Weed Eater Friction Drive Bicycle

Discussion in 'Friction Drive' started by landuse, Jan 4, 2012.

  1. landuse

    landuse Member

    I have been having some withdrawal symptoms since I finished my minibike, so I have now decided what my new project is going to be. A friction driven weed eater bicycle!! I have already gotten started with the whole project.

    I have decided to use an old Mitsubishi T50 engine that I got off a trimmer. As far as I can tell, it is a 26cc engine. I just hope it has enough guts for what I am going to use it for. I also decided to be a little more elaborate than your average back yard friction drive that you see on the net and on YouTube. I have decided to try and duplicate the Staton/DAX friction drive setup.

    So far, I have cut the steel plate into 3 equal sections and welded them together to make the U shaped housing that everything is going to bolt to. I then measured the bolt pattern of the clutch housing for the motor, and drilled the holes for that. Due to the rotation of the engine, it is going to be mounted on the right hand side of the bike. (I hope I got that right).Trying to get it all not to warp too much was difficult.

    I then cut lengths of steel strips and welded them together for the U bracket that bolts onto the bike frame. As a protection for the bike, I cut strips of rubber off an old car mat and drilled holes in that to fit my bracket.

    I am going to have to use a contact I have at a machine shop to drill out the holes in the housing for me to fit the bearings into. He is also going to machine the steel bar I have into the roller that will attach to the clutch drum. He only opens shop again tomorrow, so I will get hold of him within a few days.

    Well, that is where I am at the moment. I have included a few pics of everything mocked up together.
     

    Attached Files:


  2. 5-7HEAVEN

    5-7HEAVEN Member

    STOP RIGHT NOW!!

    My Mitsubishi TLE 43 engine runs counterclockwise; yours prolly does too.

    If you mount the engine on the right side, your bike will run backwards!:jester:

    Anyway, good design, my friend.

    Your clutch should work well. To improve its life, do not throttle the engine from a standing start. Run for 5 seconds, then apply throttle.

    Good luck, and we'll be watching you progress.:smile:
     
    Last edited: Jan 4, 2012
  3. landuse

    landuse Member

    I checked a few times, and the engine runs clockwise if you are looking at the clutch shoes. I pulled the starter rope slowly to see which way the shoes turned. Did I check correctly?

    Thanks for the compliments.
     
  4. 5-7HEAVEN

    5-7HEAVEN Member

    Ok, you would know.

    Good luck.
     
  5. landuse

    landuse Member

    Thanks. I am really looking forward to getting this on the road. It is my first build of this kind. I am usually into minibikes and go karts
     
  6. rawly old

    rawly old Member

    well, assuming the mount holes are correct, VXB has bearings by the bushel
    for cheap in any size you chose. It appears to be a 56mm clutch for which you
    can get a clutch drum & spacer from Staton-inc. not so cheap, but the only
    source I know. Slotted struts can be made from just about anything. on my
    bikes I've made plate alu brackets that use clevis pins to attach the struts at
    the bottom. These also serve as hitch mounts for my trailer.
    If for some reason the mount holes do turn out to be on the wrong side, you
    can always pivot the channel 180 degrees to get them on the other side.
    Good luck, what you have so far looks good.
     
  7. landuse

    landuse Member

    Thanks Rawly old! You are correct, it is a 56mm clutch that I got. I am going to use the drum that came with the weed eater though, and weld or braize a shaft onto it. The roller will then fit on that. I am still trying to come up with a few ideas on the easiest way for me to do it. I have attached a pic of the part that I am thinking of using (a bit modified however) to bolt onto the channel direct. There is a bearing in there already, and I won't have to hasstle with too much fabrication. I am not too sure yet though.

    I like your idea about the clevis pins. I might just do that. It will make it easier for removal if I have to. Thanks.

    I will keep you all updated on the progress
     

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    Last edited: Jan 4, 2012
  8. landuse

    landuse Member

    I thought I would share a pic or two of me welding the U channel together.
     

    Attached Files:

  9. rawly old

    rawly old Member

    Wish I could weld, nice work.
    I've built a FD using a 26cc engine; the problem I perceive is that they're
    a bit under powered for a channel setup. One of the things I've done with
    these small weed whackers was to thread one of those textured Chinese
    aluminum bike pegs right onto the shaft as a roller when a shaft is too small,
    I snip a bit of alu sheet as a bushing and secure it with JB epoxy. While the
    glue is still green simply screw it to shaft cutting thread as goes.
    I then mount this eng. to a lever which mounts to the seat stay. To start
    off one lifts the lever pulling the roller down onto the wheel while pedaling.
    ( no recoil starter required) I wish I could show you a picture, but they're
    gone with my previous PC. A company call Bumble Bee bike motors makes
    something similar.
    The only reason I mention this is that used whacker engines are cheap.
    easy to come by, but not necessarily durable enough to devote a great deal
    of labor to the build.
     
