Hi Heat Got the Big Jenny Today - Again!

[LBJ]

Saturday, July 11. Nothing left of it this time. The temp was WAY over 100 and it melted the velcro adhesive holding the flight battery in the pilot's compartment. I did a barrel roll and out came the battery. Boom, just like that. I just had to watch it go into the ROUGH, and I do mean ROUGH. Totaled it to say the least. Glad I never added the new landing gear! Can save it for another project or sell it off. I might even get another Jenny, who knows? Didn't take any pics, but not much worth looking at. LBJ

Was making the third flight today at our club July 4th fly in. The temps had to be 100 degrees or very close to it. Making some touch and goes and on the third go I cobbed it and NOTHING but a galling sound from the engine. I hesitated for a second rather than nosing over immediately. The plane came down with a bit of damage, but actually not too bad for what it could have been. A slight rebuild on the lower leading edge where the wheel came up and I will either straighten out the gear or do a rebuild.

Ed Couch figured I got hit by the thermal overload cut out. We brought it back to the pit and tested the motor, Everything worked fine. So, just got too hot out there.

I learned that it is not possible to make the plane TOO COOL as far as cooling holes for the motor, battery, and ESC's. I am going to cut the front of the cowl some to let in more air for sure. Won't really detract from the looks but will very likely save the plane from another such episode. The air can pass thru and out the front cockpit which has the windscreen which might act as a pressure cowl to help suck the air outside the model.

Monday 7 July. I didn't got elaborat eon the wing repair. Just removed the covering and took a look. Seemed easiest to just straighten out the leading edge and hot stuff it. I pulled the ribs into pretty good position and hot stuffed them. Added some cross bracing on the ribs, epoxyed everything with some thinnned down 30 minute, and let it dry. Covering was pretty easy. Turned out nice. Now I need to get to the landing gear, open up some holes in the front of the cowl, and see what else I can do to get more air moving thru there.
http://img.photobucket.com/albums/v228/numskin/IMG_0335.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0336.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0337-1.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0348.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0355.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0357.jpg

[steve1814]

.

I learned that it is not possible to make the plane TOO COOL as far as cooling holes for the motor, battery, and ESC's. I am going to cut the front of the cowl some to let in more air for sure. Won't really detract from the looks but will very likely save the plane from another such episode. The air can pass thru and out the front cockpit which has the windscreen which might act as a pressure cowl to help suck the air outside the model.


Ouch! Sorry to here that! But she does look repairable.

As far as cooling, I used my dremel and sanded out the scale vents/slots just below the fake exhaust on the cowl sides. It was really easy to do and the fiberglass is doubled in that area as if you are supposed to open them up. I cut out every other one so not to make it too weak - just in case. You can't even tell I did anything unless I actually showed you. You should give that a try.

Cheers,
Seve

[LBJ]

Yo Steve, That's prolly what I had in mind by looking at your details. I know it needs to be more than what I have done. I did add some cooling outlets next to the ESC, but I will open those up dramatically. Yep, she's repairable. Not a bad crunch. I've seen worse. I will try to fly more in the morning hours rather than the heat of the day. The older guys (not me I'm only 57) were starting to wilt a bit. Hehehehe. I was ready to go home by 2:30.

[steve1814]

Lane,

Great job on the repair! Let me guess: cub yellow Ultracote...:D the Jenny was a great trainer in her day, you can just say the patch is scale "detail":D:D

I need to get the battery box redone so I can fly here more. I did order this
http://www.harborfreight.com/cpi/photos/95800-95899/95803.gif

from Harbor Freight - I figure it will hoist the Jenny really easy and I won't have to have a ladder to bring her down. For $9.99 I got two!

Cheers,
Steve

[LBJ]

That's a good hoist system. I wish I had that option. I have to take it apart and haul it up and down the stairs.

