Narfi's Zenith CH750 Super Duty

[Netpackrat]

That's kind of a blunt airfoil. Definitely a slightly different process from what I did... All of the Bearhawk ribs were formed on one oak block, no right or left. Attach to the spars with riveted angles, not bent flanges. Springback was removed with a rubber mallet freehand. Later builders found that MDF worked just as well for the rib forms as the hardwood that the designer initially recommended. Some builders put metal bushings in the tooling holes of their form blocks so they could drill and trace or router as part of the same process. I used a transfer punch when I traced my flanges and drilled the tooling holes later.

[narfi]

These are for the stabalizer not the wing, but the wing will use the same process, just larger. I hadn't thought it looked that blunt, but maybe the elevator will put it in a better perspective?

[Netpackrat]

Those are for the stab? Dang. Most of the GA aircraft I have had anything to do with (which haven't been a lot) were tube and fabric, so much thinner empennage structure. But of course, slow flight is the name of the game with the 750.

[fallguy1000]

I have nothing to contribute, but I will enjoy seeing progress.

I recently decided a tent was a must as well for the Skoota.

Best of luck.

[narfi]

I recently decided a tent was a must as well for the Skoota.

The shelterlogic has held up very well, only problem is I wouldn't even consider heating it :/


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Ordered some zipties, unibits, 48" straight edge with metric markings, a set of smaller steel metric rulers, a cheap set of drill bits for random things, and a brass hammer with one brass side and one nylon side.
Total $86 in the tools column.

Someone should design a homebuilt called "Amazon Basics"........... Just think of the partnership and marketing potential.....

Total time spent building: 6 hours
Total Cost: $8276
Airplane + consumables + project specific costs: $5340
Tools, etc.. I will keep for future projects: $2936

[fallguy1000]

I recently decided a tent was a must as well for the Skoota.

The shelterlogic has held up very well, only problem is I wouldn't even consider heating it :/


-----------------


Ordered some zipties, unibits, 48" straight edge with metric markings, a set of smaller steel metric rulers, a cheap set of drill bits for random things, and a brass hammer with one brass side and one nylon side.
Total $86 in the tools column.

Someone should design a homebuilt called "Amazon Basics"........... Just think of the partnership and marketing potential.....

Total time spent building: 6 hours
Total Cost: $8276
Airplane + consumables + project specific costs: $5340
Tools, etc.. I will keep for future projects: $2936

No heating in mine either. Too big, too many holes. It is to keep precip away.

I could bullet heat with 100,000 btu if I was desperate, but I'd have some co concerns. If I do run it for say an ice storm that'd be the only reason. Mine is 30x40 semicircle, so the hoops is like 46 feet. 1800 feet of uni sulated wall here in Minnesota is a dealbreaker.

[narfi]

Been busy in life and aluminum still hasn't arrived.(i have a couple sheets but the first parts Roger gave me to make are all .016 and I dont have that) Turned 41 yesterday, been yelling people im ready to start the second 1/3rd of my life now.

Made it out to the tent yesterday for an hour and got most of the first flanging die done.
They will be used to flange all the different sized lightning holes in different ribs and parts throughout the build.

If Eric still had his shop and was active on here I would probably be asking him for a quote on a nice set of metal dies made up. I need 4 sizes, 51, 65, 95, and 115mm. The plywood ones I am making will work fine, but some polished steel ones would be amazing.

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Thats the 51mm hole.
Not sure exactly how I am going to finish it yet. Obviously I need to attach the two male parts together, probably use some epoxy I have. But then it sticks past the back side of the female part, so I am thinking I will double up the depth of the female part to give room for the guide section of the male part will fit.

Any thoughts or suggestions?

It was all easy to do, most of the hour was spent trying to wrap my head around it and then a few minutes doing.


Total time spent building: 7 hours
Total Cost: $8276
Airplane + consumables + project specific costs: $5340
Tools, etc.. I will keep for future projects: $2936

[narfi]

I think I was asking too much of the little circle cutter attachment for the dremel. The plastic threads started giving and I ended up with wobbley holes with steps in them.........

Made myself up a redneck circle cutter for my little handheld router (bigger router showed up and is mounted in the table now) and used a broken 1/8" bit as a pin. Worked really well and made some nice clean circles inside and out.

Epoxied the matching peices together in our mudroom entrance to the house since its too cold out in the tent. Frosting nightly and termination dust in the mountains is getting pretty low here.

Cleaned up the holes with the largest flap wheels that would fit chucked up in the drill press and the outside of the circles carefully by hand on the belt sander.

Routed the inside 45° on the table mounted router, fun to use it for the first time.

It all looks good but I am worried about the size..... they might be to bulky and ill have to cut them down smaller once I start using them inside the ribs..... Will have to see how much clearance I have inside the flanges. Its currently quite a bit bigger than the zenith specifications for steel manufactured ones.

I did a test peice and it worked but I got it a little cocked in the hole hitting it and the male die split separated between plys (not my epoxy joint) so ill need to epoxy it back together and be super careful not to hit them crooked.

Perhaps I should back the female side with another solid peice and drill a center hole to use a bold to squeeze them together instead of "wacking" them with a mallet. I dont have a press......

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Roughly 3 more hours.

Total time spent building: 10 hours
Total Cost: $8276
Airplane + consumables + project specific costs: $5340
Tools, etc.. I will keep for future projects: $2936

[narfi]

Epoxied the separated peice back together as well as solid backing plates for the female peices. Cut them down to within a few mm of the specified OD so there shouldn't be any issue fitting inside any rib flanges now. My fear of strength seems unfounded, even cut down they seem pretty stout. Used my new drill press to drill center holes through each peice to use a bolt and washers for clamping pressure. Fun using the new tools, but they are cheaper versions than I am used to from work, there isn't much travel on the drill and I couldn't go through the full stack, but did get far enough to mark the bottom of the F peice through the male plug then drilled it separately.

More clecos and pneumatic rivet puller with zenith machined heads showed up yesterday so hopefully my aluminum starts trickling in and I can start making visible progress.

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Roughly 1 more hour over 2 days.

Total time spent building: 11 hours
Total Cost: $8276
Airplane + consumables + project specific costs: $5340
Tools, etc.. I will keep for future projects: $2936

[fallguy1000]

For liability reasons, you won't be getting advice from me, but I am glad to see you taking on such a bold project. My neighbor has a Rutan ez something or other and he says he laminated something wrong years ago and quit for fear of catastrophic error or children or some such.