P-51 Still Flying

It's still in the air and flying beautifully.  I am running the 10 x 8 Master Airscrew prop.  I know it's a prop for nitro but it fits my prop adapter and works well with the Dubro 3 inch spinner.  I have a 3 blade master airscrew 10 x 7 I have not tried yet, again with a Dubro 3 inch 3 blade spinner.  I have also thought about using the stock 3 blade with the Dubro spinner but it's working as is and since it's such a bitch to balance all that and get the spinner on just right so you do not warp the backplate tightening the screws I have left it alone.  I did nose over a week ago and bent the motor shaft. (botched landing and hit on spinner)  I had a motor shaft I had order from Grayson Hobbies on hand.  It fit perfectly.  Plane is smooth and fairly docile in the air.  

I have read about using the 4s battery.  If you do so I would suggest changing the ESC to handle the extra load.  I have not tried it.  I fly for 7 min on the 3s 2200 and that leaves me battery for approach and landing.  I have some 3s 3000 but have not used them in this plane.  I don't think the extra weight of the bigger batteries would be a factor ether since the plane needs nose weight.  The 4s should make a significant difference in performance.  I am ok with it flying scale and doing aerobatics that the actual P-51 could do.  It is a beautiful plane in the air with the wheels up.  If you get everything just right it is very smooth.

I just updated the receiver today and reset everything up.  I got a Devo 7 transmitter with a Walkera helicopter and the transmitter is sweet. I am out of models on my DX6i so it's buy another transmitter or buy some receivers so I can use the Devo 7.  The lease expensive route was to pick up  a couple of RX701 receivers for the Devo.  Now if the wind will just give me a break I am ready for a test flight.

Dynam Cessna 310 twin engine (ie Grand Cruiser)

I always wanted to try a twin engine RC plane and a sale at Nitroplanes put me in the position to pick one up at the right price.  $149 and it came with a 4 channel 2.4 Ghz radio already installed, a 2200 mah battery and charger.

Is that not a great looking plane or what?

Now, I can get into this plane's story.  The Grand Cruiser ships with small scale like wheels and a spring action nose gear.  This all looks great if you are flying off a smooth surface.  You can see from the picture how tall the grass is.  I needed to put on bigger wheels.  The nose gear was the wishbone type and did not permit a larger wheel.  I picked up a ParkZone T-28 nosegrear from my LHS and replaced the stock gear. With the larger wheels take of and landing was no problem.  This thing has good power.  The props do clip the grass some and you end up cleaning grass clippings and juice off the plane after flying but so far it flies well.  I started out with the 2200 mah 20C 3S battery and got 4 1/2 to 5 minutes on a flight.  Not too bad for two motors.  The battery was quite warm as well.  I ordered a couple of 3000 mah 30C 3S batteries and flight times went up to 8 minutes.  Flights are mixed throttle setting.  This thing flies easy at 1/2 throttle.  Will go vertical easily at full throttle till it almost goes out of sight.  Still battery was pretty warm.  I decided it was not getting enough air flow.  I drilled additional air holes and added an air scoop to the battery hatch,  More air in, it has to come out so I cut a couple of exit holes in the bottom of the fuselage.

The air scoop is actually the blister package from a pink eraser set from Walmart.  I took the battery hatch cover and went to Walmart and starting looking for blister packages that would work.  The eraser set was a perfect fit and the right shape.

After the first test flight the battery was only slightly warm a marked difference from before.  I did have to cut out the air exit holes a bit after a dive from very high built up so much pressure in the fuselage that it blew out the back window.  Thanks to some sharp eyes at the field I recovered the rear window and glued it back in. With these mods the Grand Cruiser is fun to fly, it is fast and will land smoothly.  The sound of those two props is very different and cool.  It always gets attention at the field.

P-51 Update on LG

Quick update, narrower wheels did not seem to make a difference.  Next step is to rework the LG by bending the LG wire forward to get wheels in front of leading edge of wing.  This is such a great flying plane it is a shame that Dynam did not get the LG at the proper angle for take of and landings.  Oh, well I guess that's part of the fun in this hobby.  We always need a challenge.

Update on the P-51 Landing Gear mods - Test Flight

Got a chance to test fly the Mustang yesterday afternoon.  Got in 3 flights taking off on the parking lot.  Two landings were on the grass runway and after a short roll ended in a nose over.  3rd flight I landed on the parking lot and it was picture perfect with a nice roll out and taxi back to where I was standing.  The mod is good for smooth surface but not enough forward pitch for grass.  I think I will try narrower wheels to see if I can reduce the drag the grass creates.

Ready for take off.  Still have not put the LG doors back on.  That will be last if I can figure out how to get a good take off and landing on the grass runway.

This may give you an idea of the grass runway. The story will continue as I look for a way to get this great flying plane to take off and land on the grass.

The Cub Story

Four or five years ago I brought home a PZ Cub.  Nice little Electric RTF with a 27 Mhz radio.  I had been out of RC for awhile and wanted something to play with in a nearby school yard.  It flew pretty well.  I could get a good five minute flight.  I got interference one day on the 27 band and it nosed straight in.  I purchased a new body, motor mount, gear box and prop and rebuilt it.  Had to really watch where to fly because of local interference.  It sit on a shelf for a several years and I thought that technology was getting better so I did an upgrade.  HK 2.4 Ghz radio, 9 gram micro servos, 18 Amp ESC and LiPo battery pack.  Well it flew really well again and I could get 10 min flights on a 1200 mah 2S battery.  Somewhere along the way I put on bigger wheels for landing in the grass.  Still have to hand launch.

