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Re: New guy, old machine
Posted: Thu Sep 16, 2021 12:52 pm
by JPG
"IR"???
Re: New guy, old machine
Posted: Thu Sep 16, 2021 2:41 pm
by AmishMachinist
JPG wrote: ↑Thu Sep 16, 2021 12:52 pm"IR"???
IR, Internal Resistance adjustments can be made on the KB electronics boards to compensate for the resistance in the brushes and commutator of any given DC motor, also as a motor wears the brushes and commutator resistance changes too. As uniform as motors are manufactured, there is some variance from part to part, an IR adjustment can compensate for these ensuring a more ideal voltage is given to the motor. It’s actually quite surprising the difference it can make in a DC motor.
Re: New guy, old machine
Posted: Thu Sep 16, 2021 3:09 pm
by edma194
Is the IR related to the HP resistors required on the KB controllers? Can you tell me anything about how those resistors function?
As for PWM, since I've been pondering using DC motors in a conventional Model 500 headstock I think it needs to maintain torque throughout the speed range since it is a multi-purpose tool. Each of it's basic functions and use to power SPTs has different requirements. For dedicated function machines, and/or if you can change belts like a Model 10 then simple controllers for DC motors should work quite well as long as the RPM:Power ratio works for you. I'm considering powering tools with a cheap treadmill motor, I think it's a good choice for a bench grinder which needs nowhere the speed power and speed range available.
Re: New guy, old machine
Posted: Thu Sep 16, 2021 3:55 pm
by JPG
FWIW,one of the slow speed SPTs is the band saw which does not require great hp. Neither do the jig/scroll saw. Belt sander may require A bit more. Disc sanding also does not require great hp. The jointer and planer need high rpms. The planer needs great hp in addition.
So As I see it lower power at slow rpm is not a show stopper for SPTs, Turning large stuff is another matter.
Re: New guy, old machine
Posted: Thu Sep 16, 2021 7:09 pm
by AmishMachinist
edma194 wrote: ↑Thu Sep 16, 2021 3:09 pm
Is the IR related to the HP resistors required on the KB controllers? Can you tell me anything about how those resistors function?
As for PWM, since I've been pondering using DC motors in a conventional Model 500 headstock I think it needs to maintain torque throughout the speed range since it is a multi-purpose tool. Each of it's basic functions and use to power SPTs has different requirements. For dedicated function machines, and/or if you can change belts like a Model 10 then simple controllers for DC motors should work quite well as long as the RPM:Power ratio works for you. I'm considering powering tools with a cheap treadmill motor, I think it's a good choice for a bench grinder which needs nowhere the speed power and speed range available.
The IR and horsepower resistors aren’t directly related, but I do think they added to IR function because the board can be used with multiple different size motors. I’m not at all sure of why specifically they use different resistors