Hopefully it will be cutting cores and bases this 2015!!!!! Its been a long time coming and I am the worlds greatest procrastinator ditherer but lately I've got fired up and progress is being made.
Before you start on this sort of project you really need to look at why you're doing it. I am striving for repeatability, speed, accuracy, scalability , flexibility and so cnc makes sense for me to grow and develop my board designs and my business. But plenty of times I have looked at the idea of just plain outsourcing all cutting which has its merits too.
Cost of an in house cnc has to be factored in of course, my approach is to use my telecommunications electronics and IT background and build my own , partly for the fun and mainly the reality of cost meaning i must build my own to get a powerful cost effective system, and also by building my own cnc I understand the beast and the electronics and software behind it.
So a couple of years ago I started researching and at the same time accumulating the bits I decided I would need.
As much as possible I want to source the highest quality parts i can afford to get, and this dictates 2nd hand parts in some cases. So far I have scored some beauty 2.6m lengths of THK SSR30 rail and bearing blocks, some big THK ball screws 1.8m drive length, lots of THK SSR25 rail band bearings for y and z, and a lot of servo drive parts to build my controller with. Still a bit to go yet!
Lately I decided to finish my controller and driver electronics and now I have it almost done. X and Y Granite Devices VSD-XE servo drives and Motionking 940W AC brushless servos, fun to set up I am learning PID tuning now. Steppers would have been far easier but I like the idea of a closed loop positioning system. Its running Mach3 on a small PC and driving a USB smooth stepper and Homann Designs breakout board and a nice 1500w PSU for the HVDC supply. Initial servo tuning done but it will need a full tweak once its mounted on a machine. I still need another Granite Devices VSD for my Z axis too.
I'm running MonkeyCAM generated gcode through it on the bench with looping 100 times so it runs for 12+ hours continuously non stop as a burn in and de-bugging process. Today I ran the oscilloscope on the earthing and already found some stray signals so my earthing needs some improvement although its actually setup good - well I thought so until I saw the waveform between the frame ground and power supply ground......!!! shielding and earthing carefully is a must.
A few pics and a video of the controller here and motors spinning. More to come as I make progress.
The video when I first got motors spinning!!!!!
https://www.facebook.com/video.php?v=76 ... =2&theater
my controller box
controller psu's and dc wiring etc
