Narfi's Zenith CH750 Super Duty

[narfi]

Got the rack for the aluminum put together with a bonus shelf on top.

[Fuzz]

This is going to be a cool project to watch!

[Aripeka Angler]

This is going to be a cool project to watch!

I couldn’t agree more!

[narfi]

Turned the 3x14' strongback into a 4x16' table.
Unboxed and assembled the bandsaw, belt sander, drill press, and vise.

Don't think I want the tools permenantly mounted to the table in my smallish work area so have them setto the side for now except when I am using them. Will probably mount them on individual castered tables once the shop is built.

[Netpackrat]

I went looking on YouTube for information on the metal brake I posted about earlier in the thread, and I found the following video by a guy building an earlier version of Narfi's airplane:

https://www.youtube.com/watch?v=F7gyrMqrG00

Nothing in the video is going to be a real surprise to a practicing general aviation A&P like Narfi, but it should give everybody else an idea of some of the challenges involved for the majority of builders who are making this aircraft without access to commercially built sheet metal machines. Not being familiar with details of the design, it was interesting to me to learn that there are a few parts of the airframe that even the more common 8' brakes can't handle, so a CH750 builder needs access to a 10' brake. I thought that Bearhawk plans builders had it rough, needing to get access to an 8' brake for our spars and trailing edges.

Another point is that Narfi's build is a heavier duty version of the 750, so presumably some of the parts mentioned in the video as being particularly difficult to make, may be even thicker material in his airframe.

[BB Sig]

Dry video but lots of good info.

[narfi]

Fridays post,

Still waiting on aluminum.
I drew out the end rib for the stabilizer last night, will need to get comfortable with metric. Looking back I should have done my boats in metric just for the experience as the designer provides in both imperial and metric for his designs.

Router table arrived and despite my research didn't match my router, so ordered a new router from Amazon. Wife didn't even complain...... perhaps because I added the shoes from her wishlist to the same order????

Jokes aside she is really supportive even though she doesn't like flying, she knows its good for me and Landon.

20201002_060658.jpg (26.95 KiB) Viewed 1977 times

Much like I started researching what plane we would be building 3+ years ago when we started building the canoe and powerboat, we have started work on ideas to narrow down our next big project for when the plane is finished.

A 40+ ft live aboard catamaran. The goal to finish around when Landon leaves the nest which will be pushing it but doable. (Give or take a few years)

[narfi]

Got a few minutes in the tent before needing to help with Landons birthday party.

20201002_164445.jpg (47.59 KiB) Viewed 1854 times

Need to sand the bottom peice to match the top one, then radius the bending edges and add a 5% spring back to the edges, then sand out the fluting recesses.

I know the process, but doing it first time is intimidating, I think ill get comfortable with it pretty quickly though. This is a good first piece.

[narfi]

Now what I got done on Saturday (might be a week or two till I can really start pushing on the project, need to get ready for winter)

First two parts done, the stabilizer end ribs.
Did the full process to see if I liked it even though it would have been quicker to just draw them out and cut them out.

So I made a set of forming blocks(left and right) with 5 degrees bend back allowance and 1/8" bending radius routed in.
Made a set of cutting templates and used the router to cut out two blanks of .025 aluminum 6061t6

The cutting templates were made from tracing the form blocks so the tooling holes match perfectly and I used 1/4" bolts to clamp everything together through the tooling holes and used a rubber mallet to bend over the flanges and a wooden handle and a rubber coated small steel handle to bend in the fluting. I used a small hobby size steel hammer to gently form over the nose area, I was worried about them but it turned out OK.

Once done and removed I laid them down on the table and they were really flat so no need to adjust the fluting, not bad for my first try

Roughly 6 hours drawing out, cutting and shapping the forming blocks and cutting templates and making the parts. I think I can go much faster on the next ones.

20201003_133654.jpg (72.53 KiB) Viewed 1854 times

20201003_133723.jpg (53.23 KiB) Viewed 1854 times

20201003_133752.jpg (55.78 KiB) Viewed 1854 times

20201003_133810.jpg (35.49 KiB) Viewed 1854 times

20201003_133825.jpg (27.44 KiB) Viewed 1854 times

20201003_133841.jpg (56.94 KiB) Viewed 1854 times

Total time spent building: 6 hours
Total Cost: $8190
Airplane + consumables + project specific costs: $5340
Tools, etc.. I will keep for future projects: $2850

[Jeff]

Cool stuff Narfi!!!! Jeff