Thread: WCD vs Standard
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Unread 01-10-2012, 23:21
Adrian Clark Adrian Clark is offline
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Re: WCD vs Standard

Ok, multiple things:

1. If you need to hold in a bearing that is not a press fit the standard approach is to use bearing loctite, not glue or welding. Although glue is a much better idea than welding. But why are so keen on holding in your bearings?

2. A press fit is not necessarily undersized, it could also be exact size. The difference between press and slip fit depends on surface finish as well as hole size. If you have a hole that you made exact size via a rat tail file chances are that's not going to be a slip fit. I caution you if you press in your bearings, too tight a fit can make a bearing seize up.

3. I would not suggest having a drivetrain with swap-out wheels with the size variation that you're talking about. If you have clearance for a 8" wheel but you use a 4" you're just not utilizing your frame space, the idea is to get the wheels close to the ends of the frame. There is no way you can swap out a 8" wheel with a 4" without changing the gear ratio. The fact that you want to do this makes me think that you didn't fully plan out your ratios and wheel sizes to your desired torque/speed. I suggest you calculate your drivetrains speeds using your different wheel sizes and you'll see how big of a difference wheel size makes.

4. The advantage of small wheels is that they're light, they lower your CG and they require less reduction. Don't use them unless you calculate your robots speed using them, or you might end up with a very slow bot.