What did you do on your airplane project today?

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Toobuilder

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Thanks everybody. It's been a long road and this thing has so many "unconventional" aspects to it that I can hardly keep track. The downside is that all of these concepts are only semi finished and will require a bunch more work to make pretty. The cowl looks like a 5 year old's first attempt at paper mache. Same with my inlet rings, oil cooler plenum, intersection fairings... The fiberglass exhaust ejector looks and works great, but there's no way it's going to survive the heat... Time to start over with SS sheet ducts like a T-34
 

Saville

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Apr 28, 2014
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116
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Boston Ma
Well it so happened that the left hand fuel tank on my RV-8 developed a leak. Long story short the Proseal never fully cured so hence the leak. Plus this tank had been nothing but trouble (leaks of one sort or another) since I bought the plane in 2015. So I had a new tank built. It's now installed.

Given that I was getting a new tank I decided to replace the fuel selector. There were two problems:

1) It was a Left-BOTH-Righ-Off selector - bad for low wings and
2) The installation was pretty horrible:
Fuel_Selector_Bay_640.jpg

The line going to the right hand tank was run OVER the bundle of electrical wires, the fittings were "glued" into place on the selector which asked for failure, the connections were impossible to get at because you had to remove the selector from the cover plate, and it was almost impossible to get a wrench on the nuts. And too many fittings.

So I designed a new cover plate which allowed me to access the connections without having to get underneath the cover plate - the cover plate now comes off:
Assembled_Top_640.jpg
Painted and ready to go:
Plates_Ready_640.jpg


So then I started on replacing the fuel lines with flex hose.

Here is the latest on what I did with the Plane:

3_lines_connected_top_640.jpg

I do this with a clear lexan cover plate so that I can see how things are leading.

Tested the connection to the new tank:
Left_Tank_Line_Connected_640.jpg


My next task is to figure out a way to separate the bundle of wires from the fuel line underneath so that they don't chafe. They are at almost right angles to each other. My first thought was 2 Adel Clamps with a 90 degree twist in one of them.

Any ideas welcome.

Short version - tested the connection of left, right and boost pump/engine fuel lines to the selector.
 

Victor Bravo

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KWHP, Los Angeles CA, USA
My next task is to figure out a way to separate the bundle of wires from the fuel line underneath so that they don't chafe. They are at almost right angles to each other. My first thought was 2 Adel Clamps with a 90 degree twist in one of them.

Any ideas welcome.
A short piece of split rubber hose around the wire bundle and another piece around the fuel line, then both hoses Ty-Rap'ed (zip-tied) together. Adds another layer of chafe protection, and prevents any relative movement between them. And a lot lot lot less PITA than wrestling with Adel clamps in a small space :)
 

Saville

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Boston Ma
A short piece of split rubber hose around the wire bundle and another piece around the fuel line, then both hoses Ty-Rap'ed (zip-tied) together. Adds another layer of chafe protection, and prevents any relative movement between them. And a lot lot lot less PITA than wrestling with Adel clamps in a small space :)

Ooh. I like it.

Would you say that you place the lengthwise splits 180 degrees away from each other?
 

Victor Bravo

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KWHP, Los Angeles CA, USA
Ooh. I like it.

Would you say that you place the lengthwise splits 180 degrees away from each other?
Yes, of course. A drop of RTV would likely hold the split hose on the bundle or fuel line against "rotation"... this keeps the split seam on the far side as you pointed out. But one little blob of RTV can be peeled off when you need access to the bundle.

You can secure the hoses to each other by using either one larger zip tie around everything (if the hoses are close to parallel) or one zip tie on each hose and one of them capturing the other zip tie (if the hoses are closer to 90 degrees apart).
 

gtae07

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Dec 13, 2012
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Savannah, Georgia
No physical progress, but lots digitally. Been working on my electrical diagrams and panel layout and making significant headway; everything is coming together finally.

Now I just need the time to actually go implement all of it...

On a different note, been wrestling with paint ideas. I really like Daleandee's roller paint idea; when I mentioned it to my wife she said "why the heck would you do it that way and why do it yourself? Beside, you have no aesthetic sense". She (rightly) doesn't think much of my painting abilities. Her suggestion was to just go unpainted for a while (bare metal) and just have it painted professionally later. Personally I'd rather just have it done with, even if that just means all white paint and maybe some vinyl trim/graphics.
 

pictsidhe

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Jul 15, 2014
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North Carolina
I'll second zip ties. I use a lot at work. We have moving machinery with snakes nests of hoses and wires. Careful zip tying will let it run years with no problems. A bad job, it can need repair in a week. Adel clamps are nice, especially when you need to nail a wire or a hose to a flat surface, but zip ties are very useful for many spots that would take forever and/or weird brackets to clamp. I've cut original zip ties off 80s and 90s machines to change or alter stuff, they last just fine when used properly.

