Idea for ripping narrow-stock

[John2532]

Quite  a while ago I machined a mount for use in a parallel cutting jig. The mount used a Empire adjustable T-square that I picked up from either HD or Lowes.  I finally got around to making the second copy and was thinking how these could work for ripping stock narrower than the Festool rail.

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What I came up with was a simple attachment that used a ¼” rod and a pinch-system to hold it in place and allow for adjustments. (While the beta-version was made out of wood I plan to make a aluminum replacement soon)

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Instead of a built-in measuring system, I decided to keep it simple and rely on a combination square to set the dimensions.

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I tried it out on the MFT by ripping a 1" and a 1/2" piece, and even though I was fighting a slight “stiction” problem with one of the rods, I was able to keep the cut-offs parallel within .005” (1/200”) I haven’t tried it off of the MFT yet, but as long as the left side of the rail is supported by some scraps as the same thickness material as is being cut, I think it will work well.

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John

 

[Sparktrician]

Seems to me that this is where the Parallel Guide Set (P00108) comes in with the answer.  While I don't want to stifle your creativity, there's a ready-made answer just ready to go right now. 

[smile]

 

[John2532]

Oh sure, I could have just went out and bought Festool's version but where is the fun in that??  Also, I couldn't justify the $300 plus price tag for the amount of use I would get out of it, especially with some of the mixed reviews.

John

 

[AdamM]

John,
Ever think about offering these on your website?

 

[John2532]

Adam,

If there is interest I would be happy to make some available. I was curious though if most people would prefer the original "dual-purpose" mount or a approx. 1/2 size mount used only for narrow stock.

John

 

[jmbfestool]

I like the new beta-version and would be interested!  BUT!!!   At the moment your jig supports the rail right?!  Well I assume you currently made it at the same thickness of the stock you cutting in the picture.  Well what if I wanna rip 6mm? or something thicker?!     Im think making it so you can remove or add plates on the bottom to allow for different thicknesses!     I would also like atleast 3 of them  as if I was using a 2800 rail I would have one in the middle for support as well as bot ends.

JMB

 

[Alan m]

ok looks like we got another domniplate going here .
i might consider one ( a set of 3 or 4 for long rails) if the price was right

 

[jmbfestool]

Had a thought!  You could make what currently is a piece of wood on your beta version!  As thin as possible to allow for cutting 4 mm hardboard! and to hold the rod of coarse.  Then have some magnets fixed either side of the rod!  Then have four or more plates made  an 8mm (for 12mm sheet)  14mm (for 18mm sheet) 18mm for (for 22mm sheet)   Have a rebate or something to secure the plates and the magnets keep it in place.  This then allows for easy change over if needed!   And because of the size they should all fit in my TS55 box so I will always have them with me!If I add a magnet on the lid I can stick the plates on the lid so I can see them easily! And if you print the thickness on the plates that would be great!

Unlike the Festool Parallel Guide Set (P00108) which i another tool you have to carry and set up which I can not be bothered with.

JMB

Edited:   Oh can you make it some how that all you need to do is turn the knob which tightens the rod but also tightens it to the rail?! So no need for those plastic screws either side of the jig as the knob will tightens it against the rail.   lol Joking!  Im asking to much I know!

 

[John2532]

I like the new beta-version and would be interested!  BUT!!!   At the moment your jig supports the rail right?!  Well I assume you currently made it at the same thickness of the stock you cutting in the picture.  Well what if I wanna rip 6mm? or something thicker?!     Im think making it so you can remove or add plates on the bottom to allow for different thicknesses!     I would also like atleast 3 of them  as if I was using a 2800 rail I would have one in the middle for support as well as bot ends.

JMB

JMB,

Right now the jig does not necessarily support the rail, the rod holder protrudes below the rail about 5/16". My thought was to put a scrap cut-off, the same thickness as the material being cut, under the left side of the rail for support. Of course, right now, the thinnest material you could cut without some clever shimming would be 5/16".

I do like your idea of magnetic plates though, Shouldn't be too hard to work out and would definitely be convenient.

I have another idea I will try to draw up and post this evening. This would be an adaption of the full setup using the T-square and mounting the narrow-stock adapter on the "slider" used to set the length of cut. (a picture will be much clearer)

Please keep the ideas coming.

John

 

[lumbajac]

Probably would have to be a bit more substantial, but how about something like the "footplate" on the router bases that supports the overhanging portion of the router base?  Could have one on each of your brackets.

 

[AdamM]

Adam,

If there is interest I would be happy to make some available. I was curious though if most people would prefer the original "dual-purpose" mount or a approx. 1/2 size mount used only for narrow stock.

