Brodhead Pietenpol Association

My Ribs were built per plans for 1" spars. I'm building the three piece wing and see the spar is 3/4". I plan to put 1/8" sticks in the spar space of the ribs. Is that the usual fix?

There's a bracket with a bent tab that comes out the bottom. The plans show a space of 15/16" in the bracket area that fits on the spar. Since it's going on a 3/4" spar, I'm going to make it 3/4" instead of 15/16". Sound good? Or should I thicken the spar in that area with shims to get 15/16"?

There's a bracket for the pulley shown and the distance between holes is shown, but I can't find the overall dimensions.

What supports the fuel tank?

Are there any other problems I'll run into?

Thank you!

John C

On 34KP the tank sits on the plywood bottom piece. I believe on the drawings they show a cross piece attached to the spars that the end of the tank rests on.

Thanks!

The plans show no filler for the routed area of the spars. In the written manual there are specific notes about the importance of the 'wedge' between the top of the spar and the rib. There are no notes about adding a filler strip. I personally didn't add any filler and over the last two years of building haven't seen anyone talk about adding that.
I'm not sure which bracket you're referring to. I didn't have to "'pad' any of the fittings on the wing or center section.
The fuel tank is held up by a piece of wood both fore and aft epoxied to the center section spar and is elevated off the plywood floor in these areas. Since the plywood floor is curved the tank will have contact only in the center area if at all. You can purchase fuel tank hold down straps (padded) to run over the top. If you build a flat bottom tank it will not sit flat in the center section unless you also eliminate the contour of the compression struts that the plywood floor is epoxied to. You then also have to modify the bottom of the center section ribs or the flat bottom will stick out below the ribs. I have seen several different flying Piets with mods from the plans with regard to fuel tanks so you may be able to find someone who has done what you're thinking of.
The center section and wing aileron pulley brackets are outlined in the plans full size on the 3 piece wing supplement page and page 4. If you are missing these you may not have a full set of plans.

Thank you for all that!

I took another look at both the supplemental page and page four. It appears even though I'm building the three piece wing, I'll have to build some of the brackets using the page four dimensions, not the supplemental. So that straightens that out.

The ribs have 1" spaces for spars, but spars are 3/4", so I have 1/4" difference to figure out.

I think I'm good on the fuel tank now.

Thanks!

John C

Made supports for front and rear attached to spars and floor. Center supports added. Fuel tank sits on those supports. Fuel tank made to largest size possible, and is a tight press fit with felt around edges. Top cover over top of tank holds tank down. No need for any straps or drilling holes in spars for straps.

With cover on.

Not sure why pictures are upside down but right side up if you click on them.

Thank you Rob for those photos. Nice looking work there!

John C

Rob. Yours if very close to 34KP's setup (flying since 2000). The wedges were added in 34KP's case due to oil canning being heard when fuel was put in the Tank. Ours is also a very tight fit with the tank cover holding the tank in. I like that you off-set your filler to one side. Ours is in the middle and a pain to see into when fueling! Any idea of your capacity? Ours holds 13.5 gallons, just over 12 useable. Oh, it's a single fuel outlet in the corner, which doesn't thrill me.

This is what I was referring to earlier as to tank mounts. Ken didn't do this and as you can tell from my prior pictures he built the tank to fill the maximum area between the spars for maximum fuel.

Rob. I see you're building with steel tube, which would be my preference. What engine do you plan on using?

It’s the steel fuselage per original drawings. Model A Ford.

Well, I feel silly! I just realized who I was talking to. I'll blame my slowness on the weather!

Lol…I was wondering….

Wow, that is a beauty!!! Museum quality for sure. I zoomed in on the tail to see if maybe you used wire ferrules on the tail braces but it looks like conventional Nicopress with aircraft cable. Yes-? A sparkling rendition of a classic airplane.

Oscar Zuniga
Medford, OR
Air Camper NX41CC, A75 power

Thanks Oscar

Brace wires are hard wires. Also all wrapped and soldered cable ends. Everything period correct as possible.

Lovely details, all of them!

-Oscar

John,
In reference to your statement about 3/4" spar and ribs built around 1"; The spars are 1" and routed 1/8" off each side for a 3/4" center leaving 1" at the upper and lower ends of the spars. The spars are also left at 1" where all the hardware goes on. The ribs will be snug because of the 1" dimentsions at the top and bottom of the spars. Hope this helps.
JeffreyK

Thanks Jeff.

John C