Pen mandrel

[Gerhard Olivier]

Hi all

Hope to try pen turning as I've been inspired by some of the pens shown here. But I would rather spend money on the stuff I have to buy than the stuf I would enjoy making myself.

Please can someone put the basic dimentions of a pen tuning mandrel and maybe a pic as well???

Gerhard

[rleete]

A mandrel is nothing more than a steel rod threaded and center drilled at one end.  You need to size it to the type of pen/pencil kit you are making.  The ones I make (and I believe the most common size) are 7mm.  That is, the inner brass tube/sleeve fits into a 7mm hole in the wood blank.  Since you are going to have to get a kit anyway, get one and measure the inside diameter of the tube.  I'm guessing it's roughly .25 inch, but you need to check (I'm at work and can't right now).  Thread one end (centerdrill as well) for whatever size nut you want to put on it.  Can be a standard hex nut, or a knurled thumbwheel.  You'll need to purchase the bushings, or be able to harden anything you make.  Bushings are particular to each type of kit.  Although the tubes are all 7mm kits, different pen styles use different bushings.  I have three sets.  They are cheap, so I just bought them.

[tinkerer]

The mandrel is .25 in diameter and is threaded for a knurled knob on one end and drilled to accept your live center. It has a morse taper on the other end. You can eliminate the morse taper if you chuck it in your favorite collet. It also has a compression fitting to adjust the length of tubes you are turning. I will post a picture of mine as soon as I can.

[tinkerer]

Here is the picture I promised. I can tell you that the best way to do it, would be to secure the tail stock end in a chuck that spins and the other end in a chuck with a draw bar. That will prevent flexing, if you can keep tension on it. Maybe a follower rest would do the same. Will you be doing this on a wood lathe or the metal lathe? The short threaded end on the left is to screw it into a morse taper, which I don't use on the metal lathe.

[spuddevans]

Here is the picture I promised. I can tell you that the best way to do it, would be to secure the tail stock end in a chuck that spins and the other end in a chuck with a draw bar. That will prevent flexing,

If you have a mandrel that has the tailstock-end centre drilled it is also just as good to use a live-centre in the tailstock to give support to help prevent flexing 

That's how I used to do it in my woodturning days.

Tim

[Gerhard Olivier]

Thanks for replies chaps

Tink - to be used on wood lathe I've decided as it is easier for me to cut a straight line with wood chisel than to cut cutves on the metal lathe.

The size of the bar would only be inportant if you are planning on buying the spacers ( I think im going to buy these!!!)

So the plan so far looks like a 2mt er32 collet chuck and a 1/4 inch ground bar with a nut???? ( got all that exept the ground bar) unless someone has a plan that I missed.

Gerhard

Ps where do u buy the pen blanks (best prices UK)

[rleete]

I buy pen/pencil kits at Woodcraft (local store), but you can get them much cheaper online.  In the store they're $4-5, but online thay are as cheap as $2 in quantity.

There are a zillion places to get them, google search "pen kits", and find the best deal as far as shipping to you.

[tinkerer]

Here is one link for the UK.
http://www.ukpenkits.com/