Full tear down and Rebuild of a 10EE Round Dial

[GrantGunderson]

The following is the process of me purchasing my first lathe, a 1944 Monarch 10ee round dial, and then subsequent tear down and rebuilding of it. The posts may seem overly detailed, but I am hoping they will help me with the rebuild as a reference, and also for anyone else attempting the same. There is lots of information on these lathes here on PM, but I have not found a locations that documents the entire process form start to finish, step by step. so maybe this will be a good reference for it. Thanks in advance to Cal, Thermite and a whole bunch of others that have helped me so far.

I always welcome input from others, especially if there is a better way or alternative method to do things. I am not a machinist by any means, other than a guy that likes to make stuff in his home shop. I am actually a photographer by trade, focusing mostly on actions sports specifically skiing and mountian biking. You can check out my website via this link: www.grantgunderson.com

A bit more on my background, growing up, My father was a brilliant engineer. When he retired, he was one of the head engineers at the Hanford site in WA. He mostly worked at the B-plant, originally during production, but mostly on the clean up side. He always instilled upon me that there is nothing you cant solve or fix, if you take the time to understand the problem and the techniques required to fix it. He also taught me early on that its worth investing in the best tools you can afford, and learn to fix it your self. Next time that problem arrives (and there will always be a next time) all it will costs is your time. Thats a much better investment then constantly paying others to fix your problems. Fast forward to college, I spent 7 years earning a degree in plastics engineering that I have never used. I took a few tool and die making classes during that time, but that was the extent of my education with machine tools.

During college, I was way more focused on teaching myself to shoot ski photos. That ended up paying off really well, as it allowed me to pay my way through school, and landed me a position as a photographer with Powder Magazine, National Geographic Adventure, and a whole slew of other magazines and outdoor brands. That has allowed me the good fortune to spend my summers tinkering on different projects in the garage. During that course of tinkering in the garage I have learned way more about mechanics, engineering, design, etc than I ever did in school. I find I learn best with a hands on approach, and asking lots of questions and spending hours going down the rabbit hole of random topics related to whatever I am working on.

Fast forward 20 years, I ended up being caught in a rather sizeable avalanche 3 years ago. Unable to work the majority of that winter and the following summer, I was stuck at home rehabbing a badly broken body. I just so happened across a craiglist add for a Bridgeport mill for 1200 bucks with a ton a tooling. I went and took a look at it, and it was in pretty bad shape, but had good bones. So I said what the hell and bought it thinking that, if I'm stuck at home in a walking boot, I just as well do something with my hands. I then spent the next 3 months tearing it down to literally the last screw and completely rebuilding it.



I quite enjoyed the process and have used it quite a bit making custom camera mounts for work, and a whole lot of other things. It was one of those situations after rebuilding it, I dont know how I got along so long with out one. After that experience, I decided, I would really like to get a lathe. Especially after having the mill, I kept thinking of projects I would like to do, but a lot required lathe work. So I did a bunch of research and decided I'd rathe have a 10EE or a Hardinge over any of the newer import stuff. I ended up finding a used 10EE with a ton of tooling for $1500 and figured it was too good of a deal to pass up. On the 4 hour dive to pick it up, I called my dad to tell him what I was up to, and all he said, is I think they where pretty good machines, and I am pretty sure we buried a bunch of them at work. If they where good enough for Hanford's use, than its more than good enough for me.

Ok, enough with the background. I started to chronicle this process over at Garage Journal, and asking questions here, and doing a bunch of research on this forum, You Tube and other forums and asking the occasional specific question on here. The following is me copying my posts from Garage Journal to here. Going forward, I will keep this thread active with where I am at to both minimize the number of random threads that I start on this site, but also to hopefully serve as a step by step set of instructions for anyone that chooses to do a rebuild on one of these machines. At the least it will be a good journal for me to reference when I get to the reassembly stage.

This lathe is a 1944 Round Dial 10EE

This thread is in the order I tore my machine down. I have tried to include links to other's directions where I used them. If I forgot a link, or there is one, it would be great if Cal or one of the moderators could add them.

