Logan, SouthBend, Atlas, ER collet chuck

[Ringo]

there is a adjustable clutch in the carriage, or apron. on the power feed engage handle there is a adjustment jam nut for clutch tension.
this was my Dad's lathe and I had trouble with it over the years, sometimes it wouldnt power feed. sometimes it would chatter. sometimes couldnt hold a dimension number.
For a long time I was disappointed. But, since then I found out the spindle bearings were not preloaded, the dovetail gibbs were loose, and when you tighten the gibs the carraige wouldnt feed.
then I found out about the clutch, which was setup loose. Besides all that the original pulleys were way too fast. it wouldhave been great on aluminum.
I re-pulleyed it slower and now I can take a decent chip load on steel.
Now, I got this thing running nicely.

now you got me thinking about the clutch and threads. I never did just run into the carriage stop and let it eat away. I allow the clutch to be safety not to crash.
However, I did have a couple thread passes that I did not understand where the heavy cut come from?
Now, you got me thinking.

[Ringo]

Cut the metric OD thread this morning.
I'm happy with it.




I think I need a better quality set collets, as I move around a test bar I get different TIR.
The best I can tell I'm at about .0015" six inches out from collet. A test indicator on the cavity doesn't even move, and I removed/installed the chuck several times.





This is sooo much smaller than the 5C, I'm sure this will become my favorite


I got interchangeable between the mill and lathe



I tried to duplicate the thread style of the R8 chuck, (no thread relief)
I set a carriage stop at end of thread, and ran carriage up to it, open halfnut, and then repeated passes.

[Ringo]

Thanks to all that posted comments, assistance, and answered questions
This is my best project thus far and I'm happy with it.
Everything in this picture has a thread, or assist, or comment on it.
Thanks to all

[mattthemuppet]

super cool beans Ringo, looks awesome. Quick work too.

As to the run out - does it follow the mark on the chuck or the mark on the rod? If it follows the chuck (runout in the chuck, collet or nut) then does it repeat if you remove the rod and reinsert it? How tight are you tightening the nut? It needs a fair bit more than you'd think. Do you have another rod to test it with? I remember using a rod to test mine and discovering that the beautiful ground rod I was using was ever so slightly banana shaped.

If the runout is truely in the chuck/collet/nut then better collets or a better nut would be worth looking into. My runout dropped a bit with a decent ball bearing chuck - tightens a bit more, bit higher quality. They're not that expensive.

[Ringo]

super cool beans Ringo, looks awesome. Quick work too.

As to the run out - does it follow the mark on the chuck or the mark on the rod? If it follows the chuck (runout in the chuck, collet or nut) then does it repeat if you remove the rod and reinsert it? How tight are you tightening the nut? It needs a fair bit more than you'd think. Do you have another rod to test it with? I remember using a rod to test mine and discovering that the beautiful ground rod I was using was ever so slightly banana shaped.

If the runout is truely in the chuck/collet/nut then better collets or a better nut would be worth looking into. My runout dropped a bit with a decent ball bearing chuck - tightens a bit more, bit higher quality. They're not that expensive.

I tried 2 different rods, a 3/4" O1 TGP, and a Ebay MT2 test bar. The Ebay MT2 test bar is an odd size it is not 5/8" nor is it a common metric mm, it too fat for 5/8 and too skinny for 11/16.
I tried indexing the collet, indexing the rod, and I could not really come up with an answer.
My test indicator is a chineseium .0005" item and on the cavity, it tells me .0000" TIR
Now, on my in initital setup on the lathe compound taper, in the above pic in post #26, I saw a little bit of 'waist' in the collet. As in a waist line at your belt. I accepted the readings at each end of the collet and ingnored the center waist. Given a collet with a suspected 'waist' I took that with a grain of salt.
But, I tried a different collet with a different bar (banana) and got a different result.
Without my own better metrology tools, I'm thinking to call this good,
Y'know, if the TIR is this difficult to nail down as to its origin, then it might not exist.
Besides, I de-mounted/mounted this thing a few times and it did repeat the .0000" in the cavity.

[JRouche]

If I am mis-using it, then what is the secret?
Thus far I can turn more metal with HSS than this type carbide, that being the carbide chips where HSS keeps plowing onward.

Ooops.. Solly. I did not in any way meant You. Other folks with OD turning don't like the brazed on TC bits. I do. Big time. I grab those for the follow up after a insert cut.

I sharpen the brazed bits down to razor, if that is whats needed. Don't stall them, they will be toast. And NO!!! I have never seen one or wanted to use one. An internal threading tool? No thanks.

Do what you did.

Great work. Thanks. JR

[BCRider]

Ringo, when I did my 5C chuck which is much like your ER chuck but with a draw tube instead of a front end nut I found runouts of much the same degree with some collets. Thinking I'd messed up I rigged up a gauge to read deep into the parallel portion and also checked the small and big end of the taper on the nose. Those three spots were all good to less than a half thou. And that stayed the same despite unmounting and remounting the chuck a few times. So it wasn't the chuck. Check your chuck's taper. If they are good then it's either the nut or it's the collets causing the issue.

I've got a couple of 5C collets which are marked as not being all that ideal. And one which was WAY out by around .004 actually got tossed in the scrap metal bucket and replaced. The new one from Grizzly as it happens with the so called higher end South Bend name on the box proved to be worth the extra $1.50 over the cheap no name version. Testing for trueness showed that it's a match for the best of the others.

[mattthemuppet]

I tried 2 different rods, a 3/4" O1 TGP, and a Ebay MT2 test bar. The Ebay MT2 test bar is an odd size it is not 5/8" nor is it a common metric mm, it too fat for 5/8 and too skinny for 11/16.
I tried indexing the collet, indexing the rod, and I could not really come up with an answer.
My test indicator is a chineseium .0005" item and on the cavity, it tells me .0000" TIR
Now, on my in initital setup on the lathe compound taper, in the above pic in post #26, I saw a little bit of 'waist' in the collet. As in a waist line at your belt. I accepted the readings at each end of the collet and ingnored the center waist. Given a collet with a suspected 'waist' I took that with a grain of salt.
But, I tried a different collet with a different bar (banana) and got a different result.
Without my own better metrology tools, I'm thinking to call this good,
Y'know, if the TIR is this difficult to nail down as to its origin, then it might not exist.
Besides, I de-mounted/mounted this thing a few times and it did repeat the .0000" in the cavity.

yes, figuring out runout is not a trivial task, that's for sure. I dived down that rabbit hole to get my lathe and tail stock properly aligned and it took a couple of days to properly get into it, but it was worth the effort. What diameter is your MT2 test bar in mm? ER32 collets have a 1mm collapse range, so if you have a complete set there should be a collet that will take that rod somewhere in its collapse range.

you can also chuck up the largest piece of alu that the chuck can hold, take a skim cut with a sharp tool and measure the diameters at both ends. that should give you an idea if there's any runout further out from the chuck.