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Location: Northeast Pa
I got these kits from Arizona Sil. Also got Norsman 7/8 twist drill bit. I've seen Tim Yoder video on making the tube, and read Barry Gross' magazine article on same. The drilling seems daunting on drill press, so I tried Barry's method of using the lathe with the 1 1/4 Burmese Blackwood blank held in scroll chuck. The entry is a bit rough until the twist bit is fully engaged. I made up a couple of blanks of 2x construction material to practice. I just drilled two of them.
As I pull the blank off the lathe, the entry hole is 0.880 to 0.900. The tubes mic at 0.845. The bit is 0.875. Way to sloppy for my taste. For those who know:
- can epoxy make up 0.055?
- is the construction pine throwing me off? I haven't tried hardwood yet.
-any suggestions for improvement?
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03-14-2017, 07:52 PM
(This post was last modified: 03-14-2017, 07:57 PM by Arlin Eastman.)
Yah Pine is pretty soft but should go OK
What I do is predrill big holes, say if I was drilling a 1" hole I would use a 3/4" bit and while it was still on the lathe widen just the front of the hole part so the drill bit goes in and centers better.
Also get a better drill bit that will fit better in the hole for the brass. I will try to find one on line that will work better for you.
Looking forward to seeing what you make.
I have made mine directly from Spanish Ceder and I have two to make and embellish as soon as I get better.
As of this time I am not teaching vets to turn. Also please do not send any items to me without prior notification. Thank You Everyone.
It is always the right time, to do the right thing.
Posts: 21,259
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Location: IA
OK this will fit right into your tailstock morris taper
This is only a tad big at .8594 or 55/64" and you wanted .845 or the next smallest one is .8438 or 27/32
Here is the link for either one
http://www.wttool.com/index/page/categor..._params%3D
As of this time I am not teaching vets to turn. Also please do not send any items to me without prior notification. Thank You Everyone.
It is always the right time, to do the right thing.
Posts: 347
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Joined: Dec 2004
Location: Northeast Pa
Thanks! Got both sizes underway.
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Epoxy can handle that gap easily. It has excellent gap filling capabilities.
Rodney
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I think you'll get less of a gap with hardwood than with softwood. For one, the construction lumber was probably pretty green (high moisture content), so as the drill bit enters, it's heating up and expanding the wood, which causes you to cut a larger hole. I think you'll be fine with your blackwood. If you want to verify, find a scrap piece of oak or some other well cured hardwood.
Still Learning,
Allan Hill
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Some other things to try:
Slow your drill WAY down when starting the hole. It is likely chattering badly on the endgrain.
Drill into the side of a tubafo and see if it the it is the endgrain or the bit that is causing the problem.
Try a forstner bit rather than a twist drill.
You want the face that you're starting to drill to be as rigid as possible. Clamp your part to something square and clamp that to your drill press table or bury your part in your lathe chuck using spigot jaws. I only have a 1" hole in my chuck and the spindle is solid so I can't even do this one. My next lathe will have a hollow spindle like the metal lathes I'm used to running. <sigh>
A 1/4" pilot hole will make that drill start better.
Drill a 1/16" under size then finish with a reamer to hit your size better.
Good luck with your project.
We do segmented turning, not because it is easy, but because it is hard.
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Joined: Dec 2004
Location: Northeast Pa
To update
I got contact with Barry Gross, he says the .875 is needed with the tubes so as to not starve the epoxy joint.
I took the good advise here and made up an ash block 1 1/4 square, drilled on the lathe with 1/4 forstner, followed by
1/2 twist drill, then the 7/8 twist at very slow speed.
Worked perfectly, I drilled 4 1/2 in deep. entry end at 0.879, back end at 0.878.
Thanks all.