This is with the stock Motor\Gearbox\Prop\ESC\Battery. These results seem a bit low but based on the last P-51 I just built, this is enough to fly the plane although it leaves little room for error in low speed turns and will be mediocre in performance but should be sufficient for sustained flight.

I will repeat this test with a 2 cell lipo and post the results.

Ok..after thinking about it the numbers above look weak. I'm thinking the gear ratio is wrong. This plane needs 45 watts to be marginal and 55 watts would be mediocre 70 watts decent. So I will be thinking about a BL setup for this plane. So much for flying it with the stock power train

Well at least its got decent servos

So the airframe, servos (3) ESC, TX, 7 cell battery are decent. The motor\gearbox would be good in a GWS Cub.

I'm going to try a "A" ratio gear and see what happens before I give up on the brushed setup.

EDIT..a 8cell pack can be used to get the stock setup to fly!

Ok..this gear is weird. I had to bend it to get it the way I wanted. I have it so the wheels are even with the LE of the wing. The way it is stock, the wheels are in the middle of the wing and would surely cause a nose over.

Well back to the thrust tester and see If I can figure something out.


Here is a HF Mustang flight report from over at parkfliers.....https://www.rcgroups.com/forums/show...&postcount=836

apparently the rx works decent in that one. But still it seems weak to me. I'll look futher into it.

...

Ok, I tested a lot of different props and such and found a 8.5x8.0 gives 56 watts which should work. I'm determined to fly this on the stock power train. I have plenty of BL motors and controllers but were is the challenge in that? I want it to fly of the stock power system and that is what I'm going for. The first upgrade is the battery, not the motor. with the new prop the motor is drawing 7.5 amps which should keep it airborne. I could use a Lipo but were is the challenge in that

So the plan is, stock power Train with larger prop. Power train in this case is stock motor\gearbox, 7cell battery.

Note..there is no mention of the COG in the instructions. From what I can tell, it seems a bit tail heavy which is not good. So I may have to add some clay but well see.

I also have a BL motor and 3 cell set aside for this plane with a power output at 70 watts and eventually it will go in but for now its gonna fly with the motor it came with.

Originally Posted by papabatman

dang modfly you got me hooked and at 80 bucks looks like it's better than Guan LI p-51 so far and close to a art-tec mini p-51 have them both with mods they are great. will wait for the esc surprise cliff hanger
link me to the site in case i want one thanks

I have been biting my tongue to not say anything. But, I really hate it when someone comes on a thread and plays cloak and dagger with some mod. And will only revel the mod to a select few if they kiss his a$$ and essentially make them beg for the mod. Everyone one else shares information openly for which I am eternally grateful. I think we all understand that we use any information at our own risk. Geesh. You would think we were children.

SO, HERE IS THE MOD (I have used it for years):
Take the (arming) button out and solder or splice the red and black leads together and viola' - no more hard cutoff. The plane will simply fly slower and slower until it won't fly anymore (meanwhile, the servos will still operate normally).

AJ
P.S. There are a few cautions to the above mod and I will share them in the next day or two when I calm down.

hmm..wow, ajbaker. You are quite rude. FYI, I have posted this mod in this thread here...https://www.rcgroups.com/forums/show...9&postcount=14.

I don't know why you have taken it on your self to be so rude towards me. The reason I have been reluctant to post this info in a public forum is because of safety issues but I thank you all the same for your post as I will use it to draw attention to the safety aspects of this mod.

WARNING! if you mod the ESC as shown in post#14, there are safety issues that you should be aware of. This mod as shown defeats the prop safety interlock..do this mod at your own risk!

in case it was not clear..this mod converts the HF ESC from Hard LVC to Soft LVC.

Originally Posted by ajbaker

I have been biting my tongue to not say anything.
SO, HERE IS THE MOD (I have used it for years):
Take the (arming) button out and solder or splice the red and black leads together and viola' - no more hard cutoff. The plane will simply fly slower and slower until it won't fly anymore (meanwhile, the servos will still operate normally).

AJ
P.S. There are a few cautions to the above mod and I will share them in the next day or two when I calm down.

uh..yea..thats called "Soft Low Voltage Cut" And now I think everyone reading this is aware of the difference. IMO, any ESC that is limited to HLVC is JUNK!

I decided to quit playing around and get the plane out for its maiden today. When I got to the flight area, I notice there was quite a bit of wind, Id say about 12-18 mph gusting. Not the best time to maiden a war bird but hey, If I waited for wind to stop around here, I would never get to fly Anyway, got the plane ready to go with the 7 cell batt hot off the charger, set it on the runway and let it rip..just as the plane left the ground, it suddenly pitched up and went 10' up before I got it level but it stalled and started to nose down and head for the deck..so I pulled back full elevator and jambed the throttle forward and the plane almost leveled out before it hit the ground it pancaked on the pavement and collapsed the gear but the prop and gearbox were not damaged so it was still flyable. I had added a little up elevator adjustment and apparently it was too much..so I readjusted it with just a touch of down and decided to go back to the hanger for landing gear adjustments..The stock gear as it comes out of the box has the wrong bends in it and would never work. So got that sorted out and went back to the flying area. I have also added some nose weight as this plane is tail heavy. 2 ounces of clay added to nose. So I get it lined up and gun the throttle and up she goes! Looking good this time and it seems to have decent power so I take it way up and do some nice rolls, then a few loops. Then some yank and bank..this plane flys very well once its balanced..I don't see how it could fly out of the box as tail heavy as it is. This plane flys very well in wind, well It should because with the 7cell pack and 2oz clay its hauling 5oz! The plane should no tendency to tip stall and is easy to land even in strong wind. The major thing with this plane is the COG. There is no mention of any COG measurement in the instructions so unless an experienced r\c pilot gets this plane its doomed. In the hands of a beginner and that is the likely customer of this plane, I can't see how its gonna work as it comes out of the box. So this Mustang is now flight worthy and I know were the COG is and I only sustained minor damage figuring it out. Oh..that pavement pancake incident would have broke a regular EPS foam plane in half but only caused some wrinkles small chunks missing from this EPO foam Mustang.

