Internal thread

:grin: Easiest machines to run and program were the Leblond Makino slant lathes . Conversational programming was a snap . I wish I still had the use of one , I would get rid of everything else . :)
 
mmcmdl said:
:grin: Easiest machines to run and program were the Leblond Makino slant lathes . Conversational programming was a snap . I wish I still had the use of one , I would get rid of everything else . :)
Click to expand...

I wish you still had access to one too & lived closer.... so you could teach me & hopefully let me use it sometimes. :big grin:
 
Since it is a non-standard thread make sure that it is a 60° angle before buying an insert tool.
 
darkzero said:
Wudda wudda wuh? I'm still CNC illiterate. :D
Click to expand...
M03 is clockwise rotation, M04 is counter-clockwise. That'd be about as exciting as not putting the lathe in back gear when firing up the motor with the half nut already engaged. Ask me how I know (thank goodness for a foot brake . . .).

Bruce
 
rzw0wr said:
...
I made a boring bar for threading but it keeps flexing. The hole is 1" deep.
^^^^^
...
Click to expand...

What did you make it from? what does the cutting end look like. How thick is it. Is it flexing because you are trying to "bully" the cut? Could it be dull?

I just cut a 1/2-20 internal thread for my Craftsman 109 lathe faceplate with a 3/8" diameter mild steel bar with a 1/8" broken drill bit as a cutter, and it worked just fine.
 
Victor machinery has special pitch taps . 1/2 inch taps run from about 11 bucks to 20 bucks. I don’t think I would fight threading one for that cheap of price. Plus you have the tap for the next time you need it.
 
I make my own internal threading tools out of 01 tool steel to suit the job at hand. I like square blanks so the rake angle can be easily maintained. I use a 60 degree carbide bit to turn the tooth profile then mill off a little more than half the diameter to provide clearance. This leaves you with two perfect cutting teeth. One in the front and one in the back. Grind off the one you don't need. Heat cherry red and then dunk in motor oil. I don't bother tempering. Sharpen by stoning the flat on top so the tooth profile remains unchanged. You can make these as big or small as you want and they can go quite a while between sharpenings. DSC_0774.JPGDSC_0786.JPG
 
You must log in or register to reply here.
Back
Top