Attempting to Route Precise Parallel Grooves

[Frank Pellow]

This is a project that I have not yet finished.  I will document it by extracting entries from my journal:

Jan 4th:

The first Greater Toronto East Woodworker's breakfast meeting of the year was held this morning and I got what I thought was a good idea for a gift from Mack Cameron.  He is now turning lots of pens and has come up with a simple and elegant design for a pen box.  His design is best shown with a picture:

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The hinges are pin hinges sold by Lee Valley.  My idea is to extend the box both in width and length so that it can hold 24 pens.  We are giving my granddaughter Isla 24 very good drawing pens for her birthday on January 18th.

I worked quite a bit on a prototype today, but the results of my work were not good.  I thought that I would route 12 grooves each long enough to hold two pens.   If I made the board into which I was routing the grooves long enough, I could then cut it in half to get both the top and bottom of the box.  After a lot of attempts both on my router table and my Festool MFT, here is the best that I managed to do:

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It has a couple of auto body filler patches correcting really bad mistakes and, even then, the grooves are not precise enough.  They are not perfectly straight and the space between grooves is not consistent.  

I have an idea about another approach and will try it tomorrow.

 

[Jesus Aleman]

Frank, I've seen 2 methods to get fairly accurate grooves. One is with an INCRA positioner (or similar product).  You can dial the movement of the router table fence very precisely.  The second method was with a grooved spacer. Similar to a box joint. The spacer has a notch were the bit sits and thus you get equally spaced grooves.    However, you may not get parallel grooves with the later.  Are you having issues with parallelism or spacing?

JGA.

 

[Frank Pellow]

Frank, I've seen 2 methods to get fairly accurate grooves. One is with an INCRA positioner (or similar product).  You can dial the movement of the router table fence very precisely.  The second method was with a grooved spacer. Similar to a box joint. The spacer has a notch were the bit sits and thus you get equally spaced grooves.     However, you may not get parallel grooves with the later.  Are you having issues with parallelism or spacing?

JGA.

Thanks Jesus, at the time I posted the above, I was having trouble with both parallelism or spacing. 

However, as you will see from the the post I am about to make, I appear to have solved the problem when routing on my MFT.

I will check into the INCRA positioner to see if it will be of help with my router table.

 

[Frank Pellow]

Jan 5th:

I am happy to say that the new approach appears to work.  I borrowed an idea that Jerry Work documented in his manual about the Festool Multi-Fence System Multi-Routing Template (which I will reference using the acronym MFS).   Jerry described how to make multiple saw cuts and I simply used the same setup to route multiple parallel grooves.
I will not go into all the details covered by Jerry but will show the set-up and briefly describe it:

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(1) Four MFS fences (two 40cm and two 70 cm) have been joined to make a rigid and very accurate rectangle.  Another MFS fence (1 metre long), which I will call the reference fence, has been loosely attached to the outside set of holes in a Festool Multi-Function Table (MFT) using two regular Festool clamps inserted through holes and into the slot in the bottom of the fence then tightened from below the table.
 
(2) The rectangle has been aligned to the edge of the MFT guiderail making use of the straight oak board then it is temporarily clamped into position.

(3) As shown in the picture below that I extracted from Jerry's manual, markers are put at 30cm point on both scales.  Then these points are aligned and the reference fence is clamped down tight.

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(4) The clamp is removed from the rectangle.  

Now the set-up is complete and precision swing and/or routing can commence.  The distance that the 30cm mark on the rectangle is moved to the left of the 30 cm mark on the reference fence is the distance that the right-hand edge of the rectangle is from the right-hand edge of the guide rail.

One moves the rectangle to the desired location, clamps it down, places the wood to be sawn or routed tight to the rectangle, clamps it down, lowers the guide rail, then saws or routes.  Of course, if you are routing, it is also necessary to compensate for the distance from the guide rail to the router bit.  In the case of the work I am about to show below, a test showed that the distance from the right-hand edge of the guide rail to the right-hand edge of the routed groove was exactly 5 centimetres.

