Generic bushings?

[Woodchipper]

I tossed my HDPE bushings as I had drilled to 7mm instead of 1/4 inch. Worked for me but the ID caused a blank to turn off center. One side was thicker than the accepted diameter and the other side was so thin I got down to the tube. I'm pondering turning bushings that are drilled 1/4 inch for the mandrel and tapered to accept a number of IDs for tubes. An engineer said he used aluminum 6061 T6 and said it turns good. Should turn with HSS tools. Softer alloys not so good.
As always, I welcome your input, experience and donations to the shop fund.

 

[Curly]

What you seem to want to do is turn between centres. In that case get a 60º dead centre (no bearing) for the headstock and a 60º live centre for the tailstock. They are steel and fit all sizes of tube You turn one tube at a time and measure to get the right finished diameter.

 

[Dieseldoc]

John: I suggest you contact rherrell (member) to have him make bushings. I have him make me several setts they are top notch bushing out of quality steel .

 

[Woodchipper]

What you seem to want to do is turn between centres. In that case get a 60º dead centre (no bearing) for the headstock and a 60º live centre for the tailstock. They are steel and fit all sizes of tube You turn one tube at a time and measure to get the right finished diameter.

Have all that but I want to eliminate the bushings for the kits. Only one that would remain the same is the 7mm bushings for Slimline and similar kits. I made a mandrel saver by removing the point of a live center. Here it is. Eliminated the HDPE bushings yesterday. Metal bushing is within a few thousandths of the opening.

 

[sorcerertd]

I have gotten to where I don't bother to use the correct bushings. I just grab a set that fits the tube ID and slide them on adapter bushings (see pic) made specifically for TBC (turning between centers). Once I've turned them down close to the proper size, I take the bushings out completely and TBC as @Curly said, with the brass tube directly on the centers. Obviously, you don't want to tighten the tailstock too much as it will flare the tube and, even worse, damage your blank. I use calipers to measure the barrel diameter ends so that they match the hardware in the kit. I'm going to do that anyway, so why bother with exact(ish) bushings? The trick is that you need to have the ends trimmed/sanded completely flat and even at the tube ends or you will get an out of round finished barrel.

 

[Woodchipper]

The HDPE bushing has been eliminated as per my previous post. I want to copy that general profile with the taper to fit several different tube IDs.

 

[GaryMGg]

I use TBC bushings for the different pen sizes.
I believe it's the easiest and most effective and efficient method.
I buy them from folks who machine accurate TBC bushings to eliminate out of round and other issues.

In the final analysis, especially if you're selling your product, it's probably the best option.

If you're not a machinist doing this on a metal lathe, the likelihood is less than ideal homemade bushings based upon my experience. I got close but theirs are just better.

Spend the money; make it up in sold products.

 

[Woodchipper]

I could have my son get in on this and make up a drawing. Part of his responsibilities is head of the machine shop. Good to have friends in high places.