Here are a few quick links to my various sections:
Armstrong Tool Post disassembly

Making Custom Skates with Leveling feet

DC Control Panel component ID

Speed Pot removal and inspection

Wiring Connections

Gear Box

Speed Control Shaft Removal

DC Panel rewire

Resistor Testing

Compound

Tail Stock

Lead Screw removal

Feed Shaft Removal

Feed Selector Removal

Gear Train Removal

Gear Disassembly

Feed Shaft Bearing Assembly Removal

Tumbler Clutch Assembly removal

Tumblr Shaft Dissasymbly

Gear Box Removal - Start with lead screw removal and do in order.

Head stock removal Starting with Control Switch Removal - Must pull gear box first.

Chasing Dial Assembly Removal

Apron Removal

Thread Chasing dial and take up Bearing bracket disassembly

Carriage Removal

Main Contactor Removal

Rack Removal from bed.

Bed Removal

Lifting the Bed

DC Exciter removal

Generator and motor Removal

Painting

Sump Drain Installation

Exciter Tear Down

Back Gear Box removal and tear down.

DC Motor tear down

Generator disassembly

Main Contactor and wiring Installation.

 

[GrantGunderson]

Well I made it home with the lathe and my tarp job, while it looks sketchy did a great job of keeping it dry despite driving through one of Seattle’s classic Juneuary Monsoons.

Here is an image of its future home. It’s going to go on the left just past the bikes. After mostly lurking on here for years, I’m starting to think I should start a thread on my garage as it’s pretty heavily action sport based and is a bit different than the average garage on here.

Here is a bit of the tooling it came with. (The mitutoyo stuff wasn’t part of it. I brought it down with me to inspect the lathe)

All for less than what a South Bend 9 in beater shape with no tooling typically goes for around here. The collet set is a full set of Hardinge 2J collets. All the way down to 1/32”. What the hell would you possibly turn that’s that small?

I am already cursing it a bit thou as I dropped one of the 20lb cast iron access panels on my foot, when I slipped unloading the slick wet wooden deck of the trailer. Small price to pay I guess. However the good news is so far my wife hasn’t given me the toung lashing for buying it that I expected on returning home, but I have a feeling that’s coming. I did show her the CL listing for one a guy is selling locally that has been cleaned up for $10.5K, so hopefully that helps my cause with her.

Next step is figure out a leveling foot / castor setup. Ideally I’ll install both. With leveling feet retracted, let it move on castors, then extend leveling feet to lift it off castors snd level. I need to get that sorted as I want to install them when I rent a forklift to unload. I’ll temporarily lower it on 4x6’s to safely install the feet / castors. While I’m doing that I’m going to start tossing the tooling into my ultrasonic cleaner to start cleaning it.

BTW if anyone is interested here is a link to the restore I did on my Bridgeport. I tore it all the way down to the last screw when I got it.

 

[GrantGunderson]

Here is a pic of it after I pulled the panels for lifting it and before I fully tied it down. It’s a diamond in the rough at this stage. I also Lag bolted the holes in its base to the trailer deck. Ended up being a bomber way to transport.

I think the only major thing missing is the taper attachment. I’m sure as I start to dig into it I’ll find a list of small things here and there that are missing, but it does seem to be mostly there and the machine is 100% original (that’s a good and bad thing given the age of the wiring. )

I’ll need to source a machinist level, but not to concerned about that yet as the rebuild process needs to happen before it comes to its final resting spot. I’ll keep an eye put for one. It took me 3 years to find the right project lathe for the right price as there isn’t a lot of true tool room lathes for sale in the PNW, despite all of the years of Boeing being based here.

Dealing with a machine this heavy, its important to make sure what ever I do is safe and a factor of safety is also included. Dropping that damn cover panel on my foot when I slipped on the wet trailer deck is more than enough of a reminder about that.....hence I am up at 5 am icing my foot.....its also why I pressure wash my deck every year. Any horizontal surface that isn't, gets a good layer of evergreen tree pollen on it every spring, if that stuff isnt removed it's slicker than ice when it gets wet... especially if the surface is wood.

 

[GrantGunderson]

I ended up ordering some skate wheels and leveling feet from McMaster today. Once they arrive in a few days I will custom make a skate / leveling foot setup for the machine. Once thats done I can get it unloaded from the trailer and in the garage.... at least the weather looks decent, and the tarp is keeping it dry until then.

