Tuesday, May 23, 2006

Size does matter

Having done a few measurements and tried a few things, I think I can just about to work around the problems of length and breadth posed by the famous auger bit extension. You see the "chuck" is very, very ingenius, but it's also larger in diameter than my required 5/8" holes - so obviously it can't go through those holes. That also means the combined length of the "chuck", which is quite long, and the bit I use can't exceed the distance between the arm and the seat of the chair. That's about 8 1/2", which isn't much. So all auger bits are automatically out, even dowel bits (if I had one). So I turned to the centre bits; an improved centre bit with a lead screw proved to be the only one capable of making any kind of dent in the beech, but the nearest I have is 1/2". Bum.

So here's the plan. I bore the hole in the arm with a regular 5/8" Jennings bit. The I thread through the ABE with the 1/2" bit chucked in from below, then I just start the 1/2" bit enough to give the lead screw the angle. Remove the arm and follow up with the 5/8" again, hoping I can keep the angle right. I thought about putting out a plea for a 5/8" improved centre bit, but a) this is getting ridiculous, and b) as the bits get bigger, they also get longer... I even considered getting a brand new spoon bit if it'd do the job, but measurement from a picture suggests it's miles too long.

All I need now is a day when I don't feel like death warmed up and a gallon or two of courage and I'm good to go. You'll know when 'cos I'll either be so elated I'll be unbearable - or so depressed, well, ditto...!

4 comments:

  1. Alf,

    I wonder if you're getting too hung up on getting the angles dead right. Don't most makers just eyeball the angles? Surely there'll be enough bend in the dowels to cope with any slight mis-alignment.

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  2. Nick, it's a fair point and one I've given a lot of debate to. Couple of things that bothered me; one, it's my first go and I have no feel for the angle (and it being a nebulous "here" to "there" without the arm in place is an additional complication). Secondly, I don't delude myself that any handmade article is going to struggle to impress in the mind of an 18 yr old brought up in the machine-made, mass produced world so I want to get it as good as I possibly can. But yeah, more than once I've thought "what the hell are you doing?!' to myself and considered breaking out the Mk 1 eyeball!

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  3. And of course you have a lot of personal investment in it already. I guess in the end it has got to be what you feel most comfortable with, just don't burn too many angst calories over it. :-)

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  4. Now where would I be if I wasn't deep in angst about it? My woodworking is virtually 100% angst-fueled ;~D

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