control for DIY printer?

[Mikkel]

Hi.
I have a large, non-working 3D scanner (touch-probe) that I was wondering if I could turn into a 3D-printer?
The scanner itself is working, but the computer and powerbox are both outdated and broken down.
It's a 3-axis portal machine with ordinary stepmotors.
Anybody have an idea?

Thanks, Mikkel, DK.

[soofle616]

I would think the same RAMPS board used for most printers would work fine. Depending on the ratings of the steppers you may need to source/build higher powered stepped drivers though.

[Mikkel]

Thanks Soofle616
Do you know if anyone sells the complete 'package' between computer an printtable?
I took a look at RAMPS cards, and even though it does make some sense, I'm not sure what parts to order.
Basically what I have is a 1ton granitblock with xyz axis'es build on to it, that's it.
I need evrything else. Printhead, filaments, controlboard stepperdrives etc.
It's a lot to ask, I know, but have you heard of anyone who could help me with that?
Best, Mikkel.

[soofle616]

No idea if anyone sells a "package" of stuff that assumes you already have a mechanically complete printer. There are lots of places that will sell you a package of ramps/drivers/lcd and tons and tons of places to get filament from. As for the hotend itself, again you have options for places to buy. I'm sorry that this isn't terribly helpful but I have yet to build my own machine so I don't have a list of "known good" vendors for the electronics. Do a search here though as there have definitely been posts about where to buy the control boards and drivers.

[whythelolface]

This won't be a very useful reply, but I'd suggest against it, unless you reallllly want a large format printer.
The reason why is that not long ago I was in the same position, but having built a cnc router instead of a touch probe (overhead gantry type, using a parallel driver board being controlled by mach3) and I decided against it after weighing up the pros and cons.
Pros:
-One machine to do both tasks
-Large format

Cons:
-One machine, so it cannot do both tasks simultaneously.
-Large format, so heated bed is far too large to be practical- would require ridiculous amounts of power to heat
-Heavy moving parts, therefore would experience lots of bearing wear because of the repetitive nature of 3d print gcode.
-Also, heavy moving parts so would have to print very slowly.
-Time taken to reconfigure the machine from one mode to another would be a pain in the ass not mentioning that potential to cross wires each time, potential to go wrong.
-Would be very difficult to enclose the build area because of the size.

[soofle616]

He's not looking for a multipurpose machine (based on the original post) so that's not a concern
Heated bed may be fairly impractical but it's not impossible, it's also not necessarily required depending on the material he uses
Heavy parts do not result in lots of bearing wear IF the bearings are properly selected. Given that the machine is already assembled as is, odds are it has the appropriate bearings for it's size. Yes lots of repetitive movement can cause a bearing to get choppy but most bearing wear is the result of heat which requires either very fast movement, or loads approaching the max that the bearing can support.
Not necessarily true, but depends entirely on the size and power of the steppers
Again, only talking about one purpose so this is not a concern
Not at all, some 80/20 (or openbeam) and some acrylic sheets can be easily and cheaply purchased. Assembly is a quick bolt together operation.

[whythelolface]

Good call, I missed the meaning of the OP that it's to be a single purpose machine.

Still, I'm assuming the machine uses lead screws and has the head on a gantry, so I'd be surprised if you get more than 50mm/s out of it and it not develop backlash in 6 months.

By all means, it's possible to make a functional printer out of the machine - but in my opinion without a heated bed, an enclosed box and with moving parts that are way over-specced it's going to be effort to make a slow, power hungry printer that can only use a limited range of filaments.

[whythelolface]

To balance out my un-helpful reply with some helpfulness:
you can use the tried and proven Arduino Mega/RAMPS board configuration as your controller, but replace the XYZ Pololu/stepstick drivers with high-power stepper drivers, like these
http://www.ebay.co.uk/itm/CNC-Engrav...item1c41ea13b8
Those are up to 5A which would cover most Nema 23 sized motors.

You would connect them to the direction and pulse outputs of the ramps board to give the stepper drivers what they need to move the motors. General electrical skills required - soldering, continuity testing etc.

You would need 1 for each axis, and you can use a standard pololu or stepstick for your extruder, which you can mount on the head.

You'd probably want to use a direct-drive extruder like this and mount it on the head.
http://www.ebay.co.uk/itm/0-4mm-Nozz...item58ad63711f

For power, a 12v supply like this assuming you're on 12v:
http://www.ebay.co.uk/itm/12V-DC-30A...item3f3848735b
Or a server PSU / ATX psu with enough amps on the 12v rail.

[Mikkel]

A couple of pictires.

[whythelolface]

Looks like an interesting rig!

Are all the axis motors like the one in the picture?
It looks like a brushed dc motor (the brush-barrels in the side and the optical encoder), and arduino/ramps and all the other 3d printer control systems I can think of are designed to control stepper motors, not dc motors.

It could be easy to replace all the motors with steppers if the couplings are simple. Perhaps using 3d printed adapter plates.