I cut out every other vertical tab on the front and opened up the side louvers next to the ESC. I hope this makes a big difference in cooling.

http://img.photobucket.com/albums/v228/numskin/IMG_0360.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0359.jpg

[steve1814]

That's a good hoist system. I wish I had that option. I have to take it apart and haul it up and down the stairs.

Ugh, I'd hate to have to carry that monster up and down stairs, I'd have so much hangar rash that mine would look like the trainer for all the flunkies!

The mods look great, and should get you some additional cooling. I remember living in Alabama with all that humidity and heat (although not as hot as where you are) I couldn't stand it, you always felt like you were in a sauna and there were only two seasons - hot and cold. We still get a couple of weeks of humidity up here in Maryland, but nothing like down south. My electronics are very happy to be flying in this weather:D

So other than the Cessna, what's the next big plane you are looking at convertin'? I bet Ed's DC-3 has you looking for one yourself;)

Cheers,
Steve

[LBJ]

Steve,

Cool weather all year would be nice, for sure. We get 2 weeks perfect temps in the spring and two in the fall and that's about it. Sometimes a cool front and thunderbusters move thru in the summer and that's good for a day or two. Last weekend it was 100 degrees easy. That's rough for 6 hours at a fly in.

I currently have a RC Guys Pitts with G-38 power in the works; an AZ Model Aircrafters 1/4 scale Tiger Moth which will be G-20 powered; and have been trying to get a KMP P-38 E-Power going but gave up on Sierra getting the retracts for me. I finally had to go to Robart for them. I would have had it flying by now otherwise. That cost me about 4 months waiting on nothing. Going to use Turnigy 60 size motors and 80 amp ESCs on that one. Each boom will have its own 6S Rhino pack for power. Not going to doll up up other than go with a new paint scheme over the stock silver. Got a ton more ARF's just sitting there. Ed's C-47 is enough for me just to watch. I don't have the hauling capacity for it. Hopefully he will fly it this weekend at a local warbird meet.
http://img.photobucket.com/albums/v228/numskin/IMG_0330.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0243.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0249.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0214.jpg
http://img.photobucket.com/albums/v228/numskin/IMG_0297.jpg

[Rodney]

Just remember that the exit hole must be at least 3/2 as large as the inlet to be efficient, twice as large is even better. You can get by with quite small inlets if your outlets are large enough and the airflow channeled over the parts that need cooling.

[steve1814]

WOW!:eek:

You'll definitely keep me entertained for a while! -keep us posted on the details! I have PAM 1/4 scale T/M that has been in the box for about a year - even got custom made L/G for it that have robart struts built-in. I don know why I don't build it...on top of the other models that I have waiting...:rolleyes:

Sorry to here about sierra with the retracts, I here they make some really nice units.

Cheers,
Steve

[LBJ]

I won't get the new gear set in from Maxford in time for this weekend's War Birds meet, so I cobbled the old one together with some solder, wire, and hammering. I'll get one flight out of it for sure. May hold for more, may not. Not running the aluminum trim pieces since I'm planning of changing the old one out anyway. Looks OK.

Ed Couch found some 9 inch vintage style wheels at the LHS that might look good on the girl. These are 7 inches already. I think he said they were Williams Bros wheels. Not cheap at $40.

[LBJ]

http://img.photobucket.com/albums/v228/numskin/IMG_0361.jpg

[lmopar69]

OUCH!

That REALLY sucks.

[Conehead]

Oh NO!!!!!!!:(:(

That is terrible.
Conehead
Orrin Eldred
Honor, MI.

[LBJ]

Maxford has these on sale again for $602 Free Shipping!!! Man, tempting.

I just took a look at salvage operations. I have a working motor, ESC, and receiver. Haven't checked the servos, but they may have come thru OK since the plane absorbed most of the energy.

The motor will need new bearings from the feel of it but that's pretty minor. May even have a set handy.

