Printing in G-code

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morrows_end
Posts: 12
Joined: Tue Jun 26, 2012 2:45 am

Printing in G-code

Post by morrows_end » Wed Oct 24, 2012 8:32 pm

I'm new to 3D printing. I have a Shapeoko driven by a HobbyCNCPro 3-axis unipolar driver that i've been trying to mill PCBs with. I'm thinking about adding a printhead to it so I can also print 3d objects. Maybe I'm just missing something, but I can't seem to find information on how to print 3d parts using this kind of setup. Anyone have a toolpath or parts(such as some kind of driver for just the extruder that I could simply add to my current setup) ?

RSWeaverAz
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Location: Denver, Colorado

Re: Printing in G-code

Post by RSWeaverAz » Thu Oct 25, 2012 2:33 pm

@morrows_end »
At a minimum you will need a 4th stepper motor controller,
this is to control the stepper on the extruder that feeds the plastic filament to the "Hot End".
You could buy a Pololu and do some kind of breadboard, but it would be easier to get a controller designed for 3D printing.

Check out Bart Drings site http://www.buildlog.net/
He has build open source projects consisting of a Laser Cutter, ORDBot (3D Printer) and is now working on a Plasma Cutter.

You want to look at the ORDBot stuff. There is literally weeks of reading about ORDBot specific 3D printing topics on the site.

There are other people with Shapeoko's wanting to do 3D printing, but i don't know if there is any forum topic set aside for that,
possibly Edward could set up one ...
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jrsteensen
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Joined: Mon Jun 11, 2012 9:29 pm

Re: Printing in G-code

Post by jrsteensen » Thu Oct 25, 2012 3:28 pm

Its been in here.

If your using Mach3, there is an addon with a modified version of slicer, but you will need the 4th axis for the extruder head, and a print bed.

I wrote up a theoretical 3d printing upgrade on the wiki yesterday. http://www.shapeoko.com/wiki/index.php/ ... ting_Mach3

morrows_end
Posts: 12
Joined: Tue Jun 26, 2012 2:45 am

Re: Printing in G-code

Post by morrows_end » Thu Dec 27, 2012 11:09 am

I realize this is a bit old, but I finally got the parts to add a 4th axis to my hobbyCNC Pro motor driver board. I am using LinuxCNC for milling and I'd lie to use this for 3d Printing as well. Does anyone have suggestions in this setup? I am still missing something for controlling the temperature of the hotend and bed. I do'nt think I need a hot bed if I use PLA, but I am not sure about the hotend or how to configure linuxCNC for my 4th axis (the extruder).

cvoinescu
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Re: Printing in G-code

Post by cvoinescu » Thu Dec 27, 2012 2:13 pm

If you're printing PLA, you are correct, you don't need a heated bed. PLA sticks very well to Kapton tape on an insulating support (i.e. wood -- I have a laminated chipboard wardrobe shelf from Ikea with the Kapton on top). PLA may even stick to Kapton on more thermally conductive supports -- glass, aluminum -- but I haven't tried that. All you need is temperature control for the hot end. As long as you don't want to go fancy and vary the temperature during the print, you can use pretty much any microcontroller with an A/D converter, plus a MOSFET and a few resistors, to build a smart thermostat.

I wanted to limit software DIY to a minimum (I'm a programmer by day, so I know it tends to eat away time like nothing else), so I used an Arduino Mega 2560 with the Marlin firmware, four Pololu driver carrier boards and two MOSFETs on breadboards (one for the hot end, one for the fan). I followed the RAMPS schematic, but at 24 V supply (except for the fan). I have moved the electronics to perf boards in the meantime, and changed to separate drivers for the two Y motors, but still no purpose-made PCB yet. That setup works like a charm*, with stock software: Marlin firmware, Pronterface host, Skeinforge slicer; I use OpenSCAD for design, but I'm not entirely happy with it.

My hot end is a J-Head mk V-B with the 5.6 ohm heater resistor replaced with a 25 ohm resistor of the same type (to work at 24 V instead of 12 V); Digikey has the resistors. The extruder is a Greg's Wade Reloaded (this one) bought on eBay. That combination worked perfectly from the first try, with PLA at 185°C. I've had no problems with it at all, so I wholeheartedly recommend it.

* I really need to find a better simile. Charms don't actually work at all; my setup does.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

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