What's new
What's new

My Very Own Monarch 10EE Restoration

mechanicalman

Plastic
Joined
Nov 22, 2014
Location
Oakland, CA
I'm not a machinist by trade, but I do work as a mechanical technician and I regularly have to make use of machine tools during the course of my day. I juuuust missed out on a beautiful longbed 10ee in a government surplus auction. I ended up with a square dial, with a motor-generator and tube drive. I NEVER thought I'd end up with a Monarch 10ee in my personal shop and I'm very excited to make the most of the machine.

It was originally wired for 220v and is presently connected to a 208v three phase mains. The contactor tries to close after the warm-up timer is done, but doesn't stay latched. The heater circuit on the contactor seems fine (I bypassed it just to be sure). It looks like one of the thytrons is bad based on a few things.


1. It's the only tube not warming up
2. The heater filament ohmed out at 5k ohms
3. The same tube didn't heat up when I switched positions

So my question is: can I assume the tube went bad on its own, or do I need to investigate other components that may have caused the tube to fail?

flir_20181231T172245.jpgflir_20181227T203918.jpgIMG_20181120_194519.jpgIMG_20181231_145528.jpg
 

daryl bane

Titanium
Joined
Mar 12, 2002
Location
dallas,tx
You've already figured out the problem. If when you switched tubes, the "the good one" lit up up correctly in the bad ones spot? Looks like you just need a new, or good used tube. I don't have the post at hand but a guy on this forum designed solid state replacement for those big tubes and they seem to work quite well. That is what I would look into. All those other tubes are cheap and easily obtainable. Your unit is called a WIAD ( works in a drawer). I don't think you have a motor generator, unless you bought another lathe. :)
 

TheOldCar

Stainless
Joined
Jul 31, 2011
Location
Utah, USA
No electrical wisdom from me, just congratulations on the lathe.

MIT has 2 lathes in their physics department. Guess which ones!
 

rke[pler

Diamond
Joined
Feb 19, 2002
Location
Peralta, NM USA
I think you might have 2 different problems - the C16J that's not heating and a second problem with the EL1C rectifier. If the contactor still doesn't stay in after replacing the C16J check the voltage off the EL1C across E1 and E1-2 at the bottom of the DC panel - I'm suggesting this because the heat on the EL1C doesn't see all that high.

What are you using for the thermal imaging? Looks good.
 

mechanicalman

Plastic
Joined
Nov 22, 2014
Location
Oakland, CA
You've already figured out the problem. If when you switched tubes, the "the good one" lit up up correctly in the bad ones spot? Looks like you just need a new, or good used tube. I don't have the post at hand but a guy on this forum designed solid state replacement for those big tubes and they seem to work quite well. That is what I would look into. All those other tubes are cheap and easily obtainable. Your unit is called a WIAD ( works in a drawer). I don't think you have a motor generator, unless you bought another lathe. :)

I'm guessing it's this guy with the solid state replacement.

To the second point, if I don't have a motor-generator, what do I have? Just a motor?



I think you might have 2 different problems - the C16J that's not heating and a second problem with the EL1C rectifier. If the contactor still doesn't stay in after replacing the C16J check the voltage off the EL1C across E1 and E1-2 at the bottom of the DC panel - I'm suggesting this because the heat on the EL1C doesn't see all that high.

What are you using for the thermal imaging? Looks good.

The guy I got it from replaced the EL1C already, so I assumed it was good. Now that you mention the heat signature in the picture, I worry you might be right. I'll check the voltage next time I'm there. For thermal imaging I have a CAT S61. It's a pretty great phone, except the regular camera is garbage compared to the Google Pixel (first gen) that I traded in for. If they had just spent a little more for a better camera, or even better post processing, I'd be singing its praises to the heavens. Now if I see something I want a good picture of, I ask someone next to me to take the pic and send it to me. I recommed getting whatever phone you want and getting a FLIR One Plus. Having thermal imaging connected to your phone has a lot of advantages in terms of being able to save and share those images. Dedicated imagers are quicker and handier, but you can't do anything with that image unless you spend the money to get a unit with built in storage.

