DIY instructions for Festool MFT
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Hold Down Clamps
by
There is a video at the end of this post showing the clamp in action.
OK, I wanted a hold down which could be inserted and removed without reaching
under the table...here it is.
First, I turned a hardwood dowel to 19mm (you can buy a 3/4" dowel...I just
didn't want to go out in the Nor'easter we're having when I created this)
I cut the dowel to about 2" long and used a 7mm drill bit to drill a hole
through the length of the dowel. I positioned the bit so that the hole was
offset. (see pic below)
I then cut that dowel so the the body (the part which will go through the MFT)
was 7/8" (1" will be fine) which seems to be a good length. The dowel which is
to be used as the cam I cut to 1/2" in length. This piece can be longer and
probably should be for strength, but my bolt wasn't long enough to accommodate a
longer cam. A 1" cam and 1" body would work well and provide good strength.
Edit: For the production units I stuck with a 1/2"-ish cam and I feel it is
plenty strong so a larger one isn't necessary.
I counter bored the cam a little to fit the head of the 1/4x20 bolt and inserted
the bolt and glued it in place.
Next I created a lever out of a piece of scrap phenolic. It can be any
material. I drilled a hole in it and threaded it. I put the body dowel on the
bolt and then screwed on the lever. Tightening the lever so that the assemblies
was still loose, I aligned the lever so that it pointed at the maximum offset of
the cam...then glued it in place with some CA. Here you can see the
"production" assembly which was made with a 5-1/2" carriage bolt
I used a piece of 1/4" plywood sandwiched in between two 1/2" pieces which I laminated together with some 5 minute epoxy. My original intent was to remove some of the 1/4" layer in order to make the slot. Well 1/4" was too thin and to make the slot so if you want to do this without routing you will need to use 3/8". I ended up using my Domino to cut an 8mm slot. Laminating a 3/4" and 1/2" pieces and then cutting the slot should achieve the same thickness and strength with one less layer.
So to use it, you stick in in the hole, rotate the lever until the cam locks the
clamp from coming out of the hole, then tighten the thumbscrew. The cam does
not tighten in the hole, it rotates and forms a latch to prevent the dowel from
coming out of the hole.
So
that's it.
View
this video to see how it works.
22 April 2007
Copyright © 2007 , Bill Esposito
All Rights Reserved.