Captive Nut

Fabrickator

Fabrickator

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Jan 22, 2014
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I finished a Captive Nut Project this weekend. It turned out pretty good. I used a 7/16"-20 thread because that's what I had. In retrospect, I should have sharpened my threading tool bit first because I didn't get as clean of a cut as I could have.

I felt that a fine thread would work best and I also left some runoff area at both ends so the nut could spin off the threads just in case someone thinks that it may hold a clue to the mystery. :dunno:


Rick
G0602 Lathe

IMG_0883.JPG IMG_0885.JPG
 
I think this is a nut case :)
The top flat in the second picture in high resolution seems a bit different.
I'm not shure, but that is my first guess.

Kai
 
No, having a closer look at the first picture, I can se that the rightmost thread has a smaller pitch. That's where the secret is hidden!

Maybe?

Kai

- - - Updated - - -

It is very good though. I will try to make one myself :)

Kai
 
The secret is not in the thread pitch. I assure you if this one was made to spec there is no difference. The thread the nut rides on is cut continuously with the same pitch. Very nice work Rick. That is one of the better examples I have seen.

"Billy G"
 
I will have to give in!
I will make one myself by making it without the thicker end at one side, weld, weld, weld.... turn it in the end.
Would that be one solution?

Kai
 
Haha, very well done Rick!

Yeah, I have the same problem. Long ago, dear ol' dad sez: Git out there and practice sum threadin'.
You know the drill. Setup, align, adjust ,tweak, test cut, clean, measure, test, repeat, ...etc. Got a bit flustered, and knowin' enuff to be dangerous didn't help either. Dad leans over my shoulder and mutters "Yep, we call that a 'screwup'"...

Screwed-up.jpg
 
Kai-

That would be one solution. That, or you could get a bottle of liquid steel, preferably in cadmium color...:thinking:

Or, you could thread one of the ends to the bolt size with the nut already on it, and then cut the threads off at the joints...:shush:

You could also use some thread veneer...:lmao:

But none of those are the way I did it... :whistle:
 
Bill Gruby said:
The secret is not in the thread pitch. I assure you if this one was made to spec there is no difference. The thread the nut rides on is cut continuously with the same pitch. Very nice work Rick. That is one of the better examples I have seen.

"Billy G"
Click to expand...

Yea! but there seems to me to be a discontinuity in the thread pitch at the rightmost thread in the first picture. This could actualy be a joint with an int/ext thread :) However carefully hidden by... (Pink Floyd)

I'l make my own tomorrow. Good night!

Kai
 
Well, your partially right Kai. There is an internal threaded connection within the threaded portion, only it's about 1/3 the way up one side. I'm not sure which side it's on now, both sides are identical.

Disclaimer: It's not my idea! It's an old machinist project/exercise/trick. If you search for " captive nut project " you should find more details. I see where some of the more seasoned members here have seen it before and were nice enough to keep it a mystery today.

Have fun making yours and post a pic.

Rick
 
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