Southbend Magnaturn 612 Acorn retrofit DMM Servos

[Reedfirst]

That is one cool little machine. Nice job on the conversion. I might have to keep my eye open for one of these.

[frijoli]

Made a little progress this week.

I have the auto homing working. I ordered a new encoder for the spindle along with the cord. Got that all going today and checked out with a rpm gauge. It's getting closer to completion!

What did you purchase for an encoder?

[martyscncgarage]

Made a little progress this week.

I have the auto homing working. I ordered a new encoder for the spindle along with the cord. Got that all going today and checked out with a rpm gauge. It's getting closer to completion!

What did you purchase for an encoder?

Automationdirect.com
Medium duty, line driver encoder, at least 1000 line
Just a suggestion

[frijoli]

Made a little progress this week.

I have the auto homing working. I ordered a new encoder for the spindle along with the cord. Got that all going today and checked out with a rpm gauge. It's getting closer to completion!

What did you purchase for an encoder?

Automationdirect.com
Medium duty, line driver encoder, at least 1000 line
Just a suggestion

Yep, got that Marty. I was curious since I have the same lathe.

[dbensavage]

The encoder is from centroid. It's for a 8mm shaft 2048-line AC Encoder. Centroid Part Number 6019, Pigtail Part Number12976, 12 ft cable Part Number 10830, and Zenner Diode for 0-10v acorn spindle output Part Number 1759.

All this is plug and play. Encoder fit perfectly in place of the original which is belt driven with a 1 to 1 ratio.

[dbensavage]

Running into some problems with threading. When I try to rigid tap I get a 438 spindle error. After trying to get it to run with no luck I tried a part with single point od threading. The machine cut the threads but the pitch is off.
When I use the MID screen and enter spindle speed and rotation it checks out almost dead on with a Laser tach. But, I'm noticing when running a program the rpm is higher than what the Gcode calls for???? Anyone else have this probem?

I have a 2048 line encoder and have machine set at 8192. Shouldn't centroid keep the spindle at the exact rpm when running a program?

[martyscncgarage]

Running into some problems with threading. When I try to rigid tap I get a 438 spindle error. After trying to get it to run with no luck I tried a part with single point od threading. The machine cut the threads but the pitch is off.
When I use the MID screen and enter spindle speed and rotation it check out almost dead on with a Laser tach. But, I'm noticing when running a program the rpm is higher than what the Gcode calls for???? Anyone else have this probem?

I have a 2048 line encoder and have machine set at 8192. Shouldn't centroid keep the spindle at the exact rpm when running a program?

I think the control sees the spindle turning the wrong way.
Put a -8192 in the Wizard. (Dash tells the control to read opposite direction)
No Centroid does not try to keep the speed constant. It MONITORS the speed and adjusts the Z axis accordingly.

[dbensavage]

Marty,
Sorry, I forgot to put I did have to put in -8192 right after hooking it up as it was backwords. It still faults out with a 438 Spindle encoder position error when trying to rigid tap. The tap goes in the contacts kick out and it errors before the spindle ever tries to reverse.

Here is the G code I'm Running

N0109 G0 T0808
N0110 M8
N0111 G97 S500 M4
N0112 G4 P1.0
N0113 G0 X0. Z0.1
N0114 G99
N0115 G32 Z-0.25 F0.05 M5
N0116 G32 Z0.1 F0.05 M3
N0117 G80
N0118 G0 Z2.5
N0119 G0 X3.
N0120 G50 S1500

It errors out on line 116
I tried removing the M5 at the end of line 115 but no difference.
I was able to Run a G34 OD Thread but the pitch is slightly off.

[martyscncgarage]

Make and model of the encoder?
Check cabling and encoder connections?

Never mind...I see in a previous post it was aquired from Centroid. I assume you also got the premade cable?

[dbensavage]

Marty, That's correct. The encoder, cable, and pigtail all came from Centroid.

I am going to check my Ballscrew ratio as far as the od threading goes. It is barely off. The OAL of the Part is about .003 different than spec. May just be tool setup on the length or My ration is slightly off.

As far as the Rigid tapping and it throwing a error code goes, I'm stumped for the moment. Maybe the old KB120 isn't playing nicely with the acorn board???