Thread protector collar

[bluearc]

Anyone make one of these out of plastic for their lathe? IF not, why not.


SB9 # 415-AV

 

[Halligan]

A thread protector is just that. A protector to keep you from munging up your spindle when you use collets from an errant chip or crash or oops with a toolbit and to draw off the collet adaptor when your done. Youll go right through the plastic with a toolbit and won't be able to budge the collet sleeve.

 

[jim rozen]

Those threaded collars do have a use besides protecting the spindle threads - which is
to push off the collet adapter sleeve. For that they really have to be steel, *and* have
the hole in the side for the pin wrench.

If you only wanted to protect the threads, nylon or delrin would work OK I suspect.

 

[edkolt]

As Jim pointed out the term thread protector is a misnomer. The item is pat of a collet set up and draw bar. It is called a knock-out nut... SB item number PT995NK1 and comes with a spanner wrench. It is used to safely remove a collet from the spindle.

Source: DEPARTMENT OF THE ARMY TECHNICAL MANUAL page 20.
21 PT995NK1 KNOCK-OUT NUT
22 CE2734 SPANNER WRENCH

 

[jim rozen]

I only did mention the part about the *hole* in the side, for the simple reason
that I once made a steel version, without the hole - thinking it was just for protecting
the threads.

And kept the knock-out bar beside the lathe on the bench still.

I felt silly when dave sobel informed me of the real use for that ring.

And, I do apologize to whomever purchased that 9" model A from me, years
ago. You could toss out the knockout bar if you only drilled a hole in the edge
of the ring!

 

[FTF Engineering]

Good timing on this thread! Why just yesterday, I "made" a thread protector / collet nose ejector using a 1 1/2 x 8 big ass hex nut from McMaster as a starting point. Saved me the trouble of making the threads. I bought 90521A041 Heavy Hex Nut ASTM A194 - Cost $5.

I don't remember where I saw that idea... Probably here on PM somewhere.

I was trying to decide how to incorporate a feature to turn it with a tool, but didn't make up my mind yet. I could either put a hole in it and get a spanner, or mill a set of flats on it for a wrench, but in the meantime, I didn't do anything... I just left some the original hex on it until I make up my mind on how I'm going to do it for real.

I'll take a few pics tomorrow if anyone wants to see it.

 

[nel2lar]

Pics YES

Interested minds got to know.
Nelson Collar

 

[FTF Engineering]

OK, I got some pics uploaded... Here's the front side. I put a small taper on the front face just to make it look a little less "heavy and nut like" and to reduce the chances that I'll split the back of my knuckle open on one of the nut points when it's spinning:

Here's the back. The back face is square and makes contact to the shoulder on the spindle. You can also see the threads relieved so it runs up snug onto the shoulder and doesn't stop early because it's binding on the threads:

And here it is installed. Nothing special, but since I had nothing at all before, by definition, it's infinitely better than what I was using before I made this. And it cost five bucks . When I get energetic again, I'll do something a little more glamorous about a removal tool. Either a smaller wrench, or hole(s) for a spanner:

 

[k3vyl]

I have protectors made from bronze.They have no spanner hole,so they are not nockout nuts.(I use a bar)They do serve another purpose in that the traces of bronze left on the spindle nose are a lubricant.The bronze comes from old valve nuts found in the bonnets of large valves with double lead threads in the stems.The slugs of bronze are not always easy to get out of the bonnet.They are very easy to machine.