DIY Lap Joint Jig (for any size stock)
Morris Dovey
I really like the Bridge City Kerf-Master jig, but have been wanting to
build an open-grid top table for solar panel assembly with 2x lumber,
which is beyond the capabilities of the KM-1.
I've worked up a one-piece jig that's only suitable for use with the
blade you use to make it, but that doesn't bother me much. It should
work for anything from coffee stirrers to whatever your saw can handle.
No measurements are needed to make the jig, and only one measurement is
needed (to locate either edge of the joint) during use.
During use, you'll need a small scrap of the stock that's to fit into
the part you're cutting. In the drawing, I've labeled it "Crosspiece
Sample".
I'll leave the graphic on my web site for a week for criticism and
comment, and then either discard it or replace it with a web page with
larger graphics if feedback indicates I should.
You can see the drawings at:
http://www.iedu.com/DeSoto/Misc/LapJigHowTo.jpg
(The green block is a miter fence stop, and red is used to show cuts -
please let me know if it's confusing)
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/
Matt
about it for a while, to see if I understand it!
Matt
RicodJour
Interesting. How about holding the pieces together with embedded
magnets? Or maybe a spring-loaded arrangement - pull it apart, twist
to adjust, then the spring pulls it back together on the new setting.
R
Morris Dovey
> Interesting. How about holding the pieces together with embedded
> magnets? Or maybe a spring-loaded arrangement - pull it apart, twist
> to adjust, then the spring pulls it back together on the new setting.
Sheesh! I give you a one-piece precision jig that you can whip together
in under three minutes from whatever scrap you might have lying around
and you tell me that what you want is springs and magnets...
You're a tough customer to please! :-D
No. No magnets. No springs. No moving parts. Not even yellow paint.
(But I'm curious to see what you'd build with that extra hardware)
RicodJour
> RicodJour wrote:
> > Interesting. How about holding the pieces together with embedded
> > magnets? Or maybe a spring-loaded arrangement - pull it apart, twist
> > to adjust, then the spring pulls it back together on the new setting.
>
> Sheesh! I give you a one-piece precision jig that you can whip together
> in under three minutes from whatever scrap you might have lying around
> and you tell me that what you want is springs and magnets...
>
> You're a tough customer to please! :-D
>
> No. No magnets. No springs. No moving parts. Not even yellow paint.
>
> (But I'm curious to see what you'd build with that extra hardware)
Well, it seems to me if you're going to be putting in the time, make
it with a few standard pieces for your favorite size joints, and then
just plug and play. Color code the pieces, mass produce, buy an
island. Pretty straightforward, really. ;)
R
Han
I guess I need handholding while this jig is made and a demo of its use.
Too much of a newbie at jigs to understand, sorry Morris!
--
Best regards
Han
email address is invalid
Morris Dovey
> I guess I need handholding while this jig is made and a demo of its use.
> Too much of a newbie at jigs to understand, sorry Morris!
No reason to be sorry about anything. Do you have some scrap to play
with (say a foot-long piece of 1x4)? I'll walk you through making the
jig and cutting the first half of the first joint...
Chris Friesen
> I've worked up a one-piece jig that's only suitable for use with the
> blade you use to make it, but that doesn't bother me much. It should
> work for anything from coffee stirrers to whatever your saw can handle.
Neat setup. It relies on a stop block at the end though, which could
get tricky if you need to deal with long pieces. Also if you're doing
multiple half-laps on a single board you need to relocate the stop block
each time, which isn't as convenient for doing a grid like you're
talking about.
If you were dealing with pieces too long for a stop block, you could
combind it with a finger-joint jig, where the "finger" in the jig is the
width of the blade and placed at the desired grid spacing. Then you use
your jig to do the initial half-lap on each board, and the finger-joint
jig to do all the others at equal spacing.
Chris
Morris Dovey
> On 11/10/2009 10:05 PM, Morris Dovey wrote:
>
>> I've worked up a one-piece jig that's only suitable for use with the
>> blade you use to make it, but that doesn't bother me much. It should
>> work for anything from coffee stirrers to whatever your saw can handle.
>
> Neat setup. It relies on a stop block at the end though, which could
> get tricky if you need to deal with long pieces. Also if you're doing
> multiple half-laps on a single board you need to relocate the stop block
> each time, which isn't as convenient for doing a grid like you're
> talking about.
It /would/ be a hassle on the TS - but my RAS setup allows me to locate
as many fixed stop blocks as I want along a 12' length. There is a pair
of early photos at the bottom of
http://www.iedu.com/DeSoto/Projects/RadialArmSaw/
so the only hassle would be in setting up the first board in each
direction - but after that was done, I wouldn't even need to measure.
There /have/ been times when I've wanted a 12' miter fence, too. :)
> If you were dealing with pieces too long for a stop block, you could
> combind it with a finger-joint jig, where the "finger" in the jig is the
> width of the blade and placed at the desired grid spacing. Then you use
> your jig to do the initial half-lap on each board, and the finger-joint
> jig to do all the others at equal spacing.
Sounds like it'd work.
Morris Dovey
> Thanks from a mostly lurker, Morris. I'll have to study it and think
> about it for a while, to see if I understand it!
You're welcome. I just returned from trying it out for the first time in
the shop, and can report that I got a joint that fit exactly. It took a
fuzz under three minutes to make the jig, and about the same to make the
joint itself.