While I am waiting to get the lathe unloaded, I started in on cleaning the tooling. First up is the collets. For anything that doesn't have bearings and that will fit in my ultrasonic cleaner, I like to start with that. I have found a solution of 1 gallon water with a few gulps of simple green does a great job of cleaning all of the swarf off, and it even gets into areas I couldn't otherwise, such as the threads and the slits in the collets. I start with a 30 min run In the ultrasonic cleaner, then pull them, take a brass brush to any areas that have excessive build up and then toss them back in for another 30 minutes. Next, I pull them, and give them a light buff with my Baldor buffer.

Depending on what I am polishing I can start with a scotch bright sandpaper combo wheel and then work my way threw the various compounds / wheels. Since the collets are precision, I dont want to remove anymore material than needed. I just want to clean off the 70 years of cutting fluid residue. So for these I just started with a quick pass with the red compound, and then switched to my blue compound wheel. Here is a before / after pic of two batches of the collets.

While I was waiting for the ultrasonic cleaner to do its thing, I scrubbed the wrenches that I got with the machine with some degreaser and a brass brush. It was nice to see the included spanners where good quality Willams USA. I'll add those to the collection of the ones I already own as these are much larger than anything I had. I had to buy a bunch of spanners for the Bridgeport rebuild, so I'll be curious to see If I'll need these, or if these where from some old chucks that where not included. Most likely I'll clean them up a bit more at least.

Most of the wrenches where of usa brands. Some of which I have not heard of before. Not sure what I'll do with these, other than the pin spanner, as I have a very complete set of Snapon.

The lathe specific wrenches all seem to be of good quality as well.

 

[GrantGunderson]

Now, one of the coolest things I found in the Monarch tool cabinet that I got with the lathe, was an original Federal dial indicator specifically made for Monarch, and its case to attache it to the lathe. It was filthy. The clam shell case was packed full of chips, and the indicator didn't seem to work. I cleaned it all up, pulled the back off of the indicator and cleaned out of 70 years worth of dirt.

Low and behold, after cleaning its internals it works perfectly now. Next I pulled off the front bezel, and used some lens cleaner that I use for my day job. ROR (residual Oil Remover) is the best lens cleaning fluid I have found in all the years I've worked as a photographer. It did a great job of getting all of the old cutting fluid and grime off of the lens. The plastic of the lens has heavily yellowed over the years, and its got a few distortions due to age where its no longer perfectly smooth (plastic like glass will creep over the years). So I did my best to polish the lens best I could with a graphite lens pen. While its not perfect, It cleaned up pretty well and is very usable now.

The dial indicator attaches to the clam shell case via the post on the back of it. It's fitment is quite critical, as too deep or too shallow the indicator rod will bind on the case. I lightly tighten the set screw on the case and then moved the indicator by hand until I could fill the set screw drop into the recess on the indicator post.

It is a well thought out setup, and its amazing it still works all of these years latter. I'm not sure how much this indicator will get used by me, as I have more modern ones and plan on putting a DRO on the machine when its done. I do plan on painting the case to match the machine, once I decide on paint for the machine.... thinking a polyurethane paint, but not sure what yet. I used the rustoleum hard hat machine grey on the mill and it has held up pretty good, so far other than one brand of cutting fluid attached it. I'm thinking the 10EE deserves something a bit special tho.

 

[GrantGunderson]

The parts for the skates / leveling feet where supposed to be delivered today, but /UPS decided to stall another day on them. Thats ok, it gave me some more time to focus on cleaning up the tooling. I got all of the collets (1/32 all the way up to 1-⅜ by 32nds) cleaned and polished, as well as a few of the wrenches, a stop and a center.

The lathe came with one of the original Monarch tooling cabinets. I dont know if I will keep it yet, as space is at a premium in the garage, so I just gave the cabinet a good wipe down to get all of the swarf, chips, cob webs etc out of it. If I decide to keep it I will paint it to match the lathe. The cabinet is cool as it has built in storage for all of the collets and then some.


Even the tool cabinet is well made. Looking at the nuts that hold the collet rack in, they are machined with a washer surface on side.

 

[GrantGunderson]

Those nuts were so thin that when I needed to start the bolt in the back of the cabinet behind the collet rack, it would fall down too far in even my shallow broached Snapon socket. So I used a few o-rings in the socket to get the nut to set flush, to make it easer to start in the hard to reach spot in the back of the cabinet.

I then started in on the tool holders.. The 3 way Armstrong had me puzzled at first, then I relized you need to pull out on all 3 pistons at once to release the center. Since I only have two hands I let gravity work as the third.

