MFT and Guide Rail Alignment

[Qwas]

The Beginning of a New Fence

Why a new fence? Well, we all know the problems of keeping the aux fence aligned, having to use extra support at the end, still wanting to bow in the middle, having it hang out the end of the table if you don't want it under the guide rail. Minor nuisances, but I love Festool because of their lack of nuisances and we all get enough of them without having to get it from our tools. And I have enough other things on my mind without minor issues from a table or a fence.

I'm not going to try to replace the aux fence. I just want a great fence to take care of 90% of all of my cuts, the crosscut or 90 degree cut. When I need an angled cut, I'm willing to put the aux fence back on and use it for these cuts.

If you recall from my first post on this subject, I removed my MDF table top and cut some dados into the table top to fit an aluminum bar. By using a router with an edge guide I am assuring this dado is parallel to the MDF edge and the holes.
[attachthumb=1]

[attachthumb=2]

This aluminum bar is 1/4 inch thick and 3/4 inch wide. I have 7 of these bars sitting around removed from some old electronics project. The holes in the aluminum are from previous use and are of no importance now. I keep 2 of these bars set aside for use as a straight edge. You don't need to use aluminum like I did, 1/4 inch birch plywood should work fine.
[attachthumb=3]

With the dados I can remove the bars when I need a flat top (like the right "guide rail waste side" of the table). If you are concerned about running dados into your table, maybe just attach the aluminum bars to the MDF sides sitting above the table supports. It is about 9/16 inch high so you could run small screws or try to glue it in place. I think the dados will give more strength and easier to remove.

I put these dados on both sides and the back side. The right and back side is mainly for use as a fence, the left side (in conjunction with the back side) gives me that perfect 90 degree corner for gluing (as discussed by Jerry Work's manual on the MFT).
[attachthumb=4]
These dados do not have to run the full length of the side. You could easily get by with a 12 inch long dado on the sides and 24-32 inches on the back. If you run the back dado all the way to the right, you can put in a small length of the bar and fence to sit on the right side of the guide rail for extra board support.

My dados start at 3/8 inch from the edge (I used 1/2 inch as my centerline for the Festool router). It is 1/4 inch wide and 1/2 inch deep. The depth was determined by the fence that I will put on top of the bars.

 

[Qwas]

The New Fence

I could use these aluminum bars as my fence, and probably will when I need to cut something really wide (29 inches). But there is nothing like a professional looking fence to show off. So why not throw something on top of these bars.

I decided on a couple of Aluminum extrusions from 8020 Inc. . I used their metric series. I'm thinking my main fence will be a piece of their 25-5013 series. It is 12.5mm (just a hair under 1/2 inch) tall and 50mm (just under 2 inches) wide with a 6.5mm slot. This slot fits a 1/4 inch bar tighter than a normal 1/4 inch slot but still allows movement, main difference - no slop. The same holds true with 1/4 inch bolts, they fit tighter with less slop in the slot.
[attachthumb=1]
[attachthumb=2]

I thought about drilling a couple holes all the way through the slots in the table top. Then I could secure the fence to stop any rocking. So far, I don't think it is necessary. Also, I would have to cut my aluminum bars into smaller pieces to allow for the bolt coming up through the slot.

Most of my cuts are a single board or plywood, 1/2 - 3/4 inch thick. I can slide this extrusion under the guide rail and keep it there or very easily slide out of the way of the guide rail.
[attachthumb=3]

The drawback to this 25-5013 series is there is only one slot, no slots for adding a board stop or other jig parts. But I'm thinking I can throw a clamp on the fence for my board stop.

I also picked up some of their 25-2503 series. It is 25mm x 25mm (1 x 1 inch) with one clean face and the other 3 faces have the 6.5mm slot. The slots will not work with anything Festool but there's lots of other options with 1/4 inch jig parts that will.
[attachthumb=4]

Occasionally, when working on cabinets, I like to stack my boards and know everything is cut the same. So I picked up some 25-2550 pieces. These are 25mm x 50mm. This is as high as the TS-55 will let me cut. And it has plenty of slots to support 1/4 jig parts. In this picture I have attached a board stop using another piece 2550 and one of their joining plates, 25-4152.
[attachthumb=5]

Benefits - Extra cutting width. With just the aluminum bar in place, I have 29 inches of cutting room. With the 5013 I have 27 1/2 inches, and the 2550 has 28 1/2 inches. I can use conventional jig hardware to secure boards or other things that I haven't even thought of yet.

If you have 2 or more tables joined together, imagine lining up the dados, putting an aluminum bar in each table top, and then one long extrusion to cover all the tables! If one of your dado slots is a hair off, remove the screws from the bottom of the MDF tops, put on the aluminum extrusion, and then put the screws back in using new holes.

The aluminum was all cut with the PS-300 jigsaw, speed setting on 1, pendulum on 1, with a HS metal cutting blade. THe cuts are easily cleaned up with a hand file.

I am not affiliated with 8020 or any of their staff or the person selling on eBay. I just like what I seen from them and their prices. My main concern was cost. They have one person selling some of their excess pieces on eBay. You can get some bargain prices from him by looking for precut stock and tapped holes in the ends. If you find something better for your fence, that is fine. You might want to share that information with the rest of us.

Okay, I'm open for your suggestions, ideas, changes, improvements, and just plain criticism. So far, I haven't put alot of thought into the fence. Once I got the dados cut, I seen the alignment of the holes and that got all my attention for the past week.

 

[mhch]

I also missed the parallelogram idea at the beginning of this thread,
which I just noticed it today ...

Someone mentionned the fact that it is not possible to use
the hole pattern idea across MFTs installed side by side.

