My own FMT router guides

[Michael Simpson Virgina]

Using my FMT I wanted to create my own mortise for a 6mm x 40mm Domino. I picked up a 6mm spiral cutter and headed home.

I had a couple problems:

The first was the cutter length. The FMT jig adds about 1/2" to the overall length needed by the bit. I had to extend the 6mm bit out of the router a little more than I would like.

The FMT templates make mortise and tenons that are larger then the bits used. This means you dont get standard mortise widths, they are slightly larger. IE if you use a 5/16" bit you get a moritse and tenon at 11/32". Also the lengths of the morise and tenons are set so its not easy to match the Domino.

So what toi do?

I took my laser and a piece of 1/8" ply, I cut out the base shape of an FMT guide. I then cut another piece with a slit just large enough for the guide pin on the FMT. They are indexed with some brass screws. (The index is cut when the piece is cut.)

After I attach them shy simply snap in the guide holder on the FMT.

Works perfect.

I started thinking of some other templates I could create.

Why would I want to do this. While the Domino is quick and easy to use it works best id you can index a cut off an edge or another morise. In some instances this can be problematic. Now I can joint one piece on my FMT and the other with my Domino.

[Rick Markham]

Michael that is super slick! Never thought of that, of course, I am still saving for the domino :D but this is definitely getting filed away in the "for later" part of my brain. Very ingenious!

[Michael Simpson Virgina]

If you want to anything but slots you have to change the shape of the width. Since the router bit is half way between the two guide pins I need to multiply the template width by 2.

[Michael Simpson Virgina]

Here are the templates for a 1/2" square and a 1/2" circle.

[Rick Markham]

Great Michael! Now I am going to have to save up for a laser too :eek: That's really awesome! Too many tools... too little money... Maybe with an engineering degree someone will let me play with their expensive equipment... eventually LOL

[Gary Muto]

Michael,
Pretty cool. I've thought about making templates but never took the time. Even without a laser your construction method (2 piece) is better than anything I could think of.
So, the only rule is a 2:1 aspect ratio between length and width when designing the template?

[Wayne Morley]

So what is an FMT?

Files Maintenance Tool
Flame Maple Top
Fremont Machine & Tool, Inc
I can guess that it is some sort of router, or router jig that is designed to make mortise and tenon joints. It might be cool to see what I am missing.

By the way how long does it take to program your laser to cut the templates?

[Chris Rosenberger]

So what is an FMT?
Files Maintenance Tool
Flame Maple Top
Fremont Machine & Tool, Inc
I can guess that it is some sort of router, or router jig that is designed to make mortise and tenon joints. It might be cool to see what I am missing.

By the way how long does it take to program your laser to cut the templates?


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[Wayne Morley]

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Thanks Chris. Now I wish I did enough M&Ts to justify an FMT :cool:

[Michael Simpson Virgina]

@Wayne
The FMT is a jig by Leigh and it stands for Frame Mortise and Tenon.

@Gary
Its a little more complicated than 2:1 as you must calculate the diameter difference between the router bit and the pin used on the template side. Then you have to apply a multiplyer to the width.

I am still working on it. For instance A square template of say .5" long by 1" wide will yeald a cutout of .45"long and .54. I am using a .125" bit and the template pin is .19"

You can tweek the pin up a bit to get it closer to the. I can just about dial out the length difference but not quite. I am going to pick up a 4mm bit today so I can elimnate the difference completly. Then I can consentrate on the width ratio. Once I have that I think I can come up with a formula that works most of the time.

My goal here is to cut out a recessed shape on the FMT then take a piece of 1/8 exotic wood a and cut that shape out on the laser and insert it into the recess. I have done this with guide bushings but its a real pain with small inlays. The FMT would be perfect.

[Gary Muto]

Thanks for the clarification. I'm interested to see how you progress. Thank you for sharing.

[Michael Simpson Virgina]

I was able to cut some [erfect square and round holes. The multiplyer was about 1.77. I tried some more complex shapes like a heart to create an inlay and still dont have it dialed in yet.


I may not be able to use an exact multiplyer for the width. For each design I may have to come up with a multiplyer thats different for each cut.

ITs all Trig and I am not that great at math so we shall see. What I do know is that I should be able to do a template that allows you to cut the recess as well as the inlay cut out. It may have to be two seperate templates.

I will play with it this weekend and see what I can come up with.