a shield all day every day, take that MIG gun you waited around so long for and put it at the very very back of your workspace. Then find some ol' timer selling a good and broke in Lincoln AC/DC 225 "TOMBSTONE" welder and buy it. since youre self teaching pretty much your next step would be to go to Harbour Freight if you have one in the area and get a big box of 1/8" 6013 welding rods, some new lenses for your sheild, and a new wire wheels for your grinder instead of a chipping hammer unless you wanna hear hammer meet steel all day. so step number meh who knows go back to your work space and gather up any kind of old steel you can find. at least 1/8' thick. DOES NOT MATTER WHAT IT IS/WAS. maybe watch a short video on general technique and more importantly HOW TO SET YOUR WELDER FOR THEPARTICULAR RODS YOURE USING. (rant) LOLZ. And last but the very not leastest sit down and burn every single rod in that box. and dont go grabbing a new one if the stick it and some of the flux comes off. FREAKIN Weld it. its all about rythym. find some good tunes and concentrate. tiny circles over and over, or u's, or n's. Ive seen the time J's were a must. all that said, you do what i just told you to and going by your current MIG welds and I'd bet money you'll be kickin' tires, lightin' fires' and have pretty girls callin' you a liar lol. seriously though self teaching is the absolute best imho. i learnt how to weld on my grand daddys' old rotary dial welder when i was 12 years old. my daddy let me weld some stuff on the tractor when i was 13... neither daddy or papa ever welded on this farm again.


    P.S.S My apologies for the lack of proper grammar and loosing my period here and there... smh... i'm currently in the porta-john at this paper mill shut down. the john and i are like batman and joker. we hate. we love. we love that we hate that me love

    chop saw.jpg

    Reply 11 months ago

    What Brandon said...Dont totally ditch the mig gun ....I learned on an AC buzzbox 30 plus years ago..fabing some Willys jeep rear fenders..With a damn stick welder..I did not know any better...I was more than competent at stick welding I was reluctant to mig/tig.....point is,you learn many tricks stick welding which is more difficult to be consistent and you can weld bigger and more stuff.. Plus he is spot on about the availablity of the welders..I found mine in the junkyard ..a few bridge rectifiers and reflowing some solder,and a set of new homemade leads ,and it was about a 15 dollar investment 20 yrs ago......I love my millermatics but I still have that 60 year old 220 volt craftsman buzzbox that I go to often,not unlike seeing an old friend...Well done BTW...Bitchin scooter


    Reply 1 year ago

    You are right but you left out one thing listen to your welder and you will get the speed and flow been sticking pipe for almost 25 yrs and when I’m home I love using my old tombstone welder if it ain’t round leave it on the ground


    Question 2 years ago on Introduction

    Man, This is AWESOME!?! You may have something here! Do you think you could make a "kit" that we end users can make? We all don't have the tools to know this, but would love to! A great How-to but i'd pay the money (not much as that I'm in College and a Marine Vet)



    3 years ago

    Cool going to be a winter project


    4 years ago

    Thanks for the pics and for sharing. I had that same scooter for the same project and got it stolen. Still searching for one but will probably build the frame from scratch. Great garage/domestic tools/homemade work! What's the average speed (if measurable)? and What are the rider's average weight?



    5 years ago

    would be more balanced and take up less space if the motor were mounted above the wheel. but overall looks good


    5 years ago

    Good job mr


    5 years ago

    Good job, Good LOOKING! VERY impressive!


    Reply 5 years ago

    Thank You!


    6 years ago

    Thanks Tutor11,

    Yes it was a Mig: Hobart Handler 140. Still learning how to use it but getting better.


    6 years ago

    Great job!! What kind of welder did you use?