In the picture below, I am routing a set of parallel groves the right hand side each being 21 milimetres from the right hand side of its neighbour.

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In the photo below you can see where I have marked the 21 mm increments on the rectangle scale with a soft pencil.

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That's all for now folks -but keep watching this space to see if I end up being able to make a decent pen box for Isla.

 

[GreenGA]

Perhaps my memory is not as good I hope...  However, I think I recall last year (2007) someone posting their method for routing parallel groves on the MFT. 

I think it had something to do with using spacer blocks all cut from the same piece of exactly-sized material...?  You know, a three foot long piece of exactly 1/2" material cut into, say..., 8"-10" pieces which were used to offset the router during each pass.

Maybe I'm full of it?  I really do think I remember reading something along these lines.  Mainly because in the spring I need to route groves in some material that will be placed on each side of the front door and the method used by the poster sounded like it would be perfect for me.

Please, someone prove me correct.  :

 

[Dane]

What about using the method that Eiji used on his door building project?  Seems that he routed dozens of parallel grooves on that project and documented it in some detail.  I think it requires the hole drilling jig though....

 

[nickao]

Hi Frank, I really never noticed your picture.

Are you the little baby in the pic. Sorry if this is already stated somewhere.

Nickao

 

[Frank Pellow]

Hi Frank, I really never noticed your picture.

Are you the little baby in the pic. Sorry if this is already stated somewhere.

Nickao

I only changed my avatar about a month ago.

My new avatar is a picture of my Dad holding me in December 1942 -just before he went away to Europe for almost exactly three years to fight in the second world war. Upon his return, Dad got me started in woodworking.

 

[Dave Ronyak]

Frank,

Congratulations on posting the solution you came up with to your own parallel groove project.  If you are planning to make a lot of these pencil boxes, I think Jesus' idea of making and using a bunch of spacers would be quicker than repositioning the MFS.

I note in your photos that the base of your router is barely on the edge of the Guide Rail and the Guide Stop (Item 492601) is engaged with the outermost rib of the Guide Rail.  What are your reasons for choosing that arrangement?

Dave R.

 

[nickao]

Hi Frank, I really never noticed your picture.

Are you the little baby in the pic. Sorry if this is already stated somewhere.

Nickao

I only changed my avatar about a month ago.

My new avatar is a picture of my Dad holding me in December 1942 -just before he went away to Europe for almost exactly three years to fight in the second world war. Upon his return, Dad got me started in woodworking.

I wish I had a picture like that.

We lost all family pictures in a house fire along with all the paper work from when my descendants got off the boat in Ellis Island. I should of had that stuff in a safe deposit box.

 

[Frank Pellow]

I note in your photos that the base of your router is barely on the edge of the Guide Rail and the Guide Stop (Item 492601) is engaged with the outermost rib of the Guide Rail.  What are your reasons for choosing that arrangement?

Rick Christopherson shows the router being used this way on the guide rail in his manual about the 1400 so that's the way I first did it.  I am comfortable with the method and see not reason to change.

 

[fshanno]

Good solution.  Ruled extrusions rule.  Bun intended. It would also work for ripping wouldn't it? You could slide the rectangle over till it hits the plunged blade of the saw on the guide and set that to zero.   

I've got a stupid way to do what you're doing on the router table.  I push the fence back and clamp a board down to the table against the fence to use as a sacrificial fence.  I make a pass then go and rip the sacrificial fence on the table saw to move the next grove over.  Run the next groove, rip again and so on.  Sort of a poor man's Incra fence.  It's not pleasant, much trial and error but it has the virtue of being able to work on narrow and long pieces.  I've used this method to make custom molding with flutes and grooves. 

Do you use the little foot on the router when you do this?

What do you do for clamping when most of the work piece is under the guide?