So my next question is, can I get two of Scissio Controls' thyratron replacements and just replace the known bad tube with the Scissio unit? I know that I should be using either tubes or SCRs together, but I would like to know if I can test the (seemingly good) remaining tube, absent the proper testing apparatus.
 

thermite

Diamond
So my next question is, can I get two of Scissio Controls' thyratron replacements and just replace the known bad tube with the Scissio unit? I know that I should be using either tubes or SCRs together, but I would like to know if I can test the (seemingly good) remaining tube, absent the proper testing apparatus.

AFAIK he HAS tested and proven one of his units with the legacy Thyratron on the other hole to be able to work.

Even so, I'd rate it a bad move. Better to have both sides identical, either way.

As to "testing apparatus"? Think it through. You have the 10EE.

Can't ask for a BETTER test rig because it is the EXACT duplicate of what the components will see in real-world use!

:D
 

labeeman

Hot Rolled
Joined
Mar 29, 2016
Your problem right now is that your missing the field voltage on the motor. Does your fan come on at all?
 

mechanicalman

Plastic
Joined
Nov 22, 2014
Location
Oakland, CA
AFAIK he HAS tested and proven one of his units with the legacy Thyratron on the other hole to be able to work.

Even so, I'd rate it a bad move. Better to have both sides identical, either way.

As to "testing apparatus"? Think it through. You have the 10EE.

Can't ask for a BETTER test rig because it is the EXACT duplicate of what the components will see in real-world use!

:D

I feel like you're telling me two things. It sounds like you're telling me the 10ee is the perfect testing apparatus, but also that it would be a bad idea to only swap in one SCR in place of the bad C16J, even if only to test the 'good' C16J tube.

Your problem right now is that your missing the field voltage on the motor. Does your fan come on at all?

If you're referring to the little cooling fan near the tailstock that is vented to the back of the lathe, then yes. It comes on as soon as power is applied.
 

labeeman

Hot Rolled
Joined
Mar 29, 2016
That tells me that your fuses are good for the field voltage tubes. You need to check for field voltage on the main motor if present then check the contact on the field loss relay and clean them. The field voltage will only be present while pressing the on button.
 

thermite

Diamond
I feel like you're telling me two things. It sounds like you're telling me the 10ee is the perfect testing apparatus, but also that it would be a bad idea to only swap in one SCR in place of the bad C16J, even if only to test the 'good' C16J tube.
Well.. yes.. it IS "two things". To do a "test" one way. Then actually RUN it the other way! "Balanced", whichever way you choose.

One could prove "a" tube good, find a buyer right here, then run the new plug-in SCR's as a pair?

I did not have a "Module" drive NOR a WiaD, just MG units, so it wasn't an option.

I went directly to 4Q Eurotherm/Parker SSD drives instead. "Four Quadrant" brought some really nice bennies, so I'm good with that.

More than just a few ways to spin a 10EE's spindle, and they ALL can make chips.

:)
 

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
I'm guessing it's this guy with the solid state replacement.

To the second point, if I don't have a motor-generator, what do I have? Just a motor?

...
Yes. That's the guy. His name is Timothy Jones. Here's the thread he started when he was developing the module:
And here's a link to his data sheet for the module, which includes a schematic of the circuit:
I'm sure he would be happy to answer any questions that you have. Contact information link is on the main page:

The drive that you have is know as a "Works in a Drawer" or WiaD drive. Motor Generator (MG) drives used an AC motor coupled to a DC generator and exciter to produce the DC voltages for the the spindle motor, etc. You have a DC spindle motor, but no motor/generator; the WiaD drive takes the place of the MG.

