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'42 Round Dial Apron Assembly

kmsorensen

Plastic
Joined
Oct 24, 2017
An alternate title for this post could be “42’ Round Dial Apron Assembly for Dummies”. To be clear, the dummy is me. I’m pretty inexperienced and the material in this and any following posts is nearly all gleaned from this Monarch Forum.

This is about refreshing Monarch 10EE Round Dial serial number 16238 which came off the line in October 1942. I’m starting with the apron.
See attached images.

Apron parts annotated.jpgApron images.jpg

The second image shows the parts that came out of my apron after cleanup and prep for assembly. The first is the same image with parts numbers that more or less parallel part numbers from the page named

“Parts Picture No. E-6 APRON”

as seen in the “OPERATOR’S MANUAL for MONARCH MODEL “EE” SENSITIVE PRECISION TOOL MAKER’S LATHE”. The Operator’s Manual is available on line as a PDF and is also the manual Monarch supplied me when I bought a manual for my machine from them.

The parts shown in my image and in the Monarch Manual are nearly all the same, but there are some differences. I have below short descriptions of some of the labeled parts in image 1, and comments that might be helpful if you’re planning to take your apron apart. I’m planning to continue the post to include a complete assembly of my apron and I’ll refer to these parts numbers in later posts. One could use this series of posts backwards as one possible way to take an apron apart.

Parts 5,6 & 7, I left assembled. These with parts 8 & 10 comprise the Handwheel Clutch.

Part 9 “Wormwheel shaft Snap Ring. I believe this is a misprint in the manual. I believe this is the Handwheel Shaft Snap Ring.

Parts 14 & 16 I left assembled. This combination drives the Bijur oil pump arm part 129.

Parts 27, 28, & 29 deserve special comment. They are the longitudinal Friction Handle, Cam and two Cam bushings. There is a taper pin fixing the Friction Handle (27) to the Cam (28). These taper pins were originally put in at the factory by drilling and reaming by hand in situ after assembly. This means that this cam and handle and pin are a set and are not interchangeable with their cousins on the cross feed friction group. Can you guess how I know this? Also there is a setscrew fixing the cam bushing (29) which is closest to the Friction Handle (27) in the Friction Front Cap (31). There is another setscrew associated with the cross feed friction group front cap. The setscrews in my friction caps were not the same diameter or drive type.

My apron did not have a part 32, Pointer Tit Key.

Part 33, the Friction Stem is drilled and reamed for a taper pin which fixes part 40, the Friction Stem Collar to it’s end. The Friction Stem and Friction Stem Collar and their taper pin go together only one way, and they are not interchangeable with their cousins in the cross feed friction group.

Part 38, a thrust bearing, does not have it’s bearing balls in a captive cage. It’s entirely possible on disassembly to have this thrust bearing or parts of it drop into the oil reservoir or whatever direction is down at the time. As an aside, the longitudinal friction group of parts is held in compression between the big end of the Friction Stem (33) and the Friction Stem Collar (40). Held in compression in order starting at the big end of the Friction Stem are the Cam Washer (34), a thrust bearing (39), the Longitudinal Friction Gear (41) and Longitudinal Friction Pinion Bushing (42), the Spring Washer (36), the Friction Spring (37), a Thrust Bearing (38), the Longitudinal Friction Pinion (43) and Longitudinal Friction Disc (44) and the final Thrust Bearing (39). The bearing balls of the two Thrust Bearings (39) are held in captive cages. These cages on the cross feed friction group in my apron were corroded enough to not be quite captive. So one can’t count on not having to chase bearing balls. I’ve read in this forum that these thrust bearings (38 and 39) are not available commercially any more. I managed, just barely, to not loose any parts of these. Do be careful here.

Here is where the differences start between my apron and my manuals page “Parts Picture No. E-6 APRON”. These differences have to do with the mechanisms for reversing feed directions and locking out feed when the half nuts are closed. I believe the manual reflects the situation in an earlier design. If I were less lazy I’d take a look at the 1939 Monarch patents to see.