Got a total of 5, 7minute flight in today on the Mustang..Its a very good flier after its correctly balanced and trimmed and I'm pretty happy with it.

Note..all my maidens are on pavement.
This was my first maiden of a GWS 1st Gen warbird size plane with a 7cell pack and stock brushed motor! Well, now that I think about it, I have never tried a ni-mh in any warbird so this was a first for me.

This was the first maiden in a long time that had any damage to the airframe. The gusty conditions really made things very difficult and I'm sure under better conditions I would not have done the pancake move.

Yesterday after walking a lot to position the plane for take off and then walk to the LZ and fetch after landing made me want a steering tail wheel like all my other planes so I added one today.

The plane flew with the stock motor and 7cell pack but it needed a minimum of 1 oz clay in the nose to balance. After flying yesterday several times, I remembered why I don't like ni-mh battery's in a warbird model..they don't last long enough! So I went to fit a 2 cell TP1320PL lipo @2oz in this plane and could not get it to balance without adding more dead weight. It would take another 1.5 oz of clay to balance with the 2 cell for a total of 2.5 oz dead weight in the nose. Well, thats too much IMO so I got the idea to install a 400 speed(380) motor and gearbox as it weighs ~1.50 oz more than the stock 370 + GB. The only problem is the 380 with gearbox is too big to fit..so after some tinkering, decided to modify the 380 G-Box so that it will fit and it does. My goal is to eliminate all dead weight and with this new motor and the right lipo, I should be able to do that and still keep the AUW under 17 oz.
I guess you see were this is going..its going to eventually get a 3 cell lipo

I also like this setup because it has a 4mm prop shaft and resists bending in a nose over or bad landing.

I'm using an Electrifly C12 ESC in this plane.

This is the new radio setup. I like these GWS pico rx as they are lite weight and have a small foot print. This is the rx I ran yesterday and it is working good in this plane. I changed the ESC to a Electrifly c12. Same stock servos as they work perfect. So this finalizes the radio setup. Nice and simple and cheap but works very good.

I will be using the stock HF ESC in my Military J3 cub.

I really don't like the battery mount in this plane either as it has you bumping the wires and ESC, rx etc when field changing the battery so I have an idea on how to remedy that..see next post.

With the new 400 speed motor, this plane will now balance with the stock 7 cell ni-mh battery @3.20 oz or a 2cell TP1320PL @2oz. The lipo sits in a different location from the ni-mh and the weird thing is there is room enough to install both at the same time but we won't be doing that. the point is I found a lipo mount farther forward than the stock location and it does not require the airframe to be cut or modified to use. Check the pics below for more info on this cool mod.

This plane just got a lot better with this mod. I did not like mounting the battery in with the electronics..not a good idea IMO. A 3 cell lipo can also use this location. I happen to have one that fits. Its a lower capacity the the TP cells (850mah) but fits like a glove. So we will have a 3 cell before its over but I want to test the new motor with the stock 7 cell and 2cell lipo before proceeding to the 3 cell. That way I will have the plane mapped out for a battery I want to run be it 2 or 3 cell or ni-mh.

Really nice decals that come with this plane. Got those installed and it looks great to me. So got the newly detailed plane to the flying area and this time taxied to take off position thanks to the steering tail wheel and took off. This combo has about 55 watts which is adequate but nothing to get excited about. Now I notice that I need to trim up a bit so the plane is no longer tail heavy. I'm flying in some good wind about 12mph and the plane handles that just fine. Did several ROG and landings and flew 4 packs through the plane including a modified AH Storm Launcher 2cell 740maH lipo and it did well. I noticed on landing that the LG is too bouncy and the wheels are to small for this rough pavement. With ths motor\lipo mod, the plane is now balanced and flies very well. Does nice rolls even at this low power rate and is less twitchy in the pitch axis..So it can fly off the stock 7cell ni-mh or 2cell lipo. Next I will replace those spring loaded LG struts and wheels. The wheels are to small in diameter for rough pavement. I also will be fitting a 3cell lipo thats going to up the power to 75 watts.

This thing should roll good now! I also have added a 850mah 3cell lipo and EP 9.50 prop for 75watts. Waiting for wind to die down a bit to try it.


I have also just discovered a major difference in the HF airframe compared to the GWS model. The wing "Angle of Incidence" is different from the GWS model. The HF model has a larger angle of attack by a few degrees positive.