The brushed motor didn't last long before it overheated and quit.  Gears were getting pretty worn by then as well.  Dropped in a 300 size brushless outrunner motor and went to a 8x6 electric prop. Wow, now it's a rocket.  I fly mostly at 1/3 to 1/2 throttle.  WOT it can go vertical.  I notice the new PZ Cub is available with the brushless motor.

I decided that with all this new speed I really needed ailerons.  I set about cutting the wing and making ailerons using a couple of 5 gram micro servos on each wing.

That seemed like a great idea. However in practice the ailerons are ether too small or the servos are not quite right.  It could even be that I am disturbing too much air flow under the wings or even added too much weight, but the ailerons seem quite ineffective.  I still had to use rudder to get turns.  Lucky I had a spare wing and with the stock wing back on it is flying great.  A good park flyer for school yard flyer.  Looks great in the air and will slow down for a gentle landing.  Hand launches are easy since it will practically pull straight up. Launches are even easy with half throttle.  I still keep looking at that other wing thinking there has to be some way to make the ailerons work.  I think next try will be to replace the servos with 9 gram micros to get more throw and faster response.  It will be an interesting experiment.  I will post the results from the test flight.

Parkzone Corsair

This Saturday at the field one of our members brought out a Parkzone Corsair. There it was sitting right behind his SE5 WWI war bird. This plane looked new except for the dust and chipped prop.  He had a "For Sale" sign on it with a price of $90.  I had looked at the PZ Corsair at my LHS and even with our member discount it was going to be $180 plus tax.  $90 was half price so I asked why he wanted to sell it.  He simply says he doesn't like the way it flies it is too twitchy for him.  The only Corsair I have flown is the one in the Phoenix Flight Simulator and that one flies really nice.

$90 from my airplane fund and I was mine.  It did not have a receiver, but I had a Hobby King Spectrum compatible park flyer 6 channel receiver on the shelf. After a little clean up, a new prop (Same prop as the PZ T-28 which I had a spare.) and installing a receiver it's ready for a test flight.

Test flight was off our grass runway.  A couple of nose overs till I realized you need to hold UP elevator when you open the throttle.  It took off in 6 feet and was a handful for a minute until I could get it trimmed.  Once trimmed it would fly hands off in a nice straight line.  Handled the wind very well as well.  Power was very good (I don't know if the motor is stock.) using the 2200 mah 3S battery.  Slow speed was really good, stalls flat.  Lands very easy and with a bit of up elevator just before wheels touch will do a nice 3 point and not flip over, even on the grass.  I like this plane it is smooth and really quiet especially flying at half throttle.  Glad I decided to go flying on Saturday.

Dynam 1200 mm P-51 with retracts

Let me tell you about my Dynam P-51 Mustang.  I've had this one for about 2 weeks now.  On the first flight I found that it does not like a grass runway.  It kept flipping over each time I tried to add power for a take off.  Finally I carted it over to the parking lot and took off.  Wow, it took off in about 10 feet.  Plenty of power.  The retracts are really cool and realistic going up and down.  The plane flies well on a 2200 mah 3S pack.  Side note here; I purchased this particular plane because it used these batteries which I have a dozen or so of.  I did not want to have to buy a new size battery, so I have tried to keep the planes to what I have batteries for. Anyway I am pleased with the way it flies.  Landing on the grass was slow and easy with the plane nosing over as soon as the wheels caught in the grass.  Upon reading the forum I realized that Dynam had set the landing gear straight down right about the CG.  I tried moving the gear forward by placing a shim under the back set of landing gear screws and that gave me a few degrees of forward pitch.  Still not enough for grass but take off and landing on a smooth surface were nice.  Last night I increased the pitch by doubling the shim on the back of the landing gear mount.  This gives a more pronounced forward pitch.  I will post the results of the test flight when I can get to the field.  Presumably when it stops raining sometime this week.  Here are some pictures showing the plane after the mod.  

Landing gear now has a forward pitch.

 The wheels are now slightly forward of the leading edge.

Notice I had to trim the landing gear well in the wing a bit to compensate for the forward pitch on the latest mod.

Landing gear door will be reattached to the gear after the test flight.

Other things I did to the plane was to change out the stock 3 blade prop for a two blade 11 x 8 APC thin electric prop, change spinner to 2 blade SIG and change the prop adapter to a Great Planes adapter for a 4 mm motor shaft.  The stock prop adapter was a off center and caused a great deal of vibration.  A real problem when you have a 3 inch spinner.

Radio Rx is a Orange Spektrum compatible 6 ch from Hobby King for about $8 plus $3 shipping.  Tx is a Spektrum DX6i.  The plane was purchased from Grayson Hobbies in Atlanta for $109 with $12.95 shipping.  What a deal, my last P-51 was a Top Flight nitro kit.  I spent months building and finishing the plane and this one went together in less than an hour.  Prop, adapter and spinner from LHS here in Louisville all for about $15.