My apron does not have part 46, Crank Retaining Screw.

My part 47, the Reverse Knob, is a knob and shaft that is fixed to my part 104, Interlocking Fork with a taper pin. This pin was the only item that gave me real trouble during disassembly. I could not get it to come out. I found through the forum that I was not alone, and with some trepidation, I drilled it out. Every other time during disassembly of anything on this lathe when I thought I needed more force than seemed reasonable to get things apart or together, I was wrong. It was always me being confused or doing something wrong, and never the lathe. So if something seems difficult to get apart or together, and you want to reach for a hammer or other agent of destruction, it is my experience that odds are overwhelming that you are doing something wrong. What do they say? Lessons will be repeated until learned.

Part 48, Wormwheel Bearing Cap (Front), also has an opening for part 47, the Reverse Knob to go through.

My apron has no parts 50 Reverse Shifter, or 51 Reverse Shifter pin.

I left parts 55, 56, & 57, the Reverse Gear assembly, assembled.

It’s not labeled on my image, but I left parts 61 Idler Gear Bushing, and 62 24-T Idler Gear assembled.

I left part 63, the Idler Gear Spacer in the apron case.

I left parts 65, 66, & 67 the 32-T Compound Gear, the Compound Gear Bushing, and the 28-T Compound Gear, assembled.

I left part 68, the Idler Gear Spacer, in the apron case.

For parts in the Cross Feed Friction group please see the comments regarding the Longitudinal Friction Feed.

It’s not shown in the image, but part 88, the Idler Gear Bushing is left in part 89, the 36-T Idler Gear.

Part 90, the Idler Gear Spacer, was left in the apron case.

I have no part 103, Interlocking Fork Shaft.

Parts 113, the Eccentric Bearing Shims, are not shown.

Parts 117, the Worm Bushings, were left in the apron case.

Parts 124 and 125, the Oil Compression Bushing and Sleeve are not shown.

So that’s it with preliminaries for the apron assembly. More to follow.
 
You are well organized and thorough. I agree with Cal that it's a great reference thread for others.
Your no dummy.
 
Thanks Cal and mulld22 for your kind comments.

The first things that went back in my apron casting were the Reverse Knob (part 47, referenced to the image in the last post), the Wormwheel Bearing Cap(Front) (48), and the Interlocking Fork (104). I’d had trouble getting these out and had drilled out the taper pin.

I had an internal debate about how to recover from drilling the pin out. It had been mostly successful, but the hole for the taper pin had evidence of the event. I made up a new taper pin from a slightly longer than needed one and decided to use some anaerobic adhesive in combination with the pin. If you’re unlucky enough to be in this situation and elect to use glue, have everything ready and do a careful trial fit before glue goes anywhere. It sets enough to fix things immovably pretty quickly.

My finishes are not up to the high standards of other 10EE posts on this forum. But my machine was built in The War and it came with a War Finish. I’m using phosphoric acid, primer, and alkyl enamel with a brush. I’m not doing any masking. After everything is dry I’m chasing threaded holes with taps, and running surfaces that need it lightly over 220 sand paper glued to a scraped cast iron surface plate. That’s why it looks, well, kind of sad compared to others on this forum.

On disassembly I had one bad bearing and decided to replace the six bearings that are commercially available. Replacement bearings are shown an accompanying image.

The images also show the correct orientation of the Interlocking fork on the Reverse Knob shaft.
 

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The first things that went back in my apron casting were the Reverse Knob (part 47, referenced to the image in the last post), the Wormwheel Bearing Cap(Front) (48), and the Interlocking Fork (104). I’d had trouble getting these out and had drilled out the taper pin.

