Need Advice on a New Chuck

[mikey]

A 5" is available on Amazon. The same seller also has a 4".

 

[mattthemuppet2]

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.

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.

 

[swany]

Have you tried using some sort of material bung inside the tube to stop it from collapsing when clamped ?

Stu

Yes, I have done that. It sorta works.

 

[swany]

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?

I'm referring to the tool that is inserted into the chuck to adjust the jaws.

 

[Jim F]

I'm referring to the tool that is inserted into the chuck to adjust the jaws.

Chuck keys are easy to make.

 

[talvare]

Another option may be to purchase a 5C hex collet block as in this set:

Amazon.com: 5C Collet Block Set With Case: Home Improvement

Buy 5C Collet Block Set With Case: Tool Holders - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

and then buy the appropriate size 5C collets for the tubing you are working with. The hex block can be mounted in a 3 jaw chuck or the square block can be mounted in a 4 jaw chuck. The collets will provide good support for your tubing. Just some food for thought.

Ted

 

[fitterman1]

How about an expanding mandrel that fits the size of tubing he's machining?
What sort of tolerances are we talking about here?
I gather they're not too long or he'll have trouble parting off.

 

[C-Bag]

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.

 

[Jim F]

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.

Nope, I have 2 different sizes, 1 about 3/8 for the 3 jaw, and 1 about 5/16 for the 4 jaw.

 

[fitterman1]

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.
Bear in mind the chuck was 36" diameter.