Router Table Edge Jointing Jig

[Rudy4]

Here's a quick jig to convert a router table to a precision edge jointer. It took me about an hour to make this. It can be set up in only a few minutes and produces very true and straight joints quicky and easily.



The Youtube video shows all the details and takes a whole minute and a half to watch.

https://youtu.be/wfJiyibbyUw

[runamuck]

I don't understand how that can work without the fence after the bit being offset by the depth of cut from the section of fence before the bit.

I do most of my joining on a shaper, using what I described above.

[mirwa]

I cannot work out how its removing an even amount, traditionally your outfeed side needs to be adjustable to accomodate for the amount removed.

How are you accomodating the difference between infeed and outfeed.

Steve

[Rudy4]

Many of these types of setups use a separately adjustable outfeed fence to set the cutting depth, but that's also what creates problems for precision jointing because the fence alignment is CRITICAL in producing a truly straight jointed edge. A tiny amount of deviation from parallel in the infeed and outfeed fence can make edge jointing ineffective.

If you watch the 1-1/2 minute video you'll see that .010" aluminum flashing is cut to fit the "outfeed" side of the fence and semi-permanantly adhered with heavy duty double backed carpet tape. That surface creates the necessary offset and determines depth of cut.

There's no practical reason to adjust depth of cut when edge jointing panels and that's why the rigid single fence can be so effective. The fixed depth of cut ends up being about .015" (the total thickness of the carpet tape and flashing) so it ends up only taking a few passes to true up an edge.

If a panel has any gross irregularities along the edges it's best to hog that off with a band saw cut.

Hope that clears up the how and why of making this type of jig. It's adaptable to many types of scrap material that might be re-purposed into making a dedicated jointing fence.

[runamuck]

Hi Rudy4,

I hadn't watched the video until now so didn't know the outfeed side is. in fact, offset. And that's exactly what I do on my shaper although the offset is larger in order to get a deeper cut.

[murrmac123]

Nice work Rudy ... this is a standard method in cabinet shops of making a router jointer, although I have always made the 3" high fence out of four pieces of 3/4" MDF glued together , with the glued edges planed and faced with standard (horizontal) grade Formica, and a piece of vertical grade glued on behind the cutter to give the offset.

I am sure yours works well ... for my own part I prefer the feel of wood sliding against Formica rather than against aluminum ... just a personal preference.

As you say, there is no need whatsoever for the outfeed to be adjustable.

EDIT: Actually, Rudy, the caption in the OP pic which reads "Adjustment knob allows fence to be set perfectly straight" could be better worded. It should really read "Adjustment knob allows outfeed fence to be perfectly aligned with the cutter".

[Rudy4]

Originally Posted by murrmac123

Nice work Rudy ... this is a standard method in cabinet shops of making a router jointer, although I have always made the 3" high fence out of four pieces of 3/4" MDF glued together , with the glued edges planed and faced with standard (horizontal) grade Formica, and a piece of vertical grade glued on behind the cutter to give the offset.

I am sure yours works well ... for my own part I prefer the feel of wood sliding against Formica rather than against aluminum ... just a personal preference.

As you say, there is no need whatsoever for the outfeed to be adjustable.

EDIT: Actually, Rudy, the caption in the OP pic which reads "Adjustment knob allows fence to be set perfectly straight" could be better worded. It should really read "Adjustment knob allows outfeed fence to be perfectly aligned with the cutter".

That would be incorrect.

The adjustment knob is NOT used to set cutter position, depth of cut, or align it with the outfeed fence.

The adjustment knob is used ONLY to make the fence perfectly straight, before the fence is even attached to the table. Since the outfeed portion of the fence has aluminum flashing attached it's best to hold the straightedge against the outfeed surface and adjust the infeed portion of the fence for a uniform gap. What you're really doing is adjusting the aluminum channel to be perfectly straight, though. That's actually the critically important part. AFTER the fence is made perfectly straight it is THEN fastened to the router table, making sure the carbide router cutter tip is aligned with the SURFACE of the outfeed portion of the fence.

Hope that clears up any misunderstanding.

[murrmac123]

Sorry Rudy, maybe I am being unpardonably dim, but I fail to see how you can use an adjustment knob to make the fence "straight".

In my cabinetmaking world, you make the fence "straight" right from the git-go ... there is no adjustment ... it is neither possible nor necessary.

You manufacture the fence dead straight ... you then machine the necessary cavities for cutter accommodation and dust extraction, and attach whatever strip thickness you want for offset.

Subsequent adjustment is purely to get the offset fence in line with the cutter. If I am misunderstanding anything, then do feel free to explain.

[mirwa]

Originally Posted by Rudy4

you'll see that .010" aluminum flashing is cut to fit the "outfeed" side of the fence and semi-permanantly adhered with heavy duty double backed carpet tape. That surface creates the necessary offset and determines depth of cut.

I too had not viewed the video prior to my comment, I can now see the thin shim on the outfeed side on your original post.

Steve

[Rudy4]

Originally Posted by murrmac123

Sorry Rudy, maybe I am being unpardonably dim, but I fail to see how you can use an adjustment knob to make the fence "straight".

In my cabinetmaking world, you make the fence "straight" right from the git-go ... there is no adjustment ... it is neither possible nor necessary.

You manufacture the fence dead straight ... you then machine the necessary cavities for cutter accommodation and dust extraction, and attach whatever strip thickness you want for offset.

Subsequent adjustment is purely to get the offset fence in line with the cutter. If I am misunderstanding anything, then do feel free to explain.

No problem if this isn't within your personal work methodology.

I have a standard router fence made pretty much as you describe, that's pretty much standard fare. The precision jointing jig is a specialty application requiring a bit more accuracy than what we find in the average "router fence".

The reality of producing a fence capable of the accuracy that's necessary to produce dead-on glue joints in the average home shop is more of a challenge.
Folks who have the average home shop end up working with what is available, and tools to reach that level of precision are simply not within the grasp of many with a small home shop. My M.O. is to allow folks to do "more with less".

I've been working and providing instructional materials for musical instrument construction for many, many years and have a good feel for what the small shop user is capable of making. I maintained a website providing either free or low cost information for many years, but recently decided to step down from that. Here's the website archive if there's anyone who would have need of it:

http://web.archive.org/web/201603281...com/index.html

There's also a link there to "Conversations With Banjo Builders Of North America" in the Smithsonian Folkways collection of videos. I'm one of the featured interviews in that series.

I relate that only as a way of saying that I'm not new to the field of instrument construction.

I posted this particular jig to demonstrate how to use what's available to the average home shop. In my example here it was a fairly accurate extruded aluminum form that needed an adjustment mechanism to help it in being as straight as it needed to be to produce a precision result from its use. There are obviously many other ways of doing this, but the idea is to get the creative juices flowing.

Since I've been doing instrument work for about 30 years I have a very good feel for what it takes to make a jig that will produce the precision that edge jointing requires to produce gap-free glue joints, so that's what is presented here.

I don't care about posting something that takes cabinet shop tooling to produce; I want people to engage in making musical instruments. That's the bottom line, and this jig does it in spades. I do furniture as well as musical instruments, and love to do quality work with minimal tooling, substituting skill for large expenditures on tools.