Belt and Timing Pulley Robofocus Setup

[Rob Hamlin]

Dear All

Im wading into a project involving automating focus using a robofocus unit for a canon eos lens.

The shaft diameter of the robofocus is 6.3mm however im finding that many of the timing pulley bore diameters are either 6mm or 8mm

When choosing the belt ive measured an appropriate timing belt length to be about 450mm - all good.

However im having trouble matching the tooth of the canon lens teeth, the timing belt and then the pulley.

Anyway, if theres any feedback/ experience in selecting the appropriate parts feedback would be greatly appreciated

With thanks in advance

Rob Hamlin

[AndrewJ]

Gday Rob
You need to look at imperial bore pulleys.
6.35 is a std 1/4" shaft
( either that or get a 6mm and bore it out to 1/4" )

Andrew

[bojan]

It is easy to widen the hole from 6mm to 6.4mm.

As to timing belt pitch, do not worry about it - simple friction between belt and rubber grip (http://www.iceinspace.com.au/forum/showthread.php?t=148460&highlight=ULN2003) will the job just fine.

[Rob Hamlin]

hi bojan

much appreciated for that feedback

will leep that in mind

cheers
rob

[Rob Hamlin]

hi andrew

thanks for that info mate

will cast my eye over some stockists of these dimensions

cheers

rob