Broken threads on the QCTP of my compound slide

so I have some stainless foil.. it would work.
I assume you don't have it. But what I would do to get you by so you can redo a new bolt:
I would wrap the stud in tin foil. wrap it carefully using a tooth pick to tighten up the thread.

Then make a new stud.
if it doesn't work, consider loctite perm or bearing to hold the stud in, redo your stud, then heat the old stud and remove.
 
stupoty said:
do you have some scrap material to do some tests with ?

Stu
Click to expand...
and you can even start with plastic, delrin.. then aluminum until you get some confidence. Then repeat with steel, but take very small cuts, since the other material will spoil you.
 
stupoty said:
do you have some scrap material to do some tests with ?

Stu
Click to expand...
Yes - I have about 12'' steel rod I can test the die on as well as a steel plate that I can use to test the tap on. Realistically, I'm not going to learn single threading and then do that accurately on a new stud - it's too much too soon.
 
If you are using rethread dies (Hex) it will go a lot easier to reduce the work a bit. From your chart .616 minimum diameter would be a good starting size. Put a generous chamfer on the end of the stock to ease starting. You really should be using a round die with adjustment screws. You can buy a quality one from McMaster-Carr and get it in a day or two. But you will also need a round die holder to use it.
At any rate, unplug the lathe, put the work in your lathe chuck and your drill chuck in the tailstock. Open the drill chuck fully so only the outer edges touch the die holder. The idea is to ensure that the threading gets started perpendicular to the work. Lock the tail stock in place. Advance the quill until the drill chuck is snug against the end of the work. Use lots of treading or cutting oil. Rotate the lathe chuck using a wrench on the jaws for leverage at the same time maintaining pressure on the die with the quill advancing on the tail stock. Back the die off when it gets tight to break the chips.

It is possible to get it done with a hex die but the round adjustable dies will give better results. You can thread at the most open size on the die and try the fit in the matching hole. If too tight just adjust the set screws on the die and run it again.
 
Larry$ said:
... round adjustable dies will give better results. You can thread at the most open size on the die and try the fit in the matching hole. If too tight just adjust the set screws on the die and run it again.
Click to expand...
Yes, I have a decent round adjustable threading die with the holder. I'm familiar with the technique you describe above - and will give it a go.
 
better-lathe-than-never said:
Yes - I have about 12'' steel rod I can test the die on as well as a steel plate that I can use to test the tap on. Realistically, I'm not going to learn single threading and then do that accurately on a new stud - it's too much too soon.
Click to expand...
you'd be surprised how easy and quickly you can learn to single point thread. Especially big threads that you can create a landing point with (a place to stop easily, an undercut). My first threads were surprisingly good.
 
woodchucker said:
you'd be surprised how easy and quickly you can learn to single point thread. Especially big threads that you can create a landing point with (a place to stop easily, an undercut). My first threads were surprisingly good.
Click to expand...
I would love to learn it - it's on my radar to start learning it soon.
 
better-lathe-than-never said:
it's on my radar to start learning it soon.
Click to expand...
No time like the present! Tonight would be a good time. It really isn't very difficult. Metric on an imperial leadscrew is somewhat of a PIA but taken slowly not all that bad either. Go to the YouTube University, Joe Pie's site. Watch his videos on threading.
 
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