The tool holder is in good shape, but figured it was about time to clean out 70 years of old grease / swarf. The nice thing about using the eyebolts when I pulled the pistons out to release the handle, is that it then allowed me to use the eyebolts to push the pistons all the way back in to remove them. Each one has a spring on it, and I have a feeling it will feel way nice once the old grease is cleaned out and the springs are free to move properly again.

Turns out all but two of the tool holders where shop made, but they all cleaned up nicely with a good soak In the ultrasonic cleaner, and then some scotch bright. On one of the shop made tool holders, two of the set screws where extremely tight. I figured that the threads just needed to be chased. Since I dont have a thread chaser set (maybe its time to by one) I just attempted to chase them with a tap. They where so tight with the tap I thought I was going to break it. So I pulled it out, and checked the clearance hole with the proper tap drill. Turns out those two where drilled undersized.... guess that one was made by an apprentice. I have no idea how they taped them with out breaking a tap! So I re-driled those two and then ran a tap down them again and now the set screws fit perfectly.


Normally when I tap a hole I use a tap guide in the Bridgeport right after I drill it, but figured for something this easy that was over kill. BTW, If you have never used a Starrett tap handle, you should give them a try, they are lightyears better than any other one on the market.

Next, I wiped the tool holders down with acetone, and then applied some blueing fluid to them. Gave them a quick rinse in water, then repeated after a light rub with steel wool. After the second coat of bluing fluid, I gave them all a wipe down with Boeshield T3 ( this stuff is also the best bike chain lube I have found for the PNW). I think they turned out pretty good. If anyone has any tips for blueing I am all ears, as I am always trying to improve on the finish. I highlighted the text on the factory tool holders and the collets using a Laquer stick.

 

[GrantGunderson]

And here is the before photo of the tool holders:

The lathe came with 7 live centers. I haven’t gotten too going through them yet. So no idea on condition. One thing I didn’t get was any cutting tools. So I’ll need to look for a set plus a knurling tool. All in due time as I got a lot of work ahead of me before I start using the lathe.

Now that I got the lathe I’m going to keep an eye out for any used insert holders that pop up for sale at a reasonable time. If I get in a pitch Grizzly’s headquarters is just 5 minutes down the hill from me. However I have found their cutting tools can be a hit or miss if they are actually sharp or not. I find 99% of the time they are a disaster unless it’s made in Japan, then they can actually be really good. For example my Nepros ratchets that I brought back from a work trip years ago are way better than my Snapon ones.

 

[GrantGunderson]

UPS finally dropped off the parts for the skates / feet last night at 7pm. Sure miss the days when they actually delivered during normal business hours. I only got an hour of shop time in before my wife made me shut the mill down. Took me twice that to clean up the steel chips so my 4 year old doesn’t get into them.

I had a stick of 2” ¼ wall square tube on hand so using that for the feet. First step was to drill the ⅜ holes for the axles for the skate wheels. Using the quill feed on the mill made quick work of this. Started with a ¼” drill bit then stepped up to a ⅜. Afterwords quickly hit each hole with a countersink in the hand drill to debur the hole.

Next I used a 2” indexable mill with carbide inserts to machine a .5 deep by 4.5” slot in the bottom of the steel tube so the machine feet I ordered can retract enough to give the skate wheels clearance. The diameter of the feet is only 4”, but I wanted to have some leeway as I won’t drill the holes for the feet until I set the machine on the steel tube and mark them directly. My transfer punch set only goes to ½” so I’ll just use a drill to mark the hole location. Those will then get tapped to accept the feet

The skate wheels are rated for 400lb each and there will be a total of 16 of them so plenty of safety factor for weight. All of the hardware for the axles is grade 8. The feet I ordered from McMaster are made in the USA stainless steel machine feet. Each is rated for 2000lbs and has a 4” 5/8 stud that seems to perfectly fit the factory drilled holes for the machines kinematic base. Bellow is a shot checking the fit of the hardware and making sure my clearance slot of the feet is deep enough at .5”

The nice thing about this is if I decide to get a pallet jack in the future I’ll have plenty of room to get it under the machine.

