Help Needed - Tempest Pen Reamer

[EricRN]

HI all, I need some help. I've got a tempest pen kit. The bottom tube is 21/64 drill size. I can't find a 21/64 reamer anywhere, though, for my pen mill to square the edges. I thought I could make do with an 8mm/O sized reamer, but it's too big. 21/64 is approximately 8.33mm by my calculations; I figured the 8 mm reamer ought to work. But the 8mm reamer is 7.3mm thick. The inner diameter of my tube is 7.24mm. Go figure.

Anyway, has anyone made this kit and does anyone know where to get a reamer that will fit? The 7mm reamer doesn't seem to have a snug enough fit, and I can't find another size that is closer. I know sanding is always an option, but I'm not set up to do that and would rather just stick with my usual method, tried and true.

Thanks,
Eric

 

[pssherman]

You could make a sleeve by using a 7mm tube. Glue a drilled blank to the tube and turn it down to the size you need. I've done this for multiple kits that I had that didn't have a sleeve.

 

[EricRN]

You could make a sleeve by using a 7mm tube. Glue a drilled blank to the tube and turn it down to the size you need. I've done this for multiple kits that I had that didn't have a sleeve.

Great idea. I knew someone with more smarts and creativity than I have would come through for me here.

 

[Mr Vic]

You can also drill a 1/4 inch hole in Delrin or UHMW plastic an turn it to the diameter needed. 1/4" slips right over the 7mm reamer or pen mandrel. Prep several, never know when you might need an odd size.

 

[Bats]

You could make a sleeve by using a 7mm tube. Glue a drilled blank to the tube and turn it down to the size you need. I've done this for multiple kits that I had that didn't have a sleeve.

This is exactly what I usually do, since I'm too cheap to buy sleeves/shafts for whatever random pen kit I impulsively grabbed one of in the last order. I'll glue up some scrap wood (usually poplar, since I've got too much of it) as if it were a pen blank, stick it on a mandrel (with a spare 7mm tube used as a spacer), and then slide the big tube loosely over it. That way as I start getting close, I can slide the tube over the turned wood to test the size as I go. I suppose you could even CA finish it, but I've never bothered to.

One note - make it a little on the loose side. I've made them fit too tightly before, and if the trimmer raises a burr on the inside edge of the tube it can be hell to get the sleeve out afterwards. Once I also made one that was so close a fit that the friction caused the glue to let go and the tube to pull halfway out. Not a great situation to be in.

 

[randyrls]

This is a sleeve making technique I did a few years ago. You can use this either with a pen mill / trimmer or sanding jig. The key to this is sizing the sleeve with the tube you want to use.
https://www.penturners.org/resources/pen-mill-sanding-sleeves.343/

 

[EricRN]

Here was my ultimate solution. Somewhat similar to what someone posted above. Pen blank in a collet Chuck to hold it square. Pen mill in a Jacobs Chuck to make the cut. Worked out so well that I may start doing this for all my blanks rather than using the hand drill!

 

[Bats]

Here was my ultimate solution. Somewhat similar to what someone posted above. Pen blank in a collet Chuck to hold it square. Pen mill in a Jacobs Chuck to make the cut. Worked out so well that I may start doing this for all my blanks rather than using the hand drill!

The only potential trip-up is that it squares the ends to the exterior of the blank, rather than to the tube. Depending on when & how you round the blank (and/or how you drill it) that may or may not be a real issue, but it's worth keeping in mind.

 

[qquake]

The only potential trip-up is that it squares the ends to the exterior of the blank, rather than to the tube. Depending on when & how you round the blank (and/or how you drill it) that may or may not be a real issue, but it's worth keeping in mind.

That's exactly what I was thinking. Early on I used to trim my blanks with a disc sander and its miter. It did cause issues once in a while, when the end of the blank wasn't square to the tube.

 

[EricRN]

That's exactly what I was thinking. Early on I used to trim my blanks with a disc sander and its miter. It did cause issues once in a while, when the end of the blank wasn't square to the tube.

I hadn't considered this. In theory, it should be OK since I drill on the lathe using the same pair of chucks. But definitely something to be on the lookout for and be aware of. Thanks for flagging.