Re: [CAD_CAM_EDM_DRO] Re: Timing Belts and Pulleys

On Sun, 19 Nov 2006 18:52:05 -0600, you wrote:

>Mark Vaughan wrote:
>
>>I've bought many piloted pulleys and bored and keyed them to size.
>>
>>I have never found one where the bore is really out of centre at least not
>>that you could measure with simple machine shop kit.

I've got to agree with Mark - I've bought Chinese makes from RS and my
local bearing stockist, and also from HPC Gears (who make their own).

Never had one where the bore wasn't concentric, including sintered.

>I have bought them at various times from W. M. Berg, SDP and McMaster-Carr.
>ALL had easily measurable runout! Just use a dial caliper from the bore
>to the
>OD and take 3 measurements at random around the circumference. I've never
>seen one that was better than a few thousandths of an inch, ie. easily
>measured.

Send them back and change suppliers.

Steve Blackmore
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