What's new
What's new

1940 Monarch 10ee rehab questions

Well just to provide an update on where I am at. As I started this thread as a rehab and not a restoration my goal is to avoid a big project. I don't want to tear it all apart and repaint it etc. I just want to clean it up, inspect and replace anything that needs to be replaced and use it for a while with the goal of eventually doing a tear down and rebuild and repaint.

So as I am cleaning it up I am noticing a lot of the green paint flaking off, so I decide to scrape off the remainder of the green paint and go back to the original grey paint underneath which appears in good shape. After scraping off the green there are areas that will need to be repainted. Repainting is going to be an issue with the seeping hydraulic oil so I will need to drain and fix those leaks first, well I cant get the exact right colour so I guess the whole thing is getting a coat of paint, and so on until I am here:

View attachment 417851

I still have a long way of scraping/sanding/filling to go before paint but it is moving along. I think I have addressed all of the leaks that I know of with the exception of one that I could use some advice on.

View attachment 417852

The outer bearing on the feed shaft is a loose fit in the housing, spinning the shaft the outer race spins. Obviously oil is leaking around this bearing onto the flat belt pully and from there onto everything else. I will replace this bearing but I suspect the housing is the more likely worn part vs the hardened bearing race. Is there a missing oil seal that should be before this bearing? or does anyone have a recommendation for a sealant that could be used between the two surfaces to prevent the oil leaking?

Any suggestions on how to attack this?
IMG_9945.jpegIMG_9954.jpeg
A 6204 sealed bearing is the one you want on the end of that shaft. The inner bearing also a 6204 needs to be fully open so oil flows into the gear box. Check that the inner bearing isn’t clogged up with gunk etc. on mine a new bearing is a moderate press fit on the shaft yet slightly tighter then a slip fit in the bore. A light bead of RTV around the external bearing race would probably take care the leak. Also good idea to put a new gasket between that casting and the gear box while you have it out.
 
A 6204 sealed bearing is the one you want on the end of that shaft. The inner bearing also a 6204 needs to be fully open so oil flows into the gear box. Check that the inner bearing isn’t clogged up with gunk etc. on mine a new bearing is a moderate press fit on the shaft yet slightly tighter then a slip fit in the bore. A light bead of RTV around the external bearing race would probably take care the leak. Also good idea to put a new gasket between that casting and the gear box while you have it out.

Thank you Grant. I already ordered a replacement 6204 based off of your thread. Your rebuild thread has been invaluable to me. I am constantly going through your thread as a reference on disassembly or assembly or to find info such as which bearing numbers. The documentation you are doing is as impressive as the rebuild itself and I cannot thank you enough.

A new gasket is in the plan as well, I am replacing all gaskets as I come across them to hopefully eliminate the oil leaks. I am drawing up all the gaskets and wipers in CAD and cutting them out on a diode laser cutter. I hope to make the CAD files available somewhere for others in the future.

RTV is what I was wondering. I have used Loctite bearing retainer in the past but that is thin product and meant to hold the bearing not necessarily provide a seal. I was going back and forth between that and something like an RTV and couldn't decide. I thought I would check here with those who have gone through this already what they suggest and see if there was a better choice I was not aware of.
 
I have a couple of Sundstrand drive specific questions that hopefully someone here can help with.

I never got to see my lathe operating under power so I do not know how the original switch/contactor worked. I will be installing a VFD and want to use the original switch as the control but I need to know what the original operation was. The switch on my lathe is a 5 position switch. mom-on-off-on-mom with three wires coming out. From what I can determine from the wires is that both of the On positions energize the coil but only one of the momentary positions latch the contactor. This makes sense to me, the motor will only ever run in one direction which is required for the Sundstrand drive with a separate gear shift for FWD-Reverse. My question is why a 5 position switch? or am I missing something in my analysis of the wiring? Basically if anyone has a Sundstrand drive, how does your switch operate?

My second question is that when I received my lathe there was a thick soft rubber strip between the Sundstrand hydraulic tank and the machine base. This material was cut up strips and obviously not original but is there supposed to be something here? or does the Sundstrand tank normally bolt to the plate in the machine base directly? If there usually is a material between these two what should it be?

Thanks all.
 
From your question I am not sure what you are describing. There is an on/off switch on the front of the headstock, and there is a magnetic contactor on the back side of the headstock which is used to protect the coolant pump. It has been 20 years since I installed a single phase motor to replace the original three phase motor that drives the hydraulic pump, but about two or three years ago I finally replaced the three phase coolant pump with a single phase pump. I retained the original wiring, so I think the coolant pump is still protected by the contactor. However, I might have made additional changes. I can check how its wired if you have more specific questions.

Why are you installing a VFD? More information would be helpful.
 
VFD is just there for 3 phase conversion.

I do not have the coolant pump on mine. When I received my lathe, there is the 5 position switch on the front, which connects to the contactor at the back of the headstock. The switch activates the contactor, the contactor switches the power to the 3 phase motor that drives the hydraulic pump.

What is throwing me off is the switch on the front being a 5 position as the motor should never be reversed. So I was wondering if these extra switch positions originally had a purpose that I am not aware of.

Another question I had that I forgot to include above, is what people are doing for levelling feet on the Sundstrand variants? The base casting does not have the holes that are typically cast. Drilling any of the three pads are awkward due to the clearance but it is maybe doable at the tailstock end. The headstock end though, the base plate that bolts onto the casting, covers the clearance for the levelling feet bolt to stick up through. I have not checked if there is sufficient clearance with the Sundstrand yet that I could drill through both the casting and base plate. Just wondering if someone else has worked this out already. I am thinking about something like a machinist jack as levelling feet so there is no need to drill through both the casting and plate?

Pictures for clarity:
IMG_5292_091653.jpeg
Headstock at one the reinforced foot pad areas. That is only 2" wide so not a lot of clearance for a drill.

IMG_5291_091652.jpeg
Same area with the base plate installed.
 
Those are the same parts as my lathe has. All the way to the left is momentary contact to start the lathe and latch the magnetic contactor on the back side of the headstock. It is spring-loaded like an ignition switch in a car, so after starting it returns to the position one notch to the left and the motor keeps running. Straight up is off, and the two positions to the right do nothing.
 
Thank you. That confirms what I was able to determine from the wires. It was the presence of the two right positions that do nothing that was confusing me as I could not think of any purpose for them.

On the other questions, do you know if there is supposed to be a rubber mount between the Sundstrand drive hydraulic tank and the base plate? This is in addition to the rubber mounts between the base plate and the casting.

How did you tackle the levelling feet?
 
Thank you. That confirms what I was able to determine from the wires. It was the presence of the two right positions that do nothing that was confusing me as I could not think of any purpose for them.

On the other questions, do you know if there is supposed to be a rubber mount between the Sundstrand drive hydraulic tank and the base plate? This is in addition to the rubber mounts between the base plate and the casting.

How did you tackle the levelling feet?
I have a 1942 round dial. I just use wedge levelers under the base.
 








 
Back
Top