If you watch woodworking videos on YouTube then you probably know about Matthias Wandel and his slot mortiser. Matthias really come up with an amazing design that incorporates a lead screw and a incremented hand wheel that allows you to precisely adjust the cutter to correct height. Matthias machine, even though not exactly what I wanted to build, gave hope that it was possible to build a bench top domino.
Matthias Wandels Slot mortiser
When coming up with a design I had one thing in the mind, quick set-up. I knew if there was any fiddling or math to get a good result it would sit in corner while I find a simpler way of doing it. So with that in mind the domino has reference marks and indexing pins so guess what my mortiser will have.Easier said than done…
To use reference marks would mean the work piece must be moveable instead of the router. So how to you move the table up and down without any unwanted slop? I didn’t get this the first try…
I thought about this long and hard and decided to go with a scissor lift. The next hurdle was x and y movement. Keeping a small foot print in mind cause I want to be able to store it away and easily be able to put it on the bench when needed I ruled out drawer slides for the left and right movement simply cause of length, but for the in and out they would work just fine. My first idea for the left and right movement I went to the domino again for inspiration and decided on a router mount that swiveled on a bearing giving a range of about 2″.
I should mention that as the ideas come I would make a rough sketch up diagram. So from that I started building and it was an epic fail. There was all kind of issues but mainly the scissor lift (made from aluminum ) was just to lose and made a rough inaccurate mortise. And the bearing mount for the swivel was also to sloppy with no real way to tighten it up. Back to the drawing board.
I ended stumbling on the inclined plane height adjustment by staring at my failed mortiser. The table side supports had tapers cut into them basically for appearance and at that moment it came to me that if I make a mating taper and sliding it back and forth it would raise and lower my table WITH lots of support underneath it.
It was kind of a eureka moment but still had lots of question whether it would work. As for the left and right movement I scraped the swivel all together and decided on first a bushing and rod set up but then a drawer slide.
I figure at this point I would just go at it in the shop and see how it goes and from this point on everything seem to just fall into place. It did take a lot of shop time to get a final product but in the end I think it was worth it.
Quick, very quick as far as a tool used to make floating tenons, it perfect. Sense having in the shop I tend to find other uses for to. If I need any slot at all, I want ro use it just cause it is so quick to set up.
Cheap to build, about a 1/3 of a sheet of plywood
Small foot print takes little space compared to other mortisers
Easily remove the router if need else where, just a 5/16 nut driver and comes right out
Clean accurate slots.
Fun to make!!
Short left to right motion, travel is only about 3″ which is a sacrifice made to keep the foot print small but could be easily modified if you wanted.
Shallow depth of cut, due to the small cutters(1/4, 5/16, 3/8) you can only get about 1 1/2″ deep
Dust, no real way to collect dust