I am looking into Laniers Ulitmate Pitts and I have a Gas 42cc engine with EI. The engine weighs in at 4lbs 3oz including all electonics. The plane is rated to handle up to a 2.2 cu in gas engine. I believe mine is a 2.5 cu in. My engine swings an APC 18x6 prop at 8600 RPM. The plane has a wing spam of 60 1/4 " and a wing aera of 1110 sq in and should weigh around 14 lbs when completed. I was wondering if anyone has built this plane with a gas engine of this size and how well it flow.

I have an Ultimate Pitts and it's an excellent flying plane. Probably the best flying 60" bipe on the market tody, but it is not a 3D airplane. One of the few that will actuall let you make an approach with a dead engine at a reasonably slow speed.

I had an OS BGX 3500 in mine and it was well overpowered. The BGX was a bit lighter than the 42cc engine you want to use. I had a problem with balance. The plane was quite nose heavy until I moved the flight battery to the back of the wing saddle and added 2 ounces of lead to the tail. I would have preferred not to have added the lead, but there were no other options since I had built the plane without provisions for aft mounted servos. With yours and the intended engine, aft mounting the servos will be mandatory.

As an after thought, if the plane is not yet built, don't try to inprove on any of the flight surfaces. There's more than enough as designed.

Pat

Pat

I have not bought the plane yet and I was hoping to find others that have used a gas engine on this plane and how they like it. How much does your weigh? I am planning on mounting the servo's for the rudder and elevator as far aft as I can. I am going to be using GWS metal gear servo's that are rated at 100 oz torque. Did you use monokote or cloth to cover your Pitts with? I like cloth better becasue of the added strength it gives. I know it adds a fews oz to the plane, but I think the extra strength it give is well worth it.

Do you have any PIC's. I would like to see your plane with that big gas engine in it.

I used MonoKote for the covering. Cloth or Coverite would work out very well due to the curves in the fuselage. The structure is quite strong in all areas, so any covering will work fine. Due to the lack of reliability I had with the BGX, the engine was sold at a fly in. The plane is now hanging from the ceiling in my shop without an engine until I come across a gasser for it. That's going to be a pain since it was built around a glow engine. I haven't settled on a size yet, but something that would match a Moki 2.10 would be about right.

Change out the balsa spars in the wings and substitute bass or spruce. It increases the wing strength tremendously with little weight penalty. If you want a 3D plane it will require increasing the span of the ailerons to get them into the prop blast. That would be quite a bit of work. The elevators and rudder are quite plentiful as they are. Two servos is more than enough to handle the ailerons, one for each aileron pair. Your servo choice will be fine.

I never weighed the plane and I'm not in a position to be back at home for awhile, but the neighborhood of 14.5 to 16 pounds is in line.

It's a builders plane that requires a bit of work, and possibly replacing some of the balsa that comes with the kit, but the flight qualities of the plane more than offset the effort. You'll like the plane a lot.

Pat

Pat

Thanks for all of the helpful information. I'll look into all of the thing you suggested.

I've been drooling over this plane for a couple years.

I intended to use a 40cc gasser as well.

I think 2 servos about 50--70oz in the tail for the elevators. 1 rudder servo--probably 100oz. You could mount it either pull/pull up in the fuse--or if you need more tail weight put it in the back as a push/pull off just one side of the rudder.

Mount the elevator servos up high and the rudder servo towards the bottom if you have to stick it in the tail.

Keep the engine box strong and don't drill any lightening holes in it.

The only thing thats kept me from getting the plane is that it's a kit. I build 2 or 3 kits per year. I just finished a 4*120 a few weeks ago and I'm kinda burned out on building right now.[sm=drowning.gif]

Thanks for the info. I guess I am a little worried about the total weight of the plane when it is finished. With a total wing area of only 1112 sq in I believe the wing loading will be around 32 oz . I guess I will just keep my airspeed up on landings. I am not into 3d flying so all I do is simple loops, rolls, touch and goes and a little inverted here and there. Will this 42cc engine that weighs 4lb 3oz and swings a APC 18x8 prop at 8600 RPM have enough power for me?

Don't have any worries about the weight vs. wing area. Due to the size of the plane, the reynolds numbers stack up really well even with a wing loading as high as 36 oz/ft. She flys sweet!!! It's the ONLY bipe that I've flown in the actual aerobatic category that's a "floater" The higher wing loasding has little, if any, noticeable effect in it's handling if the balance is correct. It blows the wings off an equal sized Pitts or Eagle, and lands better than a slightly larger Ultimate of similar weight. This plane slows down extremely well for the approach. I made more dead sticks with the engine I had than I care to remember and making the runway was never a problem. There's a lot of people that watched and probably still can't believe it would slow down and float that well. It really is that nice of a plane!

For the elevator servos, those are pretty big elevators, so I believe 70 ounce servos would be the minimum.

Pat

Pat

After your last comments on this plane and how well it flies I went ahead and ordered it last night from Tower Hobbies. I hope to have it buy next week. I'll post my building when I get statrted. The engine I have is a converted 42cc chain saw engine with EI that I got off of Scott Ellingson here on RC Universe. It is one sweet engine. I know it is a little heavier than the Brison 2.4 engine, but it is liter that a Fuji 32 so I think this engine falls into the right size and weight for this plane.

The servo's I plan on using are GWS metal gear rated at 100oz torque and I will be using a Hitec 425 for the throttle. I will be using only 2 servo's for the ailerons and connect the upper and lower with a 4-40 rod covered in carbon fiber.

Thanks for all of your inputs guy's. It help me to fell much better on making my decission

If that 4lb. - 3 ozs. includes the battery it is only about 4 ozs. heavier than my 2.4 Brison which weighs about 3lbs. - 15 ozs. with an 1100 - 4.8 battery, 4 ozs. is nothing .

Don

Yes the 4lbs 3oz is the complete weight of my engine(engine, muffler, EI, and 1800 mah nimh battery pack). The info you just gave me helps me out a lot. If my engine is only 4 oz heavier than your Brison 2.4 I believe I can built this plane and keep the total weight under 15lbs.

Thanks

Don't go beefing up the motor box. It's plenty strong as it is. The only issue will be accessing the inside of the box to secure it in place after you have determined the correct distance out from the firewall to suit your engine.

Looking forward to your build thread. I had a lot of fun building this plane. I actually built the fuselage twice after ending up with a tweak in the tail of the first one I couldn't get rid of. One other item I just remembered doing was changing the bottom stringers on the plane from balsa to spruce to prevent hanger rash.

Pat

Thanks for building tips on this plane. I am just finishing a Great Planes Giant Big Stick with a Brillelli 25cc GT engine in it. As soon as I am done with it the Lanier Ultimate Pitts goes on the building table.

Thanks

You can save the 4 ozs. by going to a smaller battery pack. Mine is 1100 mah and is good for 10 -12 flights fully charged. I did have an 850 nicad pack on it one time and had no problem getting 5 - 6 flights after full charge.

Don

Thanks for this information about the battery weight. I'll look for a 800 mah nimh battery pack.

Thanks