Thorp Air Command - T18.net

Stunning! So many questions, not enough time.

Marhyde SEP or epoxy primer?
How are you going to close the l/g fairing? Pops? Ever tried the hinge method? (Dick Penman wrote about it.. also used on the RVs?)
That piece on WL42 supporting the panel... does it pick up on the frame or the skin too?
How will you to isolate your panel from vibration? (That's where I am at now... I welcome ideas.)

I'll save the other 994 questions for the gathering.

Thanks for sharing your work, Lee.

d

Answers for you Mr Wolff ...

The outside was etch primed and then epoxy primed with ppg products, the interior is a sem etchprimer.

The fairing will be closed with #6 ms and nutplates, I like the hinge set up but as a point of personal preference I like screws.

The panel mount is shaped like a "T" and ties strictly into wl42, once the panel is bolted to it its plenty stout.

the panel is 2 laminated pieces of .40 glued together with contact cement (pliobond), that provides quite a bit. The panel lays on cork and has rubber bushings on the top mounts.

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

Lee - do you have a NL covering this panel mounting method?

If not, more questions:
Is the panel leaning back with respect to WL42, or is that just an optical delusion?
What keeps the bottom from sliding fore and aft? (I assume a simple screw or bolt on each side.)
How would said bottom screw be isolated from the airframe? Grommet?
Why two layers glued as opposed to one piece?

I went around in circles again designing a tip back panel on a cross rod, with a rubber bushing on each side for as suspension. It was a neat idea but not as light or simple as what you did here. After lots of paralysis by analysis... I remembered the Prime Directives of airplanes:
1) Simplicate
2) Add Lightness

And one can't argue with proven.

D

Here you go Dick.

I added a progress shot of the panel since we're on that subject. If you would like to go down the tip back route I have all of the Ken Knowles hardware required for the tip back install that he sold (just collecting dust on my shelf). I considered to too heavy, it took up some valuable panel real estate (at least to me) and with the floor board removable, getting behind the panel is fairly easy. Even with that being said I only need to remove six AN3's and my panel is ready to remove.

Take a look at the sketch but put short the lower mount is sandwiched between two pieces of cork and the upper mounts are isolated with nylon bushings. Oh and no the panel is not angled forward it is vertical in level flight.

Hope that helps!

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

Dick,

The double thickness with glue in between is an old Northrup trick -- deadens the panel and thus, helps keep vibration down.

_________________
Bob Highley
N711SH
SN 835
KLAL

That's basically how I made my panel. The upper flat portion is a laminate of 2 pieces with a layer of double-sided sticky tape in between. The only gyro I have is a turn coordinator, and I have never seen the need for any additional vibration dampening. My panel is bolted directly to the W.L.42 extrusion on both sides, and to two standoff brackets at the top, for a total of four 3/16" bolts/screws. That and a good dynamic prop balance job, and my panel is very "dead" & vibration-free.

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

By the way, your anti-oil canning mod to the forward bays is exactly what the Boeing engineers told us to do to keep the fuselage from twisting under heavy torque..
Cubes

N30WW's panel is a single sheet of .063 2024 aluminum mounted using two hinges that allow the dash to be tipped back for access. I believe the multi-layer panel was the result of the old steam gauges poor shock tolerance.

Thx all. Great info.

BTW, if anyone else intends to make a pair of those "T" plates like Lee did, keep in mind that they should not be exactly square, because WL42L is not parallel to WL42R where the panel goes across.

Don't ask me how I know. (D'oh)

D

They certainly should be, Dick.

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

Sorry Dick .. should have said an "italic "T"

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

Hi John,

I think what Dick is saying is the sides are still widening out at that position. So the "T" plates would need to be a 90+ degree angle instead of a 90 degree. I could be wrong...

_________________
Matt Smith
Des Moines, IA
55RC

"T" That is funny.

_________________
Matt Smith
Des Moines, IA
55RC

Clever, you guys. Nothing like a good public mocking once in a while. ;-)

BTW, the Panel is looking great Lee. The rivets around the outside.. just to keep the two sheets from debonding from the edge??

d

Of course... that was dumb of me. Carry on.

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE