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Very early Monarch 10ee

stricht8

Plastic
Joined
Jan 7, 2023
Hi All,
I just acquired a Monarch 10ee. I’ve never used a lathe before so I have a lot to learn. This is a 1939 machine with serial number 6486! I assume it once had the sundstrand drive but it has since been repowered with an ac motor and VFD.
It runs on 3 phase power but I only have 1 phase. I’ll have to see if the VFD is ok to run on 1 phase. I don’t know what the FLA of the motor is yet. Haven’t dug that far. Anyone have any thoughts on this? I was also thinking of using a rotary phase converter. Can I plug a VFD into a rotary phase converter?1C086EE5-C507-4FFE-A16F-C562AAAACBB3.jpegA7D11C13-DFD6-4210-ABD7-0686C7DF04B1.jpegEE76515C-0316-420E-96D7-C0B99897AC03.jpeg9A0D2C04-96A6-4858-9EE7-279B2036F395.jpeg5F9320DB-F336-442E-B367-48BB92CEF8C4.jpeg95838182-58D5-4D38-AB52-69D729B458EA.jpeg95838182-58D5-4D38-AB52-69D729B458EA.jpeg
 
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This is the oldest 10EE to show up on the forum since I've been here. The next oldest machine that I know of is EE6642, we don't have a photo of its data plate, but order sheet lists a July 1939 "promised on" date.

According to our Monarch history summary, the first three 10EEs shipped were EE-6156, S/N EE-6207 and EE-6208, so your machine (EE-6486) is within 300 machines of the very first 10EEs. Bear in mind that serial numbers were assigned as machines were ordered, regardless of size, so those 300 machines included a lot of lathes other than 10EEs; also, some machines that were ordered wound up getting canceled and those serial numbers were not reused.

For folks that somehow think that early 10EEs had a 12" swing, please note that the build information tag on this machine shows the Actual Swing as 12.5":
5f9320db-f336-442e-b367-48bb92cef8c4-jpeg.386032


This was definately once a Sundstrand drive machine. Does it have a taper attachment? What motor was used with the VFD and does it use a back-gear?
 
The information plates are in unbelievable great shape, for a 82 year old lathe. The lathe also looks to be in great shape.

Hal
 
It does have
This is the oldest 10EE to show up on the forum since I've been here. The next oldest machine that I know of is EE6642, we don't have a photo of its data plate, but order sheet lists a July 1939 "promised on" date.

According to our Monarch history summary, the first three 10EEs shipped were EE-6156, S/N EE-6207 and EE-6208, so your machine (EE-6486) is within 300 machines of the very first 10EEs. Bear in mind that serial numbers were assigned as machines were ordered, regardless of size, so those 300 machines included a lot of lathes other than 10EEs; also, some machines that were ordered wound up getting canceled and those serial numbers were not reused.

For folks that somehow think that early 10EEs had a 12" swing, please note that the build information tag on this machine shows the Actual Swing as 12.5":
5f9320db-f336-442e-b367-48bb92cef8c4-jpeg.386032


This was definately once a Sundstrand drive machine. Does it have a taper attachment? What motor was used with the VFD and does it use a back-gear?
Interesting that it’s the oldest one to surface! Yes, it does indeed have a taper attachment. I’m not sure what motor it has yet but I suspect a Baldor to go with the VFD. I have not removed any covers. Waiting for the weather to warm up in a day or two and will report back. Not sure what a back gear is.
 
The information plates are in unbelievable great shape, for a 82 year old lathe. The lathe also looks to be in great shape.

Hal
Yes the plates are very clear and crisp! As far as condition goes it definitely could use some fresh paint. I have not really assessed it for wear yet but it was being used in an Indiana factory until recently.
 
Not sure what a back gear is.
It's a two-speed transmission with a 6:1 speed reduction. They were used on DC motor drive 10EEs. Here's the spindle motor and backgear for EE6642, mentioned earlier:
EE6642 DSC05763-M motor conversion.jpg
The gray unit on the front of the motor is the backgear.
 
It's a two-speed transmission with a 6:1 speed reduction. They were used on DC motor drive 10EEs. Here's the spindle motor and backgear for EE6642, mentioned earlier:
View attachment 386083
The gray unit on the front of the motor is the backgear.
Ok I see. I will let you know in a day or so. How do you switch between the two speeds?
 
On DC motor drive 10EEs, there's a lever that's coaxial with the speed control knob. You don't have it. The square opening in your headstock drive cover is where the speed control handwheel for the Sundstrand drive once lived. That's where the speed control knob on a round-dial DC drive machine is located.
 
So some research on this forum seems to indicate that Mobil DTE Heavy Medium is the appropriate oil for the headstock. What about other parts of machine? Way oil?
Also the sight glasses are filthy. I watched a video on YouTube where some guy removes, cleans and puts back together and uses three cork gaskets. Are these available anywhere? As far as manuals go, I can’t find anything for a machine this early. Not sure where to go!
 
So some research on this forum seems to indicate that Mobil DTE Heavy Medium is the appropriate oil for the headstock. What about other parts of machine? Way oil?
Also the sight glasses are filthy. I watched a video on YouTube where some guy removes, cleans and puts back together and uses three cork gaskets. Are these available anywhere? As far as manuals go, I can’t find anything for a machine this early. Not sure where to go!
Oils have been discussed at great length on the forum. Basically Mobil DTE Light for the front and rear spindle bearings (the site glasses at the far left and right on the headstock) and DTE Heavy Medium for the center gear section of the headstock (the center site glass) as well as the gear box. Problem is DTE Light is tough to get in anything other 5 gal pals, and you only need like 8 ounces! The apron and tailstock use way oil, something like Mobil Vactra #2 is good.

The sight glasses are tough to get out without damaging anything unless you make a three pronged tool to twist them out using the screw holes once the screws are removed. Here is a picture from this forum of the tool I'm talking about. You can get the cork gaskets from Monarch I believe, but I just used rubber o-rings instead. Easier, cheaper and reusable if you take the glasses out again in the future. Place one on each side of the glass.

Sightglassremovaltool2.jpg
 
HR beat me to the draw...

DTE Heavy Medium is correct for the center reservoir of the headstock only. Heavy Medium also goes in the quick-change gearbox and in the backgear unit (which you don't have). The spindle bearing reservoirs take DTE Light, but it's not currently available in gallons. Best bet there is to call around to CNC machine shops and find one that will sell you a quart or two of DTE Light. DTE 24 hydraulic oil, or any hydraulic oil, is NOT the right stuff. The apron and tailstock take Vactra #2 way oil.

To remove the sight glasses you need to twist them to break them free. Basically you need a pin-type face spanner. HR's tool, above, is one way to go. Folks have also used face spanners sold for bicycles (Park Tool sells them) and for opening watch cases (HF has them). A couple of holes drilled in a piece of bar with appropriate sized pins works as well.

O-rings are definitely the way to go. Topics related to sight glass removal and O-rings are discussed here:

I don't think there was much of a manual for Sundstrand drive machines. What there was had mostly to do with the drive. The round-dial manual linked in the sticky has most of the information that there is on round-dial 10EEs. US Patent 2381422 (1939) covers the machine in great detail, but it's not really very useful as an operator's manual.

One thing you need to know, and that isn't covered by any manual, is that certain things will won't drop into gear unless the spindle is in the right position. When things won't engage, just roll the spindle until they do. You may have to go a full rev of spindle to line things up. You may also need to roll the feed-rod back and forth a bit to get the quick-change gearbox to shift.
 
Very nice early machine! I especially like all the early features that are in amazingly good condition. By 1940, many of these were eliminated, and in 1941 more were eliminated. These are the ones I noticed:

The feed/thread control dial and handle
The pointer on the cross slide for the compound angle
The domed covers for adjusting the feed clutches
The knob on the apron for selecting fwd feed / threading /rev feed

It also has the early design taper attachment which changed in 1941 to the model that was used for the rest of 10EE production.

And the gearbox has the chrome plated iron knobs and round dial. In 1941 these changed to zinc or aluminum.

And of course, it has the original castings, like the headstock covers and the base with the right hand extension, all of which changed in 1941 when the mg came out.

I think that if you get a copy of the 1939 sales brochure, which is posted on the forum, you will see all those features.

Inside the door in the center of the lathe should be a 5C collet rack, which also was eliminated starting in 1941. That rack came in two or three varieties: most common was the single layer rack which holds a full set graduated by 1/32”. The double rack would hold a full set graduated by 1/64”. I think we have seen one early lathe with a third layer, so it held squares and hexes in addition to 64ths. Pretty amazing.

