Auto Width Dado Jig 2.0

glenn bradley

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I felt bad about the mean things I have said about my original "beater" dado jig. I only had one last jig planned to make before getting back to other things but, decided to sneak this one in as well. So I give you version 2.0. Like my original version seen here, I use a template guide instead of relying on the outer edge of the router plate. I cut the ledge for the template bushing a bit extra deep so that the router will create a 'zero' edge on the first pass. I also cut a whompin' rabbet to accept the eemerson tools AIO (all in one) clamp. The not-often used DRO on my router table comes in handy for geting the depth right when making multiple stepped passes.

Dado Jig 2.0 (1).jpg . Dado Jig 2.0 (2).jpg

Here's the fixed and adjustable fences with the connector plates and clamp setting around. The connector plates get fixed to the fixed fence. The adjustable fence has slots and is fastened in place with carriage bolts and star knobs.

Dado Jig 2.0 (3).jpg . Dado Jig 2.0 (4).jpg . Dado Jig 2.0 (5).jpg

I modify a few 1/4" flat head machine screws to fit the odd slots on the AIO clamp. The flats keep the screw from turning in the slot. I slide the screws in and set the jig onto the clamp and fasten it in place with some small round knobs.

Dado Jig 2.0 (6).jpg . Dado Jig 2.0 (7).jpg . Dado Jig 2.0 (8).jpg

cont'd . . .
 
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Many of you are familiar with this basic type of dado jig. You clamp a piece of the actual material that you will be using in order to set the jigs width. Slide the adjustable jaw for a snug fit and tighten the star knobs. Now your width is set.

Dado Jig 2.0 (15).jpg . Dado Jig 2.0 (12).jpg . Dado Jig 2.0 (9).jpg

You then clamp the jig to the material to be dado'd aligning the now-fixed opening to your setup lines. Now you can route the dado with the template bushing riding the fences making sure you get a perfect fit. Here's a pic with the rig flipped over with the stock clamped in place as well as a couple overall shots from above and below.

Dado Jig 2.0 (11).jpg . Dado Jig 2.0 (13).jpg . Dado Jig 2.0 (10).jpg . Dado Jig 2.0 (14).jpg

The adjustable fence will have some non structural material removed to lighten the thing up a bit. There is also an access cutout planned for the clamp handle end to allow clean starts without tearing into the jig by accident:rolleyes:. After that it just need a sealer applied and some paste wax on the work surface. The jig will slide onto any of the Contractor Series AIO clamps so I can use shorter or longer clamps as required. I made the jig to make dados from 5/16" through 1-1/2" in width and up to 33" long. I may shorten it up as dados that long are rare in my work. I may also just make a shorter version. Since they don't require a clamp except when in use I am not out the clamp. They could store easily on the shelf arms my planer sled and taper jig store on.
 
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Excellent idea and implementation. Now we talking. I can see this being adapted to a similar jig used for skill saw cutting of large sheets. I am always finding the use of individual clamps end up getting in the way of the tool. Thank you for the idea and well done.:thumb:
 
glenn that thin wood will stand up to the daily use with the clamp attached? looks pretty thin but i know you have jig making down pat...

Right there with you Larry. I was going to add a lamination similar to 'slips' on a drawer to add thickness. I made a short test piece out of the same BB ply and tried to break it. I did succeed but, only by putting the thin part into a vise and leaning into it. After that experience I decided that the thin part was OK. Believe me, if it fails to provide good service I will post about it ;-)

I will try to finish off the details after work today and get some shellac on it so I can really put it to the test. I'll post the results. I'm still caught between thinking that for the bulk of shorter dados I will make and the occasional requirement for a longer dado, that this jig is a bit over-sized. To allow me to rest easy, I will leave the "far" end connector plate un-glued till I decide for sure.
 
Here she is with the non-functional material removed to reduce weight.

Dado Jig 2.0 (16).jpg

I added the opening in the clamp-handle end connector plate. This lets me get e clean start on the dado.

Dado Jig 2.0 (17).jpg

The other end is just assumed to be far enough out that I won't have to go all the way to the small connector plate. You can see by this how much extra I left when I cut the rabbet for the template bushing.

Dado Jig 2.0 (18).jpg

With the shellac on and a good wax job, the router really floats through the cut.

Dado Jig 2.0 (19).jpg

That's about it for this one.
 
Did you consider adding an adjustable stop?

Nice looking jig Glenn. I like Teds idea too, guess that depends on the user and what they use it for most of the time.

Not real flashy but, I just do this for a stop:

Dado Jig 2.0 (20).jpg

well, what are the 3 dark colored pieces on your table saw glenn look like drawer frnts..

Old Eagle-Eye strikes again :). Those are DMT diamond stones I had out to touch up a small scraper. Bad habit of mine when I just need a quick, dry, touch up; I don't go over to the sink . . . I just land wherever is close :eek:.
 
After doing a lot of Google searching, I've just discovered this router jig and It combines all the best features of all the others I've seen. Can you give me some idea of the width of both the fixed and adjustable fences? I've been playing around with the size of my Elu router base but it would save some time to have this info. Yours looks perfect to me. Thank you for sharing this. The only improvement (?) I'm thinking of adding is hardwood edging to the inside of the fences and attaching them with screws so as to accommodate different combinations of bushing and spiral bits. Any thoughts?
 
