Sport JTEC RADIOWAVE 26% Pitts Model 12

[stangflyer]

Progress on the Pitts is starting to slow up. It's those finishing up things that seem to take forever to complete. I finally got around to cutting the belly and the landing gear plate openings. I figured I best get to that while I had the plane upside down while building the throttle servo support. After getting the covering cut and sealed off, I covered the belly hatch and the landing gear cover plate. I think they turned out ok. Sure is going to be much nicer than the gaping open hole in the belly. JMO.

I also got the Hall sensor mounted and the ignition wiring pretty much tidied up. Also the throttle servo support is now in place.

I got the tail gear mounted and hooked up to the rudder for ground control. I also test fit the upper wing center section with the aileron servo harnesses in place. This plane should be very easy to assemble at the field. Slide in the bottom wings, plug in servo harnesses, install wing bolts. Slide in the top wing outer sections, plug in the servo harnesses, install retaining bolts....gas, fly. hee hee.

I probably won't be posting any more photos of the plane assembled until it is basically ready to go except for the paint on the cowl and wheel pants. I have not decided yet if I am going to maiden it with the pants on and the cowl painted or just wait until I see how she flies. I don't anticipate having to change the thrust of the engine, but if I do I would sure hate to cut away anymore of the cowl for thrust angle fit "after" it has been painted. And until I have put a couple of flights on it, I really don't want to install the wheel pants. Plus, I still want to use White Rose mains. Which means I would not be hiding them behind wheel pants. I thought I had some the right size, but apparently I do not. I may have to order some. The information on the Pitts calls for 3.5" mains. They seem kind of small to me so I wanted to use 4" mains. If anyone has a nice set of 4" White Rose mains they would like to turn loose of, let me know.

More tomorrow....

 

[Doc]

I don't 3D nor have an idea about the torque requirements for the rudder but I was thinking a matchbox (or similar) would surely solve the problem of too few ports, particularly on rud or elev where matched movement is what you need leaving the Rx channels for custom programming.
Doc

 

[Doc]

About the smoke oil residue damaging the airframe, I haven't seen any attempt to use resin or some outer sealer on the exposed wood parte of the model, is this not done or you just haven't gotten to it yet. Is this considered too heavy to do , or what.
Doc

 

[stangflyer]

I don't 3D nor have an idea about the torque requirements for the rudder but I was thinking a matchbox (or similar) would surely solve the problem of too few ports, particularly on rud or elev where matched movement is what you need leaving the Rx channels for custom programming.
Doc

It's not the issue of not enough ports...I definitely have plenty with the Smart Fly Micro 12. It is a matter of "commanded control" from an out put channel. Perhaps I am missing the point or am failing to understand what and how the exact and proper setup of a matchbox is and does. A couple of you have suggested this option. My understanding is, it is in its simplest explanations an expansion board/box with optional gain for tunability and programming. Or even simpler than that, a glorified "Y" harness with some nifty fine tuning features built in. Smart Fly also offers something similar. But for my setups, (especially this one) I have no need for such a device. My Hitec has all the programming I need. Also, the Hitec digital servos are also programmable and thus with my programmer and radio, I can achieve pretty much anything a matchbox can do. A separate channel would still be required to access the full features of individual channel fine tuning as what I was seeking. As for torque requirements for 3D, a lot of that requirement is totally dependant upon a few very important parameters. A few of them being, weight of the plane, speed the plane is intended to be flown at, the amount of deflection the surface will be moved, and most important is the size of the control surfaces. For the lil 26% Pitts and the amount of angle the surfaces will be deflected and combined with the size of the surfaces, the weight and the overall intended flight envelope of this plane, I could surely get by with something like an HS5645 Hitec digital servo. It is the only servo I would use in my pre 50cc airplanes. But the centering of the later released 7000 and up series servos is nearly impossible to beat. IMO....

About the smoke oil residue damaging the airframe, I haven't seen any attempt to use resin or some outer sealer on the exposed wood parte of the model, is this not done or you just haven't gotten to it yet. Is this considered too heavy to do , or what.
Doc

Again, the anticipated combined weight of the Pitts, (probably around 23-25 lbs.) and the components of a smoke system and then you add on the weight of an outer sealer.... I highly doubt even attempting to fly such an equipped plane would prove to be beneficial. Let alone any enjoyment. This 50cc sized airframe would easily come in around the weight of most "HEAVY" 100cc airframe. Heck, as it stands it will be close to the weight of a light 100cc airframe.

 

[Jetpainter]

Your hatches look great!

 

[Doc]

The open style of structure of this type of model really would make it hard to really seal all the exposed wood, without a full firewall to block off airflow through the fuselage it would take an enormous effort and a lot of whatever you used as a sealer to accomplish that. I have often wondered if the lifespan of aerobatic models was shortened from oil absorption and general softening of the structure. I have a couple of big birds that are in the 18 to 25 year old range but they're pretty well sealed.
Doc

 

[stangflyer]

The open style of structure of this type of model really would make it hard to really seal all the exposed wood, without a full firewall to block off airflow through the fuselage it would take an enormous effort and a lot of whatever you used as a sealer to accomplish that. I have often wondered if the lifespan of aerobatic models was shortened from oil absorption and general softening of the structure. I have a couple of big birds that are in the 18 to 25 year old range but they're pretty well sealed.
Doc

I can only speak of what I've seen or experienced. My 100cc Pilot Edge covering started peeling off after 5 flights with the smoke system installed. The wood underneath got quite wet. My son's 43% PAU Edge was pretty much the same way. I peeled back the covering on my Pilot and soaked the wood with alcohol. Fortunately I was able to get the covering to reseal after extensive cleaning with Monokote Trim Solvent then neutralizing with more alcohol and final cleaning with Amonia. My son on the other hand was not so lucky. He completely stripped and recovered his PAU. I am sure if an airframe were sealed somehow, It would be fine. I've seen my friends planes with smoke on them. Nearly everything he owns has smoke on them. Yeah they look cool bellowing out those heavy plumes in the air. But once on the ground...yuk. No smoke for me.

 

[Doc]

Bummer I guess if I were to run smoke Id find a way of closing all the holes on the firewall and sealing it with resin, not tons but a lite coat and seal in the LG area. That would have to help. What percent oil do you run in your fuel?
Doc

 

[stangflyer]

Bummer I guess if I were to run smoke Id find a way of closing all the holes on the firewall and sealing it with resin, not tons but a lite coat and seal in the LG area. That would have to help. What percent oil do you run in your fuel?
Doc

My fuel mixture after breakin is 40:1 Premium non ethanol/Red Line. New "dubs" get 32:1 Lawn Boy Ashless. New Chinese get 32:1.

 

[acerc]

My "Red Eagle" Pitts with the wrapped headers leaves absolutely no residue on the airframe. Pre heat the oil and adjust the pump appropriately for a clean burn, simple as that. A little over two years and have not had to clean it other than for dust collected while in the trailer. And the three other airframes with smoke are the same way...