Is this 10EE worth saving?

[Donn]

I'm going back to look for the exciter tomorrow. Anyone got a pic of what it looks like?

 

[Donn]

Other than all TF over the Monarch forum on {PM?



Yea. You got me there. Should have looked there first instead of google images.
I'm pretty sure I saw that at the shop.

 

[Donn]

Went back to the shop and couldn't find the exciter. Time to look at work arounds and figure out how to proceed.

 

[Cal Haines]

The exciter can be replaced with a simple bridge rectifier circuit, the parts are about $20. It's the big Ohmite rheostats that you need to have enough parts to attempt to put the original drive back in service. However, the old drive was taken out of service for a reason. It might have been something as simple as a failed exciter, but there's no telling. I can suggest a possible source for the rheostats, if you're interested in going that route.

Cal

 

[Hobby Racer]

... It's the big Ohmite rheostats that you need to have enough parts to attempt to put the original drive back in service.

... Meanwhile.. "dollars and cents-wise, it is WELL WORTH trying to find an OEM exciter!

Better yet, a complete MG with one still on it.

If you decide to go the route of restoring the MG drive system I have an entire MG drive with the exciter still attached AND a set of Ohmite rheostats left over from my drive conversion.

You can contact me via private message or email through the site.

 

[Donn]

I spoke at length today with the previous owner about the history of the machine. He is 91 years old and purchased the machine in the early 1960s. The machine left the factory with the standard M/G setup and standard tailstock. It was then retrofitted with the turret tailstock and control cabinet, which eliminated the need for the exciter, which is 60 years gone. The wire box above the generator is part of the retrofit and leads out and up to a multi pin connector which the big control cabinet plugs into. Perhaps the tubes and circuits in that cabinet did the work of the exciter. In any case, I do intend to use the original DC motor and replace what is missing as time and funds allow. The speed pot and chain and sprocket linkage are also missing. Thank you for the suggestions and impressive knowledge you have shared. I continue to learn about these machines by the day. Also, the logging grapple was not used. Its slung from a hook just below it.

 

[Cal Haines]

I spoke at length today with the previous owner about the history of the machine. He is 91 years old and purchased the machine in the early 1960s. The machine left the factory with the standard M/G setup and standard tailstock. It was then retrofitted with the turret tailstock and control cabinet, which eliminated the need for the exciter, which is 60 years gone. The wire box above the generator is part of the retrofit and leads out and up to a multi pin connector which the big control cabinet plugs into. Perhaps the tubes and circuits in that cabinet did the work of the exciter. In any case, I do intend to use the original DC motor and replace what is missing as time and funds allow. The speed pot and chain and sprocket linkage are also missing. ...


View attachment 344431 View attachment 344440

It looks to me as if the original DC Control Panel and motor/generator (sans exciter) are still part of the system. This makes no sense if the spindle motor is an AC motor. Can you post a photo of the data plate on the spindle motor:

Cal

 

[Donn]

I'm sorry, I thought I mentioned earlier that the owner removed the DC motor and back gear and stuck that 3 phase motor in it. I think its 2 or 3 HP.
He said the machine was awkward and cumbersome to use with all the switches and early automation for the turret the cabinet was designed for so he replaced the motor and didn't use the control cabinet. It only made a small part every couple of years. Here's a pic of the original motor that I have.
Edit- after reading your post again, I think you know that and want to see the tag on the three phase. I'll get a pic.

 

[Donn]

Motor is a 3 HP 3 phase wired to 220V. Voltage is also split off to the coolant pump. It is disconnected from the rest of the machines wiring.

 

[Cal Haines]

What controls it? Is it just set up to run at a single speed?

Cal

 

[Donn]

Yes. There is just an on/off push button visible on top of the machine. Single speed.

 

[Cal Haines]

My original concern with this machine was that the motor/generator (MG) drive had been decommissioned because it failed. That's apparently not the case. Based on what you've posted, you're in pretty good shape to put it back in service. The main thing you need to round up is the rheostat pair and it's possible to work around them. So if I were you, that's the way I'd go.

The 3-phase motor that you have is too small to be satisfactory with a VFD.