Cal
 

mechanicalman

Plastic
Joined
Nov 22, 2014
Location
Oakland, CA
I already spoke with Timothy today and placed two SCR's on order. He also stated that it would be fine to replace a single thyratron with an SCR to confirm the function of the other thyratron! So, it looks like I'll be able to sell the working tube (if it indeed does work) and cover my some of my costs.
 

reidry

Aluminum
Joined
Dec 27, 2012
Location
Cocoa, FL
I already spoke with Timothy today and placed two SCR's on order. He also stated that it would be fine to replace a single thyratron with an SCR to confirm the function of the other thyratron! So, it looks like I'll be able to sell the working tube (if it indeed does work) and cover my some of my costs.

Congratulations on the lathe, they are wonderful to operate.

I tested Timothy’s C16J Solid State replacement units in my WIAD, they work perfectly. I’ve run several different projects with power demands across the board and I cannot tell a difference between the C16J tubes and the Solid State reps.

They are designed to mimic the characteristics of the analog tube, so running one with an analog tube would work fine. If fact you might consider keeping the working tube as a backup, YMMV but I find it comforting to have spare parts.

Ryan
 

TheOldCar

Stainless
Joined
Jul 31, 2011
Location
Utah, USA
Interesting! Their website shows only the two 10ee lathes.

EDIT: This shows only in the physics shop. They have what they call Central Machine Shop which probably has lots of machinery.
 

mechanicalman

Plastic
Joined
Nov 22, 2014
Location
Oakland, CA
So, I went ahead and replaced both thyratron tubes with the SCR's from Tim and no dice. The main contactor still wouldn't close. I proceeded to check out the 10 ohm resistors (they were fine) and double checked the 3A fuses (also fine). I then started looking at the field failure relay. At no point has that relay closed while I've been fussing with everything else. So against better judgement, I used a piece of wood to hold the contact closed on the field failure relay while I pressed the start button. The main contactor closed AND latched this time. As soon as I released the field failure relay and allowed it to open, the main contactor opened. If I keep holding the field failure relay while the main contactor is latched, I'm able to toggle the direction switch, which causes the contactors at the head stock end of the lathe to operate, BUT the spindle does not spin up no matter what speed control rheostat is set at. It was getting late, so I didn't have a chance to check the field failure relay further, but what should I investigate next time I'm at the shop (FFR coil voltage, motor brushes, etc)? I already ordered the manual for my lathe from Monarch, but it's not getting here until early next week.

Also, assume I'm stupid and may indeed have bad fuses and/or bad resistors.
 

rke[pler

Diamond
Joined
Feb 19, 2002
Location
Peralta, NM USA
Have you checked the field voltage? That's the primary reason for the field failure relay to drop out. I'd suspect the 3C23s since they're the most common failure point for the field.
 

labeeman

Hot Rolled
Joined
Mar 29, 2016
There are two smaller thyratron tubes that control the field voltage for the field you need to trouble shoot that circuit to get your field for the motor without that the field loss relay will never hold.
 

mechanicalman

Plastic
Joined
Nov 22, 2014
Location
Oakland, CA
Have you checked the field voltage? That's the primary reason for the field failure relay to drop out. I'd suspect the 3C23s since they're the most common failure point for the field.

There are two smaller thyratron tubes that control the field voltage for the field you need to trouble shoot that circuit to get your field for the motor without that the field loss relay will never hold.

Dammit, more tubes. Any tips for diagnosing that circuit? What kinds of voltage values should I see across the coil terminals of the FFR?
 

labeeman

Hot Rolled
Joined
Mar 29, 2016
Dammit, more tubes. Any tips for diagnosing that circuit? What kinds of voltage values should I see across the coil terminals of the FFR?
Yep more tubes the FFR relay is a current relay and the voltage is small less than 5 volts have not measured it but it operates on current. You need to see at least 40 VDC on the field of the motor when you press the on button the nominal voltage is 120 VDC.
 








 
Top