How do I set My Spindle CW/CCW output to be momentary?

I currently have the card relays for forward and reverse and enable, and the drive's enable signal is routed through my e-stop relay for redundancy. I'm concerned that the dry contacts in the drive may have problems when I hold that forward/ reverse signal closed for an extended amount of time, as those inputs were intended to be momentary contacts.
I am currently only looking to have the motor run forward or reverse at the standard 60hz as I have a variable speed head that I can use to control the actual spindle speed. Yes I do intend to get an encoder on that spindle, but it's not going to happen until my experience as a machinist is at a point where I need it. This is my first mill and I do feel like I jumping right into the deep end by buying a running mill and gutting it to make it a LinuxCNC mill.
Part of the reason I am choosing to run the motor at 60 hz is because the motor was built in '82 which was before drive rated motors were really a thing, and I know that drives are hard on motors and can destroy non drive rated motors. So my thinking is if I run the drive at 60 hz the way the motor was originally intended to run my chances of it surviving longer are better.
The motor is a Tai Chin Electric Co 2ho 3 phase 220v induction motor.
the mill is a Supermax YCM-1-1/2VS, I think, the label is inaccessible behind the control cabinet. When I bought it it had an Anilam 3000m on it but that was an upgrade to the original Anilam Crusader 1100?
What I thought was cool is it is still rock solid and had been barely used over its 39 year life span

https://drive.google.com/file/d/1jZMHDmQ6g4VWjEmiB1mf2E76QcHauloJ/view?usp=sharing

spumco post=221574 userid=28776

 Only I am wondering about this 60Hz. 400Hz is usual and maximum voltage is set with parameter F05.
 

It's a Supermax mill - like a Bridgeport.  Has a pretty standard 3p induction motor and likely a nameplate frequency of 60hz (1800rpm).  The speed control as the OP mentioned is a variable pulley system.  You crank a knob/wheel on the side (only when motor is running) to adjust the speed up and down (opens/closes the variable pitch pulleys).

It might have a two-speed motor and/or a back-gear like some Bridgeports, but the OP would have to report back on that one.  These sorts of arrangements can be a little tricky to get under full CNC control - hence the OP's earlier statement about a spindle encoder.

With a direct spindle encoder he could, in theory, attach a stepper motor to the pulley adjustment wheel and have LCNC start the main motor and a gentle PID loop would adjust the pulley ratio until an AT-SPEED signal was met before continuing the program.
 

 

You nailed my plans. Thank you for the explaining this, you said it much more clearly then I did
The motor has one speed but the head has a high speed and a low speed, and to get the low speed the motor runs in reverse.

In this case, frequency control is only very limited.  So option 1 or 2 would be possible.  I would do speed control directly with encoder on spindle.  There are many retrofits here in forum.  You will find something there. Dig a little.  How do you switch between high and low speed?

To set low speed, I set the motor to run backwards and engage a lever on the head. When I get around to changing to encoder feedback on the spindle I'll probably to what my friends mill does, I'll put a micro switch on that lever and that will tell the 7i77 if high or low gear is engaged, and wont enable spindle reverse unless the micro switch is engaged. ( this would make rigid tapping take a bit more doing, so I'll have to think on that when I get that far)

 I'm concerned that the dry contacts in the drive may have problems when I hold that forward/ reverse signal closed for an extended amount of time, as those inputs were intended to be momentary contacts.

https://drive.google.com/file/d/1jZMHDmQ6g4VWjEmiB1mf2E76QcHauloJ/view?usp=sharing

The digital inputs on the VFD aren't 'contacts' in the traditional sense.  They're transistors (see diagram).  More imoprtantly, the VFD was designed to use either the 3-wire control you've got now, or a 2-wire control.  They will not 'burn out' with extended use like an overloaded relay.

When I (or someone else) is referring to dry contacts, we're talking about whatever external device is making the connection between a digital input terminal and the DI COM terminal.  A switch, relay, or whatever.  You could just connect two bare wires together if you wanted

The point is that you aren't supplying or sinking any external voltage to/from the VFD when you connect a digital input to the digital input COM.

Given that information I now have the spindle controlled with the mini relays with inputs being held closed. It's working well.
Thank you

Rockin!

Don't forget you can use some additional relays to trigger different spindle speeds. A cheat sheet taped to the head for 30/60/90hz (or whatever) would be easy. And LOW/MED/HI screen buttons might not be too hard to set up. No touching the varispeed - just three pre-set speeds.

And the issue with older motors is that they can overheat at low speed/high load situations. Don't be afraid to use the VFD to fiddle the speed a bit. 30hz to 90hz should be pretty safe if you aren't running a giant drill or face mill for a long time.