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Resurrecting 1960 10EE with 460V Sabina drive

Zener: yeah - I tested repeatedly and with different tips on the multimeter to ensure I was making good contact before I reported back. They legitimately will not read - at least on my Klein multimeter.

Normal diodes: the three that fail to read - I will probably pull at least one pin and try again just to see - before I re assemble.

Replacement diodes: I got my microscope on a few. They read 10D6.

Quick search appears they are perhaps no longer available.
Is there a way to match with available modern ones if I have to replace the 3 suspect once tested “off board” with one leg out?
 

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Components are on the way.
Desolder machine arrived yesterday - so I tested it out today - what a pleasure.

Took one of the legs out of the diodes that read .003V.
There are three of these - so I thought it was reasonable that the three could have been fried if in direct line with the shorting legs.

Once the leg was removed - all was well.
Tested .6V/O.L. just as it should.
Re-soldered the leg back in and re-tested.
.003V/.003V again.
Think we are all good there.

Don't plan to replace any diodes or other components on board before testing.
Just solder in the replacement diode on the heat sink - and see what we have.
Fingers crossed.
 
That is right, testing the diodes in circuit can only suggest that there might be a problem. You only know for sure with one lead disconnected.
 
It's alive!
Though more Young Frankenstein than one might hope.
We have a speed control issue that will need to be resolved.
More on that in a moment - but first - a huge thank you to Mr CNC for his direction here.
A week ago - the electronics were all a bunch of boxes and wires to me - with zero clue on where to look.
The fact that it turned on today was pretty encouraging.
Much appreciated!

Update:
Received the diode for the SCR heat sink today.
I ordered a reverse and normal - just betting the come.
Little confusion when I unpackaged - as the reverse one showed the opposite diode flow direction on the side icon.
I was expecting it to match what I pulled from the machine.

Below a pic of the three. Far left is burned out one I pulled off heat sink. Middle is normal flow direction that I used. Right is "Reverse" flow. I
Chose middle based on Mr CNC's prior direction, basically - the printed icon will give certainty of flow direction.

IMG_1858 2.jpg

Put the SCR assembly back together and then put that back into the machine - double checking all connections and grounds for tightness.

Here is the start up video.
As you can see, I turned the speed down before turning on - but it jumped right up to ~1200 RPM.
I suspected one of 2 things.
1. My control board has something burned out on it.
2. My speed control potentiometer is oil soaked and not working.

Hard to know which to go after.
I suspected the oil soak issue, so I spun the control knob back and forth a few times.
You can see it in the video.

Then - the unit slowed way down - and did not want to speed up again.
I didn't want to run it at low RPM like that - and killed the power.
I suppose I could likely test somehow.
There are three wires that run from the potentiometer to the control board.
Perhaps I can test the voltage there somehow with my meter?

Below is where the potentiometer's wires connect. The top two are from the motor tach. The bottom 3 (Blk/wht/red) are from the potentiometer.
IMG_1692.JPG
 
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I notice that you seem to rotate your RPM control knob many times around. My modular drive 10ee speed control rotates less than 1 turn from lock to lock. Is your potentiometer original? Is the gear mechanism that connects the knob to the potentiometer OK? You can certainly test it by removing the 3 wires and using your ohmmeter.
 
I notice that you seem to rotate your RPM control knob many times around. My modular drive 10ee speed control rotates less than 1 turn from lock to lock. Is your potentiometer original? Is the gear
It’s possible they changed it out when they rebuilt (the entire motor was also rewound for 460V).

I removed the potentiometer box so I could tilt and drain - from the gear shaft hole.

On reinstall I wondered if it needed to be clocked in any manner - but it appears not to have any special relationship to knob position.

- it currently turns stop to stop - though it’s perhaps lore then stick as you noted.
- I’ll look on YouTube for a potentiometer test with multimeter.

*Does anyone have any advice I should be aware of for removing gears from box so I can have a look inside?

Thanks.
-CM
 
A potentiometer is easy to test. They operate just like the graphic on the Sabina case. The two outside terminals have a constant resistance between them. The position of the knob will have no effect.
The center terminal goes to a brush that slides along the resistor. It goes from zero ohms to one of the outside terminals when rotated to one stop. As you rotate the knob, it will go to zero resistance to the other outside terminal. When the knob is in the middle, it will have half the resistance to either of the outside terminals. The basic idea is that the center terminal will vary its resistance smoothly from zero ohms to the specified ohms as it is rotated from one side to the other.
If you see the ohmmeter jump around as you measure the potentiometer when moving the knob, then it certainly needs cleaning but is probably bad.
 
