MT jig Mk. II...

[Schtoo]

Just some pics for now, see if you can work out what's going on since I am going to bed.

More pics tomorrow (with any luck), and a proper explanation.

Not just MT either. Should have some pics of it doing something that MT jigs don't do, dovetails...

[Rocker]

Looks like a very impressive jig. Looking forward to getting the explanation of its capabilities.

Rocker

[NewLou]

Come on Schtoo

Looking foward to your intro of the new Jig.................Watching this one with interest n waiting for full WIP Demos!!!!

Will this be the new King of Mortising?

Regards lou

[Lignum]

Will this be the new King of Mortising?

PMSL

[JDarvall]

Bloody abbreviations !.....PMSL ? ....I'm guessing MT means Mortise and tennon......I thought that was written -> M&T.

Anyway I'll have a guess. Looks interesting.

4 micro adjustments....one for each side.....a fence for each side, that runs square always thanks to the dual rails....so run the router base along each fence for each side of tennon and mortise......? something like that.

So, how do you ensure the workpiece is centred properly to the jig. Whats your process for that to weed out the inaccuracys ?

Bound to be something else though. Bet you liked lego Schoo.

[Waldo]

G'day Schtoo,

Wiggles coloured clamps! :eek: That's not very Code of Practice like.

[scooter]

PMSL - Pooed My Shorts Lignum

[Lignum]

PMSL - Pooed My Shorts Lignum

Geeze we have never met but you know me so well

[Schtoo]

Ok, I am awake now.

The last jig, based on Rocker's mortise jig had some fatal flaws, mostly a lack of rigidity that popped it's head up when cutting tenons more than anything. I used it a couple times, and it worked but I was not overly happy with it. I think that in a pure mortising operation, it should be fine, but cutting both ways with lotsa overhang, no thanks.

This one has a base that extends from back to front, all the way with a large slot cut in the sides to allow sticks to poke through. Does not deflect at all, which is a good thing. I also added a flat board on the bottom to let me clamp it to either the bench or a saw horse.

Pic 1. The jig itself, from the top. Bottom of the pic shows a small leadscrew to centre the main deck over the piece to be cut. Simple, but it works. Top left shows a large acrylic/ally square I threw together to use with this jig. Fits everywhere without too much trouble. All my existing squares were either too big or too small, but this one is juuust right.

Pic 2. A shot of the setup doohickey. The acrylic is half the width of the window, the ally is half the short width of the window. The short legs are the same as the distance from the top of the upper deck to where the stick to be mortised rests. So I can adjust the tennon stick to centre, and then set it's height so one setting on the router's depth will cut the mortise and a matching tenon.

Pic 3. Mortise mode. Stick a spacer between the ally strip and the moving sub fence, lock down subfence, cut the hole. The ally strips are so I can adjust each fence for square easily, solving another flaw from Mk I. To adjust the M/T fit, I just put tape on the spacers. Currently using a single layer of cellotape, but it's giving me a 0.06mm* undersize mortise, so I think another layer of cellotape might fix it or finding something in between cellotape and thin maskng tape.

(* 0.06mm = 0.0023")

Pic 4. Tenon mode. Slip the sub fences back, cut the tenon with a climb cut (router always moves clockwise). Leaves very clean shoulders on the tenons. The strange acrylic things are to round the shoulders on the tenon as the tenon is cut. Not perfect since there are small gaps between the mortise and tenon corners, but the joint still goes pop when pulled apart.

Pic 5. Showing one of the scales for adjustment. One setting gives both tenon or mortise size. The curved upper surface and flat lower magnify the scale to make it easy to read, and works at any angle. Simple and effective. Just need to make sure the top is a true curve otherwise it all goes funny.

No decent pics yet for underneath showing clamps (same plastic ones as last time, I notice LV carry them too.) and track/stops. Much simpler this time, just three strips of track running across.

Also no pics for the pivot which (when I iron out the bugs) will give me the ability to cut a mortise square in something, tilt the backing board and cut an angled tenon that fits the mortise.

No pics showing how I manage to lose only 7mm of plunge depth on the router. Meaning that out of the 47mm plunge on the Makita, I can get a 35mm deep mortise using a standard 8mm solid tungsten spiral bit, no extensions.

Still a few things to sort out on it, like memory stops for all the upper fences along with adjusters (simple), a better backing board for underneath and some small things. But it does work, is fully adjustable for anything I can think of and will do things I have not realized yet.

One new thing is the ability to cut stub sliding dovetails. Cut the socket in the board, put the stick in the jig with the end flush with the router runway, adjust the fences and cut the tails, even rounding off one end or the other. Will cut the tails right size, regardless of what size the stick ends up being. It works very well, except the DT bit I was using isn't very good which fouled up the joints somewhat. A new bit tomorrow should solve the problem, I hope.

That's all for now. I know it's over complicated, but it works better than I expected.

[Bodgy]

Bloody hell, Schtooo. Don't know what to say.

I got a heache looking at it.

Show us it in action.

[BobL]

Bloody hell, Schtooo. Don't know what to say.

me too!

Show us it in action.

Please.

Thanks

[Tex B]

That looks like the bees knees. Very impressive, Schtoo.

Tex

[scooter]

Looks impressive, Schmoo ( ), hoping to see a vid too


Cheers...............Sean

[Schtoo]

No pics today, too busy making it play another tune.

It does short carcass dovetail pins in about 30 seconds, wood in to wood out after 5 minutes of setup. Current thing has 32 of these things, should save me about a month of time and effort.

I'll take a video of it, just don't hold yer breath for it, the vid might be a while. It might be the only way to show how it all works, and how simple the thing really is, contrary to how it looks.


Just happy that the time and effort I put into this thing is paying off so quickly.

[Schtoo]

Ok, I lied.

First pic is what's happening underneath. Nothing special, just the cam clamps, the tracks and stop blocks. All as simple as it gets.

Second pic is the best I could do with a the shop camera, which isn't a good one. Just shows the dovetail test mentioned above. That DT is fully seated and flush with the edge of the main piece. Pushes in with very firm hand pressure, and pulls back out with a few taps and more pulling and grunting. There is no gap, which the camera does not show because the resolution isn't the best.

The reason why this is here is because it was done with the MT jig, using the same router with the same depth setting to cut both the socket and the 'tenon' and I crept up on the fit till it was perfect, and I can now pump out as many of them as I want to on any thickness stock, provided I don't use a different jig (4 pieces of scrap screwed together, real sophisticated.) to cut the socket.

I can even offset the thing.