Belt drive on a router

[JAZZCNC]

We're talking about different things. I'm not talking about the belts stretching over time (since as you say that just doesn't affect us). I'm saying when you apply a force to a belt it will stretch then spring back when you remove the force. So I agreed that when driving a ballscrew with a belt there's no problem. However I thought John S was asking about using the belt instead of a ballscrew? I.e. long open belts on either side of the gantry to push it along...

Ermm Ok but still the same applies in John's application belts will be fine.

[boldford]

I'm unsure where I saw it but one idea is to have the belt that wraps round the gantry mounted stepper motor meshed with another length of open belt firmly fixed to the machine bed. The only length of belt "unsupported" is that short length which is picked up to wrap round two idlers and the toothed pulley on the stepper motor IYSWIM.

You could also try the alternative of roller chain.

[John S]

I.e. long open belts on either side of the gantry to push it along...

I was thinking more about pulling it, tried pushing a bit of string years ago and not a good experiment

[boldford]

I was thinking more about pulling it, tried pushing a bit of string years ago and not a good experiment

Bit like putting a sausage up an entry.
Have you looked at http://www.mycncuk.com/forums/linear...elt-drive.html