MFT enhanced with built-in, incremental, parallel guide

dogutsukawu

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Joined
May 24, 2010
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I enhanced my MFT (2 tables joined end-to-end) with 2 Incra incremental rails and stops.

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This enhancement builds parallel guides into the MFT, with all the advantages of the Festool parallel guide and more.  The added benefits are due to incremental nature of the Incra rails and a "fence board" which spans the table and butts against the stops.

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The setup is as follows.  Attach 2 Incra rails, one on each side of the MFT.  Square the Incra rails to the guide rail.  Position both stops at exactly the same distance from the cutting edge of the guide rail.  Push against the stops a raw fence stock, 3/8" thick, broad enough to span the stops, and long enough to stick out beyond the cutting edge.  Cut the fence.  Set the scales on both Incra rails to read zero at the stops.  Done.

Now if you set both stops at 20 mm, push the fence board against the stops, push the stock against the fence board, and cut, you'll cut the stock at exactly 20 mm wide and parallel, every time.  Works for any dimension up to the length of the Incra rails (mine are 54").

With this enhancement, you get the following benefits of the parallel guide and more.

1. Cut stock square and parallel without measuring, marking, and aligning.

2. Cut two pieces to EXACTLY the same dimension on separate occasions (unlike the parallel guide where the stops are set by eye and not with the repeatable precision of an incremental positioner).

3. Cut wide and narrow stock with one setup (unlike the parallel guide).

4. Cut thin stock without shimming (the parallel guide requires shimming of stock thinner than the guide bars).  Make sure the fence board is at least as thin as the stock.

5. Rip a piece narrower than the guide rail.  For narrow ripping, the fence board is the same thickness, ideally, as the thickness of the stock.  In practice, I've used one fence board (3/8" thick) successfully with stock of different thicknesses.

6. Cut narrow stock to length using only one stop, just as on a chop saw.  For this purpose, don't use the fence board.  In its place, use the aluminum extension rod supplied with the Incra stop with the rod zeroed at the cutting edge.  With the parallel guide, it can be awkward to get the guide rail to sit flat on narrow stock.

7. Stays in calibration (square and parallel) once calibrated (unlike the parallel guide which may go out of calibration with use).

8. Make cuts up to 48" wide (with 54" Incra rails).  The parallel guide is limited to about 24".

One more advantage: the setup is cheaper than the Festool parallel guide.  However, the parallel guide works for ripping long stock, and it's portable.
 
This looks more complicated to me that it needs to be.  I use a square (well, rectangular) piece of MDF as a jig to make parallel cuts on my MFTs.  With the fence set square to the guide rail and one side of the MDF jig against the fence, the adjacent side is then parallel to the guide rail.  This is all you need to align cuts that will be wider than the guide rail.

For narrower cuts, I have installed a cleat parallel to the one side of the jig.  Here I place the material to be cut on top of the jig and tight against the right side of the cleat.  A piece of material (the same thickness) is placed on the left side of the cleat to support the guide rail.   I use a length of T-track for my cleat and have it set low enough for most material, but I can add pieces of 1/4" MDF on either side if needed.  Instead of a cleat, you could have a row of holes in the jig that would accept pegs or dogs to serve the same purpose.

I use Incra track for the fence on my MFTs, but any fence will work with this type of parallel jig for the MFT.  Usually, I have two MFTs joined with a 1900mm (75") guide rail and my parallel jig is big enough to make 4' cuts -- I could have even made it a little bigger, but I have a different jig that I use on my cutting table for longer cuts.  In any event, I think this type parallel jig is much simpler, offers all the same benefits as your Incra setup and is easier to remove and replace, allowing you to readily use your MFT for other operations.

On Edit:    Your setup would make more sense to me if you had oriented it the other direction -- with something like a 3000mm rail spanning the long direction.  That might work well for a table dedicated for those long, narrow rips.  The jig I have is about as big as it can be -- too much larger and it would become problematic.  I use my home-brewed parallel guide on my cutting table for those long rips -- it also uses Incra tracks.
 
I'd like to see photos of your complete MFT set-up.  Looks interesting from what I can see in the photos.  I like the Incra system the way you used it. Very nice.
 
dogutsukawu said:
I enhanced my MFT (2 tables joined end-to-end) with 2 Incra incremental rails and stops.

With all due respect, that rig looks like much more than just 2 MFT's joined together.  What you have there is a have a super modified  mobile work table/storage chest/upside down table saw.  Very cool.  I saw your holster on another thread. Sweet.  

I have a suggestion for your safer-than-a-SawStop  upside down table saw there.  You mention the problem of material thickness.  How about stiffening the back side of the guide?  Perhaps an aluminum angle?

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Crummy sketch but you get the idea.  If it provides enough stiffness you won't have to worry about material thickness.  The only issue I can see is making sure the bolts aren't in the saw path when the saw is fully plunged.

 
Corwin:

Your approach is less complex.  I considered getting by with one Incra rail and a rectangular "fence board" like yours, but the disadvantages as I see are as follows.