It occured to me that a setup jig can be built to install two MFTs
side by side so that I can use the hole pattern idea across them,
i.e. a simple piece of MDF/plywodd with 6 holes, 20mm each, forming
two rectangles with a common side, and such that 4 of my 20mm
PVC dogs can be plugged across the jig into one MFT, while the
other two are plugged across the jig into the other MFT.
Then the two tables can be secured together and jig be removed.

Do you anticipate any problem with this ?

 

[Qwas]

I've never tried to join 2 tables together but I would think you could run a long straight edge across the front edges of the MDF top to align the table tops and then tighten down the screws.

 

[mhch]

What you suggest is OK to keep table aligned on one dimension
but that does not guarantee that hole diagonals will be aligned

 

[mhch]

I forgot to say that the holes of the jig must match holes on a single MFT, so that
the 45 degree alignment is kept across the two tables

 

[Qwas]

Oh yes, I see what you mean. Your way with 45 degree fence should work for both dimensions. They might have to put some kind of spacer between the tables.

 

[Qwas]

Here is another popular bracket (25-4175) for joining the 2550 fence sections.
[attachthumb=1]

While you tightened the bolts, it might not stay at 90 degrees. So I slide the 2550 pieces onto the back and right side aluminum bars.  This holds them at the 90 degrees. Tightened the bolts and 90 degrees every time.
[attachthumb=2]

 

[Qwas]

Okay, I told you the fence would be boring. Back to the holes!

I think this is going to become my main fence.
[attachthumb=1]

Some of you might want to do something similar but you are afraid the parts you have might not come out perfectly centered in the slot.
No problem. I don't if it is readily apparent so I will show how to still make it work.
I will show an example overly exaggerated. I will move my hole insert to the other slot, a full inch out being centered.
[attachthumb=2]

Now mark the top of the fence with anything you want (sticker, magic marker, hole, etc.). Align you cutting rail...
[attachthumb=3]

By putting the fence in another set of vertical holes and keeping your mark to the top, you get a parallel cut.
[attachthumb=4]

And by moving the fence to a set of horizontal hole and keeping your mark to the right, you get a perfect 90 degree cut.
[attachthumb=5]

 

[Qwas]

By the way, those black hole insert shown above came from some Jet parallel clamps. They are 3/4 inch diameter. I've added about 4 wraps of duct tape to get them to fit the holes better.
[attachthumb=#]

 

[festeringtool]

I've learnt a lot on this thread - thanks!

 

[JayStPeter]

The best MFT enhancement I've seen.  Great job!

Jay

 

[Corwin]

I'll have to try wrapping a little duct tape around some clamping element holders so they center in my newer table's (a little sloppy) holes -- then everything should align across my two 1080s.

The other night I stripped down my MFTs to check this hole thing.  Now realigning my rail and fence is much faster.  And I'm just gettin started...  I agree that this has been a most enlightening thread -- Thanks!

Corwin

 

[Qwas]

I'll have to try wrapping a little duct tape around some clamping element holders so they center in my newer table's (a little sloppy) holes -- then everything should align across my two 1080s.

The other night I stripped down my MFTs to check this hole thing.  Now realigning my rail and fence is much faster.  And I'm just gettin started...  I agree that this has been a most enlightening thread -- Thanks!

Corwin

Thanks Corwin, I'm glad it can help others.

There have been some questions on the holes between 2 table tops. Can you give any description on how you did it and what is involved?

 

[Qwas]

And let's not forget, by sticking bench dogs (or better yet, the clamping element stops) in a horizontal row and a vertical row, we can have a 90 degree gluing corner in various spots on the table.

 

[mhch]

Oh yes, I see what you mean. Your way with 45 degree fence should work for both dimensions. They might have to put some kind of spacer between the tables.

To ensure that the hole pattern regularity extends across tables,
It looks like a 40mm or so spacer would be needed between side rails
when the shorter sides of MFTs are connected togther. I have no idea
yet whether it is of high interest to make sure that hole patterns
exacyly extend across 2 tables, but if so I think I will make the
suggested alignment jig to work from underneath and to include
the spacer between rails.

I'll experiment around this when I receive the MFT 800 to be delivered
this week (I ordered it when I saw the discontinuation notice on this
forum.

Never heard of that in France, may be the MFT2 is only NLAINA

 

[Qwas]

Thanks mhch. That's about the thickness of our 2x4 lumber. Nice to know.

I don't know myself how important it is to keep these holes aligned between tables. I guess time will tell.

 

[mhch]

Some of you might want to do something similar but you are afraid the parts you have might not come out perfectly centered in the slot.
No problem. I don't if it is readily apparent so I will show how to still make it work.
I will show an example overly exaggerated. I will move my hole insert to the other slot, a full inch out being centered.

This also works for 45 degrees angles. A simple and safe way to proceed is to consider
the mark (preferably close to one of the dogs) as a rotation center: unplug the fence,
rotate it, plug it again,

However, the misalignment issue you mention for homemade fences opens the
possibility of making errors, specially if TWO fences are needed (misalignment
is unlikely to be identical between them) or even because dogs may be dumped
while manipulating the fence, thereby changing the misalighment !

I feel much safer to use dogs which exactly fit the holes, like the ones made from
20mm PVC pipes, and to have fence, rail, workpiece resting against them.

 

[mhch]

I remember I read somewhere in this forum that Festool recently decided to slightly change
the hole diameter ....

That may explain the loose fitting seen on a new table and not on an older one.

 

[mhch]

Sorry for the typo in my prevous post: dogs may be bumped, I doubt
you would dump them