John

I would prefer the 'dual-purpose' mount.  Presumably that would be a little cheaper than buying unique mounts for each purpose.  Given that it's just a bolt/threaded knob holding each one, changing over should be pretty quick.

The 5/16" thickness under the rail could be tolerable to me, but if it could be trimmed down to 1/4" I think that would be ideal.  However, that's getting pretty thin so I guess you'd have to see if the block underneath is still tough enough to last.

 

[John2532]

I worked on Version2, and taking into consideration the desire to work easily with 6mm material, I abandoned the rod and came up with this:

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The slider is 1/4" and is the lowest portion of the jig.

Additional support plates to adjust the height is a great idea and am still working on a reasonable solution. I'm thinking along the idea of making an attachment point and the user can make their own spacers out of the stock they most frequently work with.

Should there be interest in a narrow-cut jig only, (no provisions to attach a rule) I would machine this out of one piece, avoiding the (now wooden) adapter. This would make it slightly less expensive. Those who want both capabilities could get a version similar to the pics above.

John

 

[lumbajac]

John,

Looking at your first post and picture - wondering if you could manufacture your own adjustable square of sorts like the Empire you purchased from Lowes/HD.  If you could make the portion of the square butted up against the plywood so that it could pivot 90 degrees to parallel with the upper portion.  Could also have it with a milled out center slot like the other portion of the square, then one could slide below the other for narrow rips and act just like the rod in your first prototype or the 6mm bar in the second prototype.  Could position it to proper depth with combination square as you show OR devise some sort of calibrated rule like the Festool version of parallel guides have.  The lower portion could then be pivoted back 90 degrees, back to being perpendicular with the upper portion so that it could then be used again as parallel guides for ripping sheet goods, etc.

Corey

 

[John2532]

Corey,

Thanks for the idea, I'm pretty sure I follow your logic. The sliding adjustment fixture would have a pivoting bar mounted underneath, when it is perpendicular to the rail it would be used for the "wider cuts". When it is aligned with the rail, it would used for "narrow-stock". I'll see if I can either machine or draw something up and see if it is what you had in mind.

Unfortunately I won't be able to do much with it in the next few days but I definitely appreciate all of the great ideas.

John

 

[lumbajac]

John,

Sounds like your understanding what I attempted to explain.  Looking forward to when you can get around to a prototype.

Corey

 

[lumbajac]

John,

Looking again at your first prototype in the original picture - looks like you can already adjust for 30, 60, etc. degrees on the Empire square so would just have to loosen the large black toggle and turn the two pieces so that they are parallel, one below the other, and then slide the bottom piece forward assuming it will slide right past the FS guide rail edge and then keep it going right under the guide rail itself so long as the top of the square piece slides nice and flush with the bottom of the FS rail.  Only problem is that it looks like you'll run out of travel to get it far enough under the FS guide rail to rip really narrow stock, thus the need for machining some sort of groove in the bottom piece of the Empire square unit.

Corey

 

[John2532]

Cory,

I tried your idea of turning the original crosspiece of the T-square and it does rotate and stick out plenty far to use as a extension.

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The biggest problem I see is that when you are trying to rip thin strips, the extra 48" of rule might prove to be a little cumbersome. The setup below is much more manageable and can work with the MFT

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Still open to all ideas though!

John

 

[jmbfestool]

Well you said Ideas!  Well here is my idea!   I did it quickly on sketch up!  It is to size I hope or I tried to keep it to scale any way.  

As you can see I have made an adapter for the jig.   This is to allow the jig to be made to sit flush with the Guide rail so when you cutting large stock and using the stops.  Then by adding the adapter it lifts the rail up by 6mm which is the thickness of the bar to slide under the rail for narrow stock.  It has two magnets glued in to the adapter which will allow you to have various thickness of metal plates to lift the raill even more for thicker stock.   Example I have done 3 plates in the drawing  first one is 6mm so that will let you cut 12mm thick stock and the next is 12 which will let you cut 18 and the last one is 16mm so you can cut 22mm this because the adapter has already lifted the rail by 6mm.

Looking underneath you can see the bar has a rebate and you can see a small rectangle plate which will hold everything together.  Simply loosen the knob and you can turn the plate and remove the bar and add a longer or shorter bar if you want to easily and quickly.    I like this idea as I would like a small 200mm bar cutting narrow stock and then a min 630mm bar to cut large stock at min of 620.

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[jmbfestool]

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All Together with Adapter!
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[jmbfestool]

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All together WIHTOUT adapter
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