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Posted: Sun May 08, 2011 1:30 pm
by JPG
beeg wrote:You are drawing a line across both the boards? On the spot where ya want the dowels to go.
And extending that line(squarely) onto the edge!:)

Posted: Sun May 08, 2011 2:38 pm
by beeg
JPG40504 wrote:And extending that line(squarely) onto the edge!:)

Well I'd have the boards up on edge to eliminate error from extending the line.

Posted: Sun May 08, 2011 4:46 pm
by damagi
algale wrote:Well, after all the helpful comments, I decided to see if stabilizing the main table of my 520 by putting an extension table in the tail stock and connecting it via the extension tubes would help. I have to say that it does seem to have made a difference as the sheets now line up without any noticeable offset. Thanks everybody. Now, if there was only an easy method for making sure the holes in the mating pieces line up horizontally......
Dowel pins are made for this purpose. they sit in the hole and put a small indentation on the matching board. I might have the name slightly wrong, but any woodworking store should have them.

Posted: Sun May 08, 2011 4:59 pm
by algale
beeg wrote:You are drawing a line across both the boards? On the spot where ya want the dowels to go.
Yep, I sure am.

Posted: Sun May 08, 2011 5:00 pm
by algale
beeg wrote:Well I'd have the boards up on edge to eliminate error from extending the line.
Agree; started putting the lines on the face and then realized it was better just to stack 'em flat and put a line down the edge.

Posted: Sun May 08, 2011 5:01 pm
by robinson46176
damagi wrote:Dowel pins are made for this purpose. they sit in the hole and put a small indentation on the matching board. I might have the name slightly wrong, but any woodworking store should have them.


I have heard "dowel pins" but more often "dowel centers".


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Posted: Sun May 08, 2011 7:36 pm
by horologist
I can't say I've had such trouble with table flex. If you have to apply enough force to deform your machine in order to drill holes then something is wrong. A few possibilities:
1. Old dull drill bit.
2. Bad or dull, bad drill bit. (Made in China?) Although I did buy a set of Cleveland Twist wire gauge bits once that had a number of bits ground with negative rake angles...
3. Something loose in setup. It is easy to forget to tighten one or more of the locks.
4. Too rapid a feed rate. Let the bit do the work. While this may not be true for some metals it is true for any wood.

Troy

Posted: Sun May 08, 2011 9:10 pm
by JPG
I understand table flex when 'mortising' in drill press mode, but not when boring horizontally. ???

Posted: Mon May 09, 2011 6:35 am
by algale
JPG40504 wrote:I understand table flex when 'mortising' in drill press mode, but not when boring horizontally. ???

Flex, twist. Call it what you will. But the table does have some slop in it when it is just supported on its posts/trunions.

Posted: Mon May 09, 2011 6:44 am
by dusty
algale wrote:Flex, twist. Call it what you will. But the table does have some slop in it when it is just supported on its posts/trunions.
It does! When I need to reduce that unwanted movement to near nothing, I tie the main table to the extension table using the extension tubes.

The most stable location for this is accomplished by moving the carriage and headstock to the far right side.