 

[johnsonri]

Perhaps my memory is not as good I hope...  However, I think I recall last year (2007) someone posting their method for routing parallel groves on the MFT.

Please, someone prove me correct.  :

I talked about grooves with the MFT in my Retrospective article and post on this forum. Do a quick forum search for "retrospective"
http://festoolownersgroup.com/index.php?topic=4747.0

Or, take a look at page 18 of the linked pdf:
https://share.acrobat.com/adc/adc.do?docid=b50b18ed-f056-4f59-8735-e83b179804e1

 

[Dave Ronyak]

fshanno,

Your method is certainly workable and foolproof provided you rip off the desired amounts each time you go to the table saw.  Have you considered instead making an indexing board like that shown and used by Eiji when making his fluted/ribbed panel mahogany entrance doors?  Eijis' indexing system could be expanded in capability by drilling several parallel rows of holes, each row having a different spacing interval between its holes, or several rows of holes with the same interval spacings but offset relative to the holes in adjacent rows.  This indexing board would enable precision, repeatable fluting/grooving of many different patterns.  Small PSA pieces (dots) of colored tape could be used to identify the holes you want to use if you are fluting/grooving several workpieces, as Mirko did in his tutorial on using the LR 32 Guide Rail for shelves and hinges installation.

Dave R.

 

[Notorious T.O.D.]

If I was doing this sort of work on a router table I would start with the center groove or one of the center most grooves if doing an even number of grooves. I would cut the center groove. and move back the router fence the width of the space between the grooves. Cut the next groove. Flip the board end for end and cut the matching grove. change the spacer and cut the next two outside grooves, and so on and on.  This way you only have to make 1/2 the adjustments to cut the full number of grooves.

Best,
Todd

 

[johnsonri]

Is this the operation that yo uare referring to?

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[Frank Pellow]

Good solution.  Ruled extrusions rule.  Bun intended. It would also work for ripping wouldn't it? You could slide the rectangle over till it hits the plunged blade of the saw on the guide and set that to zero.    

...

Do you use the little foot on the router when you do this?

What do you do for clamping when most of the work piece is under the guide?

Yes, this works for ripping.  I read about this method in Jerry Work's manual where he uses it for ripping.

Yes, I use the little foot on the router.

I use a Veritas Wonder Pup when most of the work piece is uner the guide.

I will add a couple of pictures, to show the operation in more detail.

First, the set-up:

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where the diagram is marked with the following steps:

___1) Clamp Rectangle against Reference Fence

___2) Clamp Stop Block from under Table

___3) Position the work against Rectangle

___4) Hold work in place with Veritas Wonder Dog

___5) Place slider support blocks beside work

And now the routing:

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It turns out that this operation is quite fast.  Yesterday morning, starting from an empty multi-function table and an unassembled multi-fence system, it took me 6 minutes to do the set up shown in the picture above.  Then it took me 5 minutes to route 6 grooves into each of 2 pieces of wood.  I did flip the wood in a similiar way to that suggested by Notorious T.O.D. to cut down on the number of adjustments.

 

[Jesus Aleman]

Frank, great thread.  How are you moving the jig for the next groove?  Are you adjusting the MFS and repositioning the workpiece, or are you turning the threaded rod on the wonder dog and moving the piece and MFS until you get to the next position.  I just want to know if the wonder dog can be used like a quasi micro adjuster.  If it can, it would be niece to position 2 along a board for ripping.

JGA.

 

[Notorious T.O.D.]

Awesome the way you worked it out and it looks like the results are what you are looking for too.  Thanks for sharing your results with us as I learned some things about using the Festool system as I am sure others will by looking at this thread.

Best,
Todd

 

[Dave Ronyak]

Frank,

If you are not using the Wonder Pup to advance the workpiece to the position for routing the next groove, why are you using it and not a Festool Clamping element which is much faster to release and reclamp at any position?

Dave R.