Leaning Shelves

[jackellis]

I'm in the process of building several sets of leaning shelves patterned after this design by Chris Schwarz. I'm borrowing the curved shelves and supports, but I'm probably going to make changes in the spacing of the shelves and I'm using solid hardwood rather than plywood and fir 2x4s. There are a number of shallow angle machining operations (7 degree lean) that required a fair amount of head scratching, but then again I'm still an amateur at this.

I made up a prototype using pieces from the scrap bin, including 5/8" ply for the shelf supports. I'd hoped the frame would be stiffer and less prone to twisting while being moved than it turned out to be. With shelves installed and leaning against a wall, it's sturdy enough, but I'm wondering whether I need to make some tweaks to the design. Namely, will hardwood (cherry or chestnut for the first set) parts for the curved shelf supports be stiffer (less prone to twisting) than plywood, and if not, does it make sense to increase the depth of the supports from 3/4" to 1" and/or increase the height of the support from 3 to 4" in order to make the frame stiffer?

I tried cutting out all of the curved parts on a bandsaw using Rockler's duplicator, but the duplicator (bought on sale for half price) is not helpful. I'll have to make another template, cut parts to rough size, and finish with a router. Thanks to all who responded to a recent thread on this topic - it was quite helpful.

Building a prototype was worth the time and effort. I was able to work through some machining and assembly problems, and now that it's sitting where the real shelves will sit, I've identified some other problems with the shelf heights.

[JR]

I wouldn't think that hardwood and plywood would have substrantially different performance in this application. If anything, plywood should resist racking more than hardwood due to the lamnation grains running in different directions.

If you're seeing a little flexing I'd look at the way the shelves and supports are attached to the uprights. Are the shelves in their dadoes with a nice snug fit?

The supports might benefit from a through mortise into the uprights (or is it a dado? I dunno, but if the ends of the supports are set tightly into the supports, it should help). That's the joint that's going to do the most to combat racking, so doing everything you can to tighten it up would make sense.

I presume you've glued the supports the shelves.

HTH,
JR

[cabinetman]

The warping and twisting would apply to using hardwood. You wouldn't have that problem with plywood. The whole system could be done with plywood, and just edge band the leading edges.

I would make the supports as high on their ends as possible, because those corners are what will prevent racking. When the supports are connected to the verticals and the shelf, they act as a gusset.

I would stop dado the verticals for the ends of the support, dado the verticals for the ends of the shelves (the machining will look like a "T"). Machine a groove lengthwise on the underside of the shelves to accept the top edge of the support. So, what you will wind up with is a shelf with a fixed support, where both the shelf and the support are set into dadoes with glue.

If you lay it all out, you can just clamp it up.

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[cabinetman]

Any update Jack?

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[chopnhack]

Jack, I don't know if you ever got around to building your project, but I happened upon this image while looking for something and remembered you saying you had an issue with angles. I don't know if you recall I mentioned to you to just jig it, ;p but here it is:

[IMG][/IMG]

[jackellis]

Mike, I've been using the prototype for a while to be sure I know how I want to set the shelf spacing for the unit that will house the flat screen TV. I'll probably start machining lumber next week.

As for the angled dadoes, I came up with a jig that gets the job done quite well. My router table is a four foot extension to the saw table and it would take a fair bit of work to modify it appropriately for the router table jig.

I'm going to live with a little twisting when I move the assembled unit, but I will probably make the curved shelf supports a but thicker and take out some of the curve to add stiffness.