Winter Build 2018/19: Hangar 9 P-47D Razorback

wilmracer

I build things that fly (sometimes)
Mentor
Plans to maiden are essentially one week from TODAY while at SEFF in GA. It's why I'm pushing so hard to finish her up. I leave on the 30th. Kind of fitting too because it will be my birthday. :)

I didn't realize that! Even more reason to party it up at SEFF!
 

F106DeltaDart

Elite member
That rivet detail and the cockpit detail are looking spectacular! Really gives it the look and feel of the full scale bird! I will be eagerly awaiting the video of the maiden flight.
 

willsonman

Builder Extraordinare
Mentor
Ok boys and girls. I'm calling the main build FINISHED! There are still a few more rivet details that I need to hash out on the hatch and canopy. I was just too tired last night. All the flight controls are working but I still need to setup my rates and expo. The elevator uses two servos so I ended up using a second channel for that since the horn placement was opposite. I could have used a reversing Y but I did not have one on hand and I had a spare channel, which brings the grand total to 13 used on this model. I did do a full systems check and everything is still working. I did get the antenna covered in foil too but did not have it installed for these pictures. OOPS!

In summary, the few remaining items are as follows:
Complete hatch/canopy rivet details and a few other minor details as well
program throws and expo
Get an idea of AUW and check CG
clean up a few spots of paint overspray/mask bleed and fully clean and detail the surface
Fabricate the transport cradle

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wilmracer

I build things that fly (sometimes)
Mentor
Spectacular work brother. This turned out even better than I had anticipated, and I know you always do great work. It is going to be so much fun watching people react to it next week :)
 

Mid7night

Jetman
Mentor
SO AMAZBALLZ!!!

Best of luck on everything between here and FFOH, because I CAN HARDLY WAIT to see this flying piece of art in person!!

Well done my friend!
 

F106DeltaDart

Elite member
Beautiful work! It’s great to see it all come together, and the final result looks amazing! I can’t help but think how this would look with a 4 blade though. Have you ever thought about doing a “display prop” like some of the larger gas warbirds have?
 

willsonman

Builder Extraordinare
Mentor
SO AMAZBALLZ!!!

Best of luck on everything between here and FFOH, because I CAN HARDLY WAIT to see this flying piece of art in person!!

Well done my friend!
Thanks! I'm hopeful that the runway conditions will be better at FF this year to fly this model. After last year, the amount of hope is small. Even if the flight line is WIDER (needs to be IMO) the canvas runway has its own issues with larger heavy birds. The harvested field is just too rough on its own. The temporary road, plastic, whatever, runway was quite bumpy, narrow, and frankly too short for a bird this size. If nothing else, she will be on display.

Beautiful work! It’s great to see it all come together, and the final result looks amazing! I can’t help but think how this would look with a 4 blade though. Have you ever thought about doing a “display prop” like some of the larger gas warbirds have?
I have actually thought about it. I've looked into a couple of static props but nothing quite large enough without spending some serious $$$. Beila props are stupid pricey but the FlightLine stuff looks nice... but small.
 

Tench745

Master member
Thanks! I'm hopeful that the runway conditions will be better at FF this year to fly this model. After last year, the amount of hope is small. Even if the flight line is WIDER (needs to be IMO) the canvas runway has its own issues with larger heavy birds. The harvested field is just too rough on its own. The temporary road, plastic, whatever, runway was quite bumpy, narrow, and frankly too short for a bird this size. If nothing else, she will be on display.


I have actually thought about it. I've looked into a couple of static props but nothing quite large enough without spending some serious $$$. Beila props are stupid pricey but the FlightLine stuff looks nice... but small.

Carve or print one? Display props don't have to be airworthy...
 

willsonman

Builder Extraordinare
Mentor
I've thought about it. I'll work on this after SEFF.

Completed the Hatch riveting and a couple of other small details.
IMG_E8047.JPG IMG_E8048.JPG

The stock wing bolts... yeah, they leave something to be desired. Trusty nylon bolts from Lowe's cut to length work much better.
IMG_E8049.JPG

Programming of the control throws is done along with some basic expo. I setup high rates and I can add some low rates later.

The fuselage cradle is basically done. 3/4" scrap foam I had laying around. I constructed the box using gorilla glue and made cutout templates from remnants of the reference printout. I then transferred the shape to the foam and cut the recesses for the fuselage to sit. I used tome automotive double sided tape to adhere some foam pipe insulation to the cradle and covered them with pieces of microfiber cloth. I used 3M Super 90 (strong hold) to tack the edges onto the cradle. No glue where the airplane would sit. I don't want any residue to bleed through and get on the aircraft. I then put the hook side of some velcro on the bottom. This stuff will stick to most car carpets and will help prevent the cradle from sliding around. Loop strips were applied to the sides for straps. When the fuselage is in the cradle, some smaller pieces of microfiber cloth go over the fuselage and the straps hold it in strong. I need to create a storage box inside the base for the bombs, fuel tanks, and spare parts specific to this airplane. I'll use foamboard and hot glue for that. I need to cut a couple of recesses into the sides to clear a bit of room for the inner gear door flaps. This will allow me to assemble the airplane in the cradle, put the gear down, and then remove it without things being too awkward.
IMG_E8050.JPG IMG_E8051.JPG IMG_E8052.JPG

I did a weight and CG check so I'll run that down next. With my X2 3S 5800mAh packs (series) and a 3S 2200mAh graphene pack for the sound module, the CG sits RIGHT AT the aft CG location. I'll likely throw in another smallish 3S pack for a little ballast to make her more nose-heavy on maiden. So, all that planning of weight up front for the sound module and dummy motor along with the addition of the OCWG and additional internal sound board beneath the battery tray... yes, it really does offset the weight of the aluminum on the tail. The AUW with the batteries is 15.2 pounds. She is a heavy warbird after all but I want to point something out. The recommended max weight from Hangar 9 is 13 pounds. So, I'm over by 2.2 pounds. Keep in mind that the Top FLite Corsair I built last year was overweight by 3 POUNDS with a smaller wing span and wing area. Let's compare wing loading:

TF Corsair: 42.8 oz/sq.ft. or 19.4 cube loading (max 14.2 recommended)
H9 P-47: 42.4 oz/sq.ft. or 17.1 cube loading (max 15.1 recommended)

Given how well the Corsair flew, I have absolutely no concern about the weight of this aircraft. Yes, my stall speed will be higher. Given the good habits of P-47s in general, I'm really not worried about this one getting off the ground.
 

wilmracer

I build things that fly (sometimes)
Mentor
I've been thinking a lot about your weight this AM and I'm really surprised she isn't heavier than that. I will put mine on the scale and CG meter before we leave so we know exactly what mine is flying at, but mine was already 13.5lbs BEFORE I added the retractable tailwheel. In the thread for the gas version it seems most guys are coming in around 14lbs on takeoff. With all the added detