Thickness of 4X4 Deardorff Lens Boards

[Kevin Crisp]

If somebody has an original Deardorff factory lens board (the smaller one) could you tell me the total thickness of the board? I'm planning on making some but don't have any for reference. I'm guess 1/2" but would rather not guess. Thanks for your help.

[Peter Galea]

Kevin, my original Deardorff 4" square board measures 5/16ths in thickness. The recessed part is 3/16ths thick and 3 1/2 inches square.
I can send you a jpeg if you want.

[Peter Galea]

The inside top of the board is also beveled from back to front 1/8".

[Kevin Crisp]

Thanks Peter, I just needed the overall dimention, I'm going to try making ones with the three parts and the tongue & groove, etc.

[Ralph Barker]

If the center portion of the board is 5/16" thick, you may encounter problems with some lenses that expect thinner boards, Kevin. If you are laminating thin stock, you might want to leave a circular opening at the center area of the back of the board large enough to acommodate the lock ring at the back of the lens. When making solid boards for my 8x10 Tachihara, I use a large Forstner bit to first create the "countersink" at the back of the solid stock, leaving about 1/8", and then finish the lens hole from the front with the smaller Forstner bit of the appropriate size.

[Kevin Crisp]

I was just going to put it back down on the router table and freehand a thinner area, with practice the hole actually does look somewhat round and after painting the inside black it looks decent. I have had problems using factory boards with modern lenses, but I sold all those so I needed the thickness measurement. Thanks.