drilling the 12.5mm on jr gent

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hazard

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What is the trick to drill the upper barrel on these pens. I broke 3 blanks with this drill bit. 2 cocobolo and one other dark exotic blank. On the 3 cocobolo blank I predrilled with the 10.5mm bit. I think next time I will go with a smaller bit for predrill.

What are your tips for this.

I use a normal drill press vise. Maybe I should come up with something to support all sides and maybe the bottem

Chris
 
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Try drilling a pilot hole, step up to a slightly larger bit, THEN drill your 12.5mm hole. Doing this is doubly beneficial: first, you'll blow out blanks very seldom this way, and second, your larger, more expensive bits will stay cooler and sharper, and last longer.
 
No need for a pilot hole. Just do not drill all the way through the blank. Cut your blank longer than needed. Drill to the needed depth. Then cut to length.
 
Originally posted by hazard
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I use a normal drill press vise. Maybe I should come up with something to support all sides and maybe the bottem
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I agree with Stan. Drilling pilot holes is, as far as I'm concerned, a complete waste of time. I don't think you need something that supports it on all sides, but you absolutely must have something to support it on the bottom. Is that where it's blowing out, as the bit exits the wood? You don't say anything about drill press RPM or how fast you're feeding the bit or how often you clear the holes, or how sharp the bit is. All of these things can contribute to blowing up blanks while drilling. If you got this bit from CS, it probably wasn't sharp when you got it. I sharpen every bit I buy before I use it the first time. I can't count the number I've purchased that were dull right out of the package.
 
I use a Jorgensen hand screw clamp to hold my blanks when drilling. I coat the end of the blank where the drill will exit with thin CA and I also use a scrap piece of wood under the blank. I make several passes drilling into the blank extracting the drill to clear the hole and keep the drill from over heating. So far this has kept me from experiencing any blowouts or cracking. I do cut my blanks about a 1/4" long in case there is a problem when the drill exits the blank. If there is a problem, hopefully I when trim that 1/4" off the blank will still be usable.
 
My drill press is running at 1100rpm. I extract the drill about every quarter inch. Maybe more or less but alot. I am feeding the drill slow and not forcing it at all. When I break thru is when I have problems. It splits the blank in half.

I will cut the blanks longer and cut off what I don't drill thru. I think this will work good for me.

Thanks
Chris
 
I probably make more Jr Gent pens than anything and have yet to have one blank problem while drilling. Actually, I don't have problems with drilling any of the blanks I use. Perhaps it's because I use a collet chuck to hold the blank while I drill the hole on the lathe.

When I drill a blank, I first put it on the lathe and turn it round then I put it in a collet chuck and drill it. Some will argue that this is a waste of time, and that's OK with me, because I'm happy with the results and don't mind the extra 1.34762 minutes it takes me. I started doing this because I was doing a lot of segment work and had to be perfectly centered AND I wanted to see what the blank was going to look like before doing a lot of work on it. Having a 3/4" round blank gave the view I wanted.

If you look at the end of a collet, you will see that the blank is held all the way around by the collet. That may help in not having blow outs, I don't know. All I know is that I haven't had a blank blow out since drilling on the lathe and have dead center holes every time.

Chris, if you're having that much trouble, perhaps you should at least give it a try.
 
When we drill we have a piece of scrap wood under the blank, so when we drill through the blank it drills into the scrap. This provides support under the blank. We drill at 700rpm and do not have ANY problems with blow out.

Mike & Linda
 
I think it may be the bit, I have had problems like that after buying and using new larger sized bits. I have used Stan's method and it's been working for me. My blanks were spliting just as my bits were exiting the blanks.
 
It must be the bit and/or no proper vise. I did lately a lot of Statesman Jr and Retros, both the same size as the Gent Jr. I am using a 1/2" drill bit and drill fast at about 1300 rpm and use PHD vise with an old piece of wood as a backer board. My drill bits are DeWalt pilot point drill bits. I think the 1/2" is for me an advantage since I do mostly acrylics for these pens and paint the inside of the blanks as well as the tube twice with Testor model paint.
 
Slow down the drill press. Somewhere around 500 to 650 rpm is very good. Are you using a drill bit from CS? If so, get it properly sharpened. As they come they are El Junko. But sharpened are OK and should last longer than you. Like the others said, pre-drilling, IMHO, is a waste of time and can introduce other problems.
 
I had the same problem this weekend. I believe the flutes of the 12.5mm bit are too aggresive for drilling acrylester. Brand new bit (Dawn bought it for me, but looked like CSUSA packaging - 12.5 mm - can't be too many sources.

Its not a BAD bit, I think I need to use it on waste wood for a while, until it does not "bite" quite so much. Probably will work great on wood.
 
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