Doug...GREAT looking pen. What type aluminum did you use. How did you turn it?
I used the 6061 grade metal, 3/4" aluminum rod from
www.speedymetals.com those guys have to minimum and a wide selection. Though about doing the same in copper until I saw the price of 3/4" rod. Cut my blanks from the 12" rod center drilled with Relton 3/8" Groo-V Tip Multi-purpose bit. This bit is designed for hard metal, granite, tile and marble. No water or oil needed for drilling the blanks, just time. The closed end was drilled to 2-3/16" I would drill just a bit deep for the next one as I had some trouble seating the top side transmission holder. Glued in the 10mm cigar tubes, squared the ends and turned them one at a time on my shortend adjustable mandrel at 2630 rpm, Jet mini. Used a round nose scraper out of my Pinnacle starter set. Didn't really know how hard it was going to be so my one of two Robert Sorby tools ($) were not going to meet aluminum rod. I did try a little with carbide tip tool I bought for stone turning, really found no difference between the two. First time I had to wear a glove (left hand) with turning. The metal shavings were hot, probably next time with wear a long sleeve t-shirt as well. Dry sanded from 80-12k, finished with this two part metal clean and shine called Nuvite NuShine II. The only problem was seating the top side transmission holder pushing it the length of the tube, ended up removing the preassembled 8mm tube from the threaded finial/clip holder, pushing that down, then reattaching the tube. So three holders later, perfected that part, almost. What started out as a bright black kit quickly trippled and good thing, cause it still was not seated deep enough. Luckily there was an extra center silver ring band. Anyway, that's how I did it.