 

[GrantGunderson]

Got the retractable machine feet and skates that I made all finished up. Just need to set the machine on them to mark the location for the tapped holes for the feet. I painted the steel tube with POR15. That stuff seems to be exceptionally durable, but is so thin its impossible to apply via brush and not get any streaks. At least these will never be visible underneath the machine, so it was a good place to try out a new to me paint product. Thinking I need to either figure out at spray system (I doubt my little makita compressor will support a HVLP system) or I need to look into other paint options for the lathe.



I was hoping to move the lathe in over the weekend, but no rental equipment deliveries on weekends, and its pouring rain today, so its looking like hopefully tomorrow will be the big day!

Spent my free time this weekend, cleaning up more tooling. The quick change tool post and the Enco 4 way (old usa one too) both turned out looking like new! The Quick change post is serial number 1200. Seems quite low.

 

[GrantGunderson]

I found a bunch of cutting tools tools in one of the boxes of misc stuff I got with the lathe, so cleaned those up too. That will get me started, but I a sure I will need more, and will need to get a good knurling tool too.

I also got both steady rests and the follower rest all cleaned up and ready to be stripped for paint. (Still gotta sort out what I will do for paint. Any suggestions are welcome!)

Before pic of one of the steady rests:

And after cleaning:

I noticed a few things while cleaning up the steady / follower rests. These along with two of the chucks all have matching EE numbers from Monarch that match the lathe's. So these where part of the original equipment that was sold with the lathe... cool!

The level of detail that Monarch put into even the steady rests is amazing, and that simply doesn't exist anymore today in manufacturing. For example all of the brass inserts for the rests are hand fitted to each position. They are each stamped with a number that corresponds to the correct spot for them in the steady / follow rests.


Its a bit hard to see in the last image, but the slot of that casting has a corresponding #3 next to the mount hole to match these two brass inserts. The three spots on the steady rests are also marked for the corresponding brass inserts. Seems overkill, but if monarch was that specific about how each of these fit, its best to pay attention and do as they intended. I cleaned all of these, by tapping out the retainer pin that holds the adjustment screws captive, and then cleaning in my ultrasonic cleaner. I then lubed everything with Super Lube and reinstalled the pin.

 

[GrantGunderson]

I was finally able to get a forklift to unload the machine. They joy I got out of letting my son go for a ride on it / play with the controls with me was worth the price of the rental alone. Here he is showing the older neighbor kid how the controls work.

The rental forklift only had 42" forks and apparently the one we loaded it with had longer 48" ones. I had no idea there was different sizes. so ended up having to buy a 6 foot lifting strap as the original 3 foot one I bought was to short, to give enough purchase on the forks to safely lift it. Once we had it all set up, I lifted it a few inches to clear the trailer, and had a bike bud pull the trailer out from under it. Next we lowered it onto some 4x6 wood blocks, so I could safely attached the shop made skates / leveling feet setup. I marked the hole locations using a scribe, then drilled and tapped them on the Bridgeport. Since the tail of the machine only has provisions to add one leveling foot, I drilled and taped the skate base I made for a 5/16 socket head bolt that I installed to keep that skate from rotating relative to the machine. Next I lifted the lathe from the bottom with the forklift and we placed it just inside the garage door.

Hot damn, the home made skates work better than expected. I can slide the machine around by my self, and turn it with the help of one person.

The machine is covered in a light. oil residue.

Luckily, this stuff dissolved quite easily and with a light spray of degreaser it wipes right off.

 

[GrantGunderson]

Now I can at least see what I am work with. First step is going to be pulling all of the electrical off of the machine. The wiring is very old, and is saturated with oil. The wiring insulation has holes in places where I can see right through it to bare wire... thats all gotta go. I'm going to pull it all so I can clean the machine and minimize the amount of cleaning fluids / oil getting on the control panel.


First time I have ever come across these sort of round terminals.... going to replace those with proper crimped ones with heat shrink.

Luckily all of the wire terminals on the machine are very well labeled. The wires themselves have these brass tags on them that are stamped with the name of the correct terminal. My plan is to pull each wire one by one and put a new heat shrink label on each end, so I know exactly how everything is supposed to reconnect when I replace the wiring.

I have a Brady PM21-Plus cable maker that I bought years ago. That thing is awesome, and unlike most lable makers it doesn't waste a ton of consumables, as you tell it exactly how long you want each label to be. Plus they make these permeated heat shrink labels for it that are ideal for labeling wires.

