flystunt

Has anyone tried to "reset" the tail twist? I had a composite sailplane once that had the same type of twist. I was taught that if you warm the empennage up with a heat gun (be careful not to overtemp it and burn the gelcoat or paint) and twist the fuse the opposite way and let it cool, it will hold the much of the new position after it cools. In essense you are bringing the resin up to a temp where it softens just enough to be manipulated. It really worked!

I just picked up a new P-7 myself so will be interesting to see if mine has the issue as well.

Sean Elliott
Oshkosh, WI

stuntflyr

Sean,
You going to make it to Chicago on May 28th?
Chris...

flystunt

Hey, Chris!

I sure am gonna try. I have some new responsibilities at work, so much will depend on my schedule. Kaos is off course ready to go and I will do my best to have the P-7 completed by then as well. We'll see!

Sean

wildnloose

I want to thank those who posted rpm numbers. I never flew this kind of plane and am not sure what to expect performance wise (Mama was kind enough to buy this plane for me, but she is not going to get anything else). So I am using my old servos (JR 537)and an old glo engine I have.

I have been testing my Magnum 52XLS with the Evo pipe. For those that are curious, here are the numbers:

Evo 11x5 15,300rpm
APC 11x5 14,000
APC 11x6 13,800

Based on what I have been seeing from u guys, these rpm's may be enough for me to compete in Novice SPA (at least for now). I will start with the Evo 11x5 because it runs in the pipe's rpm range. If its not enough I do have a 61SF a friend was kind enough to let me borrow (thanks Dan).

In the future I do plan to run electric, add electric retracts, and upgrade the servos. I am new to the electric stuff, but the performance I want is not going to be cheap. Guess its time to go to work, no more excuses.

Tim Redelman

My Feedback: (36)

Hook 57 []

hook57

My Feedback: (21)

Duh, great idea Chris. I used the epoxy/white balloon mix to make a fillet around the front/back of thefirewall; didn't think about using it for the gap. Scuff the saddle, shape the popsicle stick, and squeegee it in! Should work fine.
Awesomeness! Not me, unless you've seenme hang wallpaper!

Mark

hook57

My Feedback: (21)

That's a very interesting method Sean. With limited knowledge of its properties, I canimagine how it would work; however, I would think that the fuse would need to be heated to the point that the resin changes properties enough(without flowing)that it will take and hold that new "set". Given that the epoxy, or resin, cures by reaction or crosslinking and (I believe) itis a thermoset type of glue/plasticso any change wouldbe minimal at best; at least if done withoutcompromising the glass/epoxy (resin) blanket. I'd be interested in whether you try it. If your's has the twist, let us know how much it looks to be.
Mark

hook57

My Feedback: (21)

I know, you really want me to run that Rossi eh Tim!

hk

zedad71

My Feedback: (1)

[quote]ORIGINAL: hook57

FWIW. This technique is used very commonly in control line stunt.. although not to realign a composite fuse, the method is the same. A lot of guys use carbon fiber composite propellers. One of the reasons they do is because they can re-pitch the prop using heat. Its the same method, though typically they use a bath of boiling water as its easier to control where you apply the heat. So I have no doubts this method would work on a composite fuse as well.

hook57

My Feedback: (21)

[quote]ORIGINAL: zedad71

I'm not doubting it wouldn't work, just wondering how well it would work. I did use heat to "bend/reshape" theflanges on the epoxy cowl of my full scale RV-6 so that the intakes were better aligned. It took a lot of heat, wood blocks, clamps, and oven mits to make it work.
A sailplane fuse, cross-sectionally, is quite a bit different than the P-7. The twist might start at the wing saddle and run quite a ways aft. Then again, the twist may be an offset with justthe wing saddle. A carbon blade is,a single surface (two side airfoil yes, but not tubular, and repitching it is probably not as tricky as "re-twisting" a 54" (give or take an inch) fuse. However, if you're repitching that prop several inches (degrees or whatever), I'd think I'd just by the higher/lower pitched one. Bathing a P-7 fuse in a tub with water hot enough would mean adjusting the hot water heater setting to a point that permits the "resetting" of the fuselage to fill the tub, or some type of tub (unless using a hose to soak the area). I'm thinking some personal safety issues here regarding being scalded. Of course you can heat it it locally with a heat gun, but you still have to reach a point where the thermosetting properties are approached. I don't see how you can reshape it without applying enough heat to "soften" the epoxy. I'm guessing you're nearly boiling the water when reworking the prop pitch. Another thought is resetting the twist so that you don't pucker, kink,or partly collapse the opposite side. If that happens youmy compromise the structure and you're out thefuse. It seems less risky to shim the twist out. These are just my thoughts on the subject, but I am interested in hearing if it gets done.
hook

