# Threaded madrel for close end pens.



## alexkuzn (Sep 21, 2009)

How should a mandrel for a close end fountain pen for Lou's nib holders  plastic should look like?
I assume it's a plastic rod threaded at the end that goes into beall chuck. 
Right? 
Now, since this is not an expanding mandrel it will not fit tightly into all drilled holes. A hole made with the same drill bit has slightly different diameters in different materials. If unthreaded part of the mandrel does not fit tightly into drilled pen body hole then mandrel does not provide much support along the whole length.


Am I missing something here?


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## leehljp (Sep 21, 2009)

Here is a link to a previous post on the subject:

http://www.penturners.org/forum/showthread.php?t=46877

Within this post are 2 other links, one to SkipRats closed end mandrel and one to RedRiverPens. In the link to RRPens, scroll down to the "closed end pens" and click on those. Both of the above links work well but are somewhat different.

You are right that the farther out you go the less support there is. But this is a technique problem and most of that is patience and a sharp tool.

One other thing: Make ALL cuts starting from the closed-in end and cut towards the chuck. If you don't the blank will have a strong tendency to go flying.


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## alexkuzn (Sep 21, 2009)

Do we really need a pin chuck? 
The advantage of pin chuck over regular friction fit mandrel is to prevent rotation. 
In our case a pen body has internal thread and  mandrel has internal thread on which we screw on pen body. A pen body will not rotate and also will be centered if you have a "shoulder" on your mandrel and pen whole opening was squared.

My problem with pin chuck is that if it is not a perfect fit it'll hold hold a pen off center.  

Please feel free to correct me if I am wrong. 
You guys have real experience. My opinoin on other hand is mostly "theoretical"


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## alexkuzn (Sep 21, 2009)

What do you think about using expandable brass cylinder from "Expandable Brass Cylinder Lap" that we can screw on our mandrel?
It'll make it easy to insure  good tight fit. With this barrels you do minute adjustments to make sure it's not too loose or too tight.

It'll require us to  thread the end of our mandrel to accept the brass barrel.
In other words our mandrel has about 3/4" long threads for nib holder and then instead of long unthreaded part will have a short threaded end(just like on the shank on the picture below) to accept brass cylinder.

These brass cylinders are very accurate and stay concentric when expanded. 
Cost of a barrel is $4 and they come in small size increments. 
You can find them on www.mcmaster.com
Expanding barrel:







Adjusting screw:
(you rotate this screw to expand barrel)




Whole lap assembly:


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## Texatdurango (Sep 21, 2009)

alexkuzn said:


> How should a mandrel for a close end fountain pen for Lou's nib holders plastic should look like?
> I assume it's a plastic rod threaded at the end that goes into beall chuck.
> Right?
> Now, since this is not an expanding mandrel it will not fit tightly into all drilled holes. A hole made with the same drill bit has slightly different diameters in different materials. If unthreaded part of the mandrel does not fit tightly into drilled pen body hole then mandrel does not provide much support along the whole length.
> ...


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## rstought (Sep 21, 2009)

The nib holders sold by Lou are "stepped" (e.g. the diameter changes several times across the length of the piece), so I think what Alex is looking for is some guidance as to whether or not any mandrel he might make to support a custom front section he is making might also have to be stepped in order to properly support the piece, or could he get by with some sort of expanding gizmo, etc...

I am interested in this topic as well, since I will soon be doing the same thing.  George, in reading, it would be great if you could share some of your thoughts around front section construction here rather than in a PM...


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## nava1uni (Sep 21, 2009)

I would also be interested in hearing some of these thoughts.  I am working on learning how to make fountain pens.  I keep getting questions and requests to make.  There is something about them that is scarey to me.  Don't know what, oh well.  Must conquer this fear.
thanks


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## PTJeff (Sep 23, 2009)

like this? for holding the body.
or this?
I have made something similar, substitute tap for brass mandrel, that holds the section.


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## alexkuzn (Sep 23, 2009)

Hi Jeff,

I am not sure I understand what exactly you mean.



PTJeff said:


> like this? for holding the body.
> or this?
> I have made something similar, substitute tap for brass mandrel, that holds the section.


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## PTJeff (Sep 23, 2009)

Let me start by clarifying your question
How should a mandrel for a close end fountain pen for Lou's nib holders plastic should look like?
To me this is 2 questions.
1. "How should a mandrel for a close end fountain pen"
this represented by pic's #1 and #3
and 
2. "Lou's nib holders plastic"
This is what we call the section.  The section holds the housing, which is what Lou sells and that is what pictures #2 and #4 represent.


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## alexkuzn (Oct 6, 2009)

Jeff,

thanks for clarification.

Do you thread outside of Lou's nib housing and inside of the section?


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## PTJeff (Oct 7, 2009)

You've got it!  Just like this and that


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