Topics

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General Mach Discussion / How do I control spindle brake and gear shift?

« on: September 09, 2009, 03:42:28 PM »

Hello!

I am about to start the retrofit of an old Tree CNC milling machine.  I am at the point where I need to start purchasing the necessary equipment.  I am planning to keep the original DC servo motors and the AC spindle servo.  The plan is to use some of the new Granite drives to run the 3 axes and either a VFD or the original spindle drive for the spindle motor.  Another forum member mentioned that the original spindle drive (Fanuc) is a nice unit, but I'm not sure how I would get it set up on a PC-based system.  My goal is to come up with something that is fairly simple and very reliable.

Anyway, the main reason I started this thread is to find out the best way to control the spindle brake and two-speed geared head on the mill.  I believe that both of them use relays/selenoids that control compressed air.  Typically, are those sorts of things controlled through the I/O relay controls of a breakout board?  I'll have to take a closer look at the  head to see just how it changes gears, but I'm pretty sure it uses air lines.  The last time I ran the mill through its gear change, it did it on the fly and made an awful racket.  However, I don't think that anything was damaged (hopefully).  I've just been wondering if it would be better to just have it in high gear and use a VFD to cover the entire speed range.  I believe the original control changed from low to high around 1200 RPM (with a top speed of 6000).

Well, if anyone can give me any pointers in regard to this matter, please let me know.  As I mentioned, I've been under the impression that I could control such things through the breakout board, but I figured I'd ask to be sure.  I don't know too much when it comes to the amalgamation of electronic and mechanical systems, but I'm trying to learn!  Thank you for taking time to read my post and for any pointers you can give me.

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General Mach Discussion / Hoping to retrofit a CNC mill with Mach3. Where do I start?

« on: May 28, 2009, 04:17:15 PM »

I'm sure there have been a number of these threads in this forum.  I did a search, but the results weren't exactly what I needed to send me in the right direction.  I have an old Tree Journeyman 330 CNC knee mill that still has the original control.  I've never even been able to make any parts as the control seems to be in a constant state of disrepair.  The latest battle involves the power supply.  Instead of paying someone $800 to troubleshoot and replace $2.00 in parts, I've decided to look into a retrofit.

Anyway, the machine I have is a pretty solid piece of iron.  Everything on it is original and in good condition (control notwithstanding).  I am wondering if it would be possible to toss the old control and run the machine with Mach3.  My main interest is in reliability.  I am not worried about super-fast rapids or elaborate 4-axis movements.  The parts that I plan to make will be very simple.  The idea would be to use the machine to make a little money and eventually upgrade to a VMC.

I am hoping that someone can get me started in the right direction as I look for information about a retrofit.  I know virtually nothing about the intricacies of such an undertaking, but I am willing to learn.  I do have a few questions that probably have simple answers.  The machine has a two-speed geared head.  Would I be able to utilize this feature with Mach3?  Would I be able to keep the DC servos and drives?  How about the spindle drive?  Are those usually replaced in such a situation?

Well, I am hoping that I will be able to get this machine up and running.  I've pretty much given up hope on the original control.  Even when it's running properly, it leaves a LOT to be desired.  The machine is fantastic, but the electronics need to be put out to pasture.  Thank you for taking time to read my post!