cuttergrinder
Hot Rolled
- Joined
- Mar 16, 2007
- Location
- Salem,Ohio
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Small part in big lathe
- Thread starter cuttergrinder
- Start date
- Replies 27
- Views 4,401
johnoder
Diamond
- Joined
- Jul 16, 2004
- Location
- Houston, TX USA
NN Monarch saves the day
Mike1974
Diamond
- Joined
- Nov 5, 2014
- Location
- Tampa area
crossthread
Titanium
- Joined
- Aug 5, 2004
- Location
- Richmond,VA,USA
I would be concerned about rigidity. You might need to put a follow rest on that thing.
cuttergrinder
Hot Rolled
- Joined
- Mar 16, 2007
- Location
- Salem,Ohio
We do have a smaller chuck but we never put a smaller one on this lathe. This big one works just fine.
cuttergrinder
Hot Rolled
- Joined
- Mar 16, 2007
- Location
- Salem,Ohio
Its plenty rigid. I machine bushings like that that are 24" long
Milland
Diamond
- Joined
- Jul 6, 2006
- Location
- Hillsboro, New Hampshire
To heck with the nut, how big is that QCTP? It's got to be around 8" tall at the block or something close to that!
If it's an Aloris, what's the letter size?
If it's an Aloris, what's the letter size?
eKretz
Diamond; Mod Squad
- Joined
- Mar 27, 2005
- Location
- Northwest Indiana, USA
Maybe an Aloris E? Nice to have a QCTP. All of the big lathes in the places I worked had bar clamps on the tool posts! Exact opposite of quick change.
You know there's a place in WI that specializes in making brass/bronze nuts for machines... forget the name of the place but we got all our G&L table and head nuts there... they were more like $1k, much more palatable. And they did a good job.
There were a few times that we took the screws out and re-cut the threads so that the pitch was more uniform rather than heavily worn in the middle... for those we made our own nuts.
You know there's a place in WI that specializes in making brass/bronze nuts for machines... forget the name of the place but we got all our G&L table and head nuts there... they were more like $1k, much more palatable. And they did a good job.
There were a few times that we took the screws out and re-cut the threads so that the pitch was more uniform rather than heavily worn in the middle... for those we made our own nuts.
Milland
Diamond
- Joined
- Jul 6, 2006
- Location
- Hillsboro, New Hampshire
Yeah, I guess the block is around 5" high if one accounts for the distance from the nut (which is presumably 5" OD on the exposed cylinder).
cuttergrinder
Hot Rolled
- Joined
- Mar 16, 2007
- Location
- Salem,Ohio
The toolpost is an aloris but the tag is missing. The block is about 6" square by 5" tall.
Milland
Diamond
- Joined
- Jul 6, 2006
- Location
- Hillsboro, New Hampshire
That would make it an "E" series: https://www.aloris.com/aloris_cat/31e970.pdf
I thought it was bigger initially, as I thought the 5" nut was the thread, not the body OD.
Illinoyance
Stainless
- Joined
- Aug 24, 2015
You definitely want to turn that part around in the chuck for a more secure grip. A .375 lead will mean substantial cutting forces. You will probably need a special threading bar for that pitch & diameter combination. You may not have enough room to back out the tool and crank it out with the carriage. You will probably have to back the tool off a little and wind the tool out by reversing the spindle. I had a similar issue with a 3/4-4 Acme.
Bobnotthecat
Cast Iron
- Joined
- Jul 5, 2009
- Location
- S.W. PA
Yeah.....About 30 years ago I had the misfortune of working at a small weld shop for a very difficult owner. The Wotan horizontal boring mill pulled the threads out of the table nut. I then told him where he could buy the bronze stock to make a new one. I was not expecting what happened next. He puked onto me the most horrible string of profanity and vulgarisms I'd ever heard, to the effect that he wasn't going to pay me to machine a new nut when he could get the parts from Wotan. After a few phone calls he slinked back and told me that Wotan wanted $5000.00 for the new nut and that it had to be shipped from Germany. The bronze was then ordered and overnighted. If I remember correctly it was 5 TPI on a 50 millimeter shaft.
I quit that place right quickly thereafter.
Bob....not the cat.
I quit that place right quickly thereafter.
Bob....not the cat.
Last edited:
CAMasochism
Stainless
- Joined
- Jun 6, 2019
- Location
- DFW, Texas
Christ. I know that you don't always get the option to leave a job right off with out another lined up, but that definitely seems a case to tell the guy to F-off and make it himself after that.
cuttergrinder
Hot Rolled
- Joined
- Mar 16, 2007
- Location
- Salem,Ohio
Its all threaded. No poroblem with hanging out or with the bar. Just used an 1 1/4 bar and a 3/8 high soeed tool.
cuttergrinder
Hot Rolled
- Joined
- Mar 16, 2007
- Location
- Salem,Ohio
The thread is actually 2 1/4 acme with a 3/8 pitch. The flange of the nut which is in the chuck is about 5".
Hardplates
Stainless
- Joined
- May 8, 2019
- Location
- What once was a free country
That is a big lathe, but don't you have a smaller chuck?!?!
Changing the chuck is likely a larger job than the actual job itself
Mike1974
Diamond
- Joined
- Nov 5, 2014
- Location
- Tampa area
That is probably true, but it seems the rpm would be very very limited with a chuck that size... maybe a wash time wise?
eKretz
Diamond; Mod Squad
- Joined
- Mar 27, 2005
- Location
- Northwest Indiana, USA
Having (hopefully) somewhat sharp chuck jaw teeth and relatively soft material helps there. I would probably have had stops bolted to the chuck face so the nut could be supported behind the flange all the same. That is just good practice.
