Re: Timing Pulleys - Chain & sprockets?

>--- In CAD_CAM_EDM_DRO@yahoogroups.com, "mmurray701" <gmurray@n...>
>
> I dont think backlash would be a problem, assuming its kept tight.
> But belts are usually a better idea than chains for power
> transmission. Belts should last longer, run quiter and dont require
> frequent lubrication and adjustment for wear. I think your best bet
> would be to head over to www.sdp-si.com and pick up some timing
> belts and pulleys. I suppose it could work if you got them dirt
> cheap though. Good luck.
>
> Mark

That's the problem though, chains cannot be kept tight. A chain needs
some free play to be able to work properly and this will introduce
backlash.
Timing belts OTOH are designed for zseo backlash applications.

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I cannot see how this topic can be regarded as OFF LIST when posts on
timing belts and pullies can run at the same time. Chains and
sprockets are only a variation of the same issue.
We either encompase this until it dies a natuaral death as not being
suitable and so lie in the archives, hopefuly never to resurface or
we ban ANY topics of motor drives and mountings.
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Recently I have posted about 40 copies of my Excel timing belt
spreadsheet out to people who have asked for it. These are quite easy
to make with a simple flycutter and a dividing head or similar.
It's also well worth looking at the HTD series of belts and pullies.
In the first instance they are usually a lot cheaper to buy than the
conventional timing belts and secondly they are far easier to make,
in the smaller pitch sizes like 5mm just a row of 1/8" diamerter
holes on a calculated pitch circle then turned down to another
calculated diamer is enough to get you a finished pulley.
I am also working on an Excel spreadsheet to do these. 5mm ones are
done but I need some 8mm examples to carry on.
An example of the 5mm ones on a Taig mill are here.
http://homepage.ntlworld.com/stevenson.engineers/lsteve/files/taig1.jp
g
http://homepage.ntlworld.com/stevenson.engineers/lsteve/files/taig3.jp
g

John S.