What did you do today?

[gmax137]

I made a 1/2 by 24 tpi nut. I used a 3/8 by 24 tpi tap as an internal threading tool per this video by This Old Tony.

https://www.youtube.com/watch?v=f-YWsgAHR6A

Worked well enough, but I might do it again a little more carefully, paying attention to depth of cut. I may try it with a 10 by 24 tap to have more clearance.

[J Tiers]

Drove back 600 miles, and probably need to go back up next week. We';ll see. Not doing the Rivett 608 project any good.

[Arcane]

I had a couple of small screws I wanted to clean the buggered up threads on so I went to my tap and (hex) die set, an Ace Hanson one . It's not much of a set but they work ok as thread chasers. I grabbed the 10-24 one and couldn't get it to start. The threads weren't that bad; it should have started so I went and grabbed a new 10-24 bolt and the die wouldn't start on it either. Whatever that die is, it's not a 10-24. It's not a 10-32 either. I grabbed a few more of the small ones and two smaller ones weren't what they were stamped either. This set is around 35 years old and believe it or not this is the first time I had need of those particular sizes. If they were decent dies I'd try to get warranty on them, but as it is I will just buy some quality ones and be done with it. If I get the urge, just for curiosity sake, I might try to turn a piece of shaft down until they will thread on so I can see what tpi they are. The case is nice though.

[The Metal Butcher]

I was tasked with polishing the ceramic coating on this fancy part today at work. I don't know how much I can say about it, but picture this: Nickle based super alloy, >10lbs, lots of machining, weeks of spraying and inspection. Well, since some doofus who designed this thing didn't leave a 60 degree center in the threaded end of one end, I made an adapter which just had the thread and then a center drill hole in the other end. So I get it put in the lathe and the adapter is just running super crooked. I machined it in one setup except for the center drill, and that was within a thou or two. And it was running out like 35 thou. After a bit, I get the engineer and point it out to him.

As it turns out, the hole was tapped crooked. We're all having a discussion and the spray guy and inspection guys all noticed effects of this hole being crooked, but never actually checked it. It wasn't until the intern went to polish it that it was discovered.

IMO the part is scrap. I guess we'll see what the customer says. But the mating piece won't sit on it flat, there was a huge light gap. And it needs to sit on there very flat and concentric. Maybe they can drill it and keensert it or something.

I just don't understand how you can have such an expensive part and tap it crooked? I guess they did it by hand because it was so shallow and a super alloy? They were using a CNC lathe on this part for sure, they should have just single pointed it... It certainly would have helped if they had of specced a 60 degree chamfer on the end of the thread.

Argh, pretty sad when an 8 year hobby machinist wouldn't have made the mistakes that professionals do on $100k parts.

[mattthemuppet]

made some hobbyist mistakes () and finished the extended tailstock screw for my SB9. Cheated a bit and used acme threaded rod, which made up for me accidentally using stainless for the handle end. Came out ok though. Shown with the original screw and extension nut.

[The Metal Butcher]

I was tasked with polishing the ceramic coating on this fancy part today at work. I don't know how much I can say about it, but picture this: Nickle based super alloy, >10lbs, lots of machining, weeks of spraying and inspection. Well, since some doofus who designed this thing didn't leave a 60 degree center in the threaded end of one end, I made an adapter which just had the thread and then a center drill hole in the other end. So I get it put in the lathe and the adapter is just running super crooked. I machined it in one setup except for the center drill, and that was within a thou or two. And it was running out like 35 thou. After a bit, I get the engineer and point it out to him.

As it turns out, the hole was tapped crooked. We're all having a discussion and the spray guy and inspection guys all noticed effects of this hole being crooked, but never actually checked it. It wasn't until the intern went to polish it that it was discovered.

IMO the part is scrap. I guess we'll see what the customer says. But the mating piece won't sit on it flat, there was a huge light gap. And it needs to sit on there very flat and concentric. Maybe they can drill it and keensert it or something.

I just don't understand how you can have such an expensive part and tap it crooked? I guess they did it by hand because it was so shallow and a super alloy? They were using a CNC lathe on this part for sure, they should have just single pointed it... It certainly would have helped if they had of specced a 60 degree chamfer on the end of the thread.

Argh, pretty sad when an 8 year hobby machinist wouldn't have made the mistakes that professionals do on $100k parts.

Correction: They did leave a 60 degree chamfer. The practice part did not that I noticed. So my adapter wasn't needed, though it did find the issue with the part.

As of this morning, we were finishing it for shipping. That's going to be fun to hear what happens with that.

made some hobbyist mistakes () and finished the extended tailstock screw for my SB9. Cheated a bit and used acme threaded rod, which made up for me accidentally using stainless for the handle end. Came out ok though. Shown with the original screw and extension nut.

Wow, that looks great! With the extended nut, do you get more travel? Or just more overhang?

[mattthemuppet]

thanks! I was worried about cutting the woodruff key slot in stainless but didn't have any issues whatsoever. The last part of the mod is an extension tube that goes between the tailstock casting and the end nut that holds the screw, so the quill can retract fully - basically providing space for the extended nut.

Original post:
https://www.practicalmachinist.com/v...ilable-199095/

And a neat series with plans

I screwed up the first go at the extension tube because the thread on my "heavy" 9 is 1/8" larger than the later workshop 9s, plus I still don't have threading working on my Atlas

[ken226]

Made a floating collet chuck for reaming rifle chambers. Finished the last part this morning.

[J Tiers]

Looks good! Classic 4 pin design, nice finishing, classy engraved logo!

Looks much nicer than the one I made a while ago, for use in turret lathe.

[Dan Dubeau]

One of the projects on my list for the weekend was to weld up a workbench for the new garage layout. Browsing Kijiji this morning I found one almost the exact size I needed, well made from 2" sq tubing, and a thick wood top with a sheet metal skin. Just picked it up a lunch. I wanted a butcher block top, but I'll trade the time savings not having to make one. Now I just need to make a riser for my kennedys to sit on top and it'll be perfect. Time to build stuff is limited these days, and overtime at work is plentiful right now so i didn't mind buying some time on this one. Now I just have to jockey everything around into position. Should be fun, like building a ship in a bottle lol.

[Tungsten dipper]

Finished my shelving for my 4200+ CD's. Made from Doug Fir that were old bleacher seats.

[Dan Dubeau]

Nice work, is the trampoline to reach the ones on the upper shelves?

[Tungsten dipper]

Thanks Dan. Good thought!

[Bruno Mueller]

My lathe CT 918 A came with a faceplate chuck with four independent jaws and a diameter of 190mm. For smaller parts, I also got an independent four-jaw chuck with 85mm from Bison.
With these two clamping options I have helped myself for a very long time. That was not always very advantageous. An intermediate size had to be purchased at some point.
Since a short time I have a 125mm independent four-jaw chuck from Chinese production. I used the chuck flange of the 85mm independent jaw chuck to hold the chuck and made an intermediate plate.
The 100% true running is not important. However, the axial runout should already be very good.
After mounting the chuck, I tested the axial runout and it is less than 1/100mm.
The runout is 4/100mm.
I am fully satisfied with this.
I got the chuck, from a german trader, for a price under 60,-€ ~ approx. 72,-USD ~ approx. 52,- GBP.




I numbered the jaws so that they always sit in the same place in the chuck. Since the jaws are hardened, I have engraved the numbers with a solid carbide graver on the engraving machine.

[Tim Clarke]

Not today, but this week, I finished up assembly of this lathe for friend, Wes. He had 2 1/2 lathes. I took the best parts from the lot and assembled this one.