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fortcollinsjerry
10-23-2009, 02:31 PM
Greetings

Some years ago I had an old Atlas/Craftsman lathe which had an indexing wheel and a spring loaded pin which allowed me to divide the circumference of a workpiece into perfect divisions. The indexing wheel had 360 holes so I could simply devide 360 by the number of spaces then count the holes drop in the pin and make my mark on the work piece. I had always assumed the indexing feature was so a trained operator could cut gear teeth using the milling attachment available for that model lathe. I eventually found out that thousands (matbe millions) of these lathes were part of the war effort being shipped over during WWII. Anyway, that's the background - now here's my dilemma.

I no longer have that lathe. I'm now using an Enco without any indexing feature that I know of. Also, I'm not a trained machinist, at best I have the skills of a woodworker operating a lathe. Can anyone show how to index on this lathe? I've thought about determining the circumferance of the chuck and dividing that by 360 then use a piece of tape or something to lay out the marks with dividers ...... but that sems like a lot of work and not very accurate. Anyone help?

mechanicalmagic
10-23-2009, 02:59 PM
If you have a CAD program, draw out the divisions, and numbers. Print, and tape to the OD of the chuck. A mag base with a pointer and you are up and running.

Carld
10-23-2009, 03:17 PM
Your out of luck. You will have to make an indexing wheel to attach to the spindle some way.

How did you keep the spring loaded pin from staying in the hole while using the lathe in the normal way?

Mcruff
10-23-2009, 03:44 PM
Here was my solution to the problem.
http://i6.photobucket.com/albums/y233/mcruff/Southbend%20lathe/LatheIndexer.jpg These wheels are small in diameter and attach to the hub that bolts to the back of my spindle. I use it for internally broaching small splined shafts. The wheels are built with the same hole and key as the change gears on the machine therefore I can use the gears as indexers. The hubs are also used on my homemade mini indexer for cutting gears on my mill.
http://i6.photobucket.com/albums/y233/mcruff/Southbend%20lathe/gearcut0002.jpg

fortcollinsjerry
10-23-2009, 05:23 PM
.

How did you keep the spring loaded pin from staying in the hole while using the lathe in the normal way?

It was a spring loaded mechanism cast into the head cover of the lathe. To disengage it was a matter of giving the head of the pin a pull and a quarter turn which would park it on the casting. If you forgot and left it engaged when you hit the "GO" switch the belts would just slip and the head stock stayed still.

Mcruff - I have no where near the skill to shape and drill that indexing fixture - but the pictures are very nice.:D

Evan
10-23-2009, 06:11 PM
http://metalshopborealis.ca/pics/100b.jpg

http://metalshopborealis.ca/pics/man2.jpg

http://metalshopborealis.ca/pics/man3.jpg

http://metalshopborealis.ca/pics/index1.jpg

Carld
10-23-2009, 08:52 PM
fortcollinsjerry, using the gears as a index could be your solution.

Al Messer
10-23-2009, 09:57 PM
Evan and Carld are right! You can use change gears, or even the Bull Gear. How many teeth does your Bull Gear have? My old Logan-made Wards' Powerkraft has 72 and all I have to do is count the teeth to get the divisions I need. Some day, when I have the time, I'm going to come up with a plunger type gadget that will lock the Bull Gear when dividing. BTW: I presently use a chip of Wood shaped to go between the teeth to locate the divisions.

winchman
10-23-2009, 11:48 PM
I made a degree wheel that fits behind the chuck on my lathe. I used a section of old bandsaw blade to get 360 divisions, and a spring pawl engages the teeth to position the chuck.

http://img.photobucket.com/albums/1003/winchman/Hexasphericon%202/000_0157.JPG

The spring pawl wasn't installed when that picture was taken, but you can see the vernier.

You can see other pictures of it and how I made it here:

http://smg.photobucket.com/albums/1003/winchman/DWheel/
http://smg.photobucket.com/albums/1003/winchman/Degree%20Wheel/

The need for the degree wheel on the lathe sorta went away after I got a milling machine and a rotary table.

Roger

Rich Carlstedt
10-23-2009, 11:55 PM
Depends on what you want to index?
If its gears, then you have to do what the other posters here have done.

If you subscribe to HSM, you may recall a really sweet way, a fellow home shopper did it in an earlier issue (3 yrs ago?)
You will need to lock the spindle, or put it in carriage feed, at a very small feed rate, to hold position.
He took his 3 jaw chuck and put a level on the vertical jaw for 3 divisions, and then used the same level on 3 horizontal jaws, giving him an accurate 6 divisions......all without tooling ! ( and the lathe does not even have to be level)
If you need more, you could do the same with a 4 jaw, and then use a Adjustable square with a 45 degree face to get 8 divisions

Its the simple solutions that work best most times
Rich

oldtiffie
10-24-2009, 12:09 AM
I made a degree wheel that fits behind the chuck on my lathe. I used a section of old bandsaw blade to get 360 divisions, and a spring pawl engages the teeth to position the chuck.

http://img.photobucket.com/albums/1003/winchman/Hexasphericon%202/000_0157.JPG

The spring pawl wasn't installed when that picture was taken, but you can see the vernier.

