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- Dec 20, 2012
- Messages
- 9,422
A 5" is available on Amazon. The same seller also has a 4".
the second chuck key can be alot smaller, mine's a couple of inches or so wide with a sliding handle. Very easy to make if you have a lathe or even just a drill press. The plus with the 2 keys is that you can precisely halve the difference between two opposing jaws without the piece becoming loose. You can also tighten the two jaws against each other without affecting the reading.I fully support becoming familiar with using your 4-jaw chuck. Something I learned is to start indicating when a pair of jaws is horizontal. One of the adjusters will be at the far side of the chuck so using two keys is a bit more challenging. I only use one key (mainly because I only have one), but I make a mental note of which direction the jaw needs to move.
Have you tried using some sort of material bung inside the tube to stop it from collapsing when clamped ?
Stu
I think Stu has a very good solution if you are doing a lot of the same size tubing. Aluminum or even pvc would work.
I have basically the same lathe, a 9x20 HF. Mine came with a 5” 3jw and 6” 4jw And the original 4” 3jw. The guy I bought it from had tricked it out according to Steve Adair’s 9x20 page. But as I used it, it became evident he had not done any of the preliminary things like truing up the backing plates of the 5” or 6”. So truing up the backing plate is just basic and is what’s expected when you install a new chuck.
I’m not sure what you mean by the proper tool to use the 4jw but I assume you mean a dial or test indicator to dial in the tube in the chuck. There are a lot of good vids on YouTube on how to dial in a 4jw. It’s time consuming at first but it’s basic to becoming a machinist. if you don’t have a good indicator and either a magnetic base or a mount for the tool post that is basic tooling that would make the 4jw you have work right now. Maybe your buddy can help you do your first setup with the 4jw?
Chuck keys are easy to make.I'm referring to the tool that is inserted into the chuck to adjust the jaws.
My chuck keys(1 small 1 normal for adjusting the 4jw at the same time) work in all my chucks. I thought one key fits all chucks.I'm referring to the tool that is inserted into the chuck to adjust the jaws.
Nope, I have 2 different sizes, 1 about 3/8 for the 3 jaw, and 1 about 5/16 for the 4 jaw.My chuck keys(1 small 1 normal for adjusting the 4jw at the same time) work in all my chucks. I thought one key fits all chucks.
No, my old MacPherson had a 3/4" Allen key and a pipe handle on that.My chuck keys(1 small 1 normal for adjusting the 4jw at the same time) work in all my chucks. I thought one key fits all chucks.