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draw boring tool?
#9560
02/17/07 05:23 PM
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Joined: Nov 2006
Posts: 850
mo
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Posts: 850 |
Does anyone know of a tool that can be used to set a point for drawboring. Instead of creating a point on the tenon that is centered in the peg hole and then going back and drilling a fraction closer to the shoulder from that centered point, is there anything that saves steps? It seems a cylinder the size of your peg hole with some sort of offset spring-loaded pin would work. Then you would not have to be so careful as to not set the original point too deep. The outside of the cylinder could have some marking on it that shows the radius of center to pin to edge. Then you could go around and just whack the pin and come back and drill.
Anyone know of a tool for this or something along the same lines?
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Re: draw boring tool?
#9561
02/17/07 05:47 PM
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Joined: Feb 2003
Posts: 135
Collin Beggs
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Jon Snow makes just such a tool at: www.windysmithy.co.uk I lay my draw-bore out with out pre-assembling, so there is no extra step involved. It takes me about 10-15 seconds to lay out the draw on a tenon. -Collin
"The lyf so short, the craft so long to lerne." Geoffrey Chaucer (1343-1400)
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Re: draw boring tool?
#9562
02/17/07 06:05 PM
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Joined: Mar 2002
Posts: 344
Joel McCarty
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Posts: 344 |
Thanks for the Jon Snow reference.
I can imagine timber framers in the Americas having long discussions about the offset being too much or too little, varying by species, etc.
It is of course possible to make these tools from WOOD, with a metal pin in precisely the spot you prefer it.
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Re: draw boring tool?
#9563
02/18/07 12:28 AM
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Joined: Feb 2006
Posts: 718
Dave Shepard
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I layout the pin locations and then just move the drill over by eye to get the draw. I see the Windy Smithy had several other timber tools, but I'd hate to have to pay by the pound and then ship them here.
Dave
Member, Timber Framers Guild
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Re: draw boring tool?
#9564
02/18/07 12:50 AM
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Joined: Oct 1999
Posts: 463
Roger Nair
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Posts: 463 |
I have used a peg with a nail offset from center for years. One nice feature is you can adjust the offset by filing the point of the nail. However, I now use a Protool drilling frame and I find I can bore mortise and tenon consistantly from the layout face, thus saving some effort during assembly.
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Re: draw boring tool?
#9565
02/18/07 03:47 AM
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Joined: Nov 2003
Posts: 1,124
Mark Davidson
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I'm with Colin, layout the draw on the tenons as soon as they are cleaned, generally speaking. If you are unsure about the layout, and the fit of the joints, then drilling after a prefit is probably a good idea.
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Re: draw boring tool?
#9566
02/18/07 04:40 AM
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Joined: Jan 2006
Posts: 30
chris robinson
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using a 3/4" bit to mark the drawbore in a one inch hole offsets it 1/8", just hold it tight to the joint side of the hole. i guess a 7/8" bit would offset 1/16", but who keeps those annoying 7/8" bits around to get accidently used where the one inch was supposed to be?
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Re: draw boring tool?
#9567
02/19/07 12:47 AM
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Joined: Nov 2003
Posts: 687
Gabel
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Posts: 687 |
I've made a bunch from a peg with a nail driven in and snipped off and filed to a dull point -- really cheap (3 minutes or so).
I also have one from the UK like Jon Snow makes. It pricks the offset point as well as marking the outline of the existing hole. Nice tool.
Gabel
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Re: draw boring tool?
[Re: Gabel]
#10851
03/31/07 06:39 AM
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Joined: Nov 2006
Posts: 850
mo
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Thanks for the replies everyone. Some of you have said that you lay out the draw on the tenon without pre-assembly. How do you make sure that you are precise enough considering that if your drilling is just a fraction off then it might draw the other way.
Sometimes when I read posts about timberframing (especially mine) they can get confusing.
When we drawbore. We pre-fit and use a peg of the appropriate size slightly sanded around the circumference (thanks Joel and Gabel!) with a pin offset from center the distance we want to drawbore. If you lay-out without fitting up how can you make sure your drilling is precise enough to draw the shoulder?
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