1. With the Incra rails "built into" the MFT, they don't have to put on and calibrated with each use.  My rail is easily removed by loosening 3 bolts and sliding it off the MFT side rail if I need freer access to the table.  Since my rails are on the MFT by default, my approach is the method of first choice for making a cut since it entails no extra set up.

2. For accuracy, I would want the long edge of the rectangular board resting against the Incra rail.  This would require a big fence board for cutting wide stock, and the size of the fence board would subtract from the length of cut I could make on the table.  To insure that the fence board would not be nudged out of square, I would have to clamp it to the table.  My fence board can't go accidentally out of calibration because it butts against the stops at both ends.

3. For making narrow rips with the stock resting on top of your jig, the stock has to be supported on the waste (right) side.  This is no big deal, but it is an extra step.

Obviously, the two approaches could be combined.  With one rail installed, a rectangular fence board could be used.  With both rails installed, you would have the benefits of my approach.  One is not necessarily better than the other.  Depending on the situation, one approach might be better than the other.  With the option of two rails and my fence board, now you choose the best way.
 
fshanno:

I like your idea of stiffening the guide rail so that it won't sag in the middle of a wide cut even if it's not supported underneath.  Then most cuts could be made with a single thin fence board.  Only for super critical cuts would a fence board matching the stock thickness be required.
 
I do like your jumbo-sized MFT!  And I too am interested in further details on its construction.

dogutsukawu said:
Corwin:

Your approach is less complex.  I considered getting by with one Incra rail and a rectangular "fence board" like yours, but the disadvantages as I see are as follows.

1. With the Incra rails "built into" the MFT, they don't have to put on and calibrated with each use.  My rail is easily removed by loosening 3 bolts and sliding it off the MFT side rail if I need freer access to the table.  Since my rails are on the MFT by default, my approach is the method of first choice for making a cut since it entails no extra set up.

I don't need to calibrate my setup for each use either.  If removed and replaced, I only need to use a feeler gauge to set the track a specific distance from the backside of the guide rail -- I like some clearance there, so I use a 1-2-3 block for a feeler gauge.  This is a very quick and repeatable process.  And this also allows me to use the same Incra track for more than one type jig without having to recalibrate -- just set off the backside using the feeler gauge...

dogutsukawu said:
2. For accuracy, I would want the long edge of the rectangular board resting against the Incra rail.  This would require a big fence board for cutting wide stock, and the size of the fence board would subtract from the length of cut I could make on the table.  To insure that the fence board would not be nudged out of square, I would have to clamp it to the table.  My fence board can't go accidentally out of calibration because it butts against the stops at both ends.

As I see it, your table is limited to something like 28" long cuts no matter how wide your board is.

dogutsukawu said:
3. For making narrow rips with the stock resting on top of your jig, the stock has to be supported on the waste (right) side.  This is no big deal, but it is an extra step.

And the guide rail should be supported when making narrow rips.  If not, the weight of the saw, and the force you are applying on the saw would cause the rail to tip or flex leaving you cut messed up.  Usually you have more than just one piece of the material that you are cutting, so you already have a piece to support the left side.

Crosscutting material directly on a MFT is fine, since you don't need to set the depth of cut too much deeper than the material.  However, for rip cuts you should set your blade somewhat deeper.  So, placing your material on top of a jig or piece of sacrificial material is beneficial for ripping...
 
fshanno said:
...
I have a suggestion for your safer-than-a-SawStop  upside down table saw there.  You mention the problem of material thickness.  How about stiffening the back side of the guide?  Perhaps an aluminum angle?

[attachimg=1]

Crummy sketch but you get the idea.  If it provides enough stiffness you won't have to worry about material thickness.  The only issue I can see is making sure the bolts aren't in the saw path when the saw is fully plunged.

Depending on your hardware, you can bolt something to the top T-track without it interfering.  However, the added angle stock will be in the way when the saw is plunged deeply.  IIRC, the TS55 needs around 5/8" clearance to the left of the rail, and the TS75 needs something over an inch -- I may have these dimensions wrong, as it has been some time since I measured this.  Having said that, you would only have the saw set deep when you were working with thick stock -- therefor, you could try your idea with the angle turned upside-down from how you have shown it.  But, I really think placing another piece of material the same thickness (as the material you're cutting) is the way to go.
 
win:

There's really no conflict here.  If only one Incra rail is in play, use a rectangular fence board per your approach.  If both Incra rails are in play, then you get the added benefits of my approach.  I feel that two rails make for a more robust approach which is less susceptible to operator error.  Notice that with both rails mounted, almost the entire table still remains clear to work on the table as usual.  It's rare that a rail interferes with work and must be removed.

Because I've joined two MFTs end-to-end, I can cut stock up to 48" long (left to right).  The Incra rails I have are 52" long.  The width (front to back) is limited to 27-1/2" as usual with the MFT guide.