A short piece of split rubber hose around the wire bundle and another piece around the fuel line, then both hoses Ty-Rap'ed (zip-tied) together. Adds another layer of chafe protection, and prevents any relative movement between them. And a lot lot lot less PITA than wrestling with Adel clamps in a small space :)
 

REVAN

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Dec 6, 2016
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Tucson, Arizona USA
I modified my ultralight design project, again. I increased the wing span by 2 feet and added about 5 square feet of wing area. This is just the latest in a long series of design evolution steps. The time between changes has been increasing though, so I think it may be getting close to time to start making some parts tor testing.
 

BJC

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Just a random thought about iterative design processes, not restricted to aircraft design.

When beginning an iterative process, I found it helpful to over-compensate on the first iteration, with hopes of going in the opposite direction on the next cycle.

YMMV.


BJC
 

Toobuilder

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...or in my case with my oil cooler: "undercompensation". Flew the Rocket for 1.1 today and the oil cooling remains right on the edge of unacceptable. However, it's still breaking in, the OAT is high, and there are a couple of "sub optimal" design details to attack. The CHT approach is still very effective however. I have one bad actor which will be easy to bring into line. And "bad actor" is a relative term - it was the only cylinder to break 400 in the climb. It settled into 380 for the remainder of the flight while the other 5 ranged from 340 to 360. That's at 78 OAT at altitude... This winter, I'm going to struggle to get the temps to break 300. The augmented cowl outlet concept is proving to be very effective. The downside to my particular configuration appears to be a significant amount of near laminar flow along the fuselage bottom skin. The floor in the center tunnel is too hot to touch with a bare hand after a short time in the air. I added a small spoiler to try trip the airflow but oil/soot streaks show that the effect is very localized - the flow straightens out very quickly downstream. Figures right?

Cruise speeds are not where I'd like, but there is a LOT of drag in the rough cowl and misaligned gear leg fairings.

Cowl out.jpg
 
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pwood66889

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Sopchoppy, Florida, USA
One micro project completed: Put last 3 fasteners and washer stacks on frame repair. It was dissassembled for inspection, then not finished off. I think he ran out of nuts, etc.
 

Victor Bravo

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...or in my case with my oil cooler: "undercompensation". Flew the Rocket for 1.1 today and the oil cooling remains right on the edge of unacceptable. The floor in the center tunnel is too hot to touch with a bare hand after a short time in the air. I added a small spoiler to try trip the airflow but oil/soot streaks show that the effect is very localized - the flow straightens out very quickly downstream. Figures right?
Instead of begrudgingly accepting tripped or separated flow (on a 200 knot airplane), what about some thin sheet heat insulation on the outside of the tunnel skin (Fiberfrax, or "header tape", or some other thin heat reflector/insulator) and a layer of thin stainless on the outside of that?

You might keep your attached or low drag flow and still keep enough of that heat out of the floor .
 

Toobuilder

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Should have clarified that the "spoiler" is just a temporary experiment. I'm likely to redesign the ejector duct to T-34 style augmented tubes. That will allow me to better isolate and direct the heat. If that doesn't work I'll have to add the fiberfrax.
 

Toobuilder

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Flew .7 today and got gas. I'm sneaking up on the fuel flow K factor output from the SDS ECU and should have it dead on soon. VERY cool feature to have FF without having to use a discrete transducer (or two). Also tested the hot start performance - the SDS EFI has yet to miss a beat. It starts on the second blade, hot or cold, every time.

Took some temp readings on the floor. The good news is that the front stick well (where the fuel pumps, filter and selector valve live) "only" measured 156 degrees. Further back, the skin measures 206. That's too hot.

Air was fairly smooth today and thanks to a slight tailwind and a high power descent, I happened to glance at the groundspeed on my GPS: 246 knots.

It's nice to be flying a proper airplane again!
 

Mcmark

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Sep 24, 2013
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Owings, MD
Sooooo, so my buddy Chris and his lovey put up with me again for 2 nights and finished control hookups fwf. Exhaust is up and tight.
Still adjusting for things to fit. Have to turn the slobber pot around to have room to route the drain to the exhaust. Still have to plumb the oil cooler and the MP. That will finish the plumbing fwf. Installed the wood prop I have (Hegy, can you say old?) and torqued. Looks good.
Got the P leads on and installed my $36 PC 680 knockoff. We were aiming to hear it run this weekend. It spins well but no oil press.
I was beat and it was late. Had a cocktail or 3, dinner and went back this am. I cleaned up the mess and beat feet for home.
So research time to sort the OP prime and gather more bits and bobs to hopefully make this thing go.
I didn’t take a pic but Smizo did, hopefully he’ll post it. It doesn’t look a lot different but that’s how it goes.
 

BJC

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Congratulations, Marc. Looks good.

Take time to relax a little after getting it closed up and before first flight.


BJC
 

Marc W

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Mar 31, 2017
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469
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Colorado
No danger of flying it today! I didn't have all the screws and I had to finish fitting a new part I made. I might be able to fly it tomorrow if I get the rest of it together early enough. If it takes to long I will wait 'til Thursday morning to fly it. I don't want to make a test flight when it is hot and windy like it is now.

I am still rechecking everything before I button it up. It has been in the shop for several months and I had a lot of it apart. I had an A&P do the condition inspection but I am still paranoid! Trying to make sure we didn't miss anything.
 
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