Dumb question? Squaring an blank for 8mm tube

[sachbvn]

Question..... I'm thinking about trying a couple kits that have 8mm tubes instead of the 7mm that slims have.... I have a blank squaring/cutter thing - you know, shaft goes into the tube and cleans it out - cutter head squares blank.

Would the one I use for 7mm work the 8mm too? Or is that just headache waiting to happen?

I don't really want to buy another cutter as I am already going to need to buy bushings, drill bit, etc....


OH - another question.... when using the squaring tool... it seems like it cuts down a LITTLE too far.... like...there is a tiny amount of brass tube that sticks out past the wood blank.... I think it may be keeping my nibs from seating properly. This sound like a possibility?


Zac

[TDHofstetter]

I instantly don't like your trimmer. It should trim the brass right along with the wooden tube. I say it's defective.

To do 8mm tubes, slip a 7mm tube inside the 8mm tube. That'll get you much closer than just wallowing around inside that big 8mm tube.

[Ruffnek]

Ideally, barrel trimmers should have a "bit" for the various size tubes. Tim's idea sounds like it will help keep the trimmer centered but if there is glue in the 8mm tube, the 7mm tube won't go inside.

I think Marc and others are using disc sanders with a 90 degree jig to trim their blanks. If you don't have one, you can make one from MDF that attaches to the lathe faceplate.

[woodmangler]

Pen mills.... hate 'em

They caused me nothing but problems for me... so I started reading the forums and finding out about pen mills... and found that most turners don't use them.

I saw a couple of different jigs for a disc sander... the problem with those jigs was that it only did one size of pen, or you had to make bushings to slide over the 7mm rod... too much trouble.

So, I came up with the jig I use now... I already had a set of transfer bits from Harbor Freight, so my cost was zero... if you can pony up $10 you can make one of these and have the added benefit of having a ready made set of dis-assembly tools as part of the bargain.

Very, very simple to make, works on all pen sizes... and squares up the blanks without the risk of a pen mill deciding to dig in and ruin a blank.



woodhelp.com/Jigs.htm#SquaringJig2

[sachbvn]

Sucky part is Marc, (and I've considered just going the disc sander route) NO disc sander....so.... it'd be more than a 10 buck investment.

I may try and rig something up on the lathe using the faceplate to hold some MDF with some paper attached to that..... now just gotta come up with a way to SQUARELY bring the blank to the paper.... I don't have a check so I can't just put that on the tailstock and work backwards.... hmmm.....

I agree Marc - the barrel trimmer has totally sucked when it splits the pen black.... but - I've learned to feather it....which helps, but... I have had some tear out - HELLO $6.50 Thuya Burl blank- (That one is lathered with shavings and epoxy, we'll see how it's repair went)


Zac

[woodmangler]

OK... no sander...

If you are feeling like a jig master, and really want to save some moolah, I am sure you can come up with something like this... I made this a loooooong time ago... but it worked fine for doing segments (what I was into at the time) It just sits on the lathe with one of those plastic jig knobs underneath attached to a bolt that goes through a bar... so you tighten the knob and the bar raised up and grabs under the ways... clear as mud eh?

Picture a miter slot and a jig something like the one I use...

[Doug B]

Probably too late Zac, but I may have a solution for you...it works for me anyway

I do have 7mm, 8mm, and 10mm barrel trimmers. So I already have an 8mm but and I use it a lot because I use a lot of 8mm tubed kits. But, for a Gatsby that uses a 27/64 tube I just use my 10mm barrel trimmer.

One advantage to chucking the barrel trimmer into a drill press is that (if your pen blank is square) you can put the blank back into the pen vise and know that you will get a square trimming even if the barrel trimmer is somewhat smaller than the tube. You would be surprised how well your eyes can see if the trimmer is staying square and centered in the blank as you lower it.

This only works if your pen vise ensures that the blank is square with the drill bit/barrel trimmer. I use my 10mm barrel trimmer all the time for pen kits that require 27/64ths tubes, such as the Gatsby and Wall Street II.

Think about what you are trying to accomplish - you need the wood trimmed to the barrel perfectly squarely to the tube. Any way you can achieve that end is acceptable

Just another way to skin a cat.

[TDHofstetter]

...and yet another way - a way I employ - is to use a reloading case trimmer to trim those ends. That's just about as square as square gets.

[Doug B]

I ran across this tutorial over at IAP, and this guy has yet another method for squaring pen blanks. Very interesting.

Thought y'all might find the whole "turning between centers" topic interesting too. I sure did. I have heard about it, and Marc uses it, but it was something I never could quite wrap my mind around until I read this tutorial.

Aiy! Just when you get your procedures down pat there is always something new and better that comes along

So, here it is: www.penturners.org/forum/showthread.php?t=54760