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round dial 10EE feed-rod clutch

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
I’ve spent some time understanding how the feed-rod clutch on the round-dial 10EE works. I’m documenting it here in case it is of help to someone else down the line. Comments and corrections are encouraged. The clutch setup on my machine, built 11/1943, does not appear to match the parts pictures in the 1942 manual, so I don’t know the correct names for the parts; I’ll just try to use descriptive names.

Here’s a photo of the feed-rod clutch on my round dial 10EE:

IMG_2428.jpg

On the left is the feed-rod output shaft, on the right is the feed-rod clutch collar. Inside the output shaft is a spring-loaded piston that bears on the left end of the feed-rod (not shown). Note the set screw visible in the root of the output shaft splines, in the center of the photo. When the clutch is assembled, the setscrew is inserted in the hole in the collar and serves to retain the collar on the output shaft. The collar is, in turn, connected to the left end of the feed-rod by a tapered pin.


In normal operation, the spring-loaded plunger inside the output shaft presses the feed-rod and collar to the right. The setscrew in the output shaft splines keeps the internal splines of the collar engaged with the left portion of the external splines on the output shaft. The engaged splines cause the feed-rod to rotate with the output shaft.

A movable stop collar (E5-15), located on the feed-rod between the clutch collar and the apron, can be positioned to disengage the feed-rod clutch at any point. When the apron moves left against the stop collar, the feed-rod and clutch collar are pushed to the left until the clutch splines disengage, stopping rotation of the feed-rod. If the carriage were moving left due to apron feed (as opposed to action of the leadscrew), the carriage will stop moving and the output shaft will spin freely inside the body of the clutch collar. Moving the carriage back to the right will allow the clutch to reengage. (This should, of course, be done after stopping the spindle.)

Should the feed-rod clutch ever disengage, it is likely to reengage such that the setscrew in the output shaft no longer lines up with the hole in the clutch collar. It will be necessary to disengage the clutch and rotate the collar to line up with the setscrew before the clutch can be disassembled. Referring to the photos, note the backwards C-shape mark on the output shaft, to the left of the setscrew. It is unknown if this is a witness mark intended to facilitate proper clocking of the clutch splines, or some other mark. In order to disassemble the feed-rod clutch, it is necessary to remove the casting that contains the bearing on the right end of the feed-rod.

Cal
 
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I'm surprised and a little disappointed that nobody had any comments on this; maybe I need to work on making my posts more concise? :confused:

Anyway, prior to digging into this, I had no idea that the clutch existed or how to use it. Apparently, neither did the last owner of my machine, as the stop collar was moved all the way to the left; the carriage would run into the headstock before the clutch could engage. I also didn't see a thing in the "adjustments" section of the manual about the clutch.

It looks like the square dial machines also have the clutch, but it is appears to have all the works, including the spring, outside the gearbox. The stop collar is pretty much the same. Again, the manual appears to be mute on the clutch.

I’m curious to know how many machines are like mine, with the stop collar set so the clutch is rendered inoperative.

Could one of you round-dial guys look and see if you have a witness mark on the output shaft, in line with the set screw?

Anyone know if there is any protection for leadscrew? Does the tapered pin that connects the leadscrew to the gearbox output shaft function as a shear pin? If so, will any old taper pin work?

Cal
 
Cal, I use the "new posts" button religiously but somehow missed your first post on this topic. Sorry. Also, nice job of photo cropping this time ;)

I’m curious to know how many machines are like mine, with the stop collar set so the clutch is rendered inoperative.

When I got my December 1944 round dial, the stop collar was loose and sliding on the shaft.

Could one of you round-dial guys look and see if you have a witness mark on the output shaft, in line with the set screw?

Yep, it there on mine. Mine also has two very small and precise center punch witness marks that I think were applied by a long-ago repairman.

Anyone know if there is any protection for leadscrew? Does the tapered pin that connects the leadscrew to the gearbox output shaft function as a shear pin? If so, will any old taper pin work?

That taper pin on mine is pretty strong. It might shear but I think damage might be done somewhere else first. I don't know for sure if Monarch intended it to be a shear pin or not but I don't think so. The leadscrew shaft on mine is also a very tight fit in the gearbox output shaft, so there could be a lot of twisting force on the shaft before the pin even knows it.

Bob
 
At some point the square dial machines dropped that feature, maybe at the same time the hand wheel disconnect knob.
My 1951mfg lathe has both. I find those not of any use to me, as the feed rod clutch is hard too set for reasonable accuracy. The hand wheel clutch was defeated by the previous owner, probably due to it getting sloppy.
I would suppose the feed rod clutch would work out for repeated work in early production days and for unskilled operators, the hand wheel disconnect would keep ones privates from getting tied in a knot.
 
You know, I always thought of the the feed rod clutch as a safety, not a precision stop. i.e. set it so that your compound slide doesn't run into the chuck. I've seen enough 10EEs with the corners knocked off the compound or compound slide to know it happens...