That's a recoup of about $300. So the loss is down to about $700 I suppose. But who's counting? Right? Hahahaha

Salvage Parts
http://img.photobucket.com/albums/v228/numskin/IMG_0363-1.jpg
Trash
http://img.photobucket.com/albums/v228/numskin/IMG_0365-1.jpg

[steve1814]

Man that is hard to look at - I guess she quit where you couldn't recover, which is a shame. :(


She is a great flying bird, but with so many new ones out there it is tough decision although free shipping does make it a VERY good buy-and you now have spare parts.... ;)


Cheers,
Steve

[LBJ]

Saturday, July 11. Nothing left of it this time. The temp was WAY over 100 and it melted the velcro adhesive holding the flight receiver battery in the pilot's compartment. I did a barrel roll and out came the battery. Boom, just like that. I just had to watch it go into the ROUGH, and I do mean ROUGH. Totaled it to say the least. Glad I never added the new landing gear! Can save it for another project or sell it off. I might even get another Jenny, who knows? Didn't take any pics, but not much worth looking at. LBJ

The battery that left the plane was the receiver battery. When it left, there was nothing to do but watch. Zilch. From about 100 feet or so. I looked at the on -off switch and the wire leads. Even if I had tied it off, the end of the lead that was tied to the switch had one of the small contact fingers pulled out. So, that would have broken the contact in itself. So, all in all, I should have used velcro AND some more velcro that was SREWED to the panel to keep the battery in place. Expensive lesson and I firmly believe it was due to the extreme heat at 109, someone said.

[steve1814]

Oh, I thought your ESC gave out again. :o


Cheers,
Steve

[peppern75]

Battery leaving the airplane. It is not good.
Sorry to see the plane in that condition. Cry a tears for you...........
Man, that is hard to see the airplane in that condition. You need a lots of glue..................

[LBJ]

I am leaning toward getting another Jenny since they are on sale and free shipping. Same deal I got last year. Hard to pass up.

And, since all the components are still working, nothing else to buy, really. I WILL strap in the batteries this time around. I gotta go and redo all my other planes as that is how they are all done. Yikes.

[Ed Couch]

Gentlemen

Take a look at this picture of Lane's Jenny taken Saturday. You will see a dark object just aft of the cockpit area. Bet you can't guess what that is. I found it at the Thunderbirds home site. Murphy's law working in spads. Great shot though. ed

[LBJ]

naw, that's just a fly speck. Hehehehe

[Tipover]

Imagine trying to get a picture of that departing. How many tries it would take? Was that a frame taken from a video?

A friend recently found out that attaching the receiver pack to the hatch of a Seagull Spacewalker was also a very bad idea. Hatch came off, I was flying...sickening feeling :(

Kevin

[Ed Couch]

No video, he just happened to shoot the photo at the right time. I'm sure it nothing more than a quirk shot. As with Murphies Law, S#$% happens. You could not pull that shot off again if your life depended on it. Sure was neat though. Removed all questions and speculations as to why Jenny died. ed

[Tipover]

Now I'm curious, did the motor throttle back after the battery ejected, fail safe set? Has the motor been checked for bent shaft or magnet damage? Not to many big outrunner crashes have been reported. I'm wondering what the big electric motor crash survival rate is.

Kevin

[Ed Couch]

The motor was turning when he hit the ground but I think it was windmilling and not under power. If I remember correctly Lane stated that everything looked good but he was going to replace the bearings just because.ed

[LBJ]

Motor and ESC are ready to run again. Took the motor apart and checked the bearings. All three felt very smooth. I deburred the shaft and re assembled to test run. Everything ran straight on 6S for testing (no prop). I will run it again on something one day. Spektrum receiver tested good and I will use on another model for sure. Never did find the errant battery pack. That was a brand new NiMh 4200 battery!! Crap. Oh well, the 2 6S Rhino 4900's were pretty well bent, but may work for bench use. Haven't looked at them yet. That's 2 6S 4900 LiPo's and one 4200 NiMH to the tune of say $275 with shipping and all. Ouch!