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| vtsteam:
Hockey pucks? boat trailer bed rollers? etc. Like I mentioned earlier, freezing rubber makes it machine or drill easier. |
| S. Heslop:
I glued the next tyre on and it seems to be going okay. But now a new problem; the motor is turning the wrong way! So i'll have to change the ESC settings. In this heat just going up and down the stairs is killing me. It rained this morning too so the humidity is up. The ammeter still isn't responding, so I think the whole thing is duff. |
| S. Heslop:
Well, I figured the tyres would wear out quickly from slipping but I didn't imagine they'd do this. All the melted galled rubber made the thing bump every time it turned. For a very short while it was actually moving under its own power, except not too fast since it was still slipping. The rubber is a fairly soft rubber. The first test it didn't move at all (but did help a bit going up a hill), so I put on a much stouter spring. It might need a heavier spring yet. Not sure if i'd want to stick with the soft rubber for the sake of gripping or switch for a harder rubber that i'd imagine wont gall up as bad as that as it wears? Or maybe make a thicker tyre that can squash a bit to give more contact? I'm beginning to wonder if this idea will even work at all though, but i'm not ready to give up yet. |
| vtsteam:
Well it looks like you've got the motor going in the right direction, now, but usually you don't have to re-program the ESC just to change direction of rotation. Just switch any 2 of the 3 motor wires. Bullet connectors make that easy. The melting of the tires is probably the result of slip-- and maybe a low melting point compound. Better rubber will help plus the tension should be sufficient to prevent slip. That spring doesn't look like much. Since other roller motors seem to work on bikes, maybe investigate their rollers. Sounds like you're close to getting this working! Which is pretty amazing considering it is only the first iteration! Check my sig.... :lol: Ammeter is essential. Can you get a universal replacement automotive ammeter? Often pretty cheap. |
| S. Heslop:
--- Quote from: vtsteam on July 13, 2014, 01:09:18 PM ---Well it looks like you've got the motor going in the right direction, now, but usually you don't have to re-program the ESC just to change direction of rotation. Just switch any 2 of the 3 motor wires. Bullet connectors make that easy. The melting of the tires is probably the result of slip-- and maybe a low melting point compound. Better rubber will help plus the tension should be sufficient to prevent slip. Since other roller motors seem to work on bikes, maybe investigate their rollers. Sounds like you're close to getting this working! Ammeter is essential. Can you get a universal replacement automotive ammeter? Often pretty cheap. --- End quote --- Had no luck finding automotive ammeters cheap, and the thing that puts me off them is that you need to wire them in series I think. To have that ammeter at the front of the bike would be alot of cabling. I might just try ordering another ammeter of this style since they're reasonably cheap. Hopefully a 50amp fuse will be enough to 'monitor' the circuit though, and blow before anything overloads (with the motor rated at 65 amps). I'd still like to see the current draws out of curiosity though. For the wheel I think i'll try something like this. A step and 2 washers holding a solid rubber wheel. The blue part represents threads! Except finding solid rubber like that might be difficult. But it'd be much easier to change the wheels for new ones this way. I hadn't really considered what i'd do about the original wheels wearing out... I tried rubbing a skateboard wheel against the rim of the bike and found it got a good amount of grip, despite being very hard rubber. It's not my skateboard wheel to use though, but I think I have a set hidden somewhere. Chances are they're buried in that box of useful looking stuff. I imagine skateboard wheel rubber is probably designed to wear away... gracefully. Also in that one video of a similar motor system, it looked like instead of using strong springs to grip the wheel it used the force of the motors turning to pull them into the wheel and grip. That said, I haven't found a single video of it actually pulling a guy under load. |
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