more press questions

[plummet]

whats the ideal spacing of the ribs in a wooden press?


i want to press camber concave and kick

board about 35 inches long

im thinking every 2.5 inches or 60mm there abouts.

do you cut your board shape first and then press or do you press an oversize piece and then cut later??

pressing the right shape will take less pressure but when the finished product comes out there might be some overlap/underlap of the plys.

pressing an oversize peice will take or poundage to press and ill run into problems with pressing my concave that follows the curved shap of the board.

any thoughts?

[meaningoflife]

I am building a press tommorow and would also appreciate some insight on this....

[CrisVA]

Pressing the whole piece as opposed to the cut will take more force, thats all. I have always pressed a large piece and then cut it smaller, but I can imagine that if you are cutting it down with say 2 inches on either side of the design you would be fine.

When you press a concave, the pieces of wood don't line up on the edge anymore, and you get something that looks slightly like staircase.

Pressing a large piece will give you more leeway if you want to change your design too. I press a 4 foot X 10 inch piece and cut it down from there unless I KNOW it is going to be small, like a mini. Then it's a 2 foot X 10 inch piece that gets pressed.

Edit: Pressing a kick with concave takes a LOT of force. I just found that out.

[Lit]

ideal spacing is no spacing betwen ribs.
my ribs are cut from 2x4's
i'll draw my shape on the top layer[easier cuz its flat] then press it.
and my press is just a little wider than my sheets[my blanks are 4'x10"]
press it bottom facing up so glue will drip off the edge.
soften the wood if you want a lotta kiktail angle
http://users.pandora.be/Toothless/To...ons_index.html

[plummet]

ok im in the middle of making a press and have been thinking about rib spacing.

going on the theory that no spacing is best. heres my idea.

i screw the ribs to the base and top board at say 60mm apart then i screw a layer of ply ontop of the ribs.

theoretically i should have a smooth continious shape to press my board with.

is there anything wrong with this theory?

also it will add strength to the press and allow me to leave out a center spar that will take more time to make.

[Lit]

its sounds ideal, i was going to do that cept i got lazy.