Sliding dovetails with the MFT and OF1400??

[Jesse Cloud]

Hi all,
Just ordered the OF1400 from uncle Bob and I'm trying to figure out a way to make the tenons for sliding dovetails.  Ideally, I would like to clamp the board vertically to the mft and run the router off the guide rail.  Has anyone done this? 

Is there a better way to do it?  Open to ideas.

Thanks in advance!
Jess

 

[mysterium]

Hi Jess,

I think it is covered in Jerry Works manual on the MFT.  It's available for download at the Festool USA site.

Hope this helps, jim

 

[Jesse Cloud]

Hey Jim,
Jerry's manual is the first place I went.  Unfortunately, near as I can tell, he talks at length on how to cut the female grooves, but doesn't explain how the male parts were cut.

 

[Mirko]

I remember seeing a post on this subject, I had a look around with no luck. Keep trying the "Search" bar. I may be wrong but Jerry Work entered the conversation.

Mirko

 

[mysterium]

Jess sorry about pointing you in the wrong direction....

I also remember Jerry Works posting about sliding dovetails cut with a jig for the MFT.  But it seems like it was back on the Yahoo FOG....  If the info wasn't in his manual, then maybe you can find it with a "search" on the old site.

jim

 

[Matthew Schenker]

I also remember Jerry Works posting about sliding dovetails cut with a jig for the MFT.  But it seems like it was back on the Yahoo FOG....  If the info wasn't in his manual, then maybe you can find it with a "search" on the old site.

We need Jerry Work to move that set of topics into the new forum.

Actually, this reminds me, a lot of people still need to move their discussions into the new forum!

Matthew

 

[Corwin]

If I recall correctly, the jig Jerry had for the male portion was a fixture that attached to the side of the MFT to hold the router in a horizontal position.  Please correct me if I am mistaken.  Many woodworking magazines have an ad for this MLCS Horizontal Router Table -- maybe their illustration will give you a better idea of what the jig is...  and maybe give you some ideas of you own.

Good luck -- I'll be attempting this very thing in the near future, so let us know how you do.

Corwin

 

[Ned]

Guys,

The description of Jerry's Horizontal Router Jig for the Festool MFT begins on page 53 of his MFS guide.

Ned

 

[Dave Rudy]

Another possibility is Pat Warner's tenon/sliding dovetail jig.  He demos it in a video on finewoodworking.com for those with a membership.  You can also find a description and picture of it on his website (patwarner.com).

Dave

 

[Dave Ronyak]

It would be simpler if you could use your 1400 router with the same bit set to the same depth for cutting the male portion of the sliding dovetail.  But if you only have a few sliding dovetails to cut and if you don't want to make a horizontal setup based on Jerry Work's manual, consider mounting your router in a simple table or to a router plate, mounting a fence to your table and routing the male dovetail, with your workpiece standing on the edge to be dovetailed.  A fence can be made from a couple of pieces of 3/4 MDF or plywood screwed together at right angles with a couple of triangular braces.  Note that you can mount your 1400 router to a table or insert plate using the two 6mm threaded holes that extend through the baseplate, without need to remove the base plate.  I have a simple router "table" made old cabinet door made of birch veneered plywood; I simply clamp it to the top edge of my workbench when I want to use it.  It could be clamped to the top of the MFT as well.  Adjust the height of the bit above the table to match the depth of your female dovetail groove.  Note that with your fence out of the way, you should be able to use the female cut for setup. But it is best to test the depth of cut using a piece of scrap of the same thickness as the piece on which you plan to cut a male dovetail.  To get a centered male sliding dovetail, position your fence to cut a little from both sides of your workpiece, and adjust your fence to creep up on the final thickness.  Mounting your fence so that one end can rotate about a fixed point and the other can be moved and clamped in place makes for a simple fence that is easily adjusted and calibrations can be marked on your table.  The higher your fence the better to support your workpiece.  Good luck!

 

[Jesse Cloud]

Thanks all, and especially Ned for pointing me to the MFS guide.  I was wary of the horizontal router concept until I saw Jerry's idea of burying most of the bit in the fence.  Much safer!!

 

[CharlesWilson]

I ended up doing my male sliding dovetails with an old sheet metal Craftsman router table. Not as nice as the OF1400, but once I set the height and fence, the joints came out fine.

Charles

 

[John Stevens]

Ideally, I would like to clamp the board vertically to the mft and run the router off the guide rail.  Has anyone done this?

