Build thread:Magnaturn 612 retrofit(s) - Southbend

[frijoli]

Clay, Rev 3 is the latest C86Acorn board. You should contact CNC4PC about it....I have not yet received a rev3 for testing yet.
Rev2 has a problem coming on line, it expects all the enables to come on Acorn at once and they don't always. You show a green light on, which is correct when it is on line.

Okay so if I have a green light, it's good and if not it's wrong?
I Have a green light but haven't added the drives to the system yet. I'll do that today.
If this happens do I turn off the enable ok as a temporary fix?

The issue is that C86 wants to see all the enables on at once. The only times those happen is when you hit cycle start to home the machine or you go into MDI.
If you don't do either of those two first, and you jog, only the axis commanded to jog will enable. Watch your ENA LEDs

Understood...

[frijoli]

Spindle encoder trial.
These little southbend lathes come with four encoders. JIKI magnetic encoders with open collector output. They are very well made, and have bearings in them.

The spindle is DC motor belted 1:1 to the encoder. The motor drive unit is a KBPB-125. Same as the KBCC-125R.
Just for the sake of experimentation I ordered a line driver converters for the encoder. They're $6.50 ea. here: https://www.cnc4pc.com/catalogsearch/result/?q=C72

Long story short, at least for now, it works and is dead stable. Actually more stable than the encoder feedback from my DMM servo spindle. I can provide the pin-out if anyone wants to try this.

[martyscncgarage]

Cool Clay.
1000 line differential encoder with an index pulse is what you need for the spindle.

[martyscncgarage]

Rev 3 is what you want for C86Acorn from CNC4PC. contact them for an RMA and to get the newer one if they are selling it yet. They sent me R2 as well. I will test R3 when I get it.

Marty

[frijoli]

Rev 3 is what you want for C86Acorn from CNC4PC. contact them for an RMA and to get the newer one if they are selling it yet. They sent me R2 as well. I will test R3 when I get it.

Marty

Cool, Thanks Marty! I will contact them.
It's nice to have someone with your experience and involvement available on here!

[frijoli]

Spindle drive needs a little work. I have a tachometer coming tomorrow to verify the encoder numbers.


First cut in aluminum!

[martyscncgarage]

Nice work Clay!

[frijoli]

The factory home switch on the Southbend is in the middle of the Z travel. Is there an easy way to use this to home, and then move away in the + direction for inches and then set machine zero?
The X axis is normal.

[frijoli]

The factory home switch on the Southbend is in the middle of the Z travel. Is there an easy way to use this to home, and then move away in the + direction for inches and then set machine zero?
The X axis is normal.

FYI CNCSW confirmed
"Yes, you can add an incremental move in between the M92 line (which finds the switch) and the M26 line (which sets zero).

You will want to be sure you have a working overtravel switch at the plus end, so that when you inadvertently start the homing sequence without first jogging to the left of the home switch, it will stop with a "limit tripped" error instead of damaging something.

It could be made a little more foolproof if you modify the trip ramp to ensure that the home switch remains tripped all the way from the middle of travel to the plus limit. That way the control can tell which half of travel it is in by the state of the switch, and can start off moving minus to clear the switch if needed."

[martyscncgarage]

The factory home switch on the Southbend is in the middle of the Z travel. Is there an easy way to use this to home, and then move away in the + direction for inches and then set machine zero?
The X axis is normal.

Well, I would personally take the time to move or add a proximity sensor to the Z+ (tailstock end) Do it right. It would be easier to do that the X, but you say the X is typical, (on the X+ end, away from the spindle centerline, prox switch?)
I think you could tell the Home Wizard, soft limits setup, say you had 20 inches of travel, put -10 in the - box and 10 in the plus box. BUT you would have to make sure the carriage is on the proper side when you tell it which direction to home in so it heads in the right direction. Though I have never tried it, because....I would put the switch in the proper location.

Marty