|Topic Review (Newest First)|
|05-10-2012 12:50 AM|
|GussNemo||KISS principle guides, great. Thanks Mike. Looks like I'll have to see what's laying around that could be used for these two guides. Again, thanks Mike.|
|05-09-2012 05:40 PM|
If you do want to make a jig for this and future dados, attached are two versions.
The Woodsmith version, I just finished making for myself, just need to steal some more time to go out and use it now.
The Wood version could be made as simple as cutting a rabbet along one piece of wood (1x4 or watever) twice as long as you need plus clamping room (or two boards of course). Then using a router bushing and a straight bit, trim the edge of the rabbet to match the bushing offset. Then (if using a long board) cut it in two. Then clamp the first on your work where you want one dado edge, sandwich the shelf material and clamp the other board. This way you don't even need to make the squaring attachments of the plan, just the two guides and clamp them down real good as the vibrations have caused mine to slip a little sometimes.
|05-08-2012 01:51 PM|
I do understand using straight boards, Charles, because it's the only thing I had on hand at the time that would work. And holdling those boards down with clamps has presented problems when I have to rout close to the clamps. |
While cutting the dadoes in my current project prototype I did use clamps to hold down the guide boards. But like usual, the clamps got in the way. I decided to try screwing down the guide boards, and it worked, after a fashion, but still wasn't as quick as just clamping. I also found I had trouble getting the board square to my cut--inexperience again raring it's head.
I'm going to order two of the clamps you mentioned, along with a top bearing bit so I'll have to wait and see how it all works.
|05-08-2012 09:03 AM|
You don't have to use the straight edge clamps. You can use two straight boards, but they have to be wide enough for you to be able to apply clamps that will not interfere with the router movement. It's easier with the straight edge clamps because when they are locked into place they are completely flat and there is nothing sticking up above them to interfere with the router movement. A top bearing bit is essential to be able to cut the dado to the same width as the shelf board thickness. The beauty of working this way is that you completely avoid measurement errors and it allows for every dado to match the thickness of the shelf material no matter what thickness it is. Every shelf could be a different thickness and your joints would fit. You could do it with a collar and a smaller bit, but then the difference in diameters would need to be taken into account. If you used a collar and bit with a 1/4" difference, then you could use a scrap of your shelf material plus a 1/2" spacer to set the spacing between the straight edge clamps. It isn't as simple, but it will work. |
|05-07-2012 11:34 AM|
I had to read your post a few times, Charles, to get into my mind what you were explaining. What you're describing is a really good idea, unfortunately I don't have the straight edges you're describing. Or a top mounted bearing bit. I think there's a saying about wishes and horses. |
I like your method, Charles, as it's simple to setup and no extra cutting to make a jig. Plus, if I understand your method correctly, I don't have to allow for the distance between the bit and a guide bushing when making a jig; something I like.
Because the wood I'll be using for the two wall hanging shelves is oak, and I'm not hurring through this project, I think I look into getting the straight edges and top mounted bearing bit. I know the problems I've had just cutting the dadoes in the prototype and I'd perfer not to have them when making the two wall hanging shelves with the oak.
|05-07-2012 11:13 AM|
Since shelf stock and plywood varies in thickness I have come up with a way that cuts the shelf dados to match the shelves very easily. I place a straight edge clamp in the position where I want the top surface of the shelf and lock it in place. Then I place a second straight edge clamp across the work and sandwich a scrap of the shelf material between the two clamps and lock the second clamp in place. Then I remove the scrap. I use a small hinge mortising bit that's smaller than the thickness of the shelf with a top bearing in a fixed base router to remove all of the material between the two clamps to the dado depth desired. The bearing rides on the sides of the clamps and the dado is cut to match the spacing between the clamps. The result is a perfect fitting dado for the shelf no matter what thickness it is. |
|05-07-2012 10:46 AM|
Thanks folks. I did use a straight edge, of a sort, to make the dadoes in the shelf of the prototype. But it required several steps of setup to cut both the horizontal and vertical dadoes in the underside of the shelf. What I want to do is position the shelf once, then cut both the vertical and horizontal dadoes with the shelf in that one position. |
Rethinking the dadoes for the shelf supports, a jig may not be necessary because there's only one edge that requires a stop and a straight edge set correctly would work.
|05-07-2012 08:10 AM|
|mgmine||It sounds like you need a straight edge in which case plywood or just plain old pine would work. You could even get away with a paint stirrer or a yard stick.|
|05-07-2012 07:30 AM|
Howdy from Texas Gus, |
I don't know your situation but rather than sacrificing some wood for your application. Something to consider.
Get an undersize router bit set, they are very inexpensive. If you can justify it I would tell you to utilize a track system as a router guide. It can be as simple as a piece of lumber or a level as a track. Clamp them and rock and roll making your dados
Good luck on your project.
|05-07-2012 02:25 AM|
Material to use for jig
After working on a prototype of another wall shelf momma wants, I've come to the conclusion I'll need to make two jigs to cut the needed dadoes in the shelf supports and the underside of the shelf.
What I have on hand is 1/4" and 1/2" plywood, and wonder if either of these would work for the jigs I'll have to make. I know Masonite or plastic would hold up better to wear and tear, but it would mean a trip to town to get plastic or see if Masonite is available.
Any suggestions would be appreciated.