RAMPS for RepStrap

I've been following the reprap project for some time but am a bit new to the actual technical aspects of it. I've decided to take the plunge and have purchased a printhead from QU-BD. I have a pile of discarded printers and scanners that I hope to cannibalize for parts to make a repstrap (and if those don't work I can always purchase some NEMA servos). My primary question is what controller electronics should I go with?

After researching the issue on the website, forums and goole, RAMPS seems to be a very promising way to go given its modularity, "simply works" nature and the fact that it can be used in a Mendel when the time comes. However, before I go ahead and purchase a RAMPS package, I was wondering if the system is flexible enough to work with a repstrap system, or is it design specific to a reprap?

Thanks!

... I'm driving my Isel-CNC-mill with a RAMPS 1.2 as RepStrap and have some setups for lasercutting with it too ... so it's modular enough

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

The only issue will be your stepper motors.

They need be Bipolar motors (they have 4 or 8 wires, though sometimes 6). Unipolar motors (5 wire) will not work.

Notes:
With 6 wire motors (which have 2 centre-tapped coils) you would most likely ignore the centre taps of the motor coils. With 8 wire motors (which have 4 coils), you can wire two adjacent coils in series or parallel, depending on your need. Series wiring will draw less current, which is less likely to fry the stepper drivers.
Be wary with some 6-wire motors. I've found one that I ripped out of a printer that was simply a 5-wire motor internally, as both "centre taps" had been internally wired together. I've not seen another motor like it but it's worth checking on any scavenged motor. I suspect that the design called for a 5-wire motor and they didn't have one, so they improvised.

... which motors you can use, is mostly depending on your drivers - if they have STEP (or CLOCK) and DIR (or CW/CCW) input, then you can use them.

I have some 3-phase motors with 325Volts and configurable 200 to 1000 full-steps per turn (2000 to 10000 microsteps) and 24Volt-inputs, which I'm driving with the 5Volt/TTL-pins of the RAMPS ... simply soldered an adapter between the pololu-sockets and the pins of the driver boards.

Another adapter board feeds the pins of the motors and reference-switches to a VG-socket in my CNC-mill controller for my CNC-RepStrap.

So I can switch between 4 or more different setups for milling, FFF-printing, lasercutting, UV-printing (and more) by exchanging the boards, the adapters and the software ...

Edited 1 time(s). Last edit at 12/05/2012 02:33AM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks everyone, you've been very helpful. I think my question has been answered - RAMPS should be able to meet my needs.

Two last questions:

Are there any other electronic setups you would recommend over RAMPS?

And:

Where can I find out more about working with motors (and how not to burn out my circuit boards)?

Dogstar

... there are some other boards out there - go through the Wiki or the parent 'Electronics Folder'-threads.

I was only using the older Gen3 and the ArduinoMega with RAMPS1.2 - but most other Arduino based boards are something inbetween, so with basic electronic knowledge freely interchangeable ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I think I will be going with RAMPS ultimately as it seems to best meet my needs from what I have seen so far. I was just wanting to make sure that I wasn't missing something important.

Thanks again!

Dogstar