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kong
12-15-2003, 02:36 PM
I've just downloaded the demo of Mach2, having just set my home switches up for emc - nc switches wired in series to one input. I just can't figure out how to get all of the axes to home. I can see the button that says "ref all" which sends all axes to home, but when one hits it's switch, mach2 thinks they are all at home. Is there a ref x or ref y button somewhere?!

balsaman
12-15-2003, 07:19 PM
My home switches are working. Mine are NO. Perhaps you need to change that in the software somewhere (uncheck active low?). I don't see a ref x, y, z. I also can't figure out how to send an axis to a location...

Eric

HuFlungDung
12-15-2003, 09:53 PM
I am not sure how you have your machines set up, but logically, the setup is impossible if you are calling your home position that location where the switch opens. You should not. You should home to a given number of steps from where the switch changes state again. This will allow the continuity of the circuit to home another axis in sequence.

For machines with encoders, they never home on something as crude as a switch opening. That is merely a signal to mark the approximate position, after which the encoder index is sought in a given range from the switch break.

HomeCNC
12-15-2003, 10:59 PM
Kong, I have attached some setup screen shots of my Mach 2 setup. Look over the screen shots and compair them to yours.

HomeCNC
12-15-2003, 11:00 PM
Next one.


Also check out the Mach 2 PDF manual

balsaman
12-15-2003, 11:21 PM
Hu,

You are correct that the best way is to use the encoder's marker pulse for homing after you hit a home switch. I think there is a circuit for doing that on the CAD_CAM yahoo site. It's just another thing on my to do list that will never get done! :)

Eric

kong
12-16-2003, 08:34 AM
Thanks guys, I've wired each one on a seperate pin now, so they work ok when I use "ref all". Balsaman, the only way I can see to send an axis to a location is to use the MDI screen to input a seperate line of g-code. I'm liking this software now, will purchase at the weekend I think.
Just out of interest, what sort of pulse stream should I expect to get from an AMD 500Mhz pc, as the demo is limited to 25000Hz.

balsaman
12-16-2003, 12:22 PM
Originally posted by kong
Thanks guys, I've wired each one on a seperate pin now, so they work ok when I use "ref all". Balsaman, the only way I can see to send an axis to a location is to use the MDI screen to input a seperate line of g-code. I'm liking this software now, will purchase at the weekend I think.
Just out of interest, what sort of pulse stream should I expect to get from an AMD 500Mhz pc, as the demo is limited to 25000Hz.

Are you sure? I thought it was user selectable. Up to 35000 hz...

Maybe you are right. 25 khz is enough for my machine.

My Pll 233 puts out the 25 khz no problem.

Hey this is my 1000th post! You guys must be sick of my rambling. LOL

Eric

kong
12-16-2003, 12:32 PM
Originally posted by balsaman

Hey this is my 1000th post! You guys must be sick of my rambling. LOL

Eric
:o yawns, only joking!

Seriously, the demo will allow you to change the settings, but they seem to have no effect. In the motor tuning screen, the max speed stays the same. I can remeber reading this somewhere too. My machine requires 9500ish pulses per inch/second.:(

HomeCNC
12-16-2003, 01:21 PM
Balsaman,

I was wondering the date you would hit 1000 posts. Wow you do talk alot :D

I thought you were using TurboCNC not Mach 2.

High Seas
12-16-2003, 01:40 PM
Kong -
My PIII/500hz machine "seemed" to be ok at 35000. I say "seemed" as I was trying to work some motor problems - steps lost/gained and thought a re-tune would be usefull to explore all rates and pulse width allternatives. BUT - the problem seems to really be the motors. All indications were the system was running at 35,000 +/- but the symptoms remained the same- so off for another set!
:cheers: Jim

kong
12-16-2003, 02:05 PM
HighSeas, it's probably no help, but I have just read about on-board graphics interupting the pulse-stream. It seems in the older systems these graphics chip sets may have a higher system priority than Mach2, which I take it may cause lost steps or jerkiness in motion. Just a thought.

High Seas
12-16-2003, 04:25 PM
Hey thanks - I've already ordered the replacements - But I'll check out that graphics interrupt idea while waiting. I put the major problem down to too high an inductance for my drivers - so I can't get the speed/torque out of the motors - and then when I push it up - speed and accelleration it'd lose/gain steps. Anyway, will know when I get a "matched" set.
:cheers: Jim

balsaman
12-16-2003, 06:10 PM
Originally posted by HomeCNC
Balsaman,

I was wondering the date you would hit 1000 posts. Wow you do talk alot :D

I thought you were using TurboCNC not Mach 2.

Trying mach 2 now....I will probably register it. It took me this long to get around to installing Win 2000. I am setup dual boot right now...

Eric

HillBilly
11-27-2004, 09:09 AM
Hu,

You are correct that the best way is to use the encoder's marker pulse for homing after you hit a home switch. I think there is a circuit for doing that on the CAD_CAM yahoo site. It's just another thing on my to do list that will never get done! :)

Eric

I would like to see that circuit, I did a search there but come up with nothing. I am using this circuit. If I could define the back up speed, which seems to be preset at 50% of the homing speed, I could make this thing home like a Fanuc.

Darek