Hi guys, I'm working on a design for a coffee table with a lift top at the request of my wife, who is threatening to buy something from Ikea if I don't get this done. I've done a good amount of wood working, but this is my first attempt at designing and building a nice piece of furniture. Other than screwing on the top to the lift mechanisms, I want to use only traditional joinery techniques. I was hoping you guys could help make sure I'm doing this right.
If you take a look at the picture, you will see the joints that I have questions about. Below are the types of joints I think belong in each location, but like I said, I'm inexperienced in furniture building, so I'd really appreciate someone pointing out any issues they see. Please note that there will be a web frame (is that the right term?) on the top of the case that mirrors the one on the bottom (to provide drawer kickers and reinforce the top of the front and back panel). Also, this will be made of solid hardwood (mahogany or walnut) and the front panel is one piece because I don't want to see any seams.
1) I would prefer to do a sliding dovetail here to pull the front and back together, but I think it would take away too much material from the sides (3/4" thick), so I plan to do a mortise and tenon. The board running from front to back in this joint is 1" thick to better support the weight and racking of the lift mechanism when lifted.
2) mortise and tenon - My question is, should the joint be a bit loose to allow for expansion of two rails (not sure if that's the correct term) running left and right in the front and back of the case?
3) mortise and tenon - Same reasoning as #1
4) dovetail - The front and back rails will pull in the two boards that the lift mechanisms are attached to. My thinking is this will hold better when dealing with racking forces if the top is moved side to side when lifted.
5) I plan to have this rail pushed against the front and back but not glued or otherwise joined to the panel. My concern is that it will expand and push against the front and back panels and potentially crack them or more likely, open the exterior miter joints between the front/back and side panels. Would it help to put a dado into the front/back panels to allow for expansion?
I definitely appreciate any help on these issues and if there's anything I'm missing here, please let me know.
Thanks,
Ben