shopnotes micro adjust box joint jig

[mark kosse]

Hey all, I have a question about this.

I finall got around to building one and when I got to the point of installing the micro adjust part I started to wonder... is it neccessary? It seems if you use the feet to adjust it to an existing slot matching to your blade kerf why can't you just slide the moving rest one way or another to fit the slot? Just curious if that much controll is really needed. Would just sliding it do the same thing?

I'll try it out tomorrow and let you all know if it is nessessary.

Thanks

[Jerry Bruette]

No advice Mark but I'll be following your post as I'm very interested in building this jig and some day making a jewelry box for my granddaughter.

[mark kosse]

Jerry, It is nessessary. It seamed that I could just slide the pieces into position, but now I see how a micro adjust will help. I'll be installing it today. Mark

[Jeff Bratt]

I agree - that micro-adjuster works quite well...
http://home.roadrunner.com/~jeffnann...Joint_Fixture_

[Alan Schaffter]

A properly designed jig doesn't need a micro adjuster. Unfortunately there are no properly designed DIY (including the Shopnotes) or commercial (including the Woodsmith) jigs available . . . yet!!

That being said, micro adjust makes things easier and it also provides other benefits not realized in existing jigs . . . yet!!!!

I can't say any more, hopefully it won't be much longer.

[Jeff Bratt]

A properly designed jig doesn't need a micro adjuster. Unfortunately there are no properly designed DIY (including the Shopnotes) or commercial (including the Woodsmith) jigs available . . . yet!!

That being said, micro adjust makes things easier and it also provides other benefits not realized in existing jigs . . . yet!!!!

I can't say any more, hopefully it won't be much longer.

Well, you're obviously hinting at some new-and-improved kind of finger joint jig. I'll be interested in seeing what cool innovations you've come up with. On the issue of a micro-adjuster - I'll agree that if whatever you use for a cutter always make the exact same slot width in your stock, regardless of whether it's pine or teak, then a micro-adjuster is not needed. However, on most of the finger joint jigs I've seen so far, lack of a micro-adjuster is a design weakness. But maybe you will prove this notion wrong...

[Alan Schwabacher]

You can micro adjust most tablesaw box joint jigs with shims from a dado set. Use the shims either to widen the cut width if it's too narrow, or to space the blade over if the cut is too wide, assuming the spacer pin is on the proper side of the arbor for your saw.

[Alan Schaffter]

On the issue of a micro-adjuster - I'll agree that if whatever you use for a cutter always make the exact same slot width in your stock, regardless of whether it's pine or teak, then a micro-adjuster is not needed. However, on most of the finger joint jigs I've seen so far, lack of a micro-adjuster is a design weakness. But maybe you will prove this notion wrong...

Yup, that is the key. For perfectly symmetrical box joints you want fingers the same length, width, and thickness as the stock thickness, but in reality you can cut any width fingers in any thickness stock- like 1/8" fingers in 3/4" thick stock. But what is essential (for an adjustable or fixed jig) is a jig where the the gap between the blade and the guide pin, the width of the guide pin (fixed or adjustable), and blade/bit kerf are PRECISELY THE SAME - within a few thousandths! Though it requires some fiddling, that is not too much of a problem if you are using a router bit or totally fixed width blade. But, if the bit or blade is not spot on with the guide pin or your stacked dado isn't set exactly the same as it was the last time you used it due to wear, different shims, dust and dirt between the chippers, over/under torque of the arbor nut, etc., etc. then your joint may not fit properly.

On the other hand, if you are using soft wood (or MDF) that expands rapidly with the moisture in the glue, you may not want a perfectly cut joint- after you apply glue it, you may not be able to assemble it.

You can micro adjust most tablesaw box joint jigs with shims from a dado set. Use the shims either to widen the cut width if it's too narrow, or to space the blade over if the cut is too wide, assuming the spacer pin is on the proper side of the arbor for your saw.

That may not work if you have a jig with a fixed width guide pin- when you go to index the board for the next cut, it may be too loose on the guide pin or not fit over it at all. It can also be a pain trying to find the correct shim. You really need to adjust the width of the space AND the guide pin!

Another approach that is often less than successful is to try to set the dado width to the jig settings- that is working backwards, and too much of a pain. Unfortunately, that is what must be done with most of the current crop of fixed pin width jigs, like the router table one from Rockler. With that one, if the router bit cuts a notch that is different than the supplied guide pin, you are out of luck. Plus, your joint sizes are limited by the sizes of the supplied guide pins.

What is needed is a continuously variable spacing jig where it won't matter what cutter you use; a jig whose settings can be easily adjusted to the precise width of the actual blade/bit kerf (not a published value), but by making only one almost automatic adjustment, and without the need for calipers, test cuts, etc.! But, one that can still be micro adjusted if needed.

. . . . Something that will easily cut joints like these:

(No caliper was used to make the setup. No test cuts, either. I set it and this is what I got. I left the Forrest WWII in my saw for a bunch of joints, because I figured 1/8" joints would be the toughest test. The first three joints are just dry fit. The wider decorative joints were cut with a dado and were glued and wiped with finish to make the joint pop. I cut joints up to almost and inch wide on the table saw and router table with similar results):

Tiny 1/8" (or less? joint was made with a Forrest WWII) joints in MDF (talk about brittle fingers!!):



1/8" fingers in a wide piece of spalted maple (you can really see the effect of the ATB tips on the Forrest blade):



Longer (1"?) fingers (in a piece of dressed 2 X 4?):



Or effortless, one-step/single pass, decorative joints, like these:



A solution is on the horizon.

[Al Navas]

Now I cut them with a router, but using the precision dovetail template that came with the jig - and I can adjust the fit 0.001" at a time:









All of these cut with the D4R Pro in finger joint mode. It uses an eBush that allows the user to truly adjust the fit in increments of one-thousand of an inch. It must be experienced to be believed.

Of course, there is also the Leigh F3 Finger Joint Template, which makes it possible to cut 11 sizes of finger joints.

Al