Need help tap drill sizr

[Mike8623]

Grizzly

 

[jcp]

Look on the feed chart of the lathe (not the thread chart) and see if any of the longitudinal feeds are close. My South Bend will get close (.034) but not close enough. An asian lathe might get closer. Couldn't use the half nuts but you could cut a thread like doing a metric thread if there's a feed close enough.

 

[Mike8623]

Im pretty much an amatuer. I can use my lathe but not even close to being a machinist....

 

[Mike8623]

The grizzly will go 28 and 32 threads and i have made taps before

 

[jcp]

Send me a pic of the FEED chart please.

 

[Mike8623]

Pic

 

[woodchucker]

I could make a larger diam. Tap at 30 threads but my lathe wont cut 30 tpi

wow, I just looked at my SouthBend, 30 is not on the quick change gear box.

 

[Mike8623]

How bout gbsx1 setting

 

[jcp]

If you can thread you can do what I'm suggesting. I see settings GBSX / 1 gives .03357. Might be worth a try. I would machine a piece of stock that's easy to cut to .645 OD with generous lengths either end that are undercut by .100. 'Thread' a piece of stock using these settings and using the start/stop switches to move the carriage. Set up the compound same as threading. It would be the same as threading metric where you can't disengage the half nuts.

 

[Mike8623]

K, thanks....ill give it shot early tomorrow a.m.

Im pretty much shot tonight...im going in to vegg.