Hello from Missery, er Missouri

[tlmotorsport]

Just thought I'd say hello and bounce some ideas around and get an opinion or two. I have a CNC router (pic attached) that me and a friend built for a class about a year ago and I'm looking at performing some upgrades to the frame of it to make it stiffer and easier to take apart for transport. Its got a travel in the X, Y, and Z of 30"x30"x9" (762mm x 762mm x 228mm or so all on linear profiled rail and ball screws thanks to a local supplier who donated the parts) so with its current mode its a bit unweildly to move around as it can not be taken apart easily. While I'm doing the upgrade I'm considering adding some functionality by incorperating an extrusion head or two to add in rapid prototyping capability. Now I'm not expecting to use the full travel for an RP build area but definitely would like something bigger than seen in the normal reprap/makerbot type machines.

I'm more of a mechanical guy (mechanical engineer by trade) so the hardware side of things are easy for me to figure out, so my question is more about the control systems/software than the mechanics of the machine. We currently have a 3axis (expandable to 4) Hobby CNC controller on there that is connected via DB9 serial connection and is run via MACH 3, but with wanting to add RP capability I'd like to be able to control 5 axes (so I can have 2 seperate extruders as that functionality works its way along in the reprap community, one for build material one for support) and am thinking something along the lines of a RAMBO board would work well. Would the RAMBO be able to work with MACH3 (which I know can support USB operations as it can work with the SmoothStepper system) or would I have to have as part of the changeover between routing and RP work that I change a few plugs over for the 3 drive axes and limit switches? Also if I were to use a new control system for the router like SmoothStepper would that be able to work with opensource type stuff of the reprap community?

Anyway, thank you for reading and thank you in advance for comments/thoughts about what I'm thinking about here.

Terec

[mhackney]

Terec, a RAMBo would completely replace your Hobby CNC Controller and does not interface to Mach. You would use a host application like pronterface or Repetier to "talk to" the RAMBo. That said, this will be a LOT easier to use than Mach since it will give you built in temperature control and readout, fan control, and the ability to control 2 extruders. How large are the steppers on this machine? The RAMBos and other Arduino controllers are typically interfaced to NEMA 17 steppers.

Similarly, Smoothstepper is not going to be compatible with the open source RepRap like software. These are 2 very different worlds!

regards,
Michael

[tlmotorsport]

Michael,

The router has NEMA 23 framed motors, rated for 305 oz-in of torque off of 3A's so even dropped down to a driving current of 1.5-2A should still be more than adequate to drive the gantry around at speeds for extrusion. So given that the RAMBo/Arduino controllers cant work with MACH and MACH isn't really suited for 3D printing my best bet if I want to have the same frame/drive system would then be to have two separate controllers, and would just have a plug system to make switching the main drive motors and limit switches as being the simplest solution (or perhaps some sort of switch box for them). Or is really that much easier to have multiple machines? I was definitely hoping I could use the same frame/drives for the primary axes as its a good setup and would allow for larger print areas than I've seen from the kits which would be cool.

Terec

[mhackney]

A few of us do or have run printers from Mach and if you don't already have an investinment in the software and hardware, anArduino based system is quite cost effective AND less frustrating since you can control hot ends,get temperature feedback, etc.

It's actually easy to have control systems and switch back and forth. I did this as I was moving my H-1 from Mach to an Arduino based system. You could start with Mach and see how it works for you. Here's what you'll need:

A hot end with thermistor - the SeeMeCNC hot end is nice
An extruder, again the Steve's extruder that SeeMeCNC carries is nice and should be easily fit on your machine.
A thermostat to control the hot end. SeeMeCNC offers the Velleman kit that is easy to solder and works well.

The above would get you a simple system that you could start to use to print and see where you want to go next. The extruder and hot end can be reused on a new Arduino based machine.

Hope this helps!

Cheers,
Michael