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Messages - Davek0974

1541
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: July 09, 2016, 03:30:50 PM »
Great, that will help.

I'll get the xml tomorrow - its out in the shop.

The encoder thing is odd, i've checked the wires, the DRO's behave normally in Mach, no ePid fault messages, i had the setup working on the bench at work and tested all the drives and each motor as well, although not on a machine of course.

Following-error in tuning is still around 400.

There is some backlash/lost motion, about 0.04mm in the Y axis and around 0.15mm in the X but the thrust bearings on that axis need looking at so i'm not too concerned yet.

Edit...

In the CSMIO monitor, the x-axis encoder readout is alternating between a number and a red 255? Distance travelled is spot-on though it seems.

Also, one plus point - homing seems to be stunningly accurate, on my dial indicator it read better than 0.01mm variation. :)

1542
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: July 09, 2016, 02:56:02 PM »
Great, i realised i fitted the Y home switch at the wrong end so i set it up to home at the front and then offset to the rear which is really zero, it would be useful not to move the axis though - where is the setting that stops the axis actually moving?

When i press Reset in Mach I get a message telling me to check the encoder connections as there was an error - if i ok the message it all seems to work ok though - any ideas?

I have got rid of the vibration by doing another tuning, its much smoother now, probably too much gain maybe.

1543
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: July 09, 2016, 09:49:30 AM »
Ok, learning all the time ;)

A friend has just advised me that i have gone the wrong way and fallen head-first into the gantry mill vs knee mill trap big-time.

I was setting up so that jogging left moved the table left - this is wrong and it seems i need to start thinking of the tool NOT the table, so as i have it now, jogging left will send the tool off to the right.

I can see this is going to be a bugger to get my head round ;)

I also had homing wrong - i was thinking of the table in the bottom-left corner but in reality from the TOOL point of view, that is X- and Y+ NOT X- & Y- so when homed the table will be away from me and to the right.

1544
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: July 09, 2016, 07:38:25 AM »
Hmm, ok i can now do MDI BUT....

The DRO's in Mach are backwards ?

If i jog left the table moves left but the DRO goes negative?

I tried the "Reverse" option in homing but then the jog buttons are reversed?

Anyone?

1545
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: July 09, 2016, 07:15:06 AM »
We have motion, on one axis at least :)

Threw it all together on the bench and fired her up. I can jog and do a home run, did an auto-pid tune and the error is around 150 now.

Ok, issues to sort....

I can't do an MDI for some reason - nothing happens at all.
When i press Reset in Mach I get a message telling me to check encoder connections as there was an error - if i ok the message it all seems to work ok??
There is a vibration in the drive at lower speeds, pretty violent and would certainly show up in the cut.
7500mm/min is frighteningly fast, I have lowered it to 5000 for testing.

Anyone care to wade in with some suggestions??

1546
General Mach Discussion / Control inputs - active low/high?
« on: July 08, 2016, 04:31:07 AM »
Seems the safest way is to have the limit switch loop as active low i.e the switches are all in series and are normally closed, this way a broken wire will trigger a stop instead of being ignored.

But control inputs - cycle-start buttons, home switches etc - active low or high?

My PLC stuff was always active high - normally open contacts that supply a voltage when and action is needed - this way a short to ground of the supply wire will blow a fuse, short to ground of the return will do nothing, only a supply-return short could be dodgy as it will be seen as a request for action.

Does this all remain true in the world of CNC?

1547
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: July 07, 2016, 10:58:27 AM »
Whats everyone using as a control cabinet?

Needs to be fairly large and deep as servo drives are pretty deep, commercial control cabs are very ££££ in large sizes. I could weld something up but would not look too professional i think, also been looking at steel tool cabinets which come with doors etc :)

any other ideas ?

1548
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: July 06, 2016, 02:06:12 PM »
Nearly there with the X axis motor mount, once thats done I can lash-up the drives and do a motion test :)

1549
Sounds good :)

1550
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: July 06, 2016, 02:18:29 AM »
Hmm, ok so it may be a reasonable plan then, the e-stop also tells the CSMIO and therefore Mach3 that there is a fault so it sort of will remove the drive signal as well, but that all relies on the speed of signal transmission etc from the e-stop input to the CSMIO to Mach then back to the CSMIO and then to the drive itself.

I could easily wire the "Enable" lines through the safety circuit so they are cut the same instant that the power goes down?