Tooth belt pulley drives

[ArtF]

SO I take it those particula r gears have round valleys and slightly rounded teeth?

  Sounds doable using the spur gear method but with some changes to the tangental search..

Art

[awander]

https://sdp-si.com

has lots of pulleys and belts, and they provide 3D models of a lot of them. i donlt know if that would help in figuring out how to cut them.

I, like John, searched in vain for any info on toothed or timing Belts in MH26.

[John S]

Not only MH26 but everywher e.
These profiles have got to be the best kept secret in the world.
Spent a whole morning searching and kept getting the same old, same old regurgita ted in everyone's catalogue s, someone makes these pulleys so the info has to be out there somewhere .

I can find other looking for the same info but they always get the same answers we have got so far.

Probably the best option is to work backwards, they publish the belt specs [ missing the diameter of the tooth out ? ] so if a length of belt was drawn up and then 'rolled' round a blank pulley in CAD we should get an accurate shape.

[ArtF]

Hi Guys:

  I have managed to get soem specs of various timing gears. They are proprieta ry though and I cannot publish them. I have them stored till I can
make a page tab for timing gears. The spur gear system is not capable of doing a proper profile as they are not involute tooth gears for the most part but linear ot arc tooth types, so I think I have to do a special tab called "Timing pulleys" to give you the proper options for these.

   I will delve into such things as soon as I have a working bevel code out.
My main work this past month has been coding the math for bevels, and they are truly a bitch. We'll have to tak soon about what features we want in bevels and what we're willing to settle for , otherwise the productio n of bevels will have so many variables it will resemble a moon-shot mission control at nasa..

Art
 

[BobL]

"will resemble a moon-shot mission control at nasa"

 Awesome ....



Cheers
Bob

[awander]

found a lot of data on belts at:

http://mulco.gwj.de/en/index.htm

[John S]

Yes, belts not pulleys, loads of stuff on belts on the web.

[danmauch]

Maybe this will help http://www.roymech.co.uk/Useful_Tables/Drive/Timing_belts.html


dan mauch
www.camtr onics-cnc.com
low cost cases for gecko products.
Kits, custom and assembled systems with either stepper or servos



  A lack of specs is the typical problem you face. Even the gears we currently have were a bitch at times due to infomrati on that was conflicti ng, or diofferin g specs, or a simple lack of documenta tion.
  Its a normal thing it seems in the gearing world..

Art

[/quote]

[BobL]

Thanks for the post Dan;

You'd think in the 21st century tooth pulley gears would be well documente d...Art was right about this one..


Cheers
Bob

[John S]

Dan,
Again belt details but Art now has some factory specs on the different pulley profiles so hopefully after the bevels we may see some details.

John s.

[ahford]

I was wrong about Machinery's handbook btw.  It has the belt specifica tions for the American standard pulleys, and pulley dimension s, but not data on the tooth form.

[BobL]

Ahford;

 Thanks for the post. We'll go with John's view and see what pulley profile details we can come up with.


Cheers
Bob
 

[ahford]

I do have a related thought, and perhaps someone can correct me if I'm wrong.

Since the belt conforms to the curvature of the pulley, unlike a rigid gear form, the teeth should be fully seated in the pulley grooves.  Perhaps then the "standard" pulley tooth form is trapezoid al with clearance s outside of the sizes of the fillets on the belt teeth.  Those fillet dimension s for the belts are available with the belt specifica tions in my copy of MH 26, around page 17 million or something, after the V-belts.

[Semi_lucid]

Hello

My search for the machining dimension s for AT series belt pulleys has led me here.

I know this is an old thread, but I can't find any more recent informati on on this site.

As near as I can tell, the defining documenta tion for T and AT series pulleys is DIN 7721-2, and 7721-1 is the spec for the belts.

Are these the same reference s that Art mentioned in post 18?

Has support for these types been added?

Thanks.
John

[BobL]

John;

 I beleive they are but I'm no expert on these. To see for yourself, install GM on your pc and start it up. select the spur gear tab at the top, you'll now see the timing pulley check button on the botom left of the screen. Here you can select from the list which contains T , GT and HTD series tming pulleys. If you have any issues let us know.

Cheers
Bob