how to wire relays

Thread Starter

to old

Joined Jul 28, 2021
8
The TS has already said its an AC motor which is an unusual choice, but then the original owner was looking for traversal not positioning. It does sound like the original owner was a seat-of-the-pants engineer who could make anything work with whatever he had lying around (so kudos to him).



Not a CNC machine user then MrB? Stepper motors are the most common form of motive force for axis motion in small to medium size-machines. My CNC mill and lathe both use steppers. They are relatively cheap yet powerful, easy to drive and position. A typical stepper steps 200 to 400 steps per rev and with the right controller can microstep 8 or 10 steps between the major ones, giving 4000 step/rev or more. Coupled with a suitable leadscrew or toothed belt drive resolutions of 10um are not uncommon and as low as 0.5um are possible. You won't see tool marks...
yes he was an electrical engineer a machinist among other things and a great fiddle player and friend for over 50 yrs i also was canadian champion 8 times of course when i was much younger , sorry i got side tracked ,i a waiting for some wire and i will probably get it figured out . i just thought that somebody out there that was working at that sort of thing would be quicker thats all ,thank you all very much for your intrest bye to old
 

LesJones

Joined Jan 8, 2017
4,174
We are all keen to help but we need to know EXACTLY what we have to design which is why we are asking questions. We could design the system from scratch but the way the controls would work would probably be different to your existing setup. For example we could design it to be stopped when power was first applied. We may choose to have one button to move it to a starting position, (Say left hand rear.) Have a second button to start it and it would mill the whole area and stop when it had finished. That probably would not suit your requirements as you may want buttons to manually traverse in the X and Y directions.
What I THINK we know at the moment is the X axis motor is probably a 24 volt DC motor. (We don't know if that is PM , shunt or series wound.) We know you have NC type limit switches and we know you have some form of AC motor for the Y axis. I am guessing from the fact you mention pole transformers that you are in the US or Canada so you mains voltage is 120 volts.
I and I think some of the other members that have responded have milling machines so we have a good idea of what you are talking about. I only have X axis power feed on my mill which uses a 24 volt PM DC motor with an optical encoder which is use to give closed loop speed control.

Les.
 

LesJones

Joined Jan 8, 2017
4,174
Here is the basic idea for the Y axis motor PROVIDED IT IS A PSC TYPE INDUCTION MOTOR.
300721.jpg

It uses two DPDT relays with 24 volt DC coils.
It uses a push button to drive it back to the starting position, It also assumes that the distance traveled by the Y axis at each end of the X axis travel is controlled by the timer. I am only guessing what you want until you tell us what you want.

Les.
 

MisterBill2

Joined Jan 23, 2018
18,167
What will be most helpful will be to see the circuit for running a motor in both directions. There are different arrangements, usually either 3-wire with or without a capacitor, and 4-wire, with polarity reversal on one winding. One scheme will have a drive relay for each direction, which is latched in by a momentary contact, and is unlatched by the NC limit switch at the end of the move. Then the trick will be to have the timer latch whichever motor on that is not at an end. Of course some interlock is needed to assure both do not get latched at the same time.
 
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