Clamp down MFS in middle of work piece

[ianwalls]

Hello chaps,

I'm thinking of getting myself an MFS700, but the thing concerning me (other than the hefty price tag) is that other than buying longer rails, I can't see any way of clamping the guide to a work piece that is bigger the guide itself. For example cutting an aperture for a letter plate in a front door. The MFS700 wouldn't overhang the edges of a door and therefore it wouldn't be possible to hold it down.

Does anyone know at all what I mean? And if you do, do you have any ideas on how to get round said issue? Maybe I'm not thinking creatively enough...

 

[Jesse Cloud]

Couple of ideas... put a couple of hold down clamps like these hold-down clamps on a longer board.  Position the MFS, then clamp the long board to the MFS with the hold down, the clamp the long board to the door with regular clamps.

Also, should be pretty easy to rig up a nut-and-bolt combination that would use the groove in the side of the mfs to attach it to another board.

 

[tbellemare]

This may not be the answer you're looking for, but...

There are extension profiles available - 1 meter and 2 meters long.

Tom

 

[Tim Sproul]

Hello chaps,

I'm thinking of getting myself an MFS700, but the thing concerning me (other than the hefty price tag) is that other than buying longer rails, I can't see any way of clamping the guide to a work piece that is bigger the guide itself. For example cutting an aperture for a letter plate in a front door. The MFS700 wouldn't overhang the edges of a door and therefore it wouldn't be possible to hold it down.

Does anyone know at all what I mean? And if you do, do you have any ideas on how to get round said issue? Maybe I'm not thinking creatively enough...

Kreg bench klamp (they have 2 different length reaches).

If those aren't long enough, use a curved caul.  You can purchase these as "bow clamps," although my experience with bow clamps is less than positive.  You can obviously make them yourself too.

 

[Brice Burrell]

Welcome to the FOG ianwalls! I've done just what Jesse described with the nut and bolt and scrap piece of wood. Simple, easy and you likely already have what you need to make this laying around.

 

[ianwalls]

Cheers for all the suggestions everyone. Brice/Jesse, can you describe how you would use bolts to hold it down? I'm having trouble picturing how that would work. I was thinking of drilling a few countersunk holes in the MFS and screwing it down. But obviously that isn't always possible depending on material, finish and whatnot.

Excellent site you have Brice. I had seen it before I came here, so I already know you love the MFS!

 

[Brice Burrell]

Ianwalls, I'd be happy to give you a better explanation. I use a couple of pieces scrap 3/4" plywood (18-19mm) nailed together, I drill a hole in the ply to fit a bolt. The bolt head needs to fit into the channel that the Festool clamp fits into. I slide the bolt head in this channel tighten the wing nut to secure the plywood extension to the MFS profile then clamp it to the work piece. See the pictures below.

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[Michael Kellough]

Brice, if that wood block at the end of the MFS profile is 3/4" thick
isn't the bolt going to lift the MFS? If memory serves the MFS is a scant 5/8" thick (or less)?
Or, is the bolt threaded into the upper block and screwed out (down) to clamp the MFS to the table?
If that's the case the wing nut is non-functional and misleading.

 

[ianwalls]

I getcha. Excellent. Nice drawing by the way. I think you missed your calling. Thanks for all that info, looks like it'll work a treat.

I hear what you're saying Michael, but I can thin down something to the exact thickness of the MFS so that it wont lift. Well spotted though.

 

[AlexThePalex]

When I read the question I just thought to myself, just connect a couple of long planks on the side of the MFS. Seems Brice already visualised it.

 

[Brice Burrell]

Brice, if that wood block at the end of the MFS profile is 3/4" thick
isn't the bolt going to lift the MFS? If memory serves the MFS is a scant 5/8" thick (or less)?
Or, is the bolt threaded into the upper block and screwed out (down) to clamp the MFS to the table?
If that's the case the wing nut is non-functional and misleading.

Michael, it's all coming back, I do remember inserting a washer between the ply and profile, I believe it was just one thick washer. For those of us in N. America, I used closet bolts (toilet bolts) they fit nicely in the MFS profiles and guide rails, 1/4"/20 bolts or wings. I'd recommend keeping some around for jigs, I keep some in my guide rail bag.

IIRC, the MFS profiles are 16 mm think.

 

[Brice Burrell]

I getcha. Excellent. Nice drawing by the way. I think you missed your calling. Thanks for all that info, looks like it'll work a treat.

I hear what you're saying Michael, but I can thin down something to the exact thickness of the MFS so that it wont lift. Well spotted though.

Sorry for any confusion, it's been well over a year since I did this extension. Another options is to use thinner plywood, 12mm. A small gap under the bottom side of the ply and the work surface shouldn't be a problem. The ply should flex down to the work surface when clamped, assuming it is a real short extension.