I've successfully made narrow rip cuts without a shim supporting the non-cut side of the guide.  If I cut as usual without a shim, the guide rail will sag.  So I torque the saw clockwise as I push so that more weight bears on the cutting edge and less on the non-cutting edge.  With practice, this technique eliminates the sag or least reduces it.  It works well enough for me that I don't feel the need for a shim.
 
Hi all, i'm new to the forum so please forgive the dumb question but: the pictures included with posting don't show up for me.  i just see a small blue box with a question mark in it.  I've googled around to see what i can find out but coming up with nothing.  Is this a forum setting, or does anyone know how i can correct this?  I'm using a new Mac and have tried it with both Safari and Firefox. 

I'm dying to see the pictures of the enhanced MFT with built-in parallel guide, so thanks in advance for any help!!

Jack
 
jackstork said:
Hi all, i'm new to the forum so please forgive the dumb question but: the pictures included with posting don't show up for me.  i just see a small blue box with a question mark in it.  I've googled around to see what i can find out but coming up with nothing.  Is this a forum setting, or does anyone know how i can correct this?  I'm using a new Mac and have tried it with both Safari and Firefox. 

I'm dying to see the pictures of the enhanced MFT with built-in parallel guide, so thanks in advance for any help!!

Jack

[welcome]

The author of the post was only active on here for 1 month, so the images are gone if he used a image host. So it will be unlikely you will get to see the images now. 
 
There's a problem with the forum software/database at the moment and many, many posts are missing the photos that were originally uploaded. I'm hopeful it will eventually be fixed as it will be a massive loss if not, but we're led to believe there isn't a webmaster at the moment since Shane left, so it could be some time, if ever...  [crying]
 
carlb40 said:
jackstork said:
Hi all, i'm new to the forum so please forgive the dumb question but: the pictures included with posting don't show up for me.  i just see a small blue box with a question mark in it.  I've googled around to see what i can find out but coming up with nothing.  Is this a forum setting, or does anyone know how i can correct this?  I'm using a new Mac and have tried it with both Safari and Firefox. 

I'm dying to see the pictures of the enhanced MFT with built-in parallel guide, so thanks in advance for any help!!

Jack

[welcome]

The author of the post was only active on here for 1 month, so the images are gone if he used a image host. So it will be unlikely you will get to see the images now.
Perhaps some Fog'er saved the pictures and can repost them? I try to save pictures of all the smart solutions I find here, but this one I have missed!
 
I see them but they are blurry. I am using tapatalk on my iPhone 6+

Let me try and "snag" them. Not sure it will work that well.

Cheers. Bryan.

20aa53cd9cc5712c37a716e3eb213673.jpg


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Edit:  replaced images with the ones Tony found.
 
downtheroad said:
I right-clicked on Bryan's posted images and did a Google search and found these. Clearer pictures to me, anyway.

pic 1

pic 2

Thanks Tony!  I replaced mine with the ones you found via Google Goggles.

Cheers. Bryan.
 
Addressed to the original poster, for simplicity:

Nicely executed but - to me - it looks like a solution looking for a problem.

AFAIAC, the //guides would be useful for ripping board // to the LONG edge
... and
with the  (???) attachments, making thin stock rips for edge banding etc.

Your rather beautiful (God, I love Incra) design doesn't address the first requirement and as far as the second goes, seems over complicated. I'll admit I may be missing something here.

W-Wizard's simple notion of hanging a CMS protractor/fence off the waste end of the MFT seems a practical way of making thin rips, (albeit also off the short end of a board) which would be accurate enough for most real-world applications that I can envisage.

Now your idea will certainly be more accurate but I suspect - and I'm happily open to being corrected - that the increased accuracy would confer an academic advantage only. Of course there's no danger of making tapered slivers with your scheme whereas the Wizz's alternative would possibly require more care or there might be slight some danger of it going awry.

I find what you have done to be more aesthetically compelling, but maybe that's because I'm an Incra nut and I'm over-fond of the shininess and the engineering bling.

It's also in line with Incra's philosophy of making the "waste" side of the thin cut the precision one though I think that their stance is mainly due to the safety advantages peculiar to a moving workpiece/stationary blade of a table saw and roughly translates as, "don't trap thin offcuts between the blade and the fence which is supporting the cut," mainly because the empty kerf is now "supporting" the leading run of the cut - i.e, it isn't.

This is something WW and I have long discussed in connection with his fence on the thin side of the cut method, concluding - has have others on this forum - that his method is perfectly safe, with NO danger of kickback though this seems to fly in the face of accepted wisdom. This, however, is the result of years of conditioning and advice particular to table saws.. outside of that context the rules are a misconception.
On a tracksaw. the reference edge can be // to and as close the the cut line as one dares take it - anything greater than the blade thickness, theoretically. Practically, if there's any wood to the right of the bade and it's not just planing, then everything should be fine.

Fence to the right also means perfect repeatability with no resetting between cuts. (for thin strip cutting, obviously.)

I enjoyed examining your project and I admire how you have done it but for me, WW's idea would be more practical, and would be the way I'd go.

Thank you.
 
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