barrel trimming

[mapleman]

so, i have turned a few pens now. even my first cartridge pen ----a real one. actual .308 shell (fired by me at a deer, doe, tasty) topped with antler (had to buy the antler, i have never gotten a buck)... FWIW - I used a copper slimline kit b/c i liked the copper nib as a replicate of a copper coated bullet... Not so sure about the clip ont he other end... I have a pic of it on my phone - but not my good camera... yet.

anyway --- when you trim the wood blank with a barrel trimmer (or a sander for that matter), do you take it down flush with the brass or, if it has flattened out nicely, do you ever leave the wood proud by a 1/64" or so?

Why do I ask? Well, I am not always satisfied with the way the trimmer trims... I like the convenience of it, but sometimes I end up having to manually flatten the brass end after trimming b/c it sort of mushrooms.
Operator error or mechanical defect? I always lean toward operator error. But I had hoped that trimmers are idiot proof... But then again, I can find any loophole.

so, I thought that maybe leaving the wood 1/64" proud would be ok. the kit should still have plenty of purchase when squeezed together and it would make sure that there are no gaps between the finished kit parts and the wood.

thanks for the taking the time to read my ramblings (for the brave few who get this far )
john

[sachbvn]

John I have notices the same issue....it seems like the brass tube often pokes out just a smidgin. I have used a file, I have used the barrel trimmer just a tad more....I'm not sure if there is a problem going on here, or if it as an acceptable amount to be exposed (the brass smidgin). I would just try to be real ginger when getting close to the brass tube and see how that goes. Hey, FYI - get youself a small diamond file and hone up the back, FLAT part of each cutter face, don't mess with the angled part, just the flat part. It does wonders for the quality of the cut.

I think woodcraft has them for 7 or 8 bucks.

Zac

[TDHofstetter]

You can do'er either way, Fairby - either trim totally flush to the brass or leave the wood proud a scoche. If you find yourself with slightly proud brass, you can trim it back again by GENTLY rubbing against a piece of 220-or-better sandpaper, holding the blank perpendicular to the paper. It'll be mostly self-perpendicularizing. It takes VERY FEW STROKES on 220-grit if the paper's sharp; there's precious little brass in the end profile of a tube.

If you find that your trimmer is rolling over the end of the tube, it's DULL. Brass should scrape very clean with a sharp scraper (your trimmer).

[sawduster]

I generally cut my blanks pretty close to the length of the tube, maybe 1/64" longer so there is not a lot of leeway there. When trimming, once I see that the trimmer has removed wood in a complete circle, I'm done. Sometimes that slices ever so little off the end of a tube but that doesn't affect how the pen goes together. If I find that there are little bits of metal on the inside edge of the tube, a quick touch with a counter bore shaves those off.

[Ruffnek]

John,

I've turned a few dozen pens but am no means accomplished to the extent some of the guys here so keep that in mind.

I trim the end until I see the brass tube shine a bit, indicating that the trimmer is also cutting on it. The problem with the brass extending beyond the blank is that the trimmer is ever-so-slightly larger than the shank that it slides over. The brass, or at least a sliver of it, can push in between the trimmer and the shank, leaving it slightly longer than the blank. Like Zac said, a file will make it flush pronto.

A better method for trimming is to use a 90 degree jig and trim the glued-up blank against a disc sander. Everything will be flush that way.

[sachbvn]

Exactly what Cody described is probably what is happening.

The brass tube (which is thin) is getting between the shank the the cutter....some of the time.... so - what you need to do is either - like previously mentioned, stop just shy of the brass tube being exposed, OR - file it flat once it sticks out ever so slightly.... one thing to mention - stick the shank back in the tube and twist it a few times - just to open up any of the tube you possibly collapsed inside the blank, no need to trim anything - you are just making it circular again.


Zac

[Doug B]

John, I'm not sure if I am understanding your issue correctly. But, the barrel trimmer should not leave the brass proud of the wood when you are done. It should be exactly flush. I have 3 trimmers and none of them do this, so I thinking it might be something else. I always chamfer the tube after trimming so that the pen hardware presses in easily. If that is the problem, then that is normal and you just need to chamfer the tubes after trimming.

I've been working on documenting how I make a pen, so I just happen to have a couple pics that might help...In the pic showing the trimmer, you can see that the blades are recessed deeper into the shaft so that there is no way the brass can be left proud. Is yours like that?



And here is how I chamfer the tubes


So you guys are getting a sneak peek at a small part of the pen making instructional I'm working on...those are pics 18 and 22 out of about 50

Oh yeah, to answer your question...especially on a slimline the thin layer of wood is likely to be easily damaged without a tube under it...I would not be comfortable leaving the wood proud except on the nib end and the clip end where the hardware will protect the wood. In the middle, I would not leave any wood unsupported. But length, while sometimes critical in some pens is pretty flexible in slimline pens. The upper barrel can vary in the extreme - long or short, it does not really matter as long as it is at least long enough to cover the twist mechanism. The lower barrel length and how far you insert the twist mechanism determine the ink refill extension and retraction and is important. But, if you have a longer lower barrel you just need to insert the twist mechanism in farther and if you have a short lower barrel you would not insert the twist mechanism as far as usual. There are limits, but it is very flexible and you just need to take care when putting the twist mechanism in to make sure it is positioned where you need it. Try not to push it in too far...that is a lot harder to fix than if you don't have it in far enough.

For a cartridge pen, well, that is another matter, but you probably already have that part figured out.

[mapleman]

thanks for the help guys.

Cody and Zac,
you hit the nail on the head. upon closer inspection (and use over the weekend) I saw that brass get between the tube cleaner and the barrel trimmer. it is a modular type, so the barrel head fits over the length - but no recess.

Jerry and Tim,
I tried doing one pen (red oak, gunmetal saturn kit) and left the wood a scoach proud... and it seemed to work. now oak is harder than, say, butternut. and maybe i could not get away with it on butternut (or sycamore)... but so far so good. BUT - that is a saturn where there is more meat. i dunno about a slimline...

Doug,
thank you very much for the pics and info. I wish that my trimmer was made like yours. I got the basic PSI type trimmer, so it is a cheapy. and, by the way, i bvery much enjoyed your tutorial....

thanks again guys,
john

[Doug B]

Thanks John. I have 3 trimmers and can't remember where they came from for sure, but it might be worth getting one with the blades recessed into the shaft when you get a chance.