I think my D1-3 spindle nose is shot.

When I'm using a three jaw chuck on this lathe it can be out by more than .015, even using the collet nose I can get over .005 run out.

The question is what should the diameter of the holes in this spindle nose be. The reason I'm asking this is that I measure .594. This seems way oversized,and maybe worn to the point of needing a replacement. When I measure the studs on the back of the chuck's, 5C collet holder, and other accessories I get 9/16 so I know the studs are okay. Maybe there is a fix for this but that's why I'm asking you guys. If it is shot maybe someone could stir me to a place I could get a new one, or at least a good used one without having to go to Monarch.

I know I'm going to get some great answers here and I will appreciate everyone of them.
Thank you
Larry.

Centers on the small taper, not the pins

Look carefully at the taper and see if it is dinged up, a small digger on the taper or the face can cause enough runout to bug you

As gustafson said the chuck should center on the taper then bottom out on the back. Try bluing the back and taper of a good chuck back and mount it, see where it's touching. In the center of an area that it's not touching you'll likely find something holding it off. Stone that away, clean and repeat until you have good contact all around.

If you can't find any nerds on the taper and/or face stick an indicator on the small taper, inside taper and face and tell us what you're seeing for each of those in TIR. Maybe the lathe had a crash in it's life? It'd have to be one heck of a crash for that runout.

Larrys Metal Fab said:

When I'm using a three jaw chuck on this lathe it can be out by more than .015, even using the collet nose I can get over .005 run out.

The question is what should the diameter of the holes in this spindle nose be. The reason I'm asking this is that I measure .594. This seems way oversized,and maybe worn to the point of needing a replacement. When I measure the studs on the back of the chuck's, 5C collet holder, and other accessories I get 9/16 so I know the studs are okay. Maybe there is a fix for this but that's why I'm asking you guys. If it is shot maybe someone could stir me to a place I could get a new one, or at least a good used one without having to go to Monarch.

I know I'm going to get some great answers here and I will appreciate everyone of them.
Thank you
Larry.

Click to expand...

if this is a machine you have owned and used I'm wondering how you could think it registered on the pins? perhaps its not the spindle, and the problem lies elsewhere?

also, if you have read anything about Monarch spindles here and elsewhere, you would know a tight properly functioning spindle its not something you can just go and buy, new or used, it is an integrated system.

Dings on the spindle nose are extremely rare. i.e. unless a forklift ran into it its unlikely to be bad.

Much more likely is that your spindle tooling is worn to the point of being shot.

There are lots of posts on the forum about getting a good fit between spindle and chucks.

Even badly worn D1-3 tooling can be resurrected if you have the skill and take the right approach.

Larrys Metal Fab said:

When I'm using a three jaw chuck on this lathe it can be out by more than .015, even using the collet nose I can get over .005 run out.

The question is what should the diameter of the holes in this spindle nose be. The reason I'm asking this is that I measure .594. This seems way oversized,and maybe worn to the point of needing a replacement. When I measure the studs on the back of the chuck's, 5C collet holder, and other accessories I get 9/16 so I know the studs are okay. Maybe there is a fix for this but that's why I'm asking you guys. If it is shot maybe someone could stir me to a place I could get a new one, or at least a good used one without having to go to Monarch.

I know I'm going to get some great answers here and I will appreciate everyone of them.
Thank you
Larry.

Click to expand...

Let us know what you find out!

thermite said:

So.

- clean and deburr? Surely!

- new camlock studs? Highly likely. Can't hurt.

- new cams in the spindle? Maybe. No harm. Never a BAD idea,

- cutting on the taper and flat? "Please NOT!"

It is more likely to create a problem than solve one.

Click to expand...

If you want the 10EE's legendary accuracy, i.e. .0002" runout max and repeatable, you are going to have to work a bit harder than Bill suggests. There is no getting around the need to machine the backs of chucks to get a good fit. Plastigage does not lie, neither does the hand slap test with the cam locks undone. So unless you are exceptionally lucky, tooling purchased used has likely been in use 50 years or more and is worn enough or has been abused enough that the fit is not tight any more. The downside of the camlock design is that when you tighten the camlock, if there are chips in the way, something is going to get gouged. And it is unlikely to be the hardened spindle nose, much more likely the softer metal of the chuck. So re-cutting the taper in the chuck is a job that needs doing with used tooling. Even new tooling might be a problem.