8mm mandrel?

[Jeff Clow]

I have just started pen turning and have what I need to do a couple of different 7mm pens. I bought a kit for a pencil & it turns out to be 8mm. I got an 8mm drill, but haven't seen any mandrels for 8mm. The one I have is the type with a collet. What do you use for 8mm (or other sizes)?

[Dave Rudy]

8mm pen should work on smaller mandrel -- the bushings make up the difference. Arizona Silhouette has a really well made larger mandrel (can't remember if it's the A or B but a trip to their website should help you).

Bushings for over 7mm will typically fit both, but the beefier mandrel has less whip and is better to turn with.

HTH

[robert hainstock]

Every time you buy a different pen model, you will need to buy a set of bushings for that pen model. I have half dozen or so, and figure if I ever get out of the vortex i can use them for sinkers. GOOD LUCK! ;)
Bob

[Ben Gastfriend]

There are also special 8mm mandrels (also called a "Precision Mandrel") availiable for a select few pen kits. Most likely the bushings will make up the 1mm difference.

[Jeff Clow]

How do the bushings keep the blank centered on the mandrel? The 7mm tubes are a pretty close fit to the mandrel, with only a little play. An extra mm seems like a lot of play to potentially get off center. (Mr. Murphy says it WILL be off center).

[Mike Vickery]

How do the bushings keep the blank centered on the mandrel? The 7mm tubes are a pretty close fit to the mandrel, with only a little play. An extra mm seems like a lot of play to potentially get off center. (Mr. Murphy says it WILL be off center).
Please post what kit you are using and who makes the kit.
Some kits from Berea bushings require a large B mandrel http://www.arizonasilhouette.com/Pen_Madrels.htm for some of their larger pens.

Unlike 7 MM Pens that the 1/4 inch mandrel fits perfectly inside the tubes. Other kits with larger tubes have bushings that are stepped. Part of the bushing will fit inside the tube to keep it centered and the other part tells you when to stop cutting.

[George Heatherly]

I don't remember where it came from, but I have a metal tube for the "A" mandrel that is supposed to adapt it to do pencils.

I just looked some more and found that the tube I was referring to came with a barrel trimmer.

[Bernie Weishapl]

The bushing will probably be stepped and slip inside the tube you glued in the pen blank. I have made all kinds of pens and use the adjustable 7 MM mandrel most of the time and I do have the B mandrel also but this uses different bushings.

They will look something like these.