Exact Width Dado Jig - Lessons Learned

bobgroh · Post by **bobgroh** » Mon Jan 28, 2013 12:46 pm

I recently put together a wood rack for my son's pantry - a rack to hold cans (e.g. soup cans and the like) - sort of like a book case with shallow shelves.
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That rack is NOT the subject of this posting but it's construction did start me down a path which I thought some of you might find amusing and, maybe, even a bit educational.

The can rack involved dado's the side rails (1x4 primed pine from HD) for the 10 shelves - the can rack is 24" wide. So lots of dado's. Although I do have a dado head for the saw, I decided to try using my 'new' router (with a 1/2" up spiral bit) for the task and I decided to build a jig to make the process a bit easier and to get pretty much exactly the width I need for the wood I had. The Wood Whisperer recently had a video on such a fixture
http://www.thewoodwhisperer.com/videos/exact-width-dado-jig/
so I decided to build one of those.
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Now for my lessons:
L#1: Don't get too fancy - just build the darned thing. You inevitably will want to make changes. This at least I got right. I just grabbed some pine boards from the scrap bin and whipped it up.

L#2: I goofed a bit on this and that as you can see from the unused slot on the left. And it turned out that pine (unfinished) "dragged" on the router quite a bit (i.e. took some extra 'push' to get the router across the jig's surface.

Running out of room so will continue in another posting.

bobgroh · Post by **bobgroh** » Mon Jan 28, 2013 1:00 pm

Continuing with my posting.

L #3: The extra 'drag' was a bit of a bother so I put a couple of quick coats of shellac on the fixture (with sanding between coats) and then a coat of paste wax. That helped quite a bit.

At this point, the fixture works fairly well. I really need to do another one but this time with a few modifications.

#1: I will use some decent wood next time - good quality plywood for most of it with some hardwood for the edges. I think the stiffer wood will help the fit - even if I carefully adjust the fit around the my shelf before routing, the gap is still too small so something is moving. I compensated by adding a spacer (a thin piece of cardboard) but it would be nice to cut that down.

#2: I will spend some time and get the inside edges of the slot flat (as the WW mentions).

#3: I may use some 'slick plastic' on the top and side of the fixture so the router will easily slide. Maybe a piece of scrap counter top might work well?

#4: I only allowed for a 12" inside width but promptly came up with a project which needs more room! Next time I may set it up for 20" or so.

Overall a nice fixture. Inexpensive enough that I can move on to 'Generation 2' with little misgivings.

pennview · Post by **pennview** » Mon Jan 28, 2013 2:43 pm

You can also wax the base plate of the router to help is slide easier.

bobgroh · Post by **bobgroh** » Mon Jan 28, 2013 3:58 pm

Good comment, Art. The base plate of the router is already a pretty slippery plastic so no help there and the brass bushing (the router uses one as a guide) is also pretty slippery. The 'main sticky' so to speak seemed to be the wood surface. And, because you are pushing down on the top of the plunge router and keeping some pressure to either the left or right side to get an accurate cut, any additional friction just makes it more difficult.

pennview · Post by **pennview** » Mon Jan 28, 2013 4:43 pm

But not as slippery as wax.

JPG · Post by **JPG** » Tue Jan 29, 2013 12:07 am

bobgroh wrote:Good comment, Art. The base plate of the router is already a pretty slippery plastic so no help there and the brass bushing (the router uses one as a guide) is also pretty slippery. The 'main sticky' so to speak seemed to be the wood surface. And, because you are pushing down on the top of the plunge router and keeping some pressure to either the left or right side to get an accurate cut, any additional friction just makes it more difficult.

No 'plunge' lock?