Hello Guest it is May 13, 2021, 02:44:00 AM

Author Topic: Multiple Spindles on Independent Z  (Read 3326 times)

0 Members and 1 Guest are viewing this topic.

Multiple Spindles on Independent Z
« on: July 14, 2015, 04:40:22 PM »
I'm currently brainstorming a new router build and avoiding manual tool changes is very important to me.  I was originally looking into purchasing an ATC spindle but quickly discovered that they are often 10-20x more expensive than the regular versions.

This brings me to my current plan, which is to simply attach multiple spindles to independent Z axes.  This way I can run two or three tools per program.  The incremental cost per axis is extremely low with a shared VFD (~$400 vs $3,000+ for an ATC) and the complexity of an ATC can be completely avoided.

I found a brief reference to multiple spindles in the documentation but no concrete information.  Could I get some pointers?

I'd like this system to be transparent to the CAM so that choosing a tool enables the desired axis/spindle and sets the correct work(head?) offset.  I can code.
Re: Multiple Spindles on Independent Z
« Reply #1 on: August 05, 2015, 05:24:16 PM »
Requires dual channel Traj planner which I dont think M4 has. You would have to do a PLC script to do this in your cheaper version. In the M6 simply change the logic to set various relays to tranfer power to each motor, Then use G54 - G55 or the extended sets to move the Z to the place on the part should start. Use a relay to port the z power to the motor needed. Call G28 Z0 Tell Mach the tool has been changed. Call the G43 H?? Back to main program.....

I have over simplified on purpose. But that is the only way you could do it. You still would ahve to manually set tool heights for each tool independently which is why no one does it. Pain to run no matter how transparent. But it can be done.

Offline rdean

*
  •  94 94
    • View Profile
Re: Multiple Spindles on Independent Z
« Reply #2 on: August 05, 2015, 05:56:57 PM »
Did this a few years back Mach3 three spindles controlled by tool numbers on from the CAM program.  Simulated a Beese Rover machine.

Macros and offsets.

Ray

Offline ger21

*
  • *
  •  6,293 6,293
    • View Profile
    • The CNC Woodworker
Re: Multiple Spindles on Independent Z
« Reply #3 on: August 05, 2015, 06:57:52 PM »
Quote
But that is the only way you could do it.

No, it's not the only way.
There are Lua commands similar to Mach3's SwapAxis() command. What you do is set up the second spindle as another axis, like the C axis.
You use a range of tool #'s for one spindle, and another range for the other spindle
During a toolchange, you decide which spindle you want based on the tool #. If you need to use the C axis spindle, then you "swap" the C axis for the Z axis, making it the current Z axis.
It's easier to use G52 rather than the G54-G59 offsets, as you'll still be able to use those in addition to the G52.
I'm also building a dual spindle router.
But I'm undecided at this point if I'll be using Mach4.

Quote
You still would have to manually set tool heights for each tool independently which is why no one does it.

You could easily have the machine auto zero each tool after a tool change, which is what I do in Mach3. Not difficult at all.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html