How do you trim your barrels?!

[RyanS]

I'm beyond frustrated.

Almost every pen I turn has some degree of OOR that I think I can finally attribute to a single source: non-square barrels.

I've read here (and have experienced personally) that the drill-inserted barrel trimmer can ruin a nice blank, but I can't get my belt sander to true up my blanks well enough, even when using a miter gage and fence.

My theory is that this causes the bushing to sit slightly off axis and causes the frustrating wobble I've been experiencing, leading to barrels that are too thick on one side of the tube and too thin on the other.

Please advise!

 

[cseymour]

Have you tried using the lathe to do final squaring? I have had pretty good experience using a belt sander to get close then finish with sandpaper on a wheel mounted on headstock.

Just a thought.

Chris


Sent from my iPhone using Penturners.org mobile app

 

[mark james]

Rick Herrell's Offset Lathe sanding jig (or similar). Punch press set from Harbor freight, self made headstock sanding block.

 

[Gersh]

I use the same setup that Mark detailed.

 

[Curly]

Ryan your theory is correct. The sander you have can be made to square nicely as long as you make a transfer punch holder for it. With the punch squared up to the disc by adjusting the table and the miter gauge you'll get square ends. I'll post what I use again so you know what I mean. There are commercial versions sold by different vendors if you would rather buy it. With a belt sander you need to make sure the belt is tight against the platen and if you twirl the blank as you get close you ensure it will be square.

A little tip. Put the bushings in the trimmed barrel, then into the lathe between 60º centres. Turn the lathe on low speed and bring the tip of a fingernail to the bushing. If it is slightly out of round if you feel a little tapping it isn't quite square. If no tapping that end is good to go.

 

[WShankle]

The barrel trimmer that I use is like an end-mill with a hole drilled in the center where what I would call a reaming pin goes through the barrel (glued to the blank at this point) and cleans out any glue inside the barrel. Mine reaming pin is turned down so that you can put different size pins for different barrel inside diameters. This is all set up in a drill press and I put the blank which is un-turned and usually still square at this point in a drill press vise (untightened) with the barrel trimmer in the barrel and resting on top of the blank that I want to trim. Now I chuck up the trimmer to the drill press and with the trimmer still in the blank I tighten the drill press vise. Doing it this way I know that my blank is in alignment with the drill press spindle, and there is minimal binding. Only now do I begin to trim and I do this taking light cuts until I get to the tube and when I just see the end of the barrel getting bright, I stop, change sides, and repeat. For the reaming pins that I have that procedure yields a spot-on surface. If it's a size that I don't have a pin for, I usually trim with a 5-inch disk sander on the outer end of the wheel, typically with worn paper, being mindful of heat. I can usually eye-ball one to within a couple thousandth's if i'm looking over the wheel. If I'm turning a material that is easily fractured, such as mica, I usually size my blank with the sander method to avoid the possibility of a blow-out. Hope this helps.

 

[MPVic]

The barrel trimmer that I use is like an end-mill with a hole drilled in the center where what I would call a reaming pin goes through the barrel (glued to the blank at this point) and cleans out any glue inside the barrel. Mine reaming pin is turned down so that you can put different size pins for different barrel inside diameters. This is all set up in a drill press and I put the blank which is un-turned and usually still square at this point in a drill press vise (untightened) with the barrel trimmer in the barrel and resting on top of the blank that I want to trim. Now I chuck up the trimmer to the drill press and with the trimmer still in the blank I tighten the drill press vise. Doing it this way I know that my blank is in alignment with the drill press spindle, and there is minimal binding. Only now do I begin to trim and I do this taking light cuts until I get to the tube and when I just see the end of the barrel getting bright, I stop, change sides, and repeat. For the reaming pins that I have that procedure yields a spot-on surface. If it's a size that I don't have a pin for, I usually trim with a 5-inch disk sander on the outer end of the wheel, typically with worn paper, being mindful of heat. I can usually eye-ball one to within a couple thousandth's if i'm looking over the wheel. If I'm turning a material that is easily fractured, such as mica, I usually size my blank with the sander method to avoid the possibility of a blow-out. Hope this helps.

Sounds good - do you have any pics?

 

[JimB]

 

[JimB]

I had a little trouble posting the pic above. I use a barrel trimmer but fine tune using my little home made sanding 'disc' and a punch (harbor freight set) in a Jacobs chuck in the tail stock.

 

[RyanS]

This has all been very informative. "Likes" for all of you! Thanks, everyone.

 

[leehljp]

I use Rick Herrell's Sanding Mill.

I just put the blank (with tube in it of course) onto the sanding mill rod (7mm?) and hold it firmly on the rod and move it towards the sandpaper as the mill turns. Squares it up fine, and I am particular about square.

