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ammcoman2
11-04-2014, 10:18 AM
A few weeks ago I picked up (free) a hunk of 1 1/2" hex brass bar. I've always wanted to see how my Myford lathe could handle a thread at its maximum pitch (8tpi). Of course using brass is cheating a bit as it is very nice to machine. Was surprised how easy the lathe handled the job.

So here is a 1"-8 paper weight. The purists will note that the chamfer profile is not to spec.

http://i56.photobucket.com/albums/g189/ammcoman2/PB040004_zps4dd9ff78.jpg (http://s56.photobucket.com/user/ammcoman2/media/PB040004_zps4dd9ff78.jpg.html)

The smallest one I have made so far is 2-56 which is on the right of the photo. Of course the thread was not single pointed!

How about showing the largest and smallest "retainers" you have made. Perhaps the lathe used should be noted.

Geoff

Stepside
11-04-2014, 12:36 PM
The smallest thread I have "single pointed" was a #4-48 external thread for a street clock. The thread was cut on a 9inch South Bend Model A lathe. No picture as it is in the clock and out of sight. If I had a recording device you would hear my 7" AMMCO shaper at work. For certain jobs a shaper rules.

Pete

mars-red
11-04-2014, 12:56 PM
The smallest things that would qualify as nuts that I've made were a pair of round tapered parts with M1.4 threads:
https://lh5.googleusercontent.com/-iznxbymLiPA/UTVs09VcHrI/AAAAAAAABfg/K-kNA3RpcKk/s800/tapered%2520nuts%2520completed.jpg

Those threads were cut with a tap. The finest pitch I've single pointed so far has been 40tpi (on my old Chinese 3-in-1), the smallest diameter I've single pointed so far has been 1/4"-32tpi (on my new-to-me Rivett 8" Precision).

The largest diameters I've single pointed so far were these mating parts:
https://lh4.googleusercontent.com/-fmB1LDXEmpE/UoAGdR8Gf2I/AAAAAAAACEQ/6fhmidamTck/s912/completed%25203.jpg

Both external and internal were single pointed, 40tpi. Diameter was completely arbitrary - a bit more than 3/4".

A.K. Boomer
11-04-2014, 12:57 PM
Ammcoman, I bet you could sell that thing on e-bay, nice work.

Fasttrack
11-04-2014, 01:23 PM
Had to pick up and single point a number of 34mmx0.5 retainers for custom optics - some external to shoulders and some internal. Thats about a 50 tpi, done on a Clausing with imperial leadscrew but electric spindle brake.

Paul Alciatore
11-04-2014, 01:55 PM
Largest: I mounted a 2" lens in a barrel. I believe I single pointed 32 TPI male and female threads at a diameter slightly larger than that. One female thread in the barrel and two male mounting rings. No particular standard, just had to fit each other.

Smallest: 0-80 Of course I used the die and tap. For a HO model I was building.

Rich Carlstedt
11-04-2014, 07:17 PM
My lathe is a 10 inch Boxford
Here is a small nut (tapped)

Rich
http://i273.photobucket.com/albums/jj220/StationarySteam/1mmNutswithPenny.jpg (http://s273.photobucket.com/user/StationarySteam/media/1mmNutswithPenny.jpg.html)

Smallest is a one mm nut http://i273.photobucket.com/albums/jj220/StationarySteam/1mmNutinLathe.jpg (http://s273.photobucket.com/user/StationarySteam/media/1mmNutinLathe.jpg.html)


Also a Square Thread (32 TPI ) single pointed nut for the screw.
Thread ID .140- OD .172 or .016 thread height
The nut is on the far right ( round OD )
http://i273.photobucket.com/albums/jj220/StationarySteam/Shop%20Tools/P3250068.jpg (http://s273.photobucket.com/user/StationarySteam/media/Shop%20Tools/P3250068.jpg.html)

varjag
11-05-2014, 05:00 PM
My smallest single point nut, the titanium retainer for camera flash sync socket (the other parts were done by me as well). Was an oddball 7mm x 0.5 if I recall correctly.

https://farm6.staticflickr.com/5580/15277171862_662ca9a96e_z.jpg (https://flic.kr/p/pgZuWS)
DIY Leica Sync socket (https://flic.kr/p/pgZuWS) by varjagg (https://www.flickr.com/people/51449038@N02/), on Flickr

And on the camera:

https://farm4.staticflickr.com/3860/15090807429_9131ff3de4_z.jpg (https://flic.kr/p/oZwkhZ)
DIY Leica Sync socket (https://flic.kr/p/oZwkhZ) by varjagg (https://www.flickr.com/people/51449038@N02/), on Flickr

Daveb
11-05-2014, 05:25 PM
I went into my local stockist for some screws. On the counter was a hex nut about 8" across the flats, I asked him if he had any bolts for it, He said "Sure, is a box of a hundred OK?"

ammcoman2
11-05-2014, 06:36 PM
I am amazed at the results (and skill involved) shown on the small end of the scale. I am guessing that really big ones would not necessarily be handled in a home shop. Was thinking about making a 4TPI one on my big (to me) lathe but a scale nut would be using up a lot of metal.