It looks like most of the machine uses 18 and 12 gauge wire. I am planing on replacing it all with Machine Tool Wire. THHN would most likely work, but MTW is the proper stuff for the application and the price difference isnt horrible. I'll also bump up the 18 guage stuff to 16 or 14 while I am at it.

The control panel doesn't appear to be in horrible shape, but the items labeled #3 in the pic bellow are quite coroded.


Special thanks to Lectrician1 in this thread for helping me with these. Help ID'ing electrical Componets.
#1 is the field acceleration relay. When you have too much current draw on the armature it'll pull in to make sure that there's enough field. Field is weakened for speed above about half. It's hard to accelerate with low field so this is there to let you start the drive in a high speed

#2 is the antiplugging relay. It keeps you from going from forward to reverse unless the spindle is slow enough that it won't put a big load on the drive. Generally this is about 100-300 rpm.

#3-those are resistors

The 2000 Ohm resistor (B-E) in the upper right corner of the panel is probably bad. The two 1600 Ohms resistors (A-B) should probably be replaced as well. Note this is a Cal image from the other thread.

The 1600 Ohms resistors are not a stock item. Since they are connected in series a 3000 and a 200 Ohm resistor can be used instead.

You can order them from Newark for $7 to $9 each. Here’s what I would order:
L50J2K0E (2000 Ohm, 50W, 5%) Newark #64K5003
L50J3K0E (3000 Ohm, 50W, 5%) Newark #64K5013
L50J200E (200 Ohm, 50W, 5%) Newark #64K5007



#4 and 5 are forward reverse contactors.

The guys over there suggested Tefzel" stranded and tinned wire. How does this differ from Machine Tool Wire? I am not familiar with the Tefzel designation..... I haven't had an electrical EE class is over 20 years! So needles to say there is a lot a dont remember, a bit thats changed and I dont think we spend too much time covering this older stuff anyways.

 

[GrantGunderson]

On another note, here is the machine plaque. I thought all of the round dials where the old 12" height, but this says its the newer 12.5


And here is the SN stamped on the ways.

I am curious what that triangle with the 35 is stamped in it. This machine also has a Westinghouse inventory tag, and I believe they were the original owner.

Last night I disconnected the wires from the control panel one by one and labeled them with permatex selves.

The wires did have the factory metal tags on them, but those are not the easiest to read after 80 years. At least the panel's control terminals are still quiet easy to ready. I noticed that the F2 and GF2 connections each had 2 wires going to them, and the E1-2 wire was marked from the factory with two E1 tags.. guess they didn't want to make a E1-2 tag for that one. The E2 connection was interesting as it had 3 wires going to it and one of them was actually marked F1, but the panel has no F1 connection...

With the panel out, I can get a better view of what I got to work with.

That unit at the top of the frame is the very Large speed control potentiometer. It is controlled via a chain attached to the speed control knob on the front of the machine. Looking at it, its nice that it's wire terminals are very clearly marked. So that will make it easier when I compile my list of where each wire from the control panel terminates as I pull them one by one.

The panel was pretty filthy with 80 years of oil and grime on it.

Also of note thats the machine's 1944 circuit board. Those large coils are Zirconium wire. Same as your toaster over. When the machine switches from Forward to Reverse, it uses electronic breaking... similar to an electric car. Instead of dumping the excess electricity into a battery, it burns it off as heat with these coils. Positioned right next to oil soaked wires, what could go wrong? All of those wires will be getting replaced with modern ones.

 

[GrantGunderson]

I got the control panel all cleaned up with some degreaser and denatured alcohol. I tossed the mounting hardware for the control panel in the ultrasonic cleaner. The mounts have a rubber bushing inside them for the mounting pins to pivot in, and each pin had a rubber washer top and bottom that was totally disintegrated. I guess that was 1944 tech for insulating the rest of the machine from the control panel. I'll have to be sure to remember to replace those!


I kept two of the factory wire terminals, as you dont see those anymore.

Next up, will be removing the belts from the machine, disconnecting the chain to the speed pots, remove the wiring to the part and write the locations on the terminal diagram I made of the control panel, then remove the pots.

 

[GrantGunderson]

The 10EE is driven by 3 belts on the headstock end, two V belts that connect directly to the spindle (one was missing) and a flat belt that connects to the feed / threading gears.