Thanks.
Saw vid as well.
Was fairly easy to test.
And... it seems to be operating properly.
No Ω movement on meter when the two outer terminals are connected.
But they move reasonably smoothly in opposite directions when tested with the center wiper and a single outer terminal.
Double checked.
15.7Ω in ea. direction at max.
Goes down near zero when turned the other way.

Suspecting my regulator assembly/control board may be the issue.
Swapped out the 741 chips.
Matched the small indented dot on old vs new (looks like ejector pin location).
Assume that is the way you tell you are putting them in the correct orientation?

In any event - no change.
Spindle barely rotates - you saw in the video when it slowed down.
Will no longer turn at those speeds - and can't get it to vary.

Ready to do some desoldering - any suggestions on how I might tackle?
¯\_(ツ)_/¯
 
I notice that you seem to rotate your RPM control knob many times around. My modular drive 10ee speed control rotates less than 1 turn from lock to lock. Is your potentiometer original? Is the gear mechanism that connects the knob to the potentiometer OK? You can certainly test it by removing the 3 wires and using your ohmmeter.

The poteniometer is normally in a housing behind the speed control knob on the lower left of the gearbox. The connection is though a gearing that give about a 3:1 so the knob has to be turned several times for a full 270 rotation of the pot.

10ee_housing.jpg
 
The poteniometer is normally in a housing behind the speed control knob on the lower left of the gearbox. The connection is though a gearing that give about a 3:1 so the knob has to be turned several times for a full 270 rotation of the pot.
Thanks. Yes - this is my set up still.
If they changed the potentiometer itself - it remains in that housing.
I assumed that I would need to remove the gears from the front of the housing to access the Allen bolt and perhaps be able to remove the box cover?

As its testing alright - I am suspecting that I have something burned up on my control board.
Appreciate the photo and confirmation tho.
Thanks.
 
Your control board has 3 type of silicon devices; diodes, transistors, and the ICs. These are the most vulnerable devices to the electrical impulse that happened with the short circuit. Fortunately, they are all cheap.
However, other things can fail. Resistors can blow out, but generally they show evidence of burning.
Capacitors can also fail. Often they will short when they fail. Sometimes they will fail open, but they generally blow apart.
You do have 3 signal transformers at the bottom right of your board. Like any transformer, they can short or blow open.
Swapping the ICs is a good first step. Check the diodes. Inspect the board closely for burned parts. Inspect the board closely for blown traces. Are all fuses OK?
Do you have an oscilloscope? You are approaching the O'scope territory.
The purpose of that board is to send pulses to the SDRs. The timing of the pulses is controlled by the potentiometer. With a scope, you would look for the pulses at the SCR's. If they are timed wrong or missing, you would trace them back into the circuit. Is a schematic available for the Sabina unit?
 
Your control board has 3 type of silicon devices; diodes, transistors, and the ICs. These are the most vulnerable devices to the electrical impulse that happened with the short circuit. Fortunately, they are all cheap.
However, other things can fail. Resistors can blow out, but generally they show evidence of burning.
Capacitors can also fail. Often they will short when they fail. Sometimes they will fail open, but they generally blow apart.
You do have 3 signal transformers at the bottom right of your board. Like any transformer, they can short or blow open.
Swapping the ICs is a good first step. Check the diodes. Inspect the board closely for burned parts. Inspect the board closely for blown traces. Are all fuses OK?
Do you have an oscilloscope? You are approaching the O'scope territory.
The purpose of that board is to send pulses to the SDRs. The timing of the pulses is controlled by the potentiometer. With a scope, you would look for the pulses at the SCR's. If they are timed wrong or missing, you would trace them back into the circuit. Is a schematic available for the Sabina unit?
Ok - helpful
Sabina has the "blue prints" for my entire system.
They have offered previously to copy for me.
Probably a good $100 to spend to keep with machine for the long term.

I like their system.
It's been robust - up until I failed it.
It even worked on an underpowered RPC for 10-12 years without complaint.
Not a potato chip.

I am probably going to stop short of buying an o'scope.
Sabina will test the board for $100, or rebuild for $600.
May be time to bring them the board...

As previously noted - owner/engineer who I spoke with said it was common for some main part on the board to fail when the SCR's get shorted.
That made me think I might get lucky with either the IC's or oe of those big orange capacitors - or as you note - one of the signal transformer(s).