You can see other pictures of it and how I made it here:

http://smg.photobucket.com/albums/1003/winchman/DWheel/
http://smg.photobucket.com/albums/1003/winchman/Degree%20Wheel/

The need for the degree wheel on the lathe sorta went away after I got a milling machine and a rotary table.

Roger

Nice job nicely thought out and executed Roger.

You are the first one to address the geared-head head-stock as some do not have the drive to the gear-train on the lathe spindle. Many have a gear-reduction between the lathe spindle and the first gear in the visible gear-train - mione has a 4:1 internal reduction - hence the gear back-lash cannot be avoided with the methods used on the belt-driven head-stocks where the "indexer" is fitted directly to the lathe spindle.

Your method will cater for them all - geared and belt-driven.

[Edit]
Whoops.

Sorry Roger.

I just read that you have a vernier on there as well.

[End edit]

Is that a vernier on the "degree" scale? It will be a nice feature if it is.

J Tiers
10-24-2009, 01:41 AM
There are a variety of good ways with no added wheels.

The bull gear divisions are great, if they are good numbers... My 10" Logan also has 72, and of course that comes out to 5 degrees per tooth.

I DID make an index pin setup, a kludge, really, that worked very well. With the proper shims, I was able to get the 5 intermediate degrees as well, shimming the plunger housing up. That way I simply went around marking the 5s and 10s, then shimmed, marked all the 1,6,11,16, etc, then the 2,7,12,17 sequence, etc. Since all those were shorter marks, it was easy to get them right.

Don't use the wrong shim.... I used the one for the 4th on the first (they are NOT identical, as the angle varies slightly) and made a whole circle that were slightly off....visible, most of a line-width off. I just use the dial anyway, I didn't want to shave it down and do-over.

Then also the strip of paper on chuck I have done as well, on a different lathe. You must rig up some way of locking the spindle, and set up a pointer.

There are a couple ways to get the 360 divisions to come out right around the chuck. Too long to type both here.

Circlip
10-24-2009, 05:31 AM
The following, although an old and well used method was made to SIMPLY divide using the standard set of change wheels on a lathe without easy access to the main spindle gears. The final usage is for simple dividing and by slotting the detent plunger mounting bracket different gears can be mounted for another range of divisions. Note also, by rotating the detent through 90Deg. the number of divisions is doubled for each gear used.

Before the purists jump in, this was devised for use in model engine building and the owner is NOT going to supply parts to NASA or any of the Brit. equivalents.

http://madmodder.net/index.php?topic=2014.0

Regards Ian.

oldtiffie
10-24-2009, 07:50 AM
Here is an indexing head that came with my universal grinder. It also takes ER-32 and C5 collets. It is not at all difficult to make and mount a face-plate or a 3 or 4 jaw chuck on

http://i200.photobucket.com/albums/aa294/oldtiffie/Universal_grinder/Universal_grinder9.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Universal_grinder/Universal_grinder10.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Universal_grinder/Universal_grinder11.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Universal_grinder/Universal_grinder12.jpg

Given that a good "Spindexer" is very accurately made and indexes to 1 degree, it is hard to beat. My "Spindexer" also takes both ER-32 and C5 collets and mounting a 3 or 4 jaw chuck or a face-plate would not be too hard either.

There is no reason why - on most/many lathes at least - a 6" rotary table could not be accurately mounted - with an adaptor - on the lathe bed with the centres of the lathe spindle and the rotary table being co-incident (ie the same).

rp designs
12-30-2010, 07:02 PM
Can someone please explain to me how to index on the lathe in fairly simple terms I am having a little difficulty wrapping my head around it. I have a smithy midas mill/lathe and looking at the change gears it gets very complicated very quickly. Adding to my confusion is the low/high gearbox and the motor pulleys which make it even more complicated to look at. But even the more simple looking pictures posted here have me scratching my head on how you figure out your divisions. Any sage advise?

RussZHC
12-30-2010, 09:24 PM
IF degrees help, one of these

http://www.oregonruleco.com/dials.htm

on the back of the chuck or a home made plate. Or a degree wheel from an automotive source.

I think I saw this first on Ray B. lathe over on PM...his is the Sheldon at the top of my "to get" list.

rp designs
12-30-2010, 10:31 PM
Maybe I'm just over thinking it. I'm trying to imagine it like a dividing head with the change gears and it seems quite complex. I guess if it is just simple indexing it is pretty straight forward. I'm guessing I will most likely need to make a few sets of plates to cover most of the "likely" needs in the near future.