Cal

 

[Donn]

I got it into the shop today, disconnected the coolant pump and plugged it in. Speedometer reads 1500 rpm. Trying to figure out all the handles to see what works and what does not. I am going to figure out a work around to get the DC drive back up and running. While I'm learning how to do that and getting the needed parts I can play with it as is and fix what needs fixing. It's a bit of a learning curve with this drive but It's starting to make sense. I know how to make a DC supply with rectifiers and capacitors. Is this type of circuit along with rheostats used in place of the exciter? Does Monarch supply a manual for the specific serial number or just generic info?

 

[Cal Haines]

What do you plan to use to power the machine? Do you have 3-phase or are you planning to use something like a rotary phase converter?

A simple full wave rectifier running from 120 VAC will work to power the DC Control Panel and the fields of the spindle motor and generator, standing in for the exciter. The rheostats are not part of that. One rheostat controls the field of the generator and thus the spindle motor's armature voltage. The other is connected in series with the spindle motor's field and reduces (weakens) the field to allow the motor to run above base speed. Without the rheostats, the rectifier can be connected to provide almost full voltage to both fields and the spindle motor will run at about 640 RPM (base speed). The spindle speed will be higher, depending on the pulley ratio.

Running direct off of 120 VAC, the rectifier will put out about 90 VDC. Some exciter replacement circuits use a transformer to increase the voltage into the rectifier, so that it will put out 115 VDC under load. It wouldn't surprise me to find such a circuit in the big electrical panel. But, for initial testing, the simple rectifier is sufficient. The output should be fused at 3A.

Be aware, that model DC Control Panel has 3 resistors in the upper right corner that are prone to corrosion and failure. (Really about the only problem those panels have.)

Cal

 

[Donn]

What do you plan to use to power the machine? Do you have 3-phase or are you planning to use something like a rotary phase converter?



Cal

I have a 5 HP 3 PH converter at 220V

 

[Cal Haines]

I have a 5 HP 3 PH converter at 220V

Is this a "rotary phase converter" (RPC) or something else? A 5HP RPC is marginal for a 10EE, but some people are successfully using them. An RPC with a 7.5 HP idler motor is sufficient. It will run from a 30A, single phase 240 circuit.

There's a cast iron cover on the back of the headstock, behind the quick-change gearbox. Open that up and see if the original AC contactor (aka motor starter) is still there.

By the way, transformers, relays and other components in the big cabinet have value and can be sold on eBay, if you're so inclined. Definitely don't throw it in the dumpster just yet.

Cal

 

[Donn]

Its a rotary phase I made years ago with a reliance C face inverter duty motor. Looks like everything's there behind that cover. Maybe I should take the panel out of the big cabinet. Might go back there tomorrow. Maybe I can find the speed pot and sprocket. I have the back gear shift linkage.

 

[Cal Haines]

It looks like the contactor has a 220V coil. That's good news. A lot of machines shipped configured for 440, so you have to change the coil and overload heaters to run them from a 240V RPC.

I would be surprised if there wasn't some way to vary the spindle motor and generator fields. Some better photos of the innards of the big panel would be helpful. You mentioned something about the panel having tubes in an early post, but I don't see sockets for tubes. What does the control panel for the panel look like?

Cal

 

[Donn]

The tubes plugged in to the four sockets with labels GL-393A and one EL1 C . The front of the big cabinet has the 10 switches. I'll take better pics when I get back to the shop where it's waiting to be scraped.

 

[Cal Haines]

The tubes plugged in to the four sockets with labels GL-393A and one EL1 C . The front of the big cabinet has the 10 switches. I'll take better pics when I get back to the shop where it's waiting to be scraped.

View attachment 344723 View attachment 344724

OK, that makes sense. The four GL-393-A tubes are thyratrons; the EL-1C is a full wave rectifier. That sounds about right for a circuit that can control the field windings of both the spindle motor and the generator. (Controlling the generator's field indirectly controls the spindle motor's armature.) I don't think that you'll find the Ohmite rheostats in the cabinet. Was there any electrical documentation in the cabinet? (This was obviously a professionally designed and built system.)

Write down the part numbers of the transformers and relays. Stick the numbers into eBay and see what they're selling for. They may be worth pulling out to resell. The switches on the panel may also be of value. You might want to snag the Monarch plate at the top of the panel; someone here will definitely want that.

Cal