Question: drilling a scalloped blank.

[Freethinker]

I have made a pen with just about every style of segmenting that I know of......celtic knots, 360 herringbone, various Kallenshaan laser blanks, brass and aluminum sandwiched between wood and acrylic, but I have just now made my very FIRST scalloped-end blank........and now I am pretty anxious about drilling it.

The wooden part is a center of box elder burl, with bubinga slabs on the sides, with 0.018 aluminum between each strip....then the 45 degree scallops at the ends are ivory acrylic with aluminum sandwiched between the wood and the acrylic. (very much like the recent pens posted by wiset1)

Does anyone have any special method they use, or trick to help avoid a blow-out?

I spent quite a bit of time on this pair of blanks, all eight end pieces --four at the end of each blank-- are glued on with 5 minute
epoxy, and the acrylic I used (the only one I had on hand resembling ivory) is a tad brittle.

I have the Norseman drill bit set,.and they are excellent, but they're so sharp that they sometimes tend to be a little "grabby".

I will be drilling on the lathe.

Is it advisable to drill a small --say, 1/8" or 5/32" -- hole first, and then go to the larger bit?

Also, should I begin at the wooden end and drill toward the scallops, or go thru the scalloped end first?

If anyone has any advice or experience on this they could offer, I would be most appreciative.

Thanks.

 

[ragz]

tape the exit ends, use a center bit on the start end, go slow

 

[BRobbins629]

An old Eagle trick. Take some 2" gauze, wrap it around the blank and drizzle thin CA over it until solid. Turn it round between centers, leaving a layer of CA-ed gauze on top. Insert in collet chuck, use center bit to start, and drill with sharp bit.

 

[PenMan1]

An old Eagle trick. Take some 2" gauze, wrap it around the blank and drizzle thin CA over it until solid. Turn it round between centers, leaving a layer of CA-ed gauze on top. Insert in collet chuck, use center bit to start, and drill with sharp bit.

Beat me to it, Bruce! GREAT TIP!!!!

 

[wiset1]

It has all been said...but, I find that drilling a pilot hole first helps and I drill from the scalloped side first so you'll be drilling into it instead of pushing it out and away. Hope that helps

Lots of thin CA and tape...or gauze as noted above

Good luck

 

[Ruby pen turning]

I always use a center bit then 7mm and go up in sizes until the final bit. If there is metal go slow and let it cool for a short while GO SLOW. I have drilled starting at scallops ending at scallops. Metal is what blows the segmented pens up. Never heard of the gauze trick, I may have to try that one.

 

[Freethinker]

Good ideas all.....I knew about the gauze trick, but had forgotten it.

One concern i have always had about doing the gauze trick is that while in the collet chuck the blank is going to need to be DEAD accurate on center so as to make the the scallops look correct, and I am concerned the gauze/CA covering will not be exactly concentric.

Never thought about wrapping with gauze THEN turning between centers, THEN drilling........that might indeed provide the needed concentric centering to do the trick.

Thanks guys, for all the advice.

~~~~~~~~~~~~~~

Oh, and BTW, Tim/wiset1........your pens of this design are SO beautiful (I went to Flickr and looked at all of them) that I had to borrow your design and try one, but it will be for my own private collection. IF i manage to drill this one without blowing it up, I want to do a couple more, experimenting (as you have) with different woods.

 

[leehljp]

To be dead accurate, mark the entrance and the exit points that you want on the ends of the blank. I use a stubs type of drive center on the head stock and bring it up to the point on one end of the blank. Then I pull up the tail stock live center to the point on that end. Next, I turn the tail stock end just enough to round it and be able to change it to the head stock in a collet chuck.

From that point in the process, I drill from the tail stock end.

One other note - I am extra careful on these types of blanks. Even after drilling and gluing in a tube, I turn about 1 inch or so, at at time. I will wrap thread or gauze around that 1 inch that I just did and CA it. Then turn another part. The same. When the blank is round from one end to the other, then I begin turning the gauze and CA off and down to size. I keep CA'ing it all the way to size.

I spent considerable time on a pen stripe one a long time ago and the extra time that I mentioned here was well worth it.

 

[Freethinker]

Okay Hank. Thanks for the tips.....i would probably have NOT been as cautious as you recommend, but now that I ponder what you've said, some extra precautions like you speak of are likely worth it.......i will sure be sick if i get this thing close to finish round and it blows out.