Hatz Biplane Association

Hi Daniel,

I recently had some plywood parts cut with a laser just to see how it would work. Of course as one would expect the edges are all burned (actually black). I showed these parts to an engineer friend and he was quick to point out that this charred material (burned sap) should be removed to allow proper glue penetration. He also said that most chemicals that would remove the charred edge could penetrate the plys and weaken the plywood. Take it for what it's worth...I'm sticking with router cut parts.

Good luck with your project!

Mark Marino
http://www.hatzbantam.com

I agree with the above posts. As with any part on a project like this... spend your time making one really good version of the part to serve as a template and then make the rest from that. I spent the time to make the nose blocks, tail pieces, etc for the ribs and then whipped out the actual parts in a couple hours with the router. It's much more satisfying... and cheaper than having someone cut the parts.

I'm not against "jobbing out" some work if it makes sense... I had all the metal spar fittings cut on a water jet. They are perfect and better than I could have done myself and it saved me a bunch of time... it also cost me over $400. So weigh the pros & cons.

As for the gussetts... keep in mind that they are not precision pieces. as long as you have the coverage indicated on the drawings, you are good. The rest gets trimmed off anyway.

Take the time to think things trough and work smart. Like the gussetts.. I rough cut them on a band saw and then "stack cut" them to the final size.

Here are some shots from my site:
http://www.damowry.com/hatzribs01.html

http://www.damowry.com/hatzribs02.html

Ditto with Nick.

I used a router (mounted in a table) and trimming bit to cut all the nose ribs and tail pieces in a few hours. Each piece a perfect duplication of the original and the cuts were really clean and required only light sanding.

For the ply gussets, I cut long strips of 1/16" ply from a full size board using a utility knife and straight edge. The strips were then cut into identical squares using a stop fence on a band saw. The squares were then stacked in a "jig" for cutting into identical triangles. Like the ribs, all the gussets were made in a few hours.





-Scott

Same here...5yr old twins at home, and a biplane project in the garage (they were 3 when I started). I will say that I dont get near the build time that I'd like, but I'm doing it. I never have a dull moment, or a spare moment. check my build site and see if its something that appeals to you. I've debated the very same thing, and finally have come to the conclusion that I want to do it the old fashioned way. Mind you, I started on the fuselage not the wings, so I have plenty of time to change my mind. But I have found what all the others have said to be true. I have come to really enjoy the build process, and I want to be able to experience it all. I'm on the "10 yr plan" and although that is a little discouraging sometimes, I also enjoy my family and had to promise that this project would not take away from family time. When I started I only built during nap time and after bed time...i figured someday my kids would wake up and there would be a finished plane. Now they dont take naps anymore, and I've got even less time. What I found was opposite of what I thought would happen. I thought I'd spend more time building during the summer months, but I get a lot more done during the winter. I live in OK and it gets too hot during the summer, and too busy. I can heat my garage and the kids go to bed earlier. It takes quite an effort after a hard day working, dinner and then putting the kids to bed to actually make that step out into the garage around 9pm, but once I do it is hard to stop at 11. So that is my goal, several days per week, 9pm-11pm. I too made models as a kid, but nothing more than that. I learned to weld specifically for this project. What I've found so far is that it is easier than I thought it would be, more enjoyable than I thought it would be, and it can go faster than I thought it would. Now...other projects do get in the way...limit them all you can. My garage became too small...so I"m building a hanger, but then I wont live with my project (nearly mandatory), so after my hanger is built, I'm going to build a new house on my lot with the hanger. Then I'll be able to live with my project in a full size shop/hanger, that is on a private strip. IF all those things come together, I'll live the dream and have my biplane on my grass strip in my back yard. Sure wish I'd have been born rich instead of good looking!

Hi Daniel. Welcome! You sound just like me. Young kids and a biplane in the shop.

For the rib nose blocks, I very carefully cut and sanded one single template and then used it to router all the rest on a router table with a trimming bit. It was super fast to make all of them. The gussets I hand cut with an X-acto blade. I bet laser would be easier and maybe turn out cleaner, but there's alot to be said for crafting all the bits and pieces with your own hands. Not everybody thinks this way, but I call it "the fun bit"

Good Luck with your project. This is a great place for advice.

Nick

I recently purchased a set of Hatz classic plans and would like to spend some time building ribs to see if the project is a good fit. I have been an EAA member since the 1980's but am also a father of three young children with a full time job. So, I am expecting this project to take some time. I have a lot of RC kit building experience going back to the 1970's and 1980's. So, rib construction appears similar to balsa on plans.

Anyways, I am not trying to reinvent the wheel, but I have been giving some thought to creating my own wing kit to complete. Instead of spending a lot of time cutting plywood, I would like to have the rib nose blocks and gussets laser cut and create a bucket of parts to start building.

Is this a good idea? Is the rib template available as a dwg file?

Thanks in advance.

Daniel Findling
248-506-9190
daniel@findlinglaw.com