Threading table on my lathe is wrong or I'm an idiot.

[jcp]

I take it that the tooth count is not marked on the gears. Might want to mark each one properly for future reference.

 

[strantor]

I take it that the tooth count is not marked on the gears.

correct

Might want to mark each one properly for future reference.

Absolutely!

 

[682bear]

I thought something didn't look right with your gear setup...

I know that's an easy mistake to make... don't ask me HOW I know...

Ok, I'll admit it... I've done the same thing before...

-Bear

 

[brino]

Mystery solved! I am an idiot!

Glad it is solved, but No you are not.....

We have likely all been there at one point or another.
That's what is great about having this group; even if there's no one else on your entire block to help you figure it out the people here will always try.

The power of many minds.

Brian

 

[phubbman]

The first time I used the lathe to cut threads I got the gears in the correct configuration and cut a very serviceable LEFT HAND thread - not what I was after. We all make stupid mistakes.

 

[strantor]

The first time I used the lathe to cut threads I got the gears in the correct configuration and cut a very serviceable LEFT HAND thread - not what I was after. We all make stupid mistakes.

Well if I had gotten as far as you had, I would have made the same mistake . I would have cut a right hand thread when I actually needed a left hand one.

I ended up 3D printing what I needed because I would have had to make a special form tool for it, as well as sacrifice some choice pieces of aluminum that deserve higher purposes. I 3D modeled the 4.5TPI thread and I was so focused on getting the thread form right that its left-handedness escaped my notice. I did make it left handed, but didn't realize it was (and was supposed to be) left handed until I pulled it off the printer and tried to righty-tighty it onto the hose.

It's a "zero restriction" coupling from 1.5" NPT to 1.5" pool vacuum hose. The fittings they sell for this purpose are barbed-type and reduce the ID all the way to 1.02". Since I'm moving my pool pump further than normal from the pool I didn't want any restriction in the fittings, especially on the vacuum side.