stuntflyr

I think the reference to pitching carbon/epoxy prop blades was just to link the idea that heated epoxy softens.
You are a smart guy Mark, I on the other hand just do stuff without trying to over think it. However, I've ruined some stuff in my actions!
There is a good chance that softening the epoxy with a heat gun, and having a long moment like the fuselage's wing saddle and stab saddle, one might get it to twist.
I'm with simple, though. Tilt the stab to match the wing and fly the heck out of it.
BTW, in controline Stunt, we often pitch props to 10th's of an inch in several selected stations to get the desired performance, feel, characteristics of the near constant rpm used on tuned pipe engines. They're tuned to each design by flight test and feel of the pilot, so no off the shelf prop is usually sufficient for the top competitors.
Chris...

hook57

My Feedback: (21)

Yep, and that seems reasonable to do Chris, but it's the how hot for how long to do it.
Re: the props, I wouldn't have guessed to the tenth of inches but in retrospect it makes sense since you want/need the prop to bite as much air as efficiently as it can within it's RPM range (again I'm guessing there).
I'd rather not over think it too though so I'm with you, I'll shim it and swim it (I mean fly it). Yet I'm sure it can be done, just seems like a lot of work/risk for the reward. I wonder how much heat it would take and what effect it could have on the P-7 paint too.

Mark

stuntflyr

Oh yeah. If I did it with a heat gun it would, at best, be brown where it should be white!
I just wonder how they got that way.
Chris...

flystunt

I will be digging into my new P-7 in the next week or two. If my fuse is twisted, I will give the heat gun meathod a shot. If it works, I will post pics and details to share the fix. If it fails, I will gladly "take the heat", no pun intended.

The sailplane I did this with was a full fuse Soprano with a carbon/kevlar weave composite fuse. I was amazed at how little heat it took to allow the reset. No where near burning the paint. Helps understand why full size composites are always light colors and spars are temp monitored in some cases.

Sean

hook57

My Feedback: (21)

Great Sean, be sure to let us know how it turns out. If it doesn't take too much heat it's definitely worththe try; I may hold off shimming mine until a day or two before the maiden.
I agree regarding the FS composite airplanes; my brother has a L-IV and a good friend has a Glasair III, both researched the use of darker colors but refrained due to thereportedtempatures (internal) that could be reached while the planes sit in the sun. Given that our RC planes can sit out in the sun for some time, heating up, while at the field without distorting leads me to believe a fair amount of heat is required to reshape them. But then again, in FS aircraft we typically take the conservative approach (even overly so)to things.

I need to finish up the Rhom Air tubing, mount the air tank, mount thenosegear, and hang the pipe. A few little odds and ends and May 7 or 8is looking like the maiden date!

Mark

...

Charlie H.

My Feedback: (38)

HI Guys
I have a number of flights on my Phx 7 now , what a fun bird to fly . The E-flite retracts has given me problems from the first flight on . The nose gear retracts fine setting on the ground , but once in the air , it's a no go ! The air stream seem to hold enough pressure against it and binds it up . The electrics seemed like a good idea at the time , but I plan to pull them out and go back to air . Live and learn !


Charlie

JoeMamma

Finally got some decent weather and got the chance to maiden mine. Three nice flights. Tried all of the standard maneuvers. Even in the wind, it tracks and grooves like an arrow ! Looks like a winner.

Went with EFlite 60-120 size electric retracts. These weren’t a drop-in, but not to much work to install. This is my fourth set of EFlite retracts.........so far so good !

I wanted to pack some foam around the fuel tank, so I ditched the larger supplied tank and went with a smaller Sullivan 12 ounce pylon tank.

I went with the EVO .60NX, and for starters, an APC 11x6 prop. Because I fly from grass, I increased the size of the nose wheel by 1/2�. Final dry weight came out at 8.0 pounds.