-Dave
 
At some point the square dial machines dropped that feature, maybe at the same time the hand wheel disconnect knob.
My August 1957 square-dial toolroom 10ee has both the feed rod clutch and the hand wheel disconnect.

Wound-up privates... not good thing :eek:

- Leigh
 
I had to drill the setscrew in the clutch out. That thing was hard as glass! :eek: It took me several hours and I dulled two ball nosed carbide endmills and used up several diamond plated grinding burrs to worry a large enough pocket to get an easy out to grab.

Does anyone know a source of left-hand carbide drills or have any other suggestions for drilling out setscrews?

Cal
 
I can probably now add a bit as I just did my feed clutch...

Like Cal's, the grub screw on mine was mashed up.... And like his it was extremely hard.... I did get some way through it with a HSS drill, but I resorted to a pencil air die grinder and a pointy 3mm carbide burr to get the grub screw out...

My feed clutch is from a 11/41 machine.... Cal mentions a spring loaded piston.... Mine had no such thing, just a spring the butts up against the feed rod itself... The C mark he mentions on mine is a 0 mark.... As he surmised it is there to line up the grub screw to the outer hole for disassembly should it be needed...
 
Found this thread prepping for pickup of my 43' Round Dial. I was so busy with so many other aspects of the lathe I never noticed this. I think this is a fantastic feature that I wish more lathe's had. I frequently set up a cut and go do something else. Even if it is not PRECISE it is, for me, a huge advantage. I hope mine works!

Cal, thanks for taking the time to write this up.
 
I’ve spent some time understanding how the feed-rod clutch on the round-dial 10EE works. I’m documenting it here in case it is of help to someone else down the line. Comments and corrections are encouraged. The clutch setup on my machine, built 11/1943, does not appear to match the parts pictures in the 1942 manual, so I don’t know the correct names for the parts; I’ll just try to use descriptive names.

Here’s a photo of the feed-rod clutch on my round dial 10EE:

View attachment 223640

The setscrew in the output shaft splines keeps the internal splines of the collar engaged with the left portion of the external splines on the output shaft.

So the set screw is long enough that it extends up from the root of the output shaft spline and engages the internal spline of the collar and prevents the feed rod from pulling off towards the tail stock end? This would suggest the setscrew needs to come out before the collar / rod can be pulled off the output shaft

from your picture it doesn't look like the setscrew is long enuff for all of this?
 
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I just assembled mine the other day. You can actually just screw the setscrew further in and the splines will come apart. Making it far simpler than trying to get the setscrew in thru the hole in the female splined hub while compressing the spring inside the hub.
 
Brian, You're correct about what the setscrew is supposed to do.

Lance, That makes sense. Mine had gotten sheared off. That's what's shown in the photo. It was harder than the hubs of Hades and no fun getting out.

Cal
 
Brian, You're correct about what the setscrew is supposed to do.

Lance, That makes sense. Mine had gotten sheared off. That's what's shown in the photo. It was harder than the hubs of Hades and no fun getting out.

Cal

SO sorry for the excess questions. I'm "away" from the lathe for a while so I can't answer my own questions....right now.

I had it in my head that the "gear" or spline on the gearbox output shaft was held to that shaft with this set screw we are talking about. Obviously the setscrew can't both retain the "collar" and the spline/gear to the shaft. Then I had an epiphany....the gear on the gearbox output shaft is integral to that shaft (ie all one piece) is that correct?
 
I had it in my head that the "gear" or spline on the gearbox output shaft was held to that shaft with this set screw we are talking about. Obviously the setscrew can't both retain the "collar" and the spline/gear to the shaft. Then I had an epiphany....the gear on the gearbox output shaft is integral to that shaft (ie all one piece) is that correct?


Mine is held on with a taper pin through both.

On the topic: I usually leave the stop set so that the carriage can't run into the headstock under power, "just in case".
 
...
... the gear on the gearbox output shaft is integral to that shaft (ie all one piece) is that correct?
That's how my machine is. There were several different versions of the clutch, but yours looks like mine.

Out of curiosity, do you have the same witness marks that mine has? Might have to rotate the shaft 360 to find them.

Cal
 
So yeah, the output spline is one piece with the shaft in my case and the set screw simply adds a catch for the sleeve between the output shaft and the sleeve/feed rod. My setscrew was in good shape despite concerns from other stories here. And yes it does have a "witness" mark

Gearbox Output Shaft Witness Mark.JPG
 
So yeah, the output spline is one piece with the shaft in my case and the set screw simply adds a catch for the sleeve between the output shaft and the sleeve/feed rod. My setscrew was in good shape despite concerns from other stories here. And yes it does have a "witness" mark

View attachment 224109
OK. They stamped a "0" as the witness mark. On mine, I bet they had the stamp tilted so that it looks more like a "C". It looks like the ends of the teeth on the output shaft are banged up; you'll want to file those down even with the flanks of the teeth.

Cal
 








 
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