If it came with any accessories or the optional Monarch tool cabinet, please post some photos. The early clamshell indicators were made from iron, and are quite hard to find.

I think this will be a spectacular machine once it gets cleaned up, so best of luck with it!
 
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I will look for all those early features you mentioned! It’s definitely interesting to own a unique machine like this!
The tool cabinet does indeed have collet racks. I think 3. I’ll take a picture tomorrow and post it.
 
Oils have been discussed at great length on the forum. Basically Mobil DTE Light for the front and rear spindle bearings (the site glasses at the far left and right on the headstock) and DTE Heavy Medium for the center gear section of the headstock (the center site glass) as well as the gear box. Problem is DTE Light is tough to get in anything other 5 gal pals, and you only need like 8 ounces! The apron and tailstock use way oil, something like Mobil Vactra #2 is good.

The sight glasses are tough to get out without damaging anything unless you make a three pronged tool to twist them out using the screw holes once the screws are removed. Here is a picture from this forum of the tool I'm talking about. You can get the cork gaskets from Monarch I believe, but I just used rubber o-rings instead. Easier, cheaper and reusable if you take the glasses out again in the future. Place one on each side of the glass.

Sightglassremovaltool2.jpg
Thank you for all the info on the oils. Where can I get that sight glass removal tool or is it a homemade item?
 
HR beat me to the draw...

DTE Heavy Medium is correct for the center reservoir of the headstock only. Heavy Medium also goes in the quick-change gearbox and in the backgear unit (which you don't have). The spindle bearing reservoirs take DTE Light, but it's not currently available in gallons. Best bet there is to call around to CNC machine shops and find one that will sell you a quart or two of DTE Light. DTE 24 hydraulic oil, or any hydraulic oil, is NOT the right stuff. The apron and tailstock take Vactra #2 way oil.

To remove the sight glasses you need to twist them to break them free. Basically you need a pin-type face spanner. HR's tool, above, is one way to go. Folks have also used face spanners sold for bicycles (Park Tool sells them) and for opening watch cases (HF has them). A couple of holes drilled in a piece of bar with appropriate sized pins works as well.

O-rings are definitely the way to go. Topics related to sight glass removal and O-rings are discussed here:

I don't think there was much of a manual for Sundstrand drive machines. What there was had mostly to do with the drive. The round-dial manual linked in the sticky has most of the information that there is on round-dial 10EEs. US Patent 2381422 (1939) covers the machine in great detail, but it's not really very useful as an operator's manual.

One thing you need to know, and that isn't covered by any manual, is that certain things will won't drop into gear unless the spindle is in the right position. When things won't engage, just roll the spindle until they do. You may have to go a full rev of spindle to line things up. You may also need to roll the feed-rod back and forth a bit to get the quick-change gearbox to shift.
Thank you for the oil info. Too bad about the DTE light! Looks like it’s going to be a hassle to get some. I like HR‘s tool. If it’s a homemade thing then I’ll probably just make one from bar stock and pins as you mentioned.
With regard to getting things to line up by rotating spindle, I actually noticed that while trying to get the lead screw lever to engage in forward or reverse.
 
Thank you for all the info on the oils. Where can I get that sight glass removal tool or is it a homemade item?
Stricht8, Take a small brass punch and round the end slightly. Insert it at an angle in the screw hole of the sight glass plate and just tap it with a hammer til the ring begins to turn. Done deal. You can pull the ring, cork seal and glass right out. Pick up some cork gasket maker at Auto zone ad pop out your own gaskets. Its cheaper and works just as well.

Love your 39'. Awesome find. Don
 
I like this simple approach!
I was looking at the plate on what I assume is your Baldor VFD. If all you have is single phase, as long as you have 220/250 that you can tap into, don't fool around. I bought a couple Huanyang 10 HP VFDs, that work just fine. They will run single phase in and give you your 230 3 phase out. They are soft start so you don't get a big power surge when you turn them on. At 10 HP you'll want a braking resistor. All the wiring and set up is straight forward. Price on the last one I bought was about 250. I used to set up and use primarily Hitachi and TECO VFDs, but these are so cheap and as of now, have taken a beating without letting me down. It may be your quickest way t get up and running, as well as cheapest. Just a thought. Don
 








 
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