I am between shops right now. Hang on and I'll go out to one of the sheds and take a measure . . .

Better yet. Hardly a set of "plans" but, this is what I worked off of:

Dado-jig-2.0-SU-pic.JPG

I honestly believe the width of the piece oif plywood I started with was dictated by what I found in the scrap bin ;-)

Maybe these will help as well.

Dado Jig Refresh (4).jpg . Dado Jig Refresh (5).jpg . Dado Jig Refresh (7).jpg . Dado Jig Refresh (8).jpg

So much of the dimensions used will depend on your specific implementation but, this gives you the general idea. I would be glad to answer any other questions you have in order to help. I used the straight edge clamp to avoid having to build my own clamping mechanism as you see in other versions. I was going that way and had an accidental good idea. I can swap straight edge clamps for the length that suits the job. I happen to use the Emerson versions. These have improved over the years and others would work as well.
 
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Glenn, not only is your jig the best, but you are too. So generous of you taking the time to share this. I'm going down to the shop now to start cutting out parts. I've been collecting other pieces. Just got the T-bolts and already received a 3 set of Pro-Grip clamps; 2', 3' & 5'. I realized the jig was swappable and the same idea would work with a jig for cutting precisely with a circular saw. The self clamping really improves the ease of use of these kind of jigs. What do you think of the idea of hardwood edges that are screwed in the the edges of the fences so as to interchange different bushing/router bit combinations? Is it likely to really be useful or do you use only 1 bushing to 1 bit. And what kind of bits do you use: spirals, up or down or combination. I've been thinking of getting a 1/4" and 1/2" so as to be able to route for pieces less then 1/2" thick as well.
 
Glenn, just looked at the "refresh" photos. Am I to understand correctly, that if you have to change/correct/refresh the fence edges to accommodate wear over time our changes in bushing/router bit combinations you "redo" the edges of the fence accordingly? If so, is the idea of interchangeable hardwood edges that screw into the fence seem like an idea worth pursuing? I was thinking of a tongue and groove method to maintain alignment and short screws to make it easy/simple to modify.
 
Glenn, just looked at the "refresh" photos. Am I to understand correctly, that if you have to change/correct/refresh the fence edges to accommodate wear over time our changes in bushing/router bit combinations you "redo" the edges of the fence accordingly? If so, is the idea of interchangeable hardwood edges that screw into the fence seem like an idea worth pursuing? I was thinking of a tongue and groove method to maintain alignment and short screws to make it easy/simple to modify.

The advantage of the jig to me is that the guide bushing rides the ledge versus the router's base plate riding a fence. For the edge to line up with the desired edge of the dado to be cut, it must be a zero-clearance sort of an edge. I use a 3/8" spiral bit and a 1/2" O.D. guide bushing. This let's me cut dados from 3/8" to the maximum adjustment width of the jig in multiple passes. If I bugger the edge during use it may at some point need to be refreshed. The amount of material I need to remove to restore the edge is based on how bad I may mess it up accidentally.

In normal use the ledge and edge are good so long as you don't change bushing or bit diameters. The "version 1" of this jig . . .

Overall-1.jpg

. . . had some 'accidents' during its life BUT, I think I only had to refresh the edge once during its entire life. The memory stuck though so I made the 'version 2' with a little more generous parts in order to make it last longer. I have used version 2 quite a bit and have yet to mess it up so maybe there is a learning curve. Given this, replaceable edges may be overkill. If I ever eat away that much of the jig repairing boo-boos, I might just laminate some stock onto the edge like edge-trimming a plywood shelf. As part of the build or as an eventual fix, the choice is yours.

P.s. I had to grind the bolt heads to fit the slots in the clamp. At first I made them fit as close as possible. This turned out to make changing the clamps pretty fussy; they would bind while I was trying to slode the clamp on and off. I ground them down a bit more realizing that the bearing surface on the underside of the bolt head is what was truly important. I just mention this to save you the do-over. ;-)
 
Thanks again. Now I can discard the replaceable edge idea; makes life simpler. You're right, you can always laminate a new edge if it becomes necessary.
I've cut my fences to size and dadoed the one edge to attach to the ProGrip clamp with the bolts. I had a bit of struggle fitting the T bolts into the slot of the clamp. I was thinking of sanding a bit, then tried WD40 and it provided the lubrication needed to slide them in. Hoping not to have to slide the clamp off too frequently.
So making progress!
Really appreciate you taking the time to offer valuable, time saving advice!!
 
A fine jig, to be sure. Executed flawlessly as we have come to expect from you!

I have a question - I think the rabbet for the collar is a neat idea. Just wondering why go through the hassle of attaching a collar instead of using a dado clean out bit? Answering my own question: If your doing 3/4" +/- dados the dado bit s the way to go but, since they usually don't come in less that 1/2" diameter, you can't use it for today's "less than 1/2" plywoods". The collar method will work for dados as small as you have a straight bit for. Sound right?
 
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