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Author Topic: Bridgeport Knee Mill Conversion?  (Read 269114 times)

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Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #270 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?

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #271 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 :)

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #272 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 ?

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #273 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??

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #274 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?

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #275 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.

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #276 on: July 09, 2016, 01:32:53 PM »
Homing can be any place you like for example on a knee mill it is often advantageous to home with the Y fully positive (table at front) so that loading the work is easier.
The CSMIO have an option in their plugin so you can set the Home Off value as legacy. What that means is if you home fully positive then you can enter the distance that you are away from Machine zero and when you home it will read that distance rather than zero. The place you enter that value is Homing and Limits and it is in the Home Off box.

The default way for Home Off with the CS-Lab products is that the Home Off value actually moves the axis that distance after it homes, it was  for a long time the only way to set it up and was a PITA for quite a few of us as we wanted the Home Off to be the way Mach meant it to be (the legacy way ) but thankfully CS-Lab listened and gave us the option :)
Hood

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #277 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.

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #278 on: July 09, 2016, 03:17:35 PM »
It is under Special Functions and then Other, should see on right side the Legacy Home Offset option.

Not sure about the encoders,never seen that message. Presume you have double checked all connections and that the IP-A sees the encoder counts correctly?
If you attach your xml I will take a look and see if I can see anything.

Good news on the tuning :)
Hood

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #279 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. :)
« Last Edit: July 09, 2016, 03:42:23 PM by Davek0974 »