Centroid Community CNC Support Forum

Doing an install on a Boss5 with the allin 1dc and servos. Just like to know what the group has found works best for spindle speed control. I have a VFD that I been using a 60hz to run off of single phase and using the mechanical speed control. I intend to the same again as I don’t believe the motor may be suitable in power and may possibly overheat. This is speculation on my part and the reason for asking.
The part I need to figure out is should I interface the speed up/ down solenoid and brake to the allin 1? There will be no spindle encoder so speed will have to be toggled.
Any input will be appreciated
Thank you, Harry

i've been running VFD's on the boss spindle motors for year with no issues. use braking resistor for good decell times.
and then i retain the old air solenoid brake so its easy to change tools.
gut the vari drive if you really want a project. there are post on this forum of others doing this.

Thank you for the reply, I’ll look for the info.
Did you go 1-1 on the pulleys?
Harry

Depends on if you keep the stock motor. With non-inverter rated motors, it's usually recommended to keep the motor at 100Hz or below. You can get away with running 120Hz sometimes, but the insulation tends to break down earlier.

Pulley ratios will be dictated by the max motor rpm you can acheive and the max spindle rpm you want.

On my mill, I replaced the stock motor with a Baldor inverter rated motor with a max rpm of 6000. I then used under-driven pulleys to get my 5000rpm spindle speed and a little more low rpm torque.

If I may ask a few more questions? I doing this conversion for a guy to help him out. I would do things different if it was for me. This is a single job machine and he needs to drill at a 1000 and tap at 100., seem slow to me but he’s using a taping head. Worried if I slow the motor down that much with the vfd there may not be much torque. Removing the vari drive system could be a big Job?? Idk
Harry

If you use a sensorless vector VFD you will still have good torque at lower rpms. However for 100 rpm, just put the head in low range with the back gear. Also, you probably won't be able to change the motor on the Boss5 since it's under-mounted.

You can add a switch to the back gear lever and CNC12 will automatically reverse the spindle snd adjust for the gear reduction.

Tom, if I understand correctly, add an actuator to the gear change mechanism and activate it with cnc 12? That’s part of the problem, he has to change ranges to go from 1000 to 100.we could then get him close to the rpm’s with the vfd. If we could make this reliable if would be a game changer. Do you have a reference for the actuator?
Thank you Harry

I think what Tom was suggesting was the usual knee mill arrangement: add a sensor switch that detects the position of the back gear lever, so that CNC12 and the PLC can respond appropriately when the user shifts gears.

It is still entirely up to the operator to shift into the appropriate gear at the appropriate time.

If you wanted to make it a little more fool-proof, you could provide, for example, M41 and M42 macros that would verify that the operator had shifted to the correct gear for the upcoming operation.

That’s for all the info!! You don’t know what you don’t know.