Those all came off quite easily as none seemed to be properly tensioned. The sole V belt was also on its last legs to.

I believe the replacements are either A-90 or AP-90 belts. Will have to check. Luckily the flat belt is in good shape and the machine came with a new spare as well.
The lathe was missing one of the belt tensioners. I did find the missing one in the box of random stuff that came with the lathe.

The bearings for the belt tensioners are a very light press fit, and easily press out. However, the center shaft did not want to come off of the bearings. So I used a set of chuck wedges from my Albright chuck to get the separation going.

I then used a ⅞" end mill on the Bridgeport to make a drift out of some scrap aluminum angle and they then pressed right off.

 

[GrantGunderson]

All of the bearings seem to be in good shape. I then tossed the parts in the ultrasonic cleaner to clean them up.


Turns out the one was not installed on the machine due to a broken shaft. I'll have to give Monarch a call to order one when I order new felt. Worse case it will be an easy part to make on the lathe once I get it running again.

Next step is to drain the oil form the spindle and the gear box. There are two pipe plugs at the base of each section to do this.


I used a zip tie to hold the funnel in place while it drained. The spindle had a fair amount of oil in it. However the gear box only had a small trickle. I suspect all of the oil on the inside of the machine base came from a bad gasket on the gear box. That will have to get dealt with.

I then removed the chain from the speed selector shaft that connects to the gear on the speed pots.

A quick soak in the ultrasonic cleaner and it looks like new!

I then lubed the chain with Boeshield. Thats the best chain lube I've ever found.

 

[GrantGunderson]

Now its time to remove the speed pots. They are held in by two hex head socket screws that mound to the bottom of the gear box. So its good that I drained that first. The pots where filthy, especially the 625 ohms one, as apparently the oil form the gear box has been dripping on it for quite some time, and has even baked on, obscuring the label for the middle connection.

I removed the sprocket and the mounting bracket and gave them both a good cleaning with degreaser.

While the degreaser was doing its work, I tested both pots on my Fluke meter.
First, I checked the resistance between both ends of the coil with the pots wiper at either end.

641.2 and 602.9 with the wipers on either end of the scale. So thats with in 6% of the stated value. I think thats good enough, but I am no expert with electronics.

 

[GrantGunderson]

I then left one lead on an end of the coil, and attached the other lead to the wiper, and checked the resistance at both ends of the wipers range. 602.9 with the wiper at one end, and .4 on the other end, so it is working!


I did the same with the 375 ohms pot as well and got, 366.3 and 386.7 between the coil with the wiper at each end. Then testing the wiper to coil I got .2 and 278.8 on either end, so its working, but it was interesting to see its in the opposite direction as the other pot.

I then cleaned the pots up using some electrical cleaner and large cotton swabs and got the majority of the dried oil residue off of them.

It's also nice that the connections on the pots are labeled exactly the same as the connections on the control panel! That will make re-wiring it easy.

 

[GrantGunderson]

The control panel has 13 wire terminals on it. I will update this as I trace the wires.

They connect to the lathe as follows:

F2: has two leads, one connects to the 375Ω pot coil. The other connects to F2 on the DC motor. I believe this is the field winding.

A2: Connects to the A2 terminal on the DC motor.

A1: Connects to the A1 terminal on the DC motor.

GS1: connects to GS1 on the AC motor panel.

GF2: has two leads, one connects to the 625Ω pot wiper. The other lead connects to GF2 on the AC motor panel.

E2 : has 3 leads, one connects to the 625Ω pot coil,
Note, one was originally labeled F1. That one connects to F1 on the DC motor. I believe it’s the field winding.
The third lead connects to GF1 on the AC motor panel and has a jumper that also connects it to E2 on the AC motor panel

E1: connects to the 375Ω pot wiper

E1-2: wire had two factory E-1 tags on it. not, a E1-2 tag. It connects to E1 on the AC motor panel.

GR1: connects to the 625Ω pot coil

C1:

C2:

C3:

GA2: connects to GA2 on the AC motor Panel.

note: C1,C2,C3 use the same conduit as others to the Start/ Stop switch panel. From there they enter the upper conduit with the Switch wires and MPT1,2,3 wires from the AC panel. That conduit then goes to the Main Conductor / reset switch panel on the back of the machine. These wires are all in good shape, as is the main conductor panel, so I am planing on leaving them in place unless I find a compelling reason not to.