Big orange capacitors are easy to unsolder.
Trying to figure out how to test now.
Will attempt and report back.

Tks!
 
Capacitor test question: mine are 60V 220uf.
Can my multimeter charge them?
I get no reading on the capacitor setting when I put pos. to pos. side and neg to neg side - even if just left on their. Same for all three.
Suspect I am testing wrong - rather than discovering anything...?IMG_1875.jpg
 
Those capacitors are easily within the range of your meter to test. Electrolytic capacitors contain a dielectric liquid that maintains their capacitance. Over time, they do dry out. With that, the capacitance decreases with time. It is unlikely, but possible, that your short caused them to go bad. Do you have a known good capacitor to test your meter?
I am not sure what "OL" (overload) means in this circumstance. It could mean that the capacitor is shorted. You can test this by using the ohms scale. Measuring the ohms of a capacitor should change over time as the capacitor charges.
 
Thanks.
I didn’t have another capacitor, but I did manage to test the ohms. They properly counted up with time on all three.

Pondered status/next steps and made decision that this was probably the perfect moment to take the control box in to Sabina.
I've learned a ton - and I think I could probably claw my way to resolution - but time has a value to me as well.
Additionally - I had a meeting about an hour north of here - which was taking me right past Sabina - they are visible form the hwy.

Well worth the visit.
Great guys.
Sat with owner for 20 min and got some insights on the history.
He's second generation - and now likely in his mid mid-late 60's.

Provided me this operation manual - some pretty good information in there regarding specs and wiring. Cal - if you are reading - feel free to tag this in some manner that other's can access. I have never seen this particular manual - though perhaps it exists elsewhere.
Sabina 460V 10EE Drive System Installation & Operation Manual.

Huge thanks to Mr CNC for giving all this time/ patience (so far...) - as I have been getting up to speed.

Oh - and about that convo. Sabina owner said he would replace the potentiometer.
Suspect I am going to find they installed a non Monarch one when they rebuilt.
Wondered if that meant he thought the problem might be in the potentiometer after all.
We'll find out.
I'll post here.
 

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Board at Sabina for test.
I'm on the hunt for a replacement potentiometer.
As suspected - looks like they installed their own.
IMG_1889.JPG

15KΩ
2W (from what I read online)
Found some new old stock - and bought it. $39.00
There are times when I am happy to have an aftermarket drive in my unit...

The cast iron pot the potentiometer sits in has neither a drain hole - or a face sealing gasket.
I suspect they came with some sort of face seal between the pot cover and body originally?
I'm lacking an exploded view of the speed pot component - perhaps someone can direct me to where I might find a download (assuming they are out there).

As for the leaking - from what I've read - user error is likely at least a component.
The new shop has the floor canted for drainage - which is how it sat when I filled.
But then I lowered the back off of blocks - and it was like a small tsunami of expensive oil finding its way out of the headstock and filling the speed pot.

Plan to level machine (level with the ground) on it's three points, then fill with fluids to determine if I have a leak issue - but knowing that it is moved sometimes - a drain on the pot seams like good insurance.
 
That is a Mil spec Allen Bradley pot. It is about as good as you can get. I don't know if they are actually waterproof, but they are probably close. Are you sure that it is bad?
 
That is a Mil spec Allen Bradley pot. It is about as good as you can get. I don't know if they are actually waterproof, but they are probably close.
Well - those are pleasing words to read.
My impression of Sabina: some pride there.
Quality build.
Are you sure that it is bad?
Not at all - and in fact - it tested well!
Sabina suggested I get a replacement - and when I saw new old stock for $40 - figured I would go ahead and grab it.
Perhaps it should just go on the shelf.
I wanted to open the casting that holds it and see how it was filling with oil/ have a look at viability of a drain.
See no reason not to add a drain hole - there is zero reason to let oil find its way in to that box and submerge the pot - even if it is top notch.

Going to be about a week before I hear anything back from the Sabina group.
Shockingly - it turns out I am not their most important/ largest customer...
 
I wanted to open the casting that holds it and see how it was filling with oil/ have a look at viability of a drain.
See no reason not to add a drain hole - there is zero reason to let oil find its way in to that box and submerge the pot - even if it is top notch.
From seeing your pic of the box/cover for the speed pot it looks like it should/could have a gasket. Maybe just have a 3 sided gasket that is open across the bottom so any oil that gets in can just seep out? Something thick like cereal box, not brown paper bag....
 








 
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