Machined a part for friend

[JRD77VET]

One of the guys on another forum purchased a 5C collet positioner but it was missing the nut that held the collet in place. He attempted to make one on his lathe but had some problems doing an inside thread. He's new to metal working and this is a practiced skill.

I made a practice piece and then an actual nut to document the process.

Quick over view
I ground a carbide boring to a 60* profile for ID threading.
A dial indicator is used for depth since you can't see how far you're going in the bore.
The carriage moves left and right. The cross slide moves front and back. The compound moves on whatever angle you set it at. It is set at 29-1/2 degrees ( almost half of the 60 degree thread profile ) and that is what you move in for the actual threading process.

The "fish tail" piece is used to grind the correct profile on the cutting tool and also for setting it at the correct position for a properly cut thread.

Practice piece ( aluminum ) worked perfectly.

The "good" piece is made from 4140 alloy steel. I used Dykem bluing to "paint" the inside of the bore after I drilled and bored it to 1.203 That is the maximum size for a 1-1/4 20 thread. I took a "scratch pass" to make a mark in the bore to make sure I had my lathe set correctly for 20 threads per inch. The fish mouth tool has various threads per inch marked on it.

Success :hurray: A perfect fit. Turns in nicely without an wobble.

I put a "bull nose" center in the tailstock to support the bar and cut the correct dimensions to fit the positioner.

Finished part :cool1:

[OddBall]

You should start doing some instructional videos.

[MrPeabody]

I enjoy these threads. Although not a machinist myself, I operated printing machinery for over 30 years and my father was an aircraft mechanic. I had a roommate for four years who was a journeyman machinist at Hewlett Packard in the 80s, so I kind know what you are talking about.:seasix:

[Norm]

Have always been fascinated with machine work and tooling, gratifying to see your efforts and skills come to fruition from a scrap of metal to a machined part for service.

I was a machine shop flunky, back in the day along with my regular job, had a series of part time jobs to pay the bills. A couple boat buddies in partnership had a rented garage shop with a few used mills and lathes. They would specialize in sub-sub-contracting jobs.

One job I assisted with was a few thousand cylindrical bronze bushings, about 8" long, 3" in diameter, and around a 1/2" thick wall. Job was to take off a few thousands inside the bushing. They got to use the mills and lathes, I was relegated to a large drill press using engine cylinder hones....whew, I said "don't call me no more for these type jobs, it takes for ever". :D

[Black94lt1]

Excellent work as always! I love working with metal, I just wish I had the skills and tools to do things like this. That being said I’m happy with the simple fabrication jobs I am able to do

[SQUIRMIN VERMIN 84]

I enjoy your fabrication threads. Always something that challenges your resourcefulness. Always a nice result.

Most of my enjoyment with fabrication is making a tool or jig for whatever I need. Lot of satisfaction from that.

[JRD77VET]

You should start doing some instructional videos.

My basement shop isn't roomy enough to get a good view of what I do. Pictures with some instruction seem to work right now.



I enjoy these threads. Although not a machinist myself, I operated printing machinery for over 30 years and my father was an aircraft mechanic. I had a roommate for four years who was a journeyman machinist at Hewlett Packard in the 80s, so I kind know what you are talking about.:seasix:

Maybe next time you see a certain part somewhere, you'll go "Hey, I know how they made that".

Have always been fascinated with machine work and tooling, gratifying to see your efforts and skills come to fruition from a scrap of metal to a machined part for service.

I was a machine shop flunky, back in the day along with my regular job, had a series of part time jobs to pay the bills. A couple boat buddies in partnership had a rented garage shop with a few used mills and lathes. They would specialize in sub-sub-contracting jobs.

One job I assisted with was a few thousand cylindrical bronze bushings, about 8" long, 3" in diameter, and around a 1/2" thick wall. Job was to take off a few thousands inside the bushing. They got to use the mills and lathes, I was relegated to a large drill press using engine cylinder hones....whew, I said "don't call me no more for these type jobs, it takes for ever". :D

Sometimes you get "shit jobs" that just have to be done. It's not all fun work.

One job I worked on was a rolled piece of 3/16" stainless plate that finished at 7-1/2" in diameter and was 45" long. It also had 3/8" holes in it. A lot of them. There were 64 rows of holes. There was 68 holes in the long row and 67 holes in the short row.

There was 4320 holes in each part. I had to make fifteen of them. They were a bitch to set up ( had to make blocks to support the diameter ) and then they had to be deburred

Excellent work as always! I love working with metal, I just wish I had the skills and tools to do things like this. That being said I’m happy with the simple fabrication jobs I am able to do

I enjoy your fabrication threads. Always something that challenges your resourcefulness. Always a nice result.

Most of my enjoyment with fabrication is making a tool or jig for whatever I need. Lot of satisfaction from that.

Thanks. I've been working in a fabricating environment for over 40 years now. Plus the 20 years at my previous employer in a job shop helped form the "master of invention" approach to getting things done.

It's OK to mickey mouse something for one part but not multiples.