Spindle speed via VFD *AND* reeves drive
- 86turbodsl
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09 Sep 2024 14:59 - 10 Sep 2024 10:07 #309753
by 86turbodsl
Spindle speed via VFD *AND* reeves drive was created by 86turbodsl
Ok, this is a wierd one. I have a Hurco KM3P mill with automatic speed control. I'm moving to linuxcnc from factory controls.
The spindle is driven by a standard 3 phase motor and a servo that runs the reeves speed reduction in addition to a standard bridgeport type backgear selection. I want to abandon the backgear, and just run on the slow speed geartrain, and use the reeves drive for the first part of the speed range, then once it's maxed out, use the VFD drive to get the remainder of the spindle speed up to 4000rpm. So i'm thinking there must be a way to do this. Probably write a module? Anyone done anything like this before?
Trying to avoid screwing with the manual backgear selection depending on spindle desired speed. It's literally the only manual selection on the whole mill.
The spindle is driven by a standard 3 phase motor and a servo that runs the reeves speed reduction in addition to a standard bridgeport type backgear selection. I want to abandon the backgear, and just run on the slow speed geartrain, and use the reeves drive for the first part of the speed range, then once it's maxed out, use the VFD drive to get the remainder of the spindle speed up to 4000rpm. So i'm thinking there must be a way to do this. Probably write a module? Anyone done anything like this before?
Trying to avoid screwing with the manual backgear selection depending on spindle desired speed. It's literally the only manual selection on the whole mill.
Last edit: 10 Sep 2024 10:07 by 86turbodsl.
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- andypugh
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10 Sep 2024 12:20 #309835
by andypugh
Replied by andypugh on topic Spindle speed via VFD *AND* reeves drive
I have given a bit of thought to this, mainly due to watching RotarySMP and his Schaublin on that YouTube.
One thing that might be worth experimenting with might be using two PIDs, one to control the Reeves drive, and another that controls the VFD frequency that only turns on when the Reeves drive is on the end-stops (or when the first PID is saturated, both ought to work)
Unfortunately the LinuxCNC PID (code here , if you want to look) outputs 0 if disabled (outputting "bias" would have been useful here) so you would probably need to add the second PID output to a constant 50Hz value for this scheme to work. The hal "sum2" component would be the simplest way to do this.
One thing that might be worth experimenting with might be using two PIDs, one to control the Reeves drive, and another that controls the VFD frequency that only turns on when the Reeves drive is on the end-stops (or when the first PID is saturated, both ought to work)
Unfortunately the LinuxCNC PID (code here , if you want to look) outputs 0 if disabled (outputting "bias" would have been useful here) so you would probably need to add the second PID output to a constant 50Hz value for this scheme to work. The hal "sum2" component would be the simplest way to do this.
The following user(s) said Thank You: tommylight, 86turbodsl
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- 86turbodsl
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12 Sep 2024 10:15 #309982
by 86turbodsl
Replied by 86turbodsl on topic Spindle speed via VFD *AND* reeves drive
Great idea. I'll probably post more on this when i get closer to testing it. The 5HP vfd showed up yesterday.
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