Noz
Started building any comments
September 02, 2008 04:12PM
Hello,

Ive just started building a reprap , or maybe a repstrap.

Ive decided and already started building the framework out of 50mm angle iron,So strength is not a problem, and my working size is 1m by 1m by 1m. I think no one has tryed to build to this scale yet or strength.

I have already started working on changable tool heads but my main problem is drives.

I do like the ardrino etc but ive decided to try and do more processing on the computer, so the computer will have direct control over the drives. But i was wondering if anyone knew of any control area network enabled drives and encoders that would be usefull on this scale and power . Im aiming for a CAN network for everything. Might not be as good as the current setup but i want to try , I hope mine will be the first and could possibly help the reprap community smiling smiley

Also as a bit of a oddball i was wondering about the feaseability of using say a lego controller and servo's to control a reprap. there mass produced and fairly cheep so has anyone looked at this before?

I'll be posting pics etc soon in the developers bit in the comming weeks smiling smiley

(sorry for spelling(nearly going to sleep))

Noz
Ru
Re: Started building any comments
September 02, 2008 04:31PM
Quote

But i was wondering if anyone knew of any control area network enabled drives and encoders that would be usefull on this scale and power

Hmm, deja vu winking smiley

It still looks like you're going to have to roll your own electronics if this is the sort of thing you want. Shouldn't be too hard, though.
VDX
Re: Started building any comments
September 03, 2008 03:33AM
... look here: [www.iselautomation.de] - Isel changed some years ago to CAN-systems (what i personally didn't appreciate eye rolling smiley )

I have an old (nearly 20 years) stepper-controller with 70V/8A so with the right motors enough torque for driving heavier mechanics too. But with changing from full-/half-step to microstepping (until 1/256) i could drive with my 'small' 3A/2Nm-steppers even bigger loads, as usually performed with steel-frame-systems ...

Viktor
Noz
Re: Started building any comments
September 03, 2008 07:10AM
Ive got to admit so far this has been disheartening sad smiley
the CAN motor controllers ive found so far are big fancy and expensive, when im trying to cut costs by using CAN. Basicly im looking for a motor encoder like were using now but with a can interface. I know more expensive but i was hoping mass produced would bring down price sad smiley

At the moment i think the majourity of the cost is the motors and the motor driver boards. Just trying to figure out a way around it.

I worked in the lift industry and for some of there door gears they had a small stepper motor with encoder with a can interface. Im off too look again, i'll post pics of the frame soon.
Noz
Re: Started building any comments
September 03, 2008 10:21AM
Small sort of update... (for other people who may walk this path)

CAN for the reprap is hard work, either useless, insanely expensive , or impossible to find. The logic that car windows,transmissoin etc are using can so there mass produced and could be cheep is useless when none can be found.

Still looking at maybe using lego motors, cant get any good definitoins of there capabilitys yet. Also looking for usb motor drivers and encoders. if found for a good price may solve alot of problems.

p.s rang about 50 CAN specialist companies and they all spoke to me like a idiot, which i may be, but a determined idiot all the same
VDX
Re: Started building any comments
September 03, 2008 10:29AM
Hi Noz,

... why not simply use steppers? - common, reliable, precise, powerfull ... and not so expensive ...

Viktor
Ru
Re: Started building any comments
September 03, 2008 10:41AM
Quote

CAN for the reprap is hard work, either useless, insanely expensive , or impossible to find

You're never going to save much money by purchasing complex commercial devices, unfortunately.

The RRRF motor controllers are not that expensive really... their profit is minimal and the price is competetive with the handful of other open source stepper motor driving systems.

If you're driving stuff from the PC anyway, the cheapest option is for you to get (or make) a parallel port breakout board, some optoisolators, and run something like EMC2 to generate pulse trains for the steppers. Way cheaper and simpler than using CAN, I'd say.

The alternative, as has been mentioned before, is to create your own control electronics. This is likely to be quite expensive in terms of time and the addition of a CAN tranceiver and CAN controller and a uC (to convert CAN frames to step counts and direction) to a standard stepper driver board is going to set you back somewhere between

Edited 1 time(s). Last edit at 09/03/2008 10:43AM by Ru.
Re: Started building any comments
September 04, 2008 10:54AM
>Still looking at maybe using lego motors, cant get any good definitoins of there capabilitys yet.

[www.philohome.com]

That should keep you amused for a few minuets ;-)
Sorry, only registered users may post in this forum.

Click here to login