Dados at an angle?

[Chuong Nguyen]

Hi,

I am making a Doll house shelf for my daugther, something similar to this:
http://www.amazon.com/Guidecraft-Dollhouse-Bookshelf-Pink/dp/B000A8NTJG

For the roof, I'm guessing I would make the pitch at 30 degrees (15 degree cut on both panel).
I want to cut a dado where the left and right verticle sides will fit into.

my question is, if the roof is 30 degree pitch, does that mean, I need to angle my dado blade on my TS 30 degrees and cut, and for the left and right sides- cut the top end 30 degree angle to fit into the dado?

I hope my post is not too confusing. thank you.
Chuong

[Tony Zaffuto]

Personally, I would make a jig to do the dado's with a router. Might also be a tad safer than trying to manage a large panel over a dado blade on a tablesaw.

[Chuong Nguyen]

Good point.
Am I right with my thought on the angles though?

[glenn bradley]

The angle sounds right but, it would take a lonnnng router bit to be angled at 30* and still make the dado. Tilt the stack and remember not to capture your material between the fence and the underside of the dado stack. That is; left tilt = fence on the right, right tilt = fence on the left.

[Erik France]

If you tilt the stack 30 degrees or do a 30 degree cut with a router into the roof piece the side walls will not need to be beveled. Draw it in section and you'll see it.

What is the thickness of the walls and roof pieces? 1/4" thick members will need a very shallow dado to leave an 1/8" thickness of the roof member right above the wall. A dado in that size material would almost be just a birdsmouth.

[Kent A Bathurst]

....safer than trying to manage a large panel over a dado blade on a tablesaw.

Whaaaa??? How is a dado blade less safe than, say, cutting a panel to size on a TS? I do both fairly often. :confused: If I was 30 cats, I'd still be out of lives. :D

On the original question - I didn't look at the design/plans - but - seems to me that if you use a dado set, then when it is tilted, you get different depth-of-cut on the "lower" blade than on the "upper" blade. But - maybe that is exactly what is called for - maybe I am repeating Erik's point, perhaps?

[Chris Tsutsui]

I was having crown moulding geometry woes recently so I decided to just draw this out because I need a geometry refresher.

194129

Maybe I would cut the dado first using a tablesaw with dado blade. Use one large panel and cut both dadoes for both roof pieces in one pass at the same time.

Install regular blade and cross cut that sheet you just cut in half to give you the two roof pieces. Tilt the blade 30 degrees and cut the bevels on the roof pieces to final length so that they can join together.

This is a doll house so you might be able to simply things by just using cleats. Tilt a normal blade 30 degrees and cut a long thin strip of wood from a sheet good. Then rip it again for another thin strip that looks like a parallelogram shaped long strip. This parallelogram shaped piece will act as a cleat which can be attached to the roof inside so no dadoing would be required. Cleats will add more glue or screw surface. The reason I suggested a parallelogram shape is so you can clamp and glue the strip down easier.

[Dan Hahr]

I wouldn't go to the effort, but since the blade won't angle far enough for that cut, you would need to build a simple jig to hold the roof pieces at 30. It could ride the fence and would have to be perfectly parallel to the fence. If you really wanted to, you could make it run the slots. Oh, and it would have to be reversible or double sided.

Why don't you just cut the sides at 60* and be done with it?
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P.S. I didn't do the painting...
Dan

[John R Green]

I built a book case for my grand daughter very similar to the play house....

Forget trying to dado sides into top.
Nailing on the back will hold one side.
Nail on a decorative fascia to secure the front.
Glue small wedges under the "eaves" to provide just a little more security.
Hope this helps.194160

[Chuong Nguyen]

Thanks for the tips everyone. Thanks for the drawing Chris. That really helps.
Erik, I'm using 23/32 plywood (.72"). and your're right, I noticed that no beveling is required from Chris's pic.
John, your doll house looks great!