Cnc router to 3D printer

Dear friends,

I have been in a fantastic journey the last 3 months building my own cnc router. I have built the version 1.0 with a spindle from Dremel tool and some other maybe not so good ideas . But the first tests showed it works. To my surprise, I must admit. Now I'm in the process of completing the version 2.0 and I want to add the option of converting it into a 3D printer as well.

I have the extruder and the hot end travelling my way from the far away land of China, but I'm a bit lost about the electronics.

I have a stepper breakout and driver board in one piece, driving steppers and the spindle. Now, for 3D printer, I need the fourth stepper driver for the extruder and two heaters - for the hot end and one for the heated base. Can I use the board I have and add the missing pieces? Do I need another parallel port for the computer or is there a way to steal the pins from the existing board? I'm not sure there are any available, though with all the limits and EStop. Do people normally need two ports for 3D printer applications?

Any help or pointers in the right direction appreciated. Thank you!

Edmunds

Edited 1 time(s). Last edit at 04/21/2014 07:12AM by Edmunds.

Im presuming that some sort of parallel breakout box?

Reprap is a bit more complicated than that... we use micro contollers as the timing are critical (or you get blobs), these talk to stepper drivers with standard step and direction pins

The controllers also take care of setting and maintaining the temperature of the hotend and heated bed.

The controller also does all our gcode interpretation and handles endstops

Also our software expects a serial device and just sends raw gcode to the controller

Also a cnc, unless you have really good threads is painfully slow for a 3d printer (17+ hours for a 30x30x30mm print)

Bearing all this in mind, if you still which to try it, get yourself a cheap reprap controller, something that takes pololu drivers. don't connect those but use whatever drivers you are currently using. (presuming they do step and direction signals)

Dust,

Thank you for your prompt reply.

It is a parallel "breakout box" with onboard stepper controllers - kinda all in one thing. Parallel port, power and limit switches in and steppers and PWM spindle control out. Plus some unspecified and yet to be discovered display and manual control dongle ports. Slightly over a hundred dollars on ebay with three nema 17 included - about the right price to pay for how much I have managed to educate myself in all of this CNC thing .

I have figured out by now, I have pins from #15 to #25 unassigned in Mach3 and #16 and #17 of them being output pins I can use (not grounded, not inputs and not used by the computer for something else). So I'm trying to research what controller can I use and how to "steal" the connections from the board I have without blowing anything up. It is easy enough to have a small board with, say, screw terminals between the computer and the current board, where the not used wires would go a different way. However, I'm not quite sure yet what "component blocks" do the breakout vs stepper driver boards have. Do my two free pins of "step" and "dir" from the parallel port plug into the "cheap reprap controller that takes polulu boards"? There is also an "enable" pin for XYZ axes - what is the point of that? What is the minimalist version of these components? Any links to DIY versions? I can solder something, if need be . I need only one extra stepper motor to be controlled and two heaters.

The machine is easily moving 400mm/sec. Do you need more for 3D printing? I believe I could get it 20% up with more motor tuning, but seems speedy enough compared to the videos of 3D printers in action I have seen.

Maybe actual photos of the machine and the board I am using is helpful - pictures attached.

Edmunds

I run Mach3 with a 4-axis TB6560 driver board through a parallel port, manual control for hot end and bed. NOT complicated. There is a way to add a 4th axis to your 3-axis TB6560 board, but if it's in your budget, I'd just get a 4-axis board.

400mm/s is way more than fast enough. Most printers best quality prints are between 10mm/s to 60mm/s. Higher speeds are possible, but print quality drops off greatly, and you can easily out-run how fast your extruder and nozzle is able to lay down material.

I run a stand-alone PID controller for the hot-end, and a Velleman temp controller for the bed, both wired through the spindle relay so it is easy to have the hot bits shut off when the print ends.

For a little while there was the SeeMeCNC H-1 printer that was sold with a 3-axis TB6560, and a EasyDriver board for the 4th axis.

Look at SeeMeCNC forum for info on setting up Mach3 for printing. [forum.seemecnc.com]

I run without limit and home switches but the TB6560 boards and Mach3 are easily configured for limit switches.

Edited 3 time(s). Last edit at 04/21/2014 08:02PM by Dirty Steve.

Are you sure you can do 400 mm a second that is pretty fast what pitch screws are you using. I have a big printer that I built using Mach 3 with external temp controls for hot end and heated bed. The most I can get our my 3-D printer is only 230 mm a second and I have some pretty powerful motors and high lead ballscrews

Thank you for your replies, guys.

And sorry for the typo in speed. Of course, it is not 400mm/s, but 400mm/min, which makes 6.66mm/s. As I said, I have tried to push that to 10mm/s in Mach3 and that worked with almost no problems. Some tuning of acceleration, micro stepping and currents should be able to fix that "almost". Just haven't found the time yet. I am building large exhibition model train layout and will continue to do so for the next couple of years. This is what I need the machine for. Needless to say, most of the parts I need, will be tiny. A couple of mms across. So I'm not too concerned about the build speed. More about precision and tiny tolerances.

I am a few steps down the line by now. I have found the following controller that is the same "family" as my big controller. Now, the seller says, he does not have any manual for the board. I understand the left hand side connections, but not sure about the right hand side. Can anyone give me an educated guess on what these are? Is this something that I can connect to parallel port? Ground and respective pins?

Thank's a million.

Edmunds

I'm a big fan of Mach 3 but in your case I would start off build a regular reprap printer probably an I3 and use the standard reprap electronics package. You need something that is capable of approximately 200 mm a second for rapids to be good for a printer.

Edited 1 time(s). Last edit at 04/22/2014 10:22AM by cnc dick.