I had an internal debate about how to recover from drilling the pin out. It had been mostly successful, but the hole for the taper pin had evidence of the event. I made up a new taper pin from a slightly longer than needed one and decided to use some anaerobic adhesive in combination with the pin. ...
When you're installing a new taper pin in a location that's difficult to access, consider using a "threaded taper pin". It has threads on the large end of the pin, so that a nut can be run on to jack the pin out the next time that it needs to be removed. Of course, this assumes that there's space for the pin to stick out. Obviously, if you're making your own from a stock taper pin, you need to turn the end cylindrical for threading. Or you can buy them commercially:
McMaster-Carr - threaded taper pins

Cal
 
Thanks for the tip about the threaded taper pin option Cal! After dodging the drilling out a taper pin bullet, I moved on to the handwheel parts.

Shown in the first image is the handwheel stem (11), the Front Handwheel Stem Bearing (12), the Handwheel Pinion Spacer (13), the Pump Cam (14), and the Handwheel Pinion (16), oriented as they will be when back in the casting.

I installed these bearings using a punch, hammer, and light tapping circumferentially on the outer bearing races.

The last image shows again the orientation of the cam and pinion when back in the casting.
 

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Next into the casting went the Wormwheel Shaft (53), the reverse gear assembly (55,56,57), and the associated bearings.

Note the orientation of the reverse gears and the Interlocking Fork fit in the images

.reverse gear on wormwheel shaft.jpgfront bearing wormwheel shaft.jpgfront bearing wormwheel shaft a.jpgrear bearing wormwheel shaft_.jpg
 
Next in went the 24T-Idler Gear (62) on the Idler Gear Stud (60).

The images show it’s orientation and also the Idler Gear Spacer (63) which was left in the case and has been painted

WARNING! WARNING1 Some idiot put the 24T-Idler Gear (62) on backwards in the first two images in this post. Thankfully it is on correctly in the third image. Not the last time that errors like this are going to show up in this assembly recounting. The good news is that my apron is as I type actually assembled and seems to work correctly. So it seems I caught all errors which would prevent that at least.

orientation of gear on 24T idler gear (62).jpg24T-idler gear stud (60).jpg24T-idler gear installed.jpg
 
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Next came the Compound Gear assembly (65,66,67) on its Stud (64) and bushing.

The images show it’s proper orientation.

The Compound Gear could probably go a step or two later which might have made putting the Longitudinal Friction assembly in less fiddly. But this is what I did, and it is workable.

What is not workable is not doing the next step that is putting the Rack Pinion Gear (24) in place next but without putting in on a shaft. The rack pinion gear will not go in at all if you wait until after the Longitudinal Friction group of parts is in the casting. And if you put the Rack Pinion Gear on it’s shaft, you cannot get the Longitudinal Friction Parts in the casting.

So place the Rack Pinion Gear loose in the region where it will ultimately be on it’s shaft.

In the image It’s tied up in the corner with fishing line.


compound gear (65,66,67) orientation.jpgcompound gear stud (64) from front.jpgrack pinion gear suspended with fishing line.jpgrack pinion gear suspeded with fishing line.jpg
 
The first image shows the Longitudinal Friction group. Starting from the bottom of the image we see The Friction Stem Nut (30), two Cam Bushings (29), the Friction Front Cap (31), the Friction Stem Nut (30), the Friction Stem (33) with one Thrust Bearing (39) already on it, the Spring Washer (36) below the Friction Spring (37) and a Thrust Bearing (38), the Longitudinal Friction Gear (41) , the Longitudinal Friction Pinion, Disc, and Bushing (42,43,44), the Friction Stem Collar (40) with it’s taper pin, another Thrust Bearing (39) and the Longitudinal Friction Cap Rear.

The second image shows the parts in this group as a mock up. This is how they will be in the casting except that the Gear(s) will be on the Friction Stem.

The next image shows the Friction Stem and one Thrust Bearing in place in the casting.

The next step is to maneuver the Longitudinal Friction Gear over the Friction Stem as shown in the image.

Next place the Spring Washer, Spring, and Thrust Bearing (38) on the Friction Stem as in the image. The bearing balls in this Thrust Bearing are not captive and will give you grief if given the opportunity.


To be continued in the next post ….