 

[Morse]

Ryan your theory is correct. The sander you have can be made to square nicely as long as you make a transfer punch holder for it. With the punch squared up to the disc by adjusting the table and the miter gauge you'll get square ends. I'll post what I use again so you know what I mean. There are commercial versions sold by different vendors if you would rather buy it. With a belt sander you need to make sure the belt is tight against the platen and if you twirl the blank as you get close you ensure it will be square.

A little tip. Put the bushings in the trimmed barrel, then into the lathe between 60º centres. Turn the lathe on low speed and bring the tip of a fingernail to the bushing. If it is slightly out of round if you feel a little tapping it isn't quite square. If no tapping that end is good to go.

View attachment 222900

Hi Peter.
I use a similar set up to you , but use an engineers "V" block to hold the transfer punches, also using "earth magnets" to secure the V block, and punch to the disc sander bed.

 

[PenPal]

Please see attached my method of squaring all blanks,using two sets of pin punches (metric and imperial.The set up is accurate. Using a drill chuck as used in a hammer drill the holding jaws are longer and stronger. Self explana

tory really. This way and others you only have to do it once in the set up.

 

[randyrls]

Hmm.... I have Rick Herrell's off-set sanding jig, but I was using a square collet block the other day and realized it would work just as well on a disk sander with the transfer punches. Square Collet Block
The only reason I post this is you have the parts already why not use them.

 

[TonyL]

Rick Herrell's off-set sanding jig with 180 grit diablo 5" circular adhesive sand paper.

 

[Woodchipper]

I square on the drill press. Tried a DIY sanding disk on the lathe but didn't care for it. I square the pen mill to the bottom of the vise (not vice- got too many of them) with a precision triangle made by an ME. Photos of both attached.

 

[philipff]

I'm beyond frustrated.

Almost every pen I turn has some degree of OOR that I think I can finally attribute to a single source: non-square barrels.

I've read here (and have experienced personally) that the drill-inserted barrel trimmer can ruin a nice blank, but I can't get my belt sander to true up my blanks well enough, even when using a miter gage and fence.

My theory is that this causes the bushing to sit slightly off axis and causes the frustrating wobble I've been experiencing, leading to barrels that are too thick on one side of the tube and too thin on the other.

Please advise!

For years I have chucked up blanks that are glued up and set them square with the tailstock. Then, using a round nose scraper just turned the blank down until the brass is flush. Follow that with a bit of sanding and I am done so I then reverse the blank and do it again. Done and done. P.

 

[Woodchipper]

I've read here (and have experienced personally) that the drill-inserted barrel trimmer can ruin a nice blank

Never had a falilure along that line. Had some oily wood or synthetic material fuse to the drill bit when it got too hot. I look at the glued tube and blank. If there is some glue in the tube, I lightly ream with a fine round file. If there is a lot of wood above the end of the tube, I take small cuts on the bandsaw until I am almost to the tube. Cuts down on the time to square the ends. Plus I save the cut-offs for segmenting...one of these days.

 

[JimB]

Have you sharpened your barrel trimmer?

 

[WriteON]

Lathe trimming for me. Take my time ... works like a champ each and every time.

 

[penicillin]

I use one of the pen mill sets sold by Rockler. I like them because they have six cutting edges instead of two or four. I believe that the six-edge versions cut smoother, with less chip-out. You get four barrel cleaner inserts, a slimline tube, a small allen wrench in a small plastic box. You choose the correct insert and tighten the mill on it with the allen wrench.

https://www.rockler.com/barrel-cleaner-pen-mill-kit

I sharpen them with diamond tipped hones (small paddles). I carefully position and angle the hone so it is flat on the back of each cutting edge. The goal is to flatten the back, without rounding over the end or altering the bevel. It is far from perfect, but it works, and it helps me stretch the budget. Note: The grits are in alternating order. If you use more than one grit, you must switch paddles between steps. Rockler sells a three-paddle diamond hone set, but I chose these instead - four grits and metal paddles vs. three grits and plastic paddles. Sometimes I skip the course grits and use only the two finest grits:
https://www.rockler.com/double-sided-diamond-hone

Plastic handled alternative that I did not buy:
https://www.rockler.com/diamond-hone-sharpening-set

Someday I will build myself a proper sanding disk with a squaring/milling jig for the lathe.

 

[Woodchipper]

penicillin, here is a setup I made.

 

[penicillin]

penicillin, here is a setup I made. [Image of nice pen milling jig.]

Nice! Yeah, I will build something like that. It is far down in the woodworking queue, though.

 

[Woodchipper]

Used scraps of plywood and fasteners from the accumulated stock over 60+ years. I did spring for a faceplate to mount the disk.

 

[howsitwork]

HSS counter bores are excellent and you can get ones with interchangeably guide pins retained by grub screws on the shaft.
I have a solid one with a 6.1mm pin which is excellent for slim line tubes. It was sold as a counterbore for an m8 cap head screw, I just checked the size of the guide pin and it's fantastic. It has 4 cutting edges and cuts a flat bottom led hole ie level face around the tube.