Bosch 35w motors

[Max]

Hi, what size wheels do most people use with Bosch 35w motors?

[PJ-27]

I was thinking about getting a couple of Bosch 35s, how tricky is it to get a wheel on the shaft? Do most people file a flat? I don't have the tools to put a keyline in it.

[psycho_fling]

the shaft on bosch 35s is removable so some might not come with them, i used a 4mm allen key which fits in the gearbox 'hole' nicely

[Max]

the shaft on bosch 35s is removable so some might not come with them, i used a 4mm allen key which fits in the gearbox 'hole' nicely

But what diameter wheel did you use?

[PJ-27]

Thanks for the tip.

360 uses Bosch 35s for drive and that moves very nicely so check out that build thread to see what size wheels Dave made up.

[Max]

Apart from building my own gearboxes is there any motor anyone can recommend for wheels between 300mm and 350mm diameter?
Of not what gear ratio would I need from the replica speed 900s off eBay for a fast flipper (so doesn't need lots of pushing power)

[PJ-27]

For wheels that big you'll have to have a further reduction after most gearboxes (Drills, Bosch 35s, Gimsons etc..)

Obviously with Speed900 you'll have to make up your own reduction somehow, so just make it large enough to compensate for the wheel size.

Alternatively you could do something like what Seraph uses, check out their build dairies. A neat solution of using timing pulley's and belts on Bosch 35s.
Or there's what we do on Bitza (about 250mm wheels) where after the drill gearbox we have a gear and then a further reduction onto a gear on the wheel.
This setup also means you can have the wheels inline with each other and offset the motors instead.
Check out our build diary for images.

[jonny]

Seraph uses Giant motors similar to wheelchair motors. For speed 900s on wheels that size you'd have to have a hefty reduction around 15-1 or higher.

[Ellis]

If you want proper power behind such large wheels scooter motors could be a possibility. They're 24v, though, and not light, but they'd give you loads of grunt. 120w versions are quite popular. http://www.ebay.co.uk/sch/i.html?_nkw=1 ... m270.l1313

If not a further reduction with timing belts or something from a Bosch 35w would get you moving quite comfortably. Even more so with a drill/Gimson.

Assuming 6000rpm (12v) from a speed 900 type motor and a 15:1 reduction with 325mm wheels you're still looking at a theoretical 26km/h. Seems way fast, meaning you'd probably want an even more extreme ratio.