About The Project:

The airplane is a home-built, scratch-built Zenith CH 750 STOL. Building from plans/blueprints is a challenging way to build an airplane, since most of the parts you use to build it are not prefabricated. I chose the Zenith CH 750 STOL for its rugged design, its STOL (Short Take-Off and Landing) characteristics and its aluminum construction. Zenith Aircraft Company has designed this airplane so that it can be built from scratch or from a kit by the average person. They provide excellent technical support for both kit and scratch builders. In addition, I'll be installing a 1965 Chevrolet Corvair 164 cid horizontally opposed, air cooled, 6-cylinder engine, with special conversion parts to make it suitable for airplane duty. This is what the airplane will look like when I'm done, although I'll have a different paint scheme:

Follow my progress below!

Saturday, May 28, 2016

Everything in .040" is done!

It's amazing how much productivity you can muster once you have the right tools! Now that the bending brake is fixed and working properly, I really went to town on the .040" parts. All of the parts in that thickness are now made. I acquired a 20-ton shop press to do various things (in addition to working on the plane), and it sure made flanging the lightening holes in this batch of parts much easier. I've put in at least an hour every single day for the past 9 days on this project...really knocked out a lot of progress. About a total of 25 hours of work in that 9 days, and I plan to do more today and tomorrow. Here are a few photos of the parts I made:

Firewall Center Stiffener, Rear Seat Support (sliding seat option) , Dual Stick Gussets & Hinge Plates, Horiz Tail Attach Gussets, Inboard Seat Belt Brackets:

Seat Channel, Firewall Side Stiffeners, Firewall Channels & Covers:

Landing Gear Channel, Firewall Rear Reinforcement, Pedal Bearing Channel, Nose Gear Gussets:

At this point in the game, I have nearly everything made in .016"/.020"/.025"/.040"/.090"/.125", except the skins. I only have yet to make about ten parts in .032" and thirty-eight in .063." Once those are done, the only other parts left are the welded steel structures, the welds for the fuel tanks, the Nyloil bearing parts and a few little odds and ends. I also nearly have the skeletons completed for the flaperons.

Now that parts fabrication is nearing completion, we'll start to see some major visual progress on the actual structures of the plane. Once the flaperons are done, I'm going to start on the elevator and the horizontal stabilizer. After that, it'll be on to the wings. The wings & fuselage take a very long time to complete, plus I'll need to detour into the welding & steel structures. Some of that fabrication will take a good bit of time. But my plan is to do the wings before I have to do any of the major welding, except for the fuel tanks. We'll see how the plan goes, or if I end up doing something completely different.

Cheers!

Tuesday, May 24, 2016

Forming the Landing Gear Channel

My sheet of .040" aluminum is getting pretty banged up in the shop. I just don't have enough space in the garage to keep full sheets of aluminum stacked against the wall without banging into them. It's too inconvenient to keep rolling them back up, only to have to unroll them to cut a part. So I decided to use up the .040" and get it out of the way before I render it completely useless with scratches and dents. In my last post, I linked to a videos series where I detail how I modified my bending brake and progressively added new bits/pieces/modifications at each step of the way. After the first bend, I had to continue to upgrade and modify the brake to be able to do each new bend, just on that one part (Landing Gear Channel). However, I now have a brake that (hopefully) can bend every part I have left in the plane, including the complicated "hat" sections. Here are some sequential pictures of the Landing Gear Channel forming process, starting with brake modifications:

New bending arm made from 5/8"x4" steel slab with original 3"x3" angle used as leverage helper. Modified Brake Hinges made from 3/4" solid rod & 3/4" schedule 40 pipe:
 

 Extended truss-style bending arm handles for more leverage and center load spreading:

2x2x1/8" square tubing used as load bearing truss for clamping bar. 3" bolts through screws allow for adjusting tension:


Landing Gear Channel part blank - 1105mm x 293mm:


Outer flanges (23mm wide) bent already, now overhanging face of narrow bending arm:


Larger Channel Bend sticking out back of brake:


Fully formed part, sort of a "hat" section of channel:
 

View of full 1105mm length of formed Landing Gear Channel. Both ends are within 1/2mm tolerance specified in blueprints.
 

It took a total of 4-6 weeks (mainly due to down time) to get the welding/modifications done on the hinges and bending arm, plus progressive modifications as I went to get the whole gear channel bent. This was the most difficult part to make thus far, mainly because I kept having to stop & figure out how to modify the brake to get each successive bend. But I'm pleased with the results, and hopefully I won't need to modify the brake any more!

Monday, May 23, 2016

More bending brake woes, but hopefully a solution now...

Folks, it's been quite a long while since my last post. Over the past several weeks, I've been trying to figure out a solution to my bending brake problems. When I first broke it, all the pop rivets pulled out of the hinge along a good portion of the length of the brake (8'). Since that time, I built a solid riveting C-Frame and re-riveted the piano hinge with solid rivets. After trying to bend the firewall upper support, I actually stretched the metal of the piano hinge, and the brake just wouldn't bend long parts without putting a twist into them.

So for many weeks, I've been working on revising the brake in my down time. All told, I probably have another 30-40 hours just in brake repairs/modifications. I've managed to make several parts during that time, but the brake was monopolizing everything. I'm pleased to say that my brake modifications and additions now allow me to bend the heavier stuff, but also allow me to bend complex parts that have opposing bends, such as "hat" style sections of channel. I managed to film a 4-part series that outlines progressive modifications and additions to the brake that I had to come up with while attempting to form the Landing Gear Channel, a "hat" style channel with opposing bends. Here's the first video in my series, and I'll post more photos later:

Bending Brake Modifications & Forming Gear Channel:


I also managed to get my cabin side skins primed and ready for solid riveting, and have the flaperon skeletons nearly ready for skins. More on those later. Thanks for stopping by!