Friction tube insertion method

**44Ronin** · 14th April 2009, 06:53 PM

Glueless method, you don't need to rough up tubes either.

1. Find an appropriate undersized drill bit for your brass tubing.

For instance, when using a 7mm brass tube, select a 17/64" (6.74mm) drill bit.

To get it right, it must be easy to line the end of the brass tube into the hole, but as you push more into the hole it becomes snug and then impossible to push in any further by hand.

You should test the suitability on some mock blanks cut from some waste. When you have it right, now use this drill bit for all fiction fit blanks.

2. Use a pin vice, quick clamp, woodworking clamp or similar to insert the tube.

Push the tube in slowly. If you push it in too fast or hard the brass tube may distort, bend, twist etc.,

The brass tube will stop where the clamp face can no longer push it.

The flatter your blank end and straighter your drilling, the better.

3. Flatten the end of the blank where the tube went in by either lightly disc sanding with a jig to set the tube at 90 degrees to the disc sander, or via your normal pen mill.

The pen mill is also the best way of testing the reliability of your friction fit, as the tube will fly out once you trim if the fit isn't any good.

4. Pen mill the opposite side down to size.

Your finished blank will probably a bit harder to get on the mandrel because of the threading for the brass mandrel nut, but all will be well.

**dai sensei** · 14th April 2009, 07:24 PM

Interesting, but not for me. Too much risk of stuffing the brass sleeve on hard timbers, or coming loose as the timber moves with temperature in the future.

**schaf** · 14th April 2009, 09:21 PM

Tell us what happens when you start to turn on the lathe.

**DJ’s Timber** · 14th April 2009, 09:33 PM

All sounds good in theory but what happens when the timber expands in winter from moisture or when it shrinks in summer when it dries out. There is a reason why they give you an oversized diameter for drilling the hole

**BoomerangInfo** · 16th April 2009, 07:57 PM

Originally Posted by DJ's Timber

All sounds good in theory but what happens when the timber expands in winter from moisture or when it shrinks in summer when it dries out. There is a reason why they give you an oversized diameter for drilling the hole

That's what I as thinking, or even just as you turn it down to a thin veneer, the pressure from the brass pushing on the wood could cause it to crack/snap.

Russell.

**Sir Stinkalot** · 16th April 2009, 09:46 PM

Why bother?

**dj_pnevans** · 17th April 2009, 10:13 PM

I would have said the same as above but today I grabbed the wrong bit so I gave it a go and it worked. I don"t think that I will do this all time, but as it was a mistake it worked out.
David

**Sir Stinkalot** · 19th April 2009, 09:09 AM

My previous post was perhaps a little short but I just don't see what the benefit is. Sure there is no glue involved but I wouldn't have thought that was much of an issue.

As others have mentioned it introduces its own problems. The tube becoming lodged half way would be just as anoying when there is no glue involved as when there is glue, same result damaged insert and possible blank loss.

If there was a way to turn a pen without the inserts that would be great but I am sure the pen will just fall in on itself without the brass supports. Not having a go at 44Ronin for posting, just interested to hear what improvements there are over the standard well tested method.

**44Ronin** · 19th April 2009, 12:22 PM

Originally Posted by Sir Stinkalot

Why bother?

There's always many ways to skin a cat.

Its just a means to an end, and it works.

**Skew ChiDAMN!!** · 19th April 2009, 05:35 PM

My main concern over the "no glue" method is the durability of the pen.

The glue isn't there just to make it easier to turn. (Although it certainly helps!) It's also there to bond the barrel into a larger, stronger, cohesive whole rather than being just a thin, fragile sleeve of material around a thinner brass sleeve.

Maybe a few years from now, a hairline fracture. Shortly thereafter, the blank lying in pieces in the bottom of a drawer...

Built-in obsolescence [shudder] may be acceptable in modern society, but it's not something I want associated with my work and/or reputation.

Mind you, for a basic slimline where the mongrels try to grind you down to under $10-, I think it'd be a good idea to keep a few "no glue" - and maybe also "no ink" - pens under the bench as substitutes...

**madcraft** · 24th April 2009, 06:48 PM

Originally Posted by Skew ChiDAMN!!

My main concern over the "no glue" method is the durability of the pen.

The glue isn't there just to make it easier to turn. (Although it certainly helps!) It's also there to bond the barrel into a larger, stronger, cohesive whole rather than being just a thin, fragile sleeve of material around a thinner brass sleeve.

Maybe a few years from now, a hairline fracture. Shortly thereafter, the blank lying in pieces in the bottom of a drawer...

Built-in obsolescence [shudder] may be acceptable in modern society, but it's not something I want associated with my work and/or reputation.

Mind you, for a basic slimline where the mongrels try to grind you down to under $10-, I think it'd be a good idea to keep a few "no glue" - and maybe also "no ink" - pens under the bench as substitutes...

Skew and maybe a "no-pen version" too

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