Monarch 10ee

Yea, they are basically diodes used to full-wave rectify the incoming A/C. Back then semiconductors were incapable of high current or high voltage. My first 'electronics' job was repairing radios and TVs in my HS electronics instructor's garage shop. Anyone remember the Quasar works in a drawer TV? It had transistors for the low voltage circuits in the drawer, but used tubes for the high powered sweep circuits for the CRT/picture tube. And then there was that nasty flyback step-up transformer that powered the high-voltage anode on the side of the CRT. Got knocked on my butt a few times by that 30kv plus circuit. Thank goodness it was very low current. I only twitched for a couple of hours after getting nailed.

But yea, I would prefer to update the drive if possible, rather than replace it. I've known for years that DC motors are WAY smoother than the old A/C motors of 50+ years ago. This is why some company's went to great lengths to come up with alternatives both electrical and mechanical for the high-precision lathes of the day. Give me a 3 hp BLDC with a uber quiet power supply, nicely filtered and isolated, and I could make that bad boy sing.

Although a good VFD and quality 3-phase motor would come close enough to likely make the difference marginal at best. But hey, it's a Monarch! :)
 
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The 10EE of this era uses an extremely complex drive that adjusts voltages to both the field and armature to give maximum torque over a range of 30:1. this all done without semi conductors. Today's drives leave one constant, often with permanent magnets, and employ semi conductor technology. Still, you don't get the large range of speed and torque that monarch obtained 50 years ago.

The repair issue is all the parts have degraded in this analog system at 50 years age. So, which parts should be replaced when its not completely broke but not working like it used to?

I had the same problem with a very old car. so, I jacked up the radiator cap and replaced everything underneath. :) IMHO, do the same with the 10EE. Shop for a used 10hp 1200 rpm 3 phase motor ahead of time as it may take a bit of searching to find this.
 
Thanks for the tip. Found one for $200 on CL less than 5 miles from home. Is that a good price?
 
MattM said:
Thanks for the tip. Found one for $200 on CL less than 5 miles from home. Is that a good price?
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$200 for a 10 HP 1200 RPM motor is a pretty good price. New price is around $1900
 
Karl_T said:
The 10EE of this era uses an extremely complex drive that adjusts voltages to both the field and armature to give maximum torque over a range of 30:1. this all done without semi conductors. Today's drives leave one constant, often with permanent magnets, and employ semi conductor technology. Still, you don't get the large range of speed and torque that monarch obtained 50 years ago.

The repair issue is all the parts have degraded in this analog system at 50 years age. So, which parts should be replaced when its not completely broke but not working like it used to?

I had the same problem with a very old car. so, I jacked up the radiator cap and replaced everything underneath. :) IMHO, do the same with the 10EE. Shop for a used 10hp 1200 rpm 3 phase motor ahead of time as it may take a bit of searching to find this.
Click to expand...

We live in an analog, not digital world. Sometimes analog solutions for certain scenarios would still be preferable today, but digital is faster to design/build, less costly, and 'close enough' for most markets.

Question? Why do you need a 10 hp motor on basically a 10x20 precision lathe? Just curious.
 
Karl_T said:
The 10EE of this era uses an extremely complex drive that adjusts voltages to both the field and armature to give maximum torque over a range of 30:1. this all done without semi conductors. Today's drives leave one constant, often with permanent magnets, and employ semi conductor technology. Still, you don't get the large range of speed and torque that monarch obtained 50 years ago.
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Both armature and field can be controlled with semiconductor controls. Even with PM motors (used because they are more efficient and cheaper) 20:1 full torque speed control is possible with feedback and a PID controller (which can be implemented in a $5 microcontroller). Give me control of the field and I can easily push that up to 30:1.

If I had one of those Monarchs I'd try hard to keep the thyratron system working just so I could watch them glow, but if I couldn't I'd still keep the original motor and control concept. You'll never match it with an induction motor + VFD. You'd have to go to a BLDC system which would cost as much as the lathe.
 
wrmiller said:
We live in an analog, not digital world. Sometimes analog solutions for certain scenarios would still be preferable today, but digital is faster to design/build, less costly, and 'close enough' for most markets.

Question? Why do you need a 10 hp motor on basically a 10x20 precision lathe? Just curious.
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Bill, when you take out the stock Monarch WiaD or later drive and replace it with VFD driven motor usually the back gear is removed. The original tube drive and its later versions with less tubes and more semi conductors had a pretty sophisticated servo feedback arrangement controlling all aspects of the motors windings (if I understand this correctly). So when you take out the back gear, if you want consistent spindle speed under a variety of loads you need a massive amount of hp to make up for the loss of low end torque at slow speeds.

On my dead stock 1956 WiaD machine you can slow spindle down to 8 rpm, have a smooth surface mounted on spindle like a bare faceplate, try to grab it with your hands to slow it down, won't happen, the drive senses the load and increases the field I believe to make up for the new increased load. Same deal at high rpms. It was and is a brilliant system seeing as they came up with this in the very early 1950s as an improvement on the motor generator set up which had similar capabilities. This system was taken to its absurd limits in the incredible 1000ee which had lots more C16Js, way more horse power, constant surface speed and every wiz bang control feature possible. The guy I bought my lathe from years ago has one, says it makes the 10ee look primitive and small.

When I went looking for an ee I looked at numerous do over machines, some very expensive jobs with huge outboard ss control boards, none of em worked as good as a WiaD machine that was operating half decently. One 7 hp conversion I looked at had the bill, 22000 bucks spent on it, funac controls, except the idiots took out the back gear and I could stall machine easily with my hands at speeds under 200 or so rpm. That experience was repeated several times before I ruled out converted machines unless they were done by Monarch and no one was selling one of those. I am sure others can describe the drive better than I , all I know is conversion machines basically are a sad replica of what the Lion of Sydney figured out 60 plus years ago with tubes. BTW they swing 12.5" according to build plate and I measure 13.25"

cheers
michael
 
I have worked on similar analog closed-loop systems. Been a long time though. I don't want to hijack this thread any more than I have, but this would make for an interesting conversation for another thread on drive control systems. :)
 
wrmiller said:
We live in an analog, not digital world. Sometimes analog solutions for certain scenarios would still be preferable today, but digital is faster to design/build, less costly, and 'close enough' for most markets.
Click to expand...
I started my engineering career designing analog motor controls. Digital isn't just 'close enough'. Modern digital systems can equal or exceed the capabilities of any analog system while still being less expensive and more reliable.
 
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