idea for linear belt drive

[Robin Hewitt]

the motor turns three times as fast = 3 x 83.33 = 250rpm

That's over 4 revs/second. If we start straying beyond the capabilities of the cheapy 40 volt stepper drivers he needs to be warned, but maybe we have already confused him enough for one day

Thanks for fixing my smilies

[ptjw7uk]

The first part of my router design arrived today a 4.4m drive belt for £6 cant be bad but the teeth on the belt are not uniform so will not lay back on itself in the the teeth are larger than the gaps.
Oh well back to the drawing board it may do for the design on this thread.
The belt is designated as RPD8 the 8 I assume is the tooth root, tried a search but nothing I could recognise but cheap enough.
Now for some pulleys.

peter

[irving2008]

That's over 4 revs/second. If we start straying beyond the capabilities of the cheapy 40 volt stepper drivers he needs to be warned, but maybe we have already confused him enough for one day

Thanks for fixing my smilies

Robin,

I get 300rpm on my crappy 10mH Astrosyn steppers and a simple L297/298 driver. Admittedly thats as fast as it will go, but they still generate a measured 0.45Nm of torque at that speed!

250rpm is doable IMHO

Irving...

ps, you're welcome

[ptjw7uk]

Only problem now is to find the pulleys or drawing of wht is listed as an RPD8 belt. Nearest I have found is listed as RPP but no drawings so I can compare.
Good score on the belts.

Peter

[irving2008]

Peter, I too did a quick scan. No info on RPD either. Maybe you can draw up the profle so we can compare it to HTD8?

[ptjw7uk]

Nearest that I have found is HTS this is for a RPP profile http://www.martinsprocket.com/2001/SecKb.pdf#J74 will do some measurements when I go down to the workshop.
Peter

[dickieto]

Nearest that I have found is HTS this is for a RPP profile http://www.martinsprocket.com/2001/SecKb.pdf#J74 will do some measurements when I go down to the workshop.
Peter

please let us know what u come up with!!
thanks again tom.

[ptjw7uk]

Tried to measure teeth but the bottom section is radiused about 3mm, so not easy to measure. Taking a resin cast at the moment to to get better measurements. Definately 8mm pitch about 25.6mm wide looking like a HTS pulley might be the one but not found any measurements to caompare to.

peter

[irving2008]

According to Gates, RPP belts will run interchangably on RPP or standard HTD profile pulleys. The main difference it would seem is that the RPP profile has a dent on the top of the tooth to reduce wear and allow the tooth to sit deeper increasing the transmission properties. Are there any markings on the belt itself? Here's a PDF with tooth dimensions for a specific brand.

[Sawa]

My idea for a cheap linear cable drive over long distances.