# Revisiting the pivot fence with a twist



## wormil (Sep 6, 2012)

I've read a number of old posts about pivot fences and I have a grip on it but in my searching I found the following video which kicks it up a notch. The magic happens at about the 6:10 mark.


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http://youtu.be/x2iDEa5PInE
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_Sorry you'll have to cut and paste, I'm not allowed to post URLs yet._

So if you look carefully, you can see the whole fence isn't just pivoting but both sides are moving. If I understand correctly there is an arc shaped slot cut into the fence along which the fence travels to keep the cut perpendicular. It's covered under US Patent 5988242 (attached). I'm not sure why this idea never took hold but it's pretty clever even if tricky to build.

My question is this, has anyone else tried to recreate this? I would like to try.


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## bobj3 (Jan 17, 2006)

Hi Rick


I have used the pivoting fence for about 5 years now and will say once you set it up you will not use the Old Way without tee tack or the side C clamps on the router table.. it's the best way I have found.... 

I have tried to get many to try it but it's hard to break the habit of the table saw fence..stuck in there mind...

I will say I don't use a wooden block I use a small device on the back side on the table top ( Alum.block with some screws sticking out of it..preset ) but use it about the same way with brass key stock and drill bits...

By the way Rick thanks for the video, the only thing I didn't like about it he didn't use push sticks of any kind..that's a big no no on the router table in my book 

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wormil said:


> I've read a number of old posts about pivot fences and I have a grip on it but in my searching I found the following video which kicks it up a notch. The magic happens at about the 6:10 mark.
> 
> 
> ```
> ...


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## friendly1too (Sep 25, 2004)

This is amazing. I use a fence attached at one end with a bolt through the table, but I'd love to learn more about how the fence can be set so easily.


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## DaninVan (Jan 1, 2012)

My mind is in slow gear this morning. If the LEFT end of the fence is fixed, and the RIGHT end pivots (making an arc) how does a distance set at the right end arc equal the distance at the arc at the bit position? The bit arc is shorter. I'm obviously missing something here.


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## wormil (Sep 6, 2012)

DaninVan said:


> My mind is in slow gear this morning. If the LEFT end of the fence is fixed, and the RIGHT end pivots (making an arc) how does a distance set at the right end arc equal the distance at the arc at the bit position? The bit arc is shorter. I'm obviously missing something here.


The router bit bisects the angle so any measurement at the right side will be halved at the bit. The pins need to be equidistant from, and in line with the bit. That's just part of the benefit of pivot fence though. The interesting part is that he makes a perpendicular cut with a swinging fence, the benefits are astounding. The fence itself replaces half a dozen different jigs.


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## DaninVan (Jan 1, 2012)

Rick; Ok, that first part is clear....but he didn't clarify the distance part on the video. So far I like it. Any deviation at the right end is only 1/2 of that at the bit; all good.
On the swinging fence part however, the material being dado'd is pivoting through an arc, theoretically the cut is not a straight line, although the arc may be insignificant if the fence is long and the piece being cut is narrow(?)...
On the push stick thing, Bob, watching him gave me the willies! Guy's got horseshoes up the ying-yang.


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## DaninVan (Jan 1, 2012)

Sorry; wrong way round ..."Any deviation at the right end is only 1/2 of that at the bit;"
Should be '_any deviation at the right end is double that of the deviation at the bit_.'


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## Harrison67 (May 30, 2012)

Does anyone have a good link to the video? For some reason, I can't get it to work.
.
Thanks in advance, Harry


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## DaninVan (Jan 1, 2012)

Harrison67 said:


> Does anyone have a good link to the video? For some reason, I can't get it to work.
> .
> Thanks in advance, Harry



Pivoted Fence with Rotating Post - YouTube

Harrison; there was an earlier similar video posted here a few months back. It was an excellent 'how to' piece..._perhaps Bob has the older link at his fingertips?
_


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## Harrison67 (May 30, 2012)

DaninVan said:


> Pivoted Fence with Rotating Post - YouTube
> 
> Harrison; there was an earlier similar video posted here a few months back. It was an excellent 'how to' piece..._perhaps Bob has the older link at his fingertips?
> _


Thanks, Dan; I'll have to watch that and reread the pdf again. Still don't get the part of accurate, 90* perpendicular, repeatable, dadoes. Must be missing something on the pivot points.


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## Mdawson (Mar 25, 2012)

Harrison67 said:


> Thanks, Dan; I'll have to watch that and reread the pdf again. Still don't get the part of accurate, 90* perpendicular, repeatable, dadoes. Must be missing something on the pivot points.


Hi

I'm struggling with the perpendicular dado as well, is he keeping the workpiece pressed against the post as he pivots the fence so the workpiece slides along the fence as he makes the cut ?

Mark


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## Harrison67 (May 30, 2012)

Yes, it seems it would cut an arc, anytime it's pivoted.

My geometry may be bad, though.:laugh:


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## jack3140 (Aug 24, 2012)

i would sure like to get more info on this fence set up i dont get the perpendicular cut either .. if i did i would make one !!!! lol


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## bobj3 (Jan 17, 2006)

Hi Mark

You got it " slides along the fence " watch the video a time or two .start it at the 610 timer and run it over and over, you will see the edge of the stock move to the right just a little bit but it will not take much to keep it true,look at the black mounting plate and the edge of the board...stop the video many times and you will see it, but it's tricky because the bit wants to pull the stock to the left,I have don't it a time or two but you need to hang on to the stock that's why you don't see a push block (hold down block) or push stick,not a safe way of doing a perpendicular slot the ski jig is the safe way...by the way watch his hands he holding it place and moving at the same time..when gets to the stop block he done.. 

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Mdawson said:


> Hi
> 
> I'm struggling with the perpendicular dado as well, is he keeping the workpiece pressed against the post as he pivots the fence so the workpiece slides along the fence as he makes the cut ?
> 
> Mark


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## wormil (Sep 6, 2012)

Harrison67 said:


> Still don't get the part of accurate, 90* perpendicular, repeatable, dadoes. Must be missing something on the pivot points.





wormil said:


> So if you look carefully, you can see the whole fence isn't just pivoting but both sides are moving. If I understand correctly there is an arc shaped slot cut into the fence along which the fence travels to keep the cut perpendicular.


This is where a picture would be worth a thousand words but I have none and since I haven't actually tried it yet I'm still guessing... but rather than the fence pivoting around the pin I believe it's actually traveling along an arc.


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