How do I?

[BellyUpFish]

Ok, I've got some 1.355" OD titanium tube I will eventually need to trim.

I've been using a lathe for a couple years, but haven't tackled anything like this yet..

What is the best way to chuck up the tube without deforming it? If I chuck it as it, it will deform either holding it on the outside or inside.

I've been thinking about making a spacer to the ID of the tube and then chucking it up like that.

Anyone?

 

[larry_g]

Custom soft jaws. Make them a bit wide so they will bore out to the size you need and envelope the work near 360*.

lg
no neat sig line

 

[BellyUpFish]

Good idea. I'll get some made up.

 

[Dennis Leigh Henry]

Are you turning the inside or outside? If turning the OD you can use a mandrel between centers. Inside will be tough.. but the extended jaws seem plausible...

 

[BellyUpFish]

Are you turning the inside or outside? If turning the OD you can use a mandrel between centers. Inside will be tough.. but the extended jaws seem plausible...

I'll just be trimming to final length.

 

[bczygan]

Ok, I've got some 1.355" OD titanium tube I will eventually need to trim.

I've been using a lathe for a couple years, but haven't tackled anything like this yet..

What is the best way to chuck up the tube without deforming it? If I chuck it as it, it will deform either holding it on the outside or inside.

I've been thinking about making a spacer to the ID of the tube and then chucking it up like that.

Anyone?

Hey!........Isn't there a limit to the good information you are allowed to get on this forum? Aren't you over your limit for the year?


Nevermind!.........If there was a limit, I'd be way over myself!

 

[rlitman]

There is a very low melting point, less than 200 degrees, metal that you pour in to fill the tube, trim, then boil out the metal. Infinitely Reusable.
Available at machining supply places. Buried deep in the enco catalog.
Anything else will allow deformation except cutting directly over any mandrel you make, and then you get slight deformation from the mandrel being too tight or too loose. I don't know your wall thickness and I don't know the flex of the material. My instructions are for any size tube, but the lack of deflection due to extra wall thickness may allow other course of action.

It's not a bad idea, but remember that these low melting point metals are pretty toxic.

 

[BellyUpFish]

Hey!........Isn't there a limit to the good information you are allowed to get on this forum? Aren't you over your limit for the year?





Nevermind!.........If there was a limit, I'd be way over myself!

This place is better than Google..

 

[rsanter]

It depends what the length of the items will be.
It also depends on what is more important, the finish on the outside or inside

If the pieces are long, more than just a few inches. Then you need an expanding mandrel that the tube will ride on and let you trim to the length you need.

If short then you have a couple of options.
Use some plastic,nylon, etc that will fit snug on the inside and let you ab with the chuck without collapsing the tube
If really short or you want to be sure to preserve the outside finish then you can machine an aluminum or plastic ring that fits snug on the outside and lets you grab the tube on the inside without deforming the tube

Bob

 

[kazlx]

I'd probably just make an aluminum plug. You don't need to grab it super tight to trim the ends. BTW, titanium has a pretty good memory. Depending on wall thickness you could probably just grab it with the jaw or make soft jaws and be fine.

 

[BellyUpFish]

The pieces are only 1" in length, will be a little shorter when trimmed.

Finish is moot.


Sent from my iPhone using Tapatalk

 

[bczygan]

This place is better than Google..

MUCH better!........And it's interactive!

 

[bczygan]

Have you got a mill?

 

[Nelson58]

An aluminum plug is a good idea- you can even heat it a bit to make the fit tighter, and when it cools, it will release.

 

[Griff93]

I'd definitely do the aluminum plug as well.

OP, I noticed you're from Alabama as well. What part?

 

[theoldwizard1]

I've been thinking about making a spacer to the ID of the tube and then chucking it up like that.

If it is thin wall, I would make the spacer.

Get some small, thin pieces of aluminum and place then between the jaw faces and the part.

 

[helterskelter]

Without knowing wall thickness it's difficult to answer your question. If it's thin pie jaws or an aluminum emergency collet should be fine.

 

[Doug Arthurs]

I would take a piece of aluminum bore it to slide over your part then slice it length ways . When you chuck the part inside the tube you made the jaws will close the tube up and hold the part and the chuck jaws won't mark it.

 

[malibu101]

This place is better than Google..

That quote right there totally sums up my opinion of this site too!

 

[Kevin54]

Make a split bushing. Take a piece of aluminum about 1.750 - 2.000 diameter and bore a 1.360 diameter hole through. Then with a saw, split one side of the piece. This will allow it to tighten up all of the way around the titanium part without tightening on three points.

If you have a lot of pieces to do, you can get creative and put a step on the inside, and a step on the outside soo it rest against the face of the jaws. And the titanium piece will stop against the step on the inside. That way, you will always have a positive stop for your part.

Something like this.......