Hi, Jesse.  Before you pursue that idea, check to see how square the side rails are to the top of your MFT.  I found--surprisingly--that mine weren't square.  I ended up making a "right angle jig" to do what you're proposing.  I've read Jerry Work's instructions for how to make a horizontal router jig for the MFT, but all I can say is that his MFT rails must be a lot more square to the table top than mine.  One of the things I found when refining my right angle jig was that any deviation from square will result in unsightly gaps in your sliding dovetails.  If they're not to be visible, then no big deal, but otherwise....

I had a write-up with pics of my jig on the old site, but I never transferred it over to this one.  I have since dismantled the jig because it was only good for M&T joints and sliding dovetails.  I don't like the sliding dovetail as a joint, and I abandoned M&T joints soon after buying a Lamello biscuit joiner.

Regards,

John

 

[AMC]

Ideally, I would like to clamp the board vertically to the mft and run the router off the guide rail.  Has anyone done this? 

Is there a better way to do it?  Open to ideas.

I've used a similar concept, but using the MFS router template. With the MFS clamped to the table, and the workpiece clamped to the side of the MFT, you can guide the router very accurately along an edge as long as the MFS extrusions you use.

I did it to get a quick result on something and made manual adjustments, but as I recall the right-angle pieces that come with the MFS were useful in repeating settings on both sides of the workpiece. Will have to go back and explore this again some day.

Matt

 

[Dave Rudy]

I've used a similar concept, but using the MFS router template. With the MFS clamped to the table, and the workpiece clamped to the side of the MFT, you can guide the router very accurately along an edge as long as the MFS extrusions you use.

I did it to get a quick result on something and made manual adjustments, but as I recall the right-angle pieces that come with the MFS were useful in repeating settings on both sides of the workpiece. Will have to go back and explore this again some day.

Matt

Matt,

I'm having trouble visualizing this.  Could you explain in more detail how you use the MFS in this setup?  Pics would also be helpful.

Thanks

Dave

 

[Dan Lyke]

Dave, I'm not Matt, and I don't know his setup, but one of the things I didn't "get" when I bought my MFS is that it has grooves in the faces, just like the grooves on the edge of the table or the bottom of the guide rail, that the Festool clamps slide into. And the MFS is stiff enough that if you can put something under the MFS, you can use the MFS and a clamp to pull the whole thing really solidly to the table.

The only picture I've got right handy is in a little jig I was using to cut a recess in a whole bunch of identical plywood blanks for stair rail mounts:



What you can't see is that I've got a Quick Clamp FS-HZ 160  up through the table and in one of the slides on the back of that MFS. So I loosen the clamp, slide a block in to the L stops also bolted on the bottom of the MFS, tighten the clamp, and everything's held down really solidly. Like "lift the table up by the end of the MFS" solidly.

So there's no reason you couldn't use another Quick Clamp to tie a piece to the edge of the table, and then cantilever the MFS off the edge of the table using a clamp from the bottom.

When I built what I thought was an MFS knockoff what I didn't get whas that the MFS isn't a flexible template, it can serve as a solid structural element. For my next project I've started a couple times down trying to design a good mortising jig and realizing each time that the MFS does what I want.

 

[Dave Rudy]

Thanks, Dan.  That is most helpful.

I just got the MFS from Bob and am still designing and building my large MFT so havent had the chance to put it to use yet.  I am amazed at the versatility of this part of the system, though, and especially interested in looking at all approaches to sliding dovetails at the moment.

Dave

 

[Dan Lyke]

I'm not sure if these pictures help any more, but I was trying to avoid getting to work, so I figured I'd play with my Festools instead ;D. Here's the MFS 400 clamped so that it extends over the side of the MFT, with a piece of purpleheart clamped to the side of the table as though I were going to route something on the end of it (sliding dovetail, tenon, whatever).

I've got a couple of tenons that I was going to cut this way, and I'm thinking that I'll need a few scrap pieces to get alignment right, both the MFS to the edge of the table, and the piece whose end I'm cutting vertical and set to the copy ring thickness below the MFS, but I think this'll work.

 

[Mirko]

Dan,
Very interesting, but could you post larger pics?

Mirko

 

[Dan Lyke]

Here are some larger pictures. The image quality is pretty lousy, the only thing I was trying to get across is that the MFS is beefy enough to function as an extension of the clamp, not just something you clamp down, and to cantilever out over the edge of the table, and clamping stuff to the side of the table is totally normal.

Something else that I have actually used to make cuts with (rather than just saying I'm going to, as in this setup  ) is to slide the rail supports to the edge of the table and run the router on the rail.