Composite-Arf Pitts Python Build

[fastford]

I received my pitts the day before leaving for the Nall. Bob Shapiro ordered me a new Pitts and 3.3 Yak at the same time. Both were delivered in perfect shape! I spent a little time this morning mocking up the plane. I'm very impressed with the perfect fit of all the componets. Bryan Zang from Aerographix will be doing a Budlight wrap on the pitts when it is close to being completed.

[JagerBomb]

Jason (Fastford) was logged in on my computer last night. Guess he didn't logout.

[fastford]

I dont know what Mark is talking about but my new plane sure is SWEET!!!!

[Cracky]

LOL, I was just reading that and thinking SWEET, formation pitts'.

[ShortBus]

	Quote: Originally Posted by fastford
	I dont know what Mark is talking about but my new plane sure is SWEET!!!!

A Yak and a Pitts!!! Nice!!!

[Cracky]

Mark, you think you'll be able to get enough throw out of those elevators??

Thanks for doing a build on this. It looks to be quite an impressive bird!!

[Kiwi]

Mark,

What setup are you going to use. I have a neat mod to get two servos inside the elevators so you don't use those push pull rods if your interested.

[JagerBomb]

Hi Kiwi,
I'm very interested!!! I have a 3W CS170 with the greeves pipes going in this bird. planning on using the Futaba S9156 servos as well. Fromeco batteries, regulators, and switches. Smart-fly distribution.

[TrojanMan]

Looks great Mark! That thing is going to be really cool!

Jim

[Kiwi]

Mark,

This setup was done with HITEC 5955 servos so you wont have any problems at all with the Futaba 9156's. I have a new 3m 260 planned and it will be fitted out with FUTABA 9156 servos as well.

The procudure is a walk in the park for you given the number of kits you must have glued together over the years.

What I done was make a dummy plate from lite ply. This allowed me to set the servo spacing up, cut the slot and work out how to fit the thing into the stabilizer

Once I had that all sized up I cut the hole in the stab so the servo package fits in neatly. Once that hole was cut I got some hard balsa stock and framed up the cut out, If you your a dab hand I would likely do this with some good quality ply next time so as to get a stronger attachment point for the screws that hold all this together. I have never had an issue with the balsa but some 1/2 ply would be no heavier and twice as strong.

As you can see you don't have much meat left at the front inner position of the plate but you can still easily ten or so screws into the stab to hold it all solid.

Now once you have it all setup I went out and got some carbon fiber plate, I made a right and a left servo attachment plate from that as it is super stiff, no flex at all. Then its just a matter of drilling and screwing the servo mounting plate with the servos attached into the stab and your done.

I found it to be extremely strong, much more so than the intended push rod setup and of course close coupled linkages give everything that added stiffness as well.

Mine has the 212 4 cyl 3W in it and its obviously nose heavy so this helped move things back, I figure the 170 with cans or pipes will likely need some tail weight as well and this does it without adding dead weight.

I would suggest you dummy fit everything to get an idea where your C of G will come in. One thing I found with the PITTS is if you need to move something around to balance it you move pounds, not ounces as the plane has a very concentrated load in the wing area.

Hope this is some use to someone if you dont need it anyway.

[JagerBomb]

Kiwi,
I will definitey see if that will work with my balance! I think it is awesome when modelers think outside the box and improve on an existing design. Here are some pics of the 3W 170

[Kiwi]

That things got to be a stump puller Mark. According to the specs it almost has the power of the 212 so your in for a great performing plane. The 212 is heavy for the PITTS but its a great show plane,

Another thing I strongly suggest is wrapping the landing gear from where it exits the fuselage and down the gear leg for two or three inches with a very strong cord. You could do it with some sort of Kevlar but I used a black synthetic thread off an industrial sowing machine. Rough up the surface with some coarse grit sand paper, bind the leg with the thread (spot tack it with CA to hold it in place) then mix some 30 minute epoxy with alcohol until its good and thin. Soak it into the thread and let it set hard, You wont de laminate that gear in a month of Sundays.
Mark the gears OK for good fields (Triple Tree or paved) but if you have a lumpy grass field the gear really takes a beating and it can (does) delaminate at the bend.

Other than that mate I'm fresh out of suggestions.