I have a 180V Brushed DC Motor that I am using to convert my Mini Lathe with, now I know I can use an SRC Speed controller with a bridge rectifier and control it this way. However what I would like to do is create a control system for this, so I can have buttons for set speeds a nice digital readout, probably the easiest part of what I am needing, secondly I also want to be able to control the motor to go to specific angles and hold that position using an absolute encoder, then be able to set a specific angle and by the press of the button move to the next position, basically an indexing, dividing head system.
Not sure if this is even possible, so any help is appreciated.
quote="djb-systems, post:1, topic:1108361"]
I also want to be able to control the motor to go to specific angles and hold that position using an absolute encoder, then be able to set a specific angle and by the press of the button move to the next position, basically an indexing, dividing head system.
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A DC motor like you have will not be able to do positioning/indexing operations, you need a servo motor/encoder for that and they are not cheap, nether is the controller to do it.
Thanks for the reply, I havent tested it at the lowest RPM, I know its Max RPM is 3800 and since my lathe is a mini metal lathe, I may have a reduction pully to cut the spindle RPM down to 2000 RPM.
I will have to do some reading as I always thought a servo motor was just a motor with positional control using an Encoder, I know its designed to deal with inertia better than the treadmill motor, but the indexing system would be at low low speed, and the motor would probably be noisy at holding position but I would lock the chuck when in position and the motor could be disconnected.
There exist two kinds of "servo". The first kind controls position, the other one controls speed. If you want both then a compromise is required and a stepper motor comes closer to both goals, but at limited speed and torque.
If I was to use a stepper I would have to find a way to engage and disengage it from the shaft as it couldnt be used as the spindle motor due to speed and torque issues. I have some Nema 34 Closed loop steppers with enough torque for indexing though, but I was hoping to use one motor to do both with costs to the minimum as the treadmill motors were free and it has good torque at 4.7 nM
As a metal lathe user, you are probably familiar with "chatter". That is where the tool cannot make a smooth continuous cut. A spindle driven by a stepping motor will ensure you have chatter.
