1-5" ACME Tap

[Scra99tch]

If my plans go belly up of boring and sleeving new acme nuts into the old Van Norman table nut, I am on the lookout for a cheap ACME tap or threading insert that someone may have. Worst case if I just have to chase the two as it seems there is a bit of out of roudness or distortion when pressing sleeves in. Leading me to believe that there will be a bit of binding until it wears through.

Thanks I'd like to be sub $60 on it if possible.

Thanks

 

[WobblyHand]

If my plans go belly up of boring and sleeving new acme nuts into the old Van Norman table nut, I am on the lookout for a cheap ACME tap or threading insert that someone may have. Worst case if I just have to chase the two as it seems there is a bit of out of roudness or distortion when pressing sleeves in. Leading me to believe that there will be a bit of binding until it wears through.

Thanks I'd like to be sub $60 on it if possible.

Thanks

Did you mean a 1" x 5 TPI acme tap?

I single pointed a test thread a couple weeks ago at that size, just to practice. Nailed that, but muffed the real part. Haven't tried making a nut of that size yet, that ought to be a challenge. . I ground the acme form from HSS.

 

[Scra99tch]

Yeah 1-5TPI.

I’d like to grind the bit out of carbide or HSS but I am having a hard time trying to get the back angle on our single lip cutter here at work.

Plus my lathe I am not very familiar with threading and don’t trust myself or the machine to be consistent.

 

[Scra99tch]

Plus I figured a tap would work best with the backlash assembly together to take out any out of roundness that may lead to binding.

 

[WobblyHand]

The guys here taught me to first do a normal vee thread to depth, then change the cutter to acme (and retime the threads) to cut the acme thread. That way you are not hogging the thread with the blunt nose. You also need to grind the acme tool with side relief due to the high helix angle. I did 15 degrees.

Second attempt at an acme thread. 1" x 5 TPI.

 

[Scra99tch]

Where do you work at? Or retired?

 

[WobblyHand]

Where do you work at? Or retired?

I'm retired now. Actually was involuntary retirement, but that's water over the dam. EE by profession, automotive radar systems engineer for 21 years, 19 years in military radars, learned (some) machining after retirement. Always learning.

 

[Scra99tch]

Nice.

Well here’s the project actually got both nuts together. Marked the start of them so that when in machine I can line up everything and not have to guess or try and work the two together. Also when I got both nuts together the was no binding when I was worried about trying to get the bores correct and concentric.

Now when in the machine with the bearings hopefully it’s still true and does not bind.

The original nuts were well worn and probably only 20%.

 

[Illinoyance]

Grind a tool and single-point it. First day on a new job, I was working on an old (40s) P & W lathe. Compound nut stripped out. Had to make a threading tool and find a piece of bronze to make a new nut.
By single-pointing the thread you can control the fit (backlash) which is not possible with a tap.














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