Re: [CAD_CAM_EDM_DRO] Stepper motor pullies

Hi John,

Yes, I'd be interested in the data, I have a "Timing Belt Pulley"
calculation program, and It would be interesting to see how this fits
in.

I have no HTD's (that I know of), just the old trapezoid stuff.

Alan KM6VV


stevenson_engineers wrote:

>
> Posted some pics and info about the Taig CNC mill I'm doing last week
> end, post# 47955
> Link to one pic repeated here:-
> http://homepage.ntlworld.com/machines/taig2.jpg
>
> I needed 6 pulleys to do this, all 22 tooth 5M HTD series.
> Unfortunatly the stockist only had 5, rang round and all the other
> supplies wanted double the price I paid for these.
> Had a look at the specs and found quite a lot of discrepencies.
> So I rang Fenners tech section up who I have a good working
> relationship with. Told them I need to to cut this pulley direct on
> to the end of a motor shaft and didn't have room to mount one, could
> they fax me the info. Sure enough the info came through with all the
> calculations.
> Seems the basis of the 5M series is a semi circle with a diameter of
> 3.1 mm or 0.122" Once you have this and the pitch circle diameter
> it's easy to make these one of three ways.
> [1] drill a series of holes on the pcd and then turn down to the OD
> [2] Index round and use a 1/8" end mill
> [3] Index round and use a convex cutter in a horizontal mill
>
> I chose the later as I had this setup already on the mill. Found a
> cutter with a 0.120" rad and cut a new pulley in about 20 minutes.
> If there is enough demand I can convert the design details into an
> easy to read table and post this in the files section.
> What complicates the matter is there are TWO pitch circle diameters.
> The usual quoted one is the theoretical belt pitch circle which is
> bigger than the OD and the pcd of the hole circles which is never
> published in tables, It's this one we need. Once this becomes clear
> these are far easier to do than the trapiezoid type of timing belt.
>
> John S.