I reluctantly dropped about $60 for the optional Jett style muffler and also had to purchase a separate muffler extension. After mounting up the NX and Jett muffler to my Phoenix, and running her up for the first time, it confirmed my reluctance..........it’s just waaaay to loud for my clubs flyin’ field. I didn’t even need to grab my db (sound) meter..........my ears could tell.

I sure am jealous of you fellah’s that don’t have any maximum db requirements at your field.[] Oh well..........it’s a sign of the times and just something I need to deal with. The supplied stock muffler has now been reinstalled.

My only problem now is glow plugs. Every time the engine is run I burn out the plug ??? Makes for some expensive flyin’ !!

Joe M.

kaosfan

Joe, what plug are you using? I used the plug that came with the engine and it didn't even last through the first 14 ounce tank on the bench. And I know I didn't run it overly lean. And what method did you use to get the Hangar 9 sticker off the rudder? Thanks.

wildnloose

JoeMamma,

Curious, what rpm's are you getting with the Evo/standard muffler and 11x6 prop?? And, any idea on how fast it is??

energyman

My Feedback: (2)

Joe M.

If you don't mind, where did you get the Jett muffler extension? I mounted my engine this evening and made the same discovery.

Also, has anyoneexperienced excessive right thrust in their firewall? I followed the instructions, and when snugging up the mount to the firewall and the engine to the mount the right thrust became apparent. The only option I can see to remedy this is to shim the engine mount. Any other suggestions would be appreciated. I would post a picture, but I have already removed the engine and mount. Also, I used the dimension given in the instructions regarding themeasurement from the back of the firewall to the thrust washer on the engine and ended up with a 3/16 inch gap between the spinner and spinner ring. I may discard the mount and install a Dave Brown mount in its place.

Thanks.

Energyman

Tripower455

My Feedback: (2)

Mine had the excessive right thrust too. I put washers behind the mount to line it up. I fixed that problem when I reinstalled the firewall.

hook57

My Feedback: (21)

How did you guys measure/determine that the right thrust was excessive or off? If it's correctly installed (factory) the spinner back plate should simply be aligned (all-around) to the nose right? What I did was to drill the front motor mounting holes first, I then have a an old machinist ruler(cut down to 8")that I rivited to a rectangular piece of aluminum to make a mini T-square. Another old machinist ruler isscrewed to that (forms anH)and I then take measurements going back to the wing leading edge (nearest the saddle) and back to the stab leading edge and compare that what is the fuselage center line. You can use string or a tailors ruler etc.; I also measure to a point on the upper or lower wing surfaces. It takes some time, but if I end up within 1/8 inch all around I'm pretty happy. My P-7 was really good in this respect, the wing saddle or fuse twist is another story!

Mark

JoeMamma

The original EVO plug had burnt out the first time I tried to peak my rpm. It was only at peak rpm for a few seconds as I was attempting to dial in about a 600 rpm drop. Subsequent plugs were O.S. #8's. Each time I ran the engine whether on the ground or in the air I had to replace the plug......very annoying This engine sure doesn't like to be lean.........even for a few seconds. Hangar 9 makes a head shim for this particular engine..........I'll probably get one. Also, O.S. makes a colder plug (#10). I'll probably get a couple of them.

The sticker ? I used Goo Gone.

Joe M.

JoeMamma

Using the Jett, 14,800 peak, then dialed down to 14,200......but too noisey.

Using the stock/supplied muffler 12,600 peak, then dialed down to 12,000. Even at 12,000, she's still burning plugs. On my last flight I dialed it down to 11,400. The plug didn't burn out, but I sure lost a lot of performance.

How fast ? I'd say in the 75-85 mph range.

In my opinion, this high-performance engine is simply not designed to be strangled with a "quiet style" muffler. Like I mentioned earlier, I'm simply going to have to get used to it.

Joe M.

JoeMamma

Muffler extension ? Would you believe I can't remember the brand. My local hobby shop carries a lot of exhaust parts, so I dug through quite a few until I found one that fit. I believe it's a Dubro ???

Excessive right thrust ? What are all of you guys considering is excessive ? I spotted the right-thrust when assembling mine, so I dragged out the protractor and from what I remember, mine had 1.5 degrees offset to the right. I didn't consider 1.5 degrees to be excessive.

Joe M.