Still haven't attempted an Acme thread - either external or internal.

Geoff

jdunmyer
11-05-2014, 08:02 PM
I made 4 nuts for the Snow engine at Buckley, MI, they're 4" X 6 TPI, about 6 1/8" across the flats. Although I have pictures, I don't have them on a host and don't have an ftp program on this computer. Will try to rectify that "soon".

Although I don't know exactly what they weigh, I calculated once that about 14# of chips went into the chip pan, just to make the hole and thread it. A bit more was removed to make the flats, of course. That was the only real job I ever did on a shaper, and actually was the only time I really needed one.

Stepside
11-05-2014, 08:10 PM
Geoff

My first Acme thread both internal and external was a 1/2-10 for my Gary Martin hand powered shaper. The external I got right the first shot. The internal took 3 trys. I would suspect a larger size might be easier. I am now in the midst of building the gear cutting attachment for the shaper. If it works well with the hand powered shaper I might build something similiar for the AMMCO. Somehow it seems so very right to be making shaper parts on another shaper.

Pete

Puckdropper
11-05-2014, 08:45 PM
I made 4 nuts for the Snow engine at Buckley, MI, they're 4" X 6 TPI, about 6 1/8" across the flats. Although I have pictures, I don't have them on a host and don't have an ftp program on this computer. Will try to rectify that "soon".

Although I don't know exactly what they weigh, I calculated once that about 14# of chips went into the chip pan, just to make the hole and thread it. A bit more was removed to make the flats, of course. That was the only real job I ever did on a shaper, and actually was the only time I really needed one.

If you're on a Windows box, there's a FTP program built in. It's called (not suprisingly) ftp. It's a command-line ftp program, but you usually only need to know a handful of things to use it. If you're interested, I'd be happy to tell you more about it. You can run it either by opening cmd.exe first, or by typing ftp hostname in the windows Vista/7 start menu search box. (I'm not sure about 8.)

jdunmyer
11-06-2014, 09:45 AM
Puckdropper,
Thanks for the tip, I made the built-in program work.

While disassembling our Snow engine, the guys had to split 3 of the 4 nuts that secure the flywheel, I elected to make the replacements. On our weekly scrapyard shopping trips, I spotted a hunk of steel about 7 1/2" diameter X 48" long, so I bought the whole thing, along with a 1 1/2" dia. boring bar that happened to be there. A friend sawed off the 4 slugs and a short slice for a spacer ring, and I was good to go.

Took the slugs to Buckley and used the 24" X 9' Lodge & Davis lathe (vintage about 1895) to drill and rough-bore the slugs:

http://www.oldengine.org/members/jdunmyer/4show/bigdrill.jpg

Took them home and used my 19" LeBlond to finish bore, face, chamfer, and thread them. I'm using a home-made boring bar with the same carbide insert that my external tool uses. Due to the vibration/chatter, I ate up 3 inserts, 3 corners/each, but I got them done. I began with a hand-ground HSS bit in a regular boring bar, but figured this would be more consistent. The material wasn't the easiest-machining stuff that I've ever put a toolbit to.

http://www.oldengine.org/members/jdunmyer/4show/threading.jpg

Made a fixture to put the now-threaded pieces on the 1915 Gould & Eberhardt shaper at Buckley. This is after spending a couple of days getting it operational. Belted up a TEFC Toshiba motor that ironically is probably made with iron from a scrapped American shaper. This is near the beginning of making a flat, we'd take about .050" DOC and .040" feed rate. The plywood box kept "most" of the chips contained.

http://www.oldengine.org/members/jdunmyer/4show/finishcut.jpg

We ended up with 4 of these:

http://www.oldengine.org/members/jdunmyer/4show/bignut.jpg

There was a bit more to it than that, of course, I made the threading/boring bar as mentioned, along with a male gauge to check the threads and several parts to the fixture for use in the shaper. I have roughly 3 days in each one, all told. As mentioned, they're 4" X 6 TPI.

MarkK
11-06-2014, 10:29 AM
Is the Snow engine running at Buckley yet -- I would like to see it

Fasttrack
11-06-2014, 11:59 AM
While disassembling our Snow engine, the guys had to split 3 of the 4 nuts that secure the flywheel, I elected to make the replacements. On our weekly scrapyard shopping trips, I spotted a hunk of steel about 7 1/2" diameter X 48" long, so I bought the whole thing, along with a 1 1/2" dia. boring bar that happened to be there. A friend sawed off the 4 slugs and a short slice for a spacer ring, and I was good to go.

Thanks Jdunmeyer, I really enjoyed that write up. Hope you ate your Wheaties before trying to lift that 7.5" diameter 48" long piece of steel into your pickup... :eek:

jdunmyer
11-06-2014, 02:17 PM
That hunk of iron weighed 600#, and a forklift was used to handle it. The slugs were heavy enough, right at 50#; they were a bit over 4" long initially.

MarkK,
I sincerely hope that I live long enough to see the Snow run, it's a long ways from operational. Once the CoolSpring crew began working on their 600 Hp Snow, it took them 9 years to get it running. If you'd like to discuss the subject further, perhaps we should start a new thread rather than hijack this one.