MFT Clamping For Dado/Groove Routering?

[jiffff]

I'm hoping to use my MFT/3 for a routing task, but not really sure what the best clamping/jig set-up might be. I have a Makita 18v router and need to run some 9mm grooves, approx 6mm deep in some 12mm plywood about 10mm in from the edge.

I tried this originally on my MFT. Bare router with side-fence attached, 9mm flute cut bit, with a couple of FS-HZ160 'hold down' clamps holding the work piece over the edge of my MFT. (The depth of the side fence means the piece needs to overhang, which isn't easy given the smaller ones are only 180mm tall.) I ended up with a nice clean cut, perfectly straight in the middle, but with a bit of a wobble at either end as the fence went off parallel entering and exiting the cut.

I have a load of these cuts to make, so want to get a better set-up to avoid the 'wobble' at either end. I've bought the plunge base for the Makita router, have two FS-HZ160 clamps and a load of bench dogs of various varieties. I was wondering if anyone had any suggestions about how to clamp things.

I was thinking about:

1. Setting a couple of bench dogs running horizontally, towards the front of my MFT.
2. Pressing a straight strip of wood against these bench dogs.
3. Sliding my cutting piece against this straight piece of wood (all of the above arrange so it overhangs the front of the MFT by 10mm or so)
4. Adding two scraps of same sized plywood either side of my cutting piece. The right hand side piece could be pressed against a couple of bench dogs.
5. Using the router with plunge base and side fence attached. Starting and ending my cut in the scraps and ensuring my fence is in contact with the scraps at start/end point.
6. After cutting, swap the next piece in and repeat.

Perhaps there is a much better way of doing this?

But if I was to take the above approach, I'm wondering how things should be secured. I only have the two hold-down clamps - but the dogs can help. Also wondering if an additional strip of wood should be laid across the top of the two scrap pieces and workpiece - with the hold down clamps, holding to wood strip (and therefore the underlying strip). I couple of  MFT-SP clamps as well.

I'm finding it a bit challenging as things start getting crowded quick. Given some of the wood is only 180mm tall - managing overhang of the MFT, space to clamp, and space to run the router itself - it all gets pretty tight.

Grateful for any advice, preferably on how I can do this with the stuff I already have - but if I need to get more clamps, or build a jig of some sort, I'm open to it.

Thanks!

 

[Bob D.]

How large are the pieces that you need to work with.

Would it be easier to move the workpiece past a fixed bit as in a router table?

I made myself a quick mini router table from a scrap of 1/4" phenolic I had for
my cordless router that attaches to my MFT/3. It hangs off the side and the top
is flush with the MFT work surface. The phenolic is tough enough that I could driil
and tap a couple mounting holes for a Freud router fence I had laying around.
There are just two knobs to attach it to the MFT/3 side rail, so it's a no tools
easy on/off setup.

It's worked out well for light duty routing tasks. I use it mostly for edge treatment
with a roundover bit but it does work for dados and rabbits too.

 

[woodferret]

Can you not add an auxiliary fence to your edge guide?  Since the grooves are inset, you don't need the gap and should be able to just pack out enough to let the metal fence hang over the edge.  A longer auxiliary should also remove the wobble as you approach the corners.

 

[mkasdin]

I have seen plans before for a dado jig build using a guide bushing? Woodpecker makes one if you are financially independent... it’s nice, but not cheap.

 

[Mario Turcot]

The woodpecker dado jig is very nice and easy to use but expensive. If you search on youtube for "Perfect Dado Jig" you will find several videos of DIY jigs.

 

[jiffff]

Thanks for all the replied on this - been a bit hectic with work so only just returning to this challenge

[member=60461]Bob D.[/member] - Your set-up looks really ideal. It's going to set me back (on what is already an overdue job), but I'm quite tempted to try and replicate what you have there. Are you able to explain how it attaches to the side of the MFT and what hardware is required or any tricks for making it entirely flush? I don't have a router fence spare, but would be keen to pick up an economical one. I won't need to do much routing normally, so I've been put of getting a full router table set-up. I've been using the Makita 18v handheld for roundovers etc, but I guess I will have future dado tasks every now and again.

[member=72072]woodferret[/member] - If I was to do this now, does auxiliary fence = scrap of straight wood screwed to the small metal fence? I guess the longer fence makes it easier not to 'tilt' when entering exiting the cuts.

[member=60789]mkasdin[/member] and [member=66597]Mario Turcot[/member] - Something like that looks great. I need this dado to fit some (alleged) 9mm material, and have a 9mm, 10mm and something in between straight cutters, so I think I'll be ok - but the principle of of those set-up looks nifty!

Thanks all.

 

[woodferret]

[member=72072]woodferret[/member] - If I was to do this now, does auxiliary fence = scrap of straight wood screwed to the small metal fence? I guess the longer fence makes it easier not to 'tilt' when entering exiting the cuts.

Yes, scrap piece.  Alternatively, if your thing isn't too big is to just shim under the workpiece so that you clear your metal edge guide.  Then you don't need anything overhanging the MFT at all, although you'll still be left with the tilt unless you use the aux fence.  Double-sided tape is also your friend. 

 

[Stan Tillinghast]

Do you have a Festool or Makita rail? I have the small Makita LXT 18V router, and it has an inexpensive accessory rail guide. It works very well, and it seems to me would eliminate the issues with the edge guide.

 

[sancho57]

Get a Makita rail, and a Makita rail guide for yer router. You should be in good shape then. Not much difference between the FT and Makita rails so it should work on yer MFT

 

[Bob D.]

"Your set-up looks really ideal. It's going to set me back (on what is already an overdue job), but I'm quite tempted to try and replicate what you have there. Are you able to explain how it attaches to the side of the MFT and what hardware is required or any tricks for making it entirely flush? I don't have a router fence spare, but would be keen to pick up an economical one."

I don't know about ideal, it works and it was a quick build so it's sorta ugly but it works well enough that I haven't tossed it in the scrap bin.

I have a couple more photos that I have included here. All that is used to secure the router to the MFT is a pair of M8 hex round head machine screws and some M8 knobs, both of which I bought from McMaster-Carr.

The base is just some scraps of 3/4 ply. The top is a piece of 1/4 phenolic I had left over from another project a few years ago. I think I got it at Woodcraft.

The screw heads slip into the T-slot of the side of the MFT, then tighten the two knobs are you are ready to go. I think it took me 30 minutes to build this thing and that included looking through my hardware cabinet and scrounging up the screws and knobs.

For a fence just make a simple pivot fence anchored on one side and the other end gets clamped down by a nut and bolt that rides in a slot. Search on "router pivot fence" and you will find plenty of examples.