Slimline drill size

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airborne_r6

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Oct 28, 2008
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279
I ran into a problem making some slimline pens last week. I have never made a slimline that required me to reverse paint the tube until last week and when I did the tube wouldn't fit after I painted the blank. I ended up slightly reaming out the hole using a .270 cal brass bore brush mounted in my drill press. However, this made the hole just big enough that when I sanded the blank to the final size I sanded through the blank and into the epoxy at one end.

A 7mm drill bit is .2756 inches. I have been thinking of trying a J drill bit which is .277 inches.

Anyone have any other suggestions?
 
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plantman

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Jan 2, 2012
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Green Bay, Wi
Wayne; The slimline is one of the hardest pens to turn because of the thin wall thickness of the blank that is left. I will usualy scrap the center band and use a larger one, or go with no band. Just add a segment to the cap end where they meet in the center. Turn the blanks oversized to the shape you like, and round over the ends where they meet the nib and cap. I often use the J bit myself. Jim S
 

RMayoIII

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Feb 14, 2012
Messages
211
Location
Belmont, NH
I usually go with the 7mm in wood and a letter J in all my acrylics and pr resin blanks sure to having to paint the tubes or the drill hole. I have never experienced the problem of sanding through, may be that I don't like super thin pens.
 

ed4copies

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Mar 25, 2005
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24,528
Location
Racine, WI, USA.
The OD of the 7 mm tube is .266". The OD of the nib is .388"

If you drilled the hole at .277 ( "J" bit which Berea suggests), this gives you .111" (.125 is an eighth of an inch. Of course you are dealing with the diameter, so your "real clearance" is .055" (just shy of 1/16"). All of this assumes your hole is absolutely cleanly cut and the tube is lying dead center--neither of which is likely.

So, one suggestion: Use spray paint. It will make a thinner coating and it is likely to be more uniform, so your hole will not have to be made larger. OR, save the "paint tube" blanks for bigger pens and use opaque blanks for slimlines.

Hope this helps!
Ed
 

airborne_r6

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Joined
Oct 28, 2008
Messages
279
I will give the J drill bit a try.

I don't like thick slimline pens, that's part of why I don't usually make them. With my slimlines you can just about hold a straight edge from nib to clip and have it touch all the way. And that is not exaggerating, I tried it with the last ones I made to make sure I was getting them as straight as I like.

I am only making them because I have had a few requests for them and I am also starting to make styluses.
 

airborne_r6

Member
Joined
Oct 28, 2008
Messages
279
The OD of the 7 mm tube is .266". The OD of the nib is .388"

If you drilled the hole at .277 ( "J" bit which Berea suggests), this gives you .111" (.125 is an eighth of an inch. Of course you are dealing with the diameter, so your "real clearance" is .055" (just shy of 1/16"). All of this assumes your hole is absolutely cleanly cut and the tube is lying dead center--neither of which is likely.

So, one suggestion: Use spray paint. It will make a thinner coating and it is likely to be more uniform, so your hole will not have to be made larger. OR, save the "paint tube" blanks for bigger pens and use opaque blanks for slimlines.

Hope this helps!
Ed

I will give the spray paint a try.

One of my brother-in-laws is 9 years old, mentally and physically handicapped and won't be around much longer. He saw some pens I made for one of his brothers and wanted me to make him one. He has an Ipad that he uses continually and so I want to make him a stylus. He won't use an actual pen but will use a stylus all the time. I asked him what color he wanted and he said blue and red and purple and yellow. The Confetti acrylic blank is perfect, but needs to be reverse painted. If the pen wasn't for him I would use a different blank or kit.
 

ed4copies

Local Chapter Manager
Joined
Mar 25, 2005
Messages
24,528
Location
Racine, WI, USA.
The OD of the 7 mm tube is .266". The OD of the nib is .388"

If you drilled the hole at .277 ( "J" bit which Berea suggests), this gives you .111" (.125 is an eighth of an inch. Of course you are dealing with the diameter, so your "real clearance" is .055" (just shy of 1/16"). All of this assumes your hole is absolutely cleanly cut and the tube is lying dead center--neither of which is likely.

So, one suggestion: Use spray paint. It will make a thinner coating and it is likely to be more uniform, so your hole will not have to be made larger. OR, save the "paint tube" blanks for bigger pens and use opaque blanks for slimlines.

Hope this helps!
Ed

I will give the spray paint a try.

One of my brother-in-laws is 9 years old, mentally and physically handicapped and won't be around much longer. He saw some pens I made for one of his brothers and wanted me to make him one. He has an Ipad that he uses continually and so I want to make him a stylus. He won't use an actual pen but will use a stylus all the time. I asked him what color he wanted and he said blue and red and purple and yellow. The Confetti acrylic blank is perfect, but needs to be reverse painted. If the pen wasn't for him I would use a different blank or kit.

In that situation, we do what has to be done!!

Another idea, knowing what you are trying to do, use the white tubes that are available on several sites (including one that shows up in my signature):biggrin::biggrin:.

They are .268". While you MAY be able to see some glue (IF you get particularly unlucky), it sounds like your "customer" is not going to "nitpick" your work. That way the final pen will be a little thicker and somewhat more durable, as well.

FWIW,
Ed
 
Joined
May 14, 2012
Messages
667
Location
Rapid City,SD
I take the tubes with no blanks on them and put them on my lathe with bushings. Then I set the speed to low and use a large chisel tip sharpi on my tool rest and coat the blanks. While that is drying (still on the lathe) I drill my blanks and usually the ink is dried and I glue them right in. I have never had a problem with this method yet.

Levi Woodard
Woodardwoodworks.com

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tommy2tone

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Mar 14, 2013
Messages
177
Location
Hampton, VA 23666
I take the tubes with no blanks on them and put them on my lathe with bushings. Then I set the speed to low and use a large chisel tip sharpi on my tool rest and coat the blanks. While that is drying (still on the lathe) I drill my blanks and usually the ink is dried and I glue them right in. I have never had a problem with this method yet.

Levi Woodard
Woodardwoodworks.com

Sent from my Galaxy player using Forum Runner
Did you mean "tubes"? You said you coat the blanks.
 

butchf18a

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Joined
Dec 3, 2010
Messages
503
Location
woodland, wa
Rat tail rasp

Get yourself a small diameter rat tail rasp. After drilling with 7mm or J size bit a few strokes with the rasp will enlarge the hole slightly, as well as provide additional surface area for glue (whatever you use) to grip. Don't forget to clean out hole after using the rasp. Simple and it works.
 

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