Hatz Biplane Association

I'm building a Classic but also have the CB-1 plans. Well worth the price as they have some of the things missing from the Classic plans. Dudley did a great job drafting the CB-1 plans.

I have a question for the CB-1 builders. The floor boards and the wing walk on the Classic plans are 3/16" plywood. The CB-1 plans show 1/8" plywood for both. Can anyone comment on how the 1/8" plywood hold up if that is what they used. The 1/8" weighs 30% less so there is some weight savings.

I used 1/8" Birch for the floor boards and have not had any problems. I think I made "U" channel supports underneath the pilots feet, that ran fore and aft (yup-sheet 18), and added stainless wear plates by the rudder pedals.
I also made each side in two pieces split over the cross tube under the passenger's seat. If you make them one long piece and need to remove them, going through the firewall is your only option.
My wing walk is my own design and I used 1/4" Birch.
Hope this helps.

Thanks Jeff.

I just might try 1/8" for the floor boards. I can see where there are a few channel supports on sheet 18 CB-1 plans. Other than getting in and out the floor boards don't carry a lot of weight. I was planning on wear guards at the rudder pedals. I also may make the floor boards one level rather then the step shown on the Classic plans. I can't see where floor on the passenger seat has to be one inch lower for any reason. I'll have to block under the whole thing except where it slants up at the front. If the one inch blocking is glued to the floor boards it'll add some structure. And some weight. Which is why I'm thinking 1/8" rather than 3/16"

Hello Murray
The step up for the pilot floor boards on the classic plans is to allow clearance for the aileron push rods. I don't know much about the pulley set up for the CB1 plans.
Regards Steve

Steve. Good to hear from you. Are you getting much time in your newly completed Hatz? we haven't heard any performance figures

I figured that out about the floor boards. I put the wings on to check the position of the torque tube and aileron linkage before I welded it all together. I was thinking of making the floor boards all one inch high so they are level front to back. The only problem I can see is the pilot rudder pedals. The opening will have to be a little larger.

The floor boards in my CB-1 are 1/4", but only 3 ply. A small unsupported section adjacent to the front stick was broken, probably by a passenger contorting to get in. I just removed the broken bit for now, but remaking them in better material wouldn't be a bad idea.I