Long friction group bits.jpgLong friction group bits mock up.jpgFriction Stem, nut, bearing thru front.jpglong friction gear on shaft.jpgwasher spring and bearing on shaft.jpg
 
I'm not cool enough to have a Monarch, but I gotta say that posts/threads like this are exactly what PM needs. Thanks for taking the time to do it.
 
Next carefully back the Friction Stem until you can get the Friction Disc and Pinion on the Friction Stem without losing any of the Washer, Spring, or Thrust Bearing parts, as in the first image.

In the next image you see the last Thrust Washer (39) and the Friction Stem Collar (40) and it’s taper pin on the end of the Friction Stem. The Spring Washer, Friction Spring, and Thrust Bearing (38) are now held captive between the Friction Gear assemblies on the Friction Stem. They need to be compressed in order to place the taper pin.

The last three images show compressing the Longitudinal Friction assembly, lining up the taper pin hole and the final result. The together and stable (in the sense that you’re now not going to lose bearing balls) Friction Stem assembly can now be sandwiched between the Front and Rear Caps.


long friction disc on shaft.jpgbearing on shaft with stem collar and pin.jpgcompressing long fricton group.jpglining up taper pin hole long friction group.jpgtaper pin in long friction grouip.jpg
 
With the longitudinal friction assembly now in the casting it’s time to put the front and rear caps on along with the rest of the stuff associated with this assembly.

The first two images show the orientation of the Friction Front Cap (31) and the Longitudinal Friction Cap Rear (45). These can be easily placed and their fasteners tightened.

The next three images show the Friction Handle (27), Friction Cam (28), a taper pin, one of the Cam Bushings (29), a Friction Stem Nut (30), and a shop made Friction Stem Nut tool. There are two Cam Bushings in the Friction Front Cap. The one on the right as seen from the apron front is fixed in place by a setscrew. In these images it’s already in. The Friction Stem assembly is now held in compression, but needs a bit more compression in order for the Friction Cam to easily slide (which it will do) into the Friction Front Cap. Orient the Friction Stem so the large hole will line up vertically so that the Cam will go through the large hole. And then tighten the Friction Stem Nut until the Cam slides easily into the assembly. The flat on the Cam should be parallel to the face of the apron casting, and facing to the rear. Install the remaining Cam Bushing which should go in with very light tapping with a very small hammer. If this doesn’t all go easily then something is wrong. Don’t seriously bang on anything. It won’t help.


orientation of front cap long friction.jpgorientation of rear cap long friction.jpgfriction handle, cam, cam bushing.jpgcam nut and cam nut tool.jpgtightening cam nut for cam placement.jpg
 
OK, here we are with the Cam in and the Friction Handle on. The images also show the Rack Pinion Gear (24) on it’s shaft. It may as well be, although in my case it’s coming off it’s shaft at some later time. Recall it’s not coming out of the casting while the Longitudinal Friction assembly is in place. My Rack Pinion (25) is really worn. Not only are the gear teeth worn to points, but you can see evidence of it’s descent into the lead screw as a result of sinking of the carriage / apron because of carriage (mostly) and way wear. And in fact I bought a used but way nicer square dial rack pinion from the nice folks at Monarch after checking with them that this part is Round Dial compatible.

For now I’m not hammering most taper pins home, and I’m not placing set screws into any idler gear bushings with the thought that I might need to nudge things around to get optimal alignment.
That and the possibility that I’ve put something together incorrectly.

cam is in.jpgfront with Long friction group in.jpg
 
I was reading through my posts in this thread and it's time for a disclaimer. I'm not in any way an authority on any of this. If any of my statements sound authoritative, keep in mind it's just me talking to myself as I put this apron back together. As you read something like "Don't seriously bang on anything. It won't help", you actually can take that as authoritative because I've tried the banging for you. And in fact it doesn't help.
 
