knight1

I know this subject has probably been beaten to death but, I was reading some of the posts on the GP Pitts about the issues with the flying wires and engine mounting for different engines, and etc....
I'm getting ready to put together my first Pitts and wanted to know to get a pretty decent setup, what to watch out for, what to change and some recommendation's, also if it's better with 2 or 4 servos in the wings.
I'm looking to put a gasser in, possibly with smoke setup, and maybe if anyone has a detailed explanation on some of the changes or mods they've made. I'll get some pics up soon on the progress.

thank's inadvance,
Mark

Goldwing-RCU

Mark,

I'm really not it the best position to answer all of your questions as I only have a couple flights on my Pitts but I'll tell you what I know. I put flying wires on the tail as I can truly see that they make a difference. The gassers when idling will show you first hand that they can really help stabilize the tail area. I think that would be even more important as air speed increases and thus energy increases over the tail. That said, I really can't see the same situation with the wings. Enough said. I'm using 4 servos in the wing as I think it looks better and if you have a failure you have more of a back up. (Which happen on my Pizzaz two weeks ago, landed with one aileron!) I wish I knew the best engine/plane combo but I don't. I'm using a Quadra 52 with electronic Ignition and it sure powers it well but does not have unlimited vertical. (Close - Maybe after breaking in and some prop experimenting it will have unlimited vertical) My engine is a bit heavier then most so I stripped out my smoke setup. My pump was mounted on the side of the engine block and the tank was mounted directly below the gas tank. The stock tank fits almost perfectly below the original gas tank with some very slight dremel work and one support. Hope this helps!

wore-out-pilot

My Feedback: (73)

With you guys using the gas engines did any of you have to add tail weight? How was the balance?

Goldwing-RCU

I balanced in the middle of the recommended and did not have to add any tail or front weight. (Using the Quadra 52) My two batteries are under the cockpit (as well as the RX and the ignition battery up by the gas tanks. (Like to keep them away from the radio equipment.) I have not played with moving the CG around for better landings. Maybe someone else has some input about that.

Sheldon

rfw1953

My Feedback: (2)

wore-out-pilot - Welcome to the Pitts. I will try to add to what has already been said. Keep in mind that there are multiple ways to do things.

If you are using a gas engine you shouldn't have any problems with the CG. Just remember that the CG reference point is with the upper wing and not the lower wing. I used a DA-50 and if anything it was nearly tail heavy so I moved as much weight as far forward as possible. My ignition battery is mounted behind the fuse firewall under the fuel tank. My servo and smoke pump batteries are mounted behind the fuel tank just aft of the forward former to the wing saddle.

If you use a gas engine, the main mod you will want to consider is in reinforcing the firewall on the mounting box and also the mounting box to the fuse firewall. I pinned the firewall and then used tristock around the mounting box to the fuse firewall. I also added tristock inside the mounting box. Then I used fiberglass cloth with finish epoxy for resin. My firewall is good and tight with no signs of weakening. See attached pictures for more detail.

I added a simple smoke system on a smoke tray and then mounted inside the wing saddle area. I used a 24 oz smoke tank with a 24 oz fuel tank, but wish I had used a 20 oz. fuel tank with a 32 oz. smoke tank. The smoke oil runs dry pretty quickly, but the smoke is great while it last.

Mine weighs between 17-18 lbs which is a bit on the heavy side, but isn't a problem with the DA-50, which provides plenty of power. My set-up does not make for a 3-D machine, but I have ample power for my flying style. The only concern I have noticed about the weight is when a DS occurs. I have had three DS's, all of which were caused by me. I was lucky to get the Pitts down all three times with minor damage once. It flies like a rock without power. Weight is not your friend on this plane.

I also used a four servo configuration, but on my first Pitts I used two servos with a slave rod. In all honesty I don't see any difference in performance between the two or four servo set-up, but using four servos does require more power and adds more weight, but then you do have servo redundancy with four.

The most challenging assembly stage has to be in getting the upper wing aligned with the lower wing. You don't want more than 1 degree variance in the alignment from left to right or right to left as you look down from the top at both wings. Measure closely when mounting the Interplane struts and have someone hold the upper wing when making your marks to drill the holes in these struts.
Also, put your upper wing mounting screws into the Cabbane holes to join both halves together before tapping into the hard-points in the fuse. If you don't do this you will find that the upper wing Cabbane mounting holes won't align properly when inserting the screws.

Lastly, I used Robart hinge points after having the stock CA hinges fail in the rudder after four flights. I got the plane down without any problems, but upon further investigation i found that all of the CA hinges were brittle and tore easily. I have used CA hinges for years without any problems, but once I went to gas I had problems. I now only use Robart hinge points in all 1/4 scale, or larger airplanes, or any plane with a gas engine. You will hear different points of view on this, but using hinge points with Gorilla provides a better hinge and is as easy to mount as the CA hinges. If you must use CA hinges at least use the Blue Radio South hinges. Note - I added additional hinge points when doing this. Three is not enough IMHO.

Hope this helps. Good luck and post some pictures........ Note the tail wheel picture. Just a different approach that has worked well for me. Ohio Superstar medium sized tail wheel with a Rocket City Hardware Connector.

wore-out-pilot

My Feedback: (73)

Thanks for all the good information. I have a G-45 and a OS 300 twin and have not made up my mine. I have purchased the Pitts and also the Christen Eagle. Hope to get to them this winter. My Pilot Christen Eagle need a sister. It has a Saito 270 twin and flys great. Its nine years old now. Its my baby.

privat pilot

Flew my Pitts today and the throttle jamed from too much locktite. Then the fuel tubing burnt through from touching on the muffler. No problems or damage to get it down though.
The plane weighed in at 16lbs with a zdz 50 and it went like a rocket took off and climed at 45 degrees on half throttle cant wait to get out to the field and fly it again. Barry

rev

I received a gift from a older fellow modeler. The Pitts 1/3 scale about 70% built. I took the upper center wing apart and reinforced the mounts and inside the fuselage for the cabane mounts, this is the first version. I plan on using a Homelite 45cc conv. motor on the plane. Is there any other things that I should address?

CaptRKO

My Feedback: (3)

Just bought one on Craigslist.......will start the build soon. Any updates?