idea for linear belt drive

[dickieto]

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

hi peter
what width is your belt and is there any more available???:naughty:
at £6 it might just be worth giving my idea a go:dance:
tom

[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]

Had a look this morning and last one has sold.
Sorry
Still to find pitch and get pulleys
Peter

[Robin Hewitt]

250rpm is doable IMHO

You are probably right. Stepper technology has moved on and I need to adjust my comfort zone.

My comfort zones are fairly well tuned, I always 'know' what thickness of material to use, what bolt size etc. But obviously I must now consider adjusting my stepper motor zone, possible my feed rate zone to. This will require a degree of experimentation.

I have had over 1000 rpm on a disc-magnet stepper and a 40 volt driver but that is one whacky stepper motor.

[HiltonSteve]

Here is another idea which i quite like for linear drive, watch the video which shows the machine using chain and belt. I like the idea of keeping the chain/belt stationary and pulling the axis along on it.

http://www.youtube.com/watch?v=vETkf...mbedded#at=154

You are probably right. Stepper technology has moved on and I need to adjust my comfort zone.

I have had over 1000 rpm on a disc-magnet stepper and a 40 volt driver but that is one whacky stepper motor.

My machine runs the steppers at 1000rpm for rapids and even had it up 1500rpm at one point but was just too fast for the machine. I am using Roy's 5A driver boards and 5A steppers, had to keep the boards cool to get these speeds with a couple of 120mm fans but no problems so far!

[Robin Hewitt]

My machine runs the steppers at 1000rpm for rapids and even had it up 1500rpm at one point but was just too fast for the machine.

Aha! You to have a comfort zone :heehee:

I have the 220 Volt drivers so presumably it should go like the absolute clappers once I get the 48MHz dedicated cpu rattling the driver pins.

Thinks: Max step rate 40Khz, divide by 1600 steps/rev, 25 rps, 1500 rpm, 10cm/second rapids resolving 2.5 microns

No, I'm not brave enough either :rofl:

[HiltonSteve]

Aha! You to have a comfort zone :heehee:

Seems that i do without even realising..!! :rofl:

[dickieto]

Had a look this morning and last one has sold.
Sorry
Still to find pitch and get pulleys
Peter

hi peter
i have just bought 2 of the same belt from epay(thanks to john for posting the link for item on ebay,tried to reply my thanks but his post has now disappeared?!!!)
they were a bargain only £0.99 each,sadly postage was £5.99 each:nope: oh well cant have it both ways.
another step closer to my build.
Tom

[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?