Messages

1

General Mach Discussion / Re: Spindle control issue...

« on: October 26, 2010, 12:33:24 PM »

Got it. It seems there was a bit of THC related stuff left in the XML from the plasma profile.

Thanks!

2

General Mach Discussion / Re: Spindle control issue...

« on: October 26, 2010, 10:06:00 AM »

That's certainly how it's acting, but there are no inputs enabled other than e-stop. 

3

General Mach Discussion / Spindle control issue...

« on: October 25, 2010, 10:20:18 PM »

I've just returned to setting up my little mini mill on my new control / drives, and I'm having a strange spindle control problem. I've got the XYZ working properly, tuned, etc. (no limit or home switches yet) and the spindle control is on an output1 relay. The manual spindle/output1 button works fine starting and stopping the spindle, but I'm having a problem with M code control.

If the code gives a M03 or M04 the spindle starts properly, but then Mach3 will not continue with the G code. If I remove the M command from the code, the rest of it executes properly. Even in MDI if I issue a M03 the spindle will start, but any subsequent commands I enter will queue and not execute until I manually press the spindle/output1 button to turn the spindle off at which point those queued commands will execute.

It's acting kind of like it's looking for a spindle index signal, but no index input is configured, and I can't find any settings that look suspect. If I set a spindle delay on the spindle tab I can see the dwell indicator come on for that delay period, but the code still won't continue after the delay period.

This isn't any sort of electrical issue since it happens with the spindle disconnected as well.

This must be a simple setting issue, but it's giving me a headache...

Thanks,

         Pete

4

General Mach Discussion / Re: which Breakout Board

« on: June 25, 2006, 08:42:40 AM »

No experience with this setup, but you might want to check the power supply if it seems to be having problems with multi axis moves and is ok with single axis moves.

Pete C.

5

General Mach Discussion / Re: Should we start a few new catagories ?

« on: January 19, 2006, 09:39:48 AM »

I'd think dividing out sections for electrical and mechanical would make sense and not divide it too much.

Pete C.

6

General Mach Discussion / Re: Spindle speed control

« on: January 16, 2006, 09:55:55 AM »

Vmax - Try measuring the voltages at the speed control pot relative to the AC line neutral. While the control is indeed using low DC control voltages, the entire drive electronics, including those DC voltages is floating at the AC line voltage. You can not connect those control voltages anywhere without isolation and indeed you can be electrocuted working on the "low voltage" control signals if you are not careful.

Remember, everything is relative, and even though the leads on the speed pot only show low DC voltages relative to each other, this does not mean that they do not have a different voltage realtive to something else like ground.

Pete C.

7

General Mach Discussion / Re: Spindle speed control

« on: January 15, 2006, 06:24:43 PM »

The speed control pot on that drive is *definately* floating at AC line potential i.e. 120VAC. In order to control these drives from Mach or other software you need an interface that provides both isolation and conversion of the signal from the computer into a control voltage for the drive. Below are two commercial options.

http://www.homanndesigns.com/DigiSpeed.html

http://www.campbelldesigns.com/mach-spindle-speed-control.php

Pete C.

8

General Mach Discussion / Re: Spindle speed control

« on: January 15, 2006, 01:11:33 PM »

The voltages on the speed control pot are floating at AC line voltage. Connecting them anywhere without isolation will make a big bang and incinerate things. Lookup Digispeed for more info, I think Campbell is also working on a similar unit.

The optical pickup could be electrically compatible if it was disconnected from the lathe electronics and only hooked to the computer, however you would need to change or modify the slotted wheel on the spindle since Mach is expecting a single pulse per spindle revolution.

Pete C.

9

General Mach Discussion / Re: My mondo router project!

« on: January 12, 2006, 09:24:40 AM »

Looks like quite a project. What is the application for this monster? What software will you be using to generate 5 axis G code?

Pete C.

10

General Mach Discussion / Re: Question about referencing

« on: January 11, 2006, 07:44:20 PM »

If it is stopping randomly before even reaching the home switch, and increasing the debounce interval helped, that pretty much confirmed that the problem is in shielding / crosstalk, probably with the stepper leads for that axis.

Debounce is intended to compensate for contact bounce in the switch when it is triggered, not for crosstalk. Increasing the debounce interval further will reduce the symptoms of the problem, but will do nothing to cure the underlying problem.

What you should do is inspect the routing of the wires for the home and limit switches on the problem axis to insure they are kept as separate from the stepper wires as practical. If it is not practical to physically separate the wiring then the wiring for the switches should be changed to shielded wire with the shield grounded at only one end, generally the control end.

Also note that the crosstalk can be occurring anywhere along the wire, not necessarily just where they meet on the axis. If the wires are close on the control end that could also be the source of the crosstalk.

Pete C.