We now move on the Cross Feed Friction assembly. This is pretty much the same as the Longitudinal Friction assembly with better access and less fiddling. In my case it’s a bit different because my Thrust Bearings (77) had corroded bearing ball cages. One cage was losing bearing balls. I made two non-captive cages from Garolite CE from McMaster Carr. After a bit of estimating I made them 0.100” thick with a center of the balls diameter of 27/32”, and a #10 drill hole size. I sized the major / minor diameters smaller than the bearing race and larger than the shaft on the Friction Stem. The 27/32” came from my estimates, Monarch’s affection for nominal English dimensions, and the fact that the dimension didn’t seem metric. So on assembly I was able to look forward to possibly loosing bearing balls from all three thrust bearings. I greased them all up and didn’t loose any that I know of.

The first image shows the Cross Feed Friction assembly bits. The second is a mock up as before in the Longitudinal case.

The third shows the Friction Stem (76) with the Cam Washer (75), and a Thrust Bearing (77), placed through the Cross Feed Friction Gear (83) in the casting.

The forth shows the Spring Washer (80), Friction Spring (81), and Thrust Bearing (82) all on the Friction Stem.

And the fifth shows the Cross Feed Friction Disc and Gear (84,85) on the Friction Stem capturing the Spring Washer, Friction Spring, and Thrust Bearing.


cross feed friction group bits.jpgcross feed friction group bits mock up.jpgcross feed group thru the front.jpgcross feed spring group on shaft.jpgcross feed gear over spring group.jpg
 
Continuing as in the Longitudinal Feed case.

The first image shows the final bearing on the crossfeed group with the friction stem collar and pin ready to be placed.

The second image shows the crossfeed group under compression and the friction stem collar and taper pin in place.

Third image is of the crossfeed group in place and ready for it’s end caps.

The last image is of the front cap going on the crossfeed group. Note the front cap has a relieved oil hole facing up as seen in the image when it’s in the case correctly. There is a non-relieved hole on the bottom.

final bearing on cross feed group.jpgcross feed group compressed and pin - collar fitted.jpgcross feed group ready for caps.jpgcross feed group front cap.jpg
 
Before continuing further it was time to plumb the casting. The first image shows the copper tubing I used. It’s “capillary tubing” and is nominally 0.156” OD and 0.100” OD. This is consistent with what’s referred to in forum postings, either 4mm or 5/32nds.

It comes coiled as seen. The tubing I took out of my apron looked like whoever installed it had little pleasure doing it. It was kinked in a bunch of places, especially the feed from the pump to the T-manifold and the line from the T-manifold back up to the casting reservoir. Both these lines transit the cavity where the half nut parts live, and the routes aren’t straight by a long shot. My original plumbing was copper, not plated steel as some have found. I decided to replace all the tubing given the state of accumulation of gunk over everything in my apron. I plumbed it wrong on my first attempt. I thought it was quite artful except for being wrong. I was helped greatly on both attempts by repeated annealing of the tubing and by including a loop in one of the lines which helped in getting the tube to go where the original installers thought it ought to. More about this in a later posting.

The second and third images show the set screw in the casting that plugs the drilled hole for the tubing which lubes the longitudinal feed group, and cleaning out the other end of that drilled hole. There is another drilled passage from the reservoir for oil to get to this dogleg tube run.


The fourth and fifth images show the start and finish of the tube to the longitudinal feed lube hole. The copper tubes are “bedded” into the casting with Locktite 638, which seems to work and is easily reversible with heat.

Lest I forget later when we come to pump and manifold hookup, the 4mm ferrules from McMaster Carr are too good (they are too long) for the plumbing fittings in my apron. I had to source some lower quality ones.


Copper tubing 0.156x0.1.jpgplumbing 5.jpgplumbing 6.jpgCu tube for cross feed.jpgplumbing 3.jpg
 
Continuing with plumbing, the first image shows the casting reservoir with it’s inflow, and outflows to the half nuts, both feed assemblies, and the worm gear.

Other images show the feed from the pump, the tubes to the feed assemblies, and the lines to the T-manifold (manifold not yet hooked up), not in that order.


.plumbing 4.jpgplumbing 1.jpgplumbing 2.jpgplumbing 7.jpg
 








 
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