POTD- PROJECT OF THE DAY: What Did You Make In Your Shop Today?

The much traveled new belt finally showed up yesterday so the lathe is back in action.
Managed to get the tailstock die holder project I started several weeks ago plus tried some trial and error thread cutting on some 1/2 bar stock.
Was not too happy with the results. My inserts must be really cheap ones because the threads are usually pretty ratty.
Is it normal to have to use a bench grinder and wire wheel to clean them up after cutting?
 

Attachments

  • DSCN9096.JPG
    DSCN9096.JPG
    80.5 KB · Views: 22
  • DSCN9097.JPG
    DSCN9097.JPG
    83.2 KB · Views: 19
finsruskw said:
The much traveled new belt finally showed up yesterday so the lathe is back in action.
Managed to get the tailstock die holder project I started several weeks ago plus tried some trial and error thread cutting on some 1/2 bar stock.
Was not too happy with the results. My inserts must be really cheap ones because the threads are usually pretty ratty.
Is it normal to have to use a bench grinder and wire wheel to clean them up after cutting?
Click to expand...
Never had ratty threads after cutting correct rod diameters with a die. So not normal. What is the diameter of the bar stock, mic it, and the die is what 1/2-13?
 
Mat'l is CRS, 1/2 OD
And yes, 13TPI
Seems to tear instead of cut after the 1st few .005" cuts.
How deep should the total cut be?
I think I went a little too deep as the nuts fit loose (edit)
as does a die.
 
Single pointing threads in mild steel can be a challenge to obtain a good finish. I have run a die over them just to clean them up. Same goes for wire wheel ,three corner file,or steel wool. I am all in for what works.
 
I have had thread cutting dies strip threads out of the part if not backed off and chips cleaned when using cheap dies. It might be the dies, or the use. Try getting it started, then manual turning the spindle and making sure you back it out to clear chips.

Sent from my SM-T500 using Tapatalk
 
finsruskw said:
Mat'l is CRS, 1/2 OD
And yes, 13TPI
Seems to tear instead of cut after the 1st few .005" cuts.
How deep should the total cut be?
I think I went a little too deep as the nuts fit loose (edit)
as does a die.
Click to expand...
if you are using hex dies, they are not for creating threads. They are maintenance dies, made to chase, or re-form damaged threads.
 
Rod diameter should be about 0.492", or less than 0.500". A 30 degree chamfer at the start also helps. Many hex dies are for chasing only. Have no idea if yours are maintenance dies, or cutting dies. If a cutting die, and the rod is 0.005-0.010" undersized, you should be good to go. Turn, back off to break the chip, turn, etc. until done. Use cutting oil! It helps a lot.
 
Negative on the dies, not using them in this instance, mine are all hex anyway.
This was with a 60* insert tool, single point threading using the back gear.

Maybe turning too slow is what is causing my poor thread quality issue? I think the next highest speed on my lathe will be too fast, will have to check that out. It only has a single motor pulley so that cuts the available speeds down by 50%.
I need to find a double pully for it.

Just trying to get my head wrapped around this single point thing.

Single point should work on .500" CRS without reducing the OD, correct?
 
Yes, it should work. Have to ask, is the tool on center height? The insert unchipped?
 
You must log in or register to reply here.
Back
Top