    Last edited: Jan 6, 2012
  10. landuse

    landuse Member

    Thanks for the info. I know exactly what you are talking about. I was thinking that if what I am doing doesn't work, I will go that route.
     
  11. BentTooner

    BentTooner Member

    Lookin Great!

    Hi, landuse

    Looks great! Thanks for the updates and the pictures.

    What is the thickness of the plate you used for the U Channel? How did you cut the plate? Did you weld with MIG or gas or what?

    Keep up the great work, the updates and thanks a lot for sharing! I'm eager to hear how it goes.
     
  12. landuse

    landuse Member

    Thanks BentTooner! The plate that I used was 3mm thick (sorry, I don't know the imperial size). I measured and marked out the 3 plates on a large sheet of plate steel, and then I actually used my angle grinder with a cutting blade to do te cutting. It doesn't give you the straightest edges, but it was all I had. I tried to make sure that at least one side of each plate was part of the original factory edge, so that I would have a straight side on each to weld to each other.

    As for the welding, I have a 130Amp stick/Arc welder. I haven't been welding for that long (maybe a year) and I am still not so good at it. I think stick welding is probably the hardest of all the types of welding.

    I got a little more done this weekend. I cut the 2 lengths ofmetal strips that will be attached to the U channel and to the sprocket area to tension the roller against the tyre. (I am not sure what they are called). I had to cut slots at the top of each so that I can tension the channel easily. I had to do this with a grinder again, so it doesn't look too pretty.....but it will work. When I went to the scrap metal yard a week or so ago, I also came across a mechanical drill press that you put your hand drill in. I didn't have a drill press cos they are too expensive, so I got this one for practically nothing. It works great!
     

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  13. 5-7HEAVEN

    5-7HEAVEN Member

    Those legs are called rear support struts, I believe.

    With struts on, you can lift the steel channel and engine maybe 2". That's good enough to raise the roller off the tire.

    What I did on my struts was to extend the slots ALL the way to the top edge. That way, I could raise the entire assembly off the struts and maybe 12" higher. That way, I can get to loosen/tighten those pesky motor mount bolts with ease. It also gets the engine WAY out of the way, if needed.

    If you bolt a small fuel tank to the top or outboard side of the iron channel, the modified struts will allow you to access the mounting bolts. It'll also give you underside access to the from U-bracket nuts and bolts.
     
  14. landuse

    landuse Member

    Thanks 5-7heaven, I will look into that.
     
  15. BentTooner

    BentTooner Member

    Hi, landuse

    Thanks for the info.

    VERY COOL drill press! What a find!

    I think 3mm steel plate is 0.118" which is a little thinner than 1/8" (0.125") plate. I made a tadpole trike this summer and used 1/8" plate for the rear drop outs. I also cut it with an angle grinder and cut off wheel. It worked fine, as you said.

    I used a MIG welder for the tadpole bike and it worked fine, too. I think you're right about stick welding being harder than MIG.

    I made those support struts out of aluminum bars. I put them together and drilled a series of holes on a line and then filed out the holes to make a long slot. I didn't think of using the angle grinder.

    You're really making progress. Do you think you'll be able to get good alignment on the bearing holes using your new drill press? I've found it hard to do that kind of stuff with my drill press.

    Best of luck!
     
  16. landuse

    landuse Member

    I am going to take the channel to a machinist and get him to drill the bearing holes. I don't think I would ever get them lined up with the equipment that I have. I am actually going to take everything to him today, and hopefully soon I will have everything back to complete the build. He is also going to make the roller for me.
     
  17. landuse

    landuse Member

    Yesterday I handed over my U channel to a machinist to drill the holes for the bearings and machine a roller for me. Because I am small fry business for him, I might have to wait a little bit before he gets the time to do my work. I will keep you all updated though on the progress.
     
  18. BentTooner

    BentTooner Member

    landuse

    What were the specs you gave the machinist for the roller? I'd be curious to know what he charges for the work.
     
  19. landuse

    landuse Member

    I pretty much gave him freedom of choice as to what is easiest for him. I did specify the roller diameter as 3cm though. He said he might have to machine a new clutch drum, so I will see what he says when he gets back to me with a quote.

    I will let you know what he says, and what work he will be doing as soon as I find out. I think there might be a bit of haggling about the price when he gets back to me. He is pretty reasonable though.
     
    Last edited: Jan 10, 2012
  20. BentTooner

    BentTooner Member

    Hi

    Ok, thanks. It would be a fair amount of work to machine a drum, shaft and roller. I'm guessing you're going to have a steel shaft that threads into the drum and then the roller will be attached to the shaft in some way like with set screws? The roller will probably be knurled steel.

    Hope he's reasonable.
     
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