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Author Topic: Bridgeport Knee Mill Conversion?  (Read 158949 times)

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Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #110 on: May 19, 2016, 06:14:19 AM »
the speed knob can be left unnamed position

Not really sure what you mean by that.

Regardingthe pulleys, either buttons or custom macros can be used, don't even need the DRO to be visible for it to work but would probably be a good idea to add it to the screenset.

Anyway
SetOemDro(56,1)
would set the pulley to 1,
SetOemDro(56,2)
Would set the pulley to 2 etc etc.

Hood

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #111 on: May 19, 2016, 06:22:18 AM »
Blasted autocorrect again, It should say "speed knob can left in one position..." ;)

I have just been playing on my laptop setup and have macros controlling the pulley DRO so that is useful.

Is there a way to stop code execution if speed requested is wrong?

All you seem to get is a message that says "spindle speed too high/low for pulley, using min/max" but that is pretty useless as using the wrong speed can get messy pretty quick.

Really just needs to pause like a tool change maybe then change pulley and press start - can that be done?
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #112 on: May 19, 2016, 07:39:34 AM »
Ok, you don't want to alter the pot once tings are set up via Mach. Not sure about VFDs but with Servos usually when you choose  a speed input method then others will be disabled so likely you wouldn't be able to use the pot anyway.

You could possibly alter the M3 and M4 macros to look at the commanded speed and pulley DRO and either start the spindle if it is in range or stop with a warning message if it is not.


There is also the spindlespeed.m1s macro, you can do all sorts of things in that :)
I used to have a gearbox on the lathe that had electromagnetic clutches for speed changes, I used the spindlespeed.m1s in conjunction with the m3.m1s for doing that.

Hood
 

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #113 on: May 19, 2016, 08:00:11 AM »
By "speed knob" I was meaning the mechanical speed knob on the mill head, my thought was to set that at say 1500rpm and then use the VFD for speeds between 500 and 3000 which are the mechanical limits for normal gear on a BP. Mach3/CSMIO would then control the VFD via 0-10v as well as fwd/rev.

I had not thought of fiddling with the m3/m4 - that would work nicely as I will only have 2 pulleys - high and low or 50-500rpm and 500-3000rpm so the logic seems easy - it would switch the spindle pulley DRO directly and just warn me to change gear on the mill with a message and "press enter to continue"

Thats the sort of control I would like.

The high speed spindle is easy as it will have it's own profile in Mach and I already know the pulley settings etc for that VFD.
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #114 on: May 19, 2016, 08:32:05 AM »
Hmmm, just messing about here...

should this work in M03.m1s...

rpm=GetRPM()
pulley=GetOEMDRO(56)

If pulley=1 then
  if rpm>500 then
    Call SetOEMDRO(56,2)
    MachMsg ("Change Back-Gear To High Range","Pulley Error",0)
  end if
else
  if rpm<500 then
    Call SetOEMDRO(56,1)
    MachMsg ("Change Back-Gear To Low Range","Pulley Error",0)
  end if
end if
DoSpinCW()

The result I get on my laptop setup is that GetRPM() is not reading the S-word from the code line "S1500 M03" for some reason??

Maybe I am not clever enough yet ;)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #115 on: May 19, 2016, 09:38:19 AM »
Seems it IS reading the S-word BUT only if it is < the current pulley Max limit.

So if pulley set is 0-1000rpm and I call S500 M03 the speed is read as 500

But if I call S2000 M03 the speed is read as 1000.

Seems odd.
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #116 on: May 19, 2016, 10:39:37 AM »
Found it....

It has to be done in SpindleSpeed.m1s....

rpm = GetRPM()
pulley=GetOEMDRO(56)

If pulley=1 then
  if rpm>500 then
    Call SetOEMDRO(56,2)
    MachMsg ("Change Back-Gear To High Range","Pulley Error",0)
  end if
else
  if rpm<500 then
    Call SetOEMDRO(56,1)
    MachMsg ("Change Back-Gear To Low Range","Pulley Error",0)
  end if
end if

SetSpinSpeed( rpm )

Seems to do exactly what i want - pulley 1 would be low range, 50-500rpm and it warns me if the current set pulley is wrong, pulley 2 would be high range 500-3000 and it warns me to move machine into high range.

Nice
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #117 on: May 21, 2016, 11:06:42 AM »
After messing with the speed control and vfd settings today , I have a sort-of workable solution but there are drawbacks - the head has some issues with worn bushes, the speed range is a bit limited, power will be affected. I also only have the smaller 1.5Hp 1440rpm motor which is odd as I thought I had the 2Hp model, oh well.

So, improvements... Is a servo motor torque really linear from zero to rated speed?? I.e. will a 1.5kw AC servo really give me 1.5kw or 2Hp at 100rpm AND at 3000rpm or have i read it wrong??

Would I be better off just fitting a 1.8kw AC servo motor for the drive and connecting at 1:1 ratio??

If it was correct then I would have full power from 1 to 3000rpm at the spindle - sounds ideal.

Would this play well with my upcoming CSMIO/A conversion - would Mach give speed control and correct rpm readout??
« Last Edit: May 21, 2016, 11:08:15 AM by Davek0974 »
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #118 on: May 21, 2016, 11:34:22 AM »
Torque is the constant, not power.

The IP-A works great with servo spindles :)

Hood
« Last Edit: May 21, 2016, 11:36:43 AM by Hood »

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #119 on: May 21, 2016, 12:11:13 PM »
It shows about 6Nm from the servo and listings show about 5.5Nm from a standard AC motor on a VFD of similar power so I am guessing a 1.8kw AC servo will be a decent replacement and also mean NO back-gear etc - full power across the board :)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives