OK I'm stumped. I'm trying to get a set of leg's in a stool I'm making.
The two front legs are pitched 10 deg out to the side and 20 deg out to the
front. My drill table rotates right and left (need deg) and what is my
degree of rotation of the work pc? Perhaps someone has a formula. The back
legs are 10 deg both ways.
Thanks
George Yoder
On 7/21/2004 "Frosty Thunder" [email protected] wrote
>OK I'm stumped. I'm trying to get a set of leg's in a stool I'm making.
>The two front legs are pitched 10 deg out to the side and 20 deg out to the
>front. My drill table rotates right and left (need deg) and what is my
>degree of rotation of the work pc? Perhaps someone has a formula. The back
>legs are 10 deg both ways.
>
>Thanks
>George Yoder
Even lower tech might be a hand drill with two sliding bevels set to the
appropriate angles. If you are only making one piece, it seems to be a lot of
set up for each hole. Lots of set up = lots of potential for error. (IMHO)
George,
The easiest way I found to do it is to tilt the drill press to 10° (in my
case, 6°) to the left and later to the right. I found out that a degree or
so off makes a big difference to the footprint of the legs, so I used a long
drill bit and machinist protractor for a more accurate setting.
(see -http://shop.woodcraft.com/Woodcraft/product_family.asp?family%5Fid=443
8&gift=False&mscssid=00025C7E3EC24C4C6CBAAE8F95A8A4D5 )
I then tilted the seat up (20° for you) using a 20° wedge. To make an
accurate wedge, I rough cut a 4" x 4" piece of cedar to nearly the angle.
Then, using a sled, I ran it through the planer for an accurate wedge. For
instance making a sled 6" long on the horizontal leg and 2 3/16" for the
vertical leg gives a 20° wedge. I believe I have a pic or two of the setup
if you want it.
For the other two legs, use a 10° shim. Just curious, why the difference in
angles between the front and rear legs?
If I read you right, you want to use one angle. Figuring the resulting
angle of the diagonal of a plane tilted 10° one way and 20° is straight
forward, given the seat dimensions, but setting up a jig with one angle to
hold the seat in the proper orientation is not. I tried this first and
found later it was easier to tilt the table and then the seat. The only
caveat is the fence on the drill press table must be 90° to a line through
the center of the drill press column and the chuck. That is easy to
achieve. Once I figure it all out and set it up, I drilled a handful of
seats in no time.
Preston
"Frosty Thunder" <[email protected]> wrote in message
news:[email protected]...
> OK I'm stumped. I'm trying to get a set of leg's in a stool I'm making.
> The two front legs are pitched 10 deg out to the side and 20 deg out to
the
> front. My drill table rotates right and left (need deg) and what is my
> degree of rotation of the work pc? Perhaps someone has a formula. The
back
> legs are 10 deg both ways.
>
> Thanks
> George Yoder
>
>
[email protected] (heyscott) wrote in
news:[email protected]:
>
> I came up with some formulas for you using trig:
>
> Let a be the angle to the front
> Let b be the angle to the side
>
<snip>
Those of you with kids, remember to save that description
in the folder of examples you whip out in answer to the
perennial question, "When would I use this in real life?"
(Some items are more difficult to answer... for history,
the only one I've gotten them to accept is "Those who
ignore history are doomed to never get jokes based on it.")
Thanks for the numbers, Scott.
Ah ha! same problem for Windsor chairmakers. I once wrote a small program
to figure the complex angle, but I find it easier to adjust the drillpress
table right or left (10-deg in your case) and put a temporary platform
plywood on top of the cast iron table with two wedges glued to the
underside. In your case, the simple angle of the wedges would be 20-deg.
No calcs needed. Dave
"Frosty Thunder" <[email protected]> wrote in message
news:[email protected]...
> OK I'm stumped. I'm trying to get a set of leg's in a stool I'm making.
> The two front legs are pitched 10 deg out to the side and 20 deg out to
the
> front. My drill table rotates right and left (need deg) and what is my
> degree of rotation of the work pc? Perhaps someone has a formula. The
back
> legs are 10 deg both ways.
>
> Thanks
> George Yoder
>
>
> OK I'm stumped. I'm trying to get a set of leg's in a stool I'm making.
> The two front legs are pitched 10 deg out to the side and 20 deg out to the
> front. My drill table rotates right and left (need deg) and what is my
> degree of rotation of the work pc? Perhaps someone has a formula. The back
> legs are 10 deg both ways.
I'd make a pair of wood blocks with the correct angles (on the TS, RAS
or MS) and use that to either:
-align the drill press table with a level
-keep the drill table level and use the block to rest the work upon.
"Frosty Thunder" <[email protected]> wrote in message news:<[email protected]>...
> OK I'm stumped. I'm trying to get a set of leg's in a stool I'm making.
> The two front legs are pitched 10 deg out to the side and 20 deg out to the
> front. My drill table rotates right and left (need deg) and what is my
> degree of rotation of the work pc? Perhaps someone has a formula. The back
> legs are 10 deg both ways.
>
> Thanks
> George Yoder
I came up with some formulas for you using trig:
Let a be the angle to the front
Let b be the angle to the side
Angle to rotate piece on table:
theta = atan(tan(a) / tan(b))
Angle to tilt the drill:
phi = atan(sqrt( tan(a)^2 + tan(b)^2 ))
If a and b are 10 and 20, then
theta = 25.85
phi = 22.02
If a and b are 10 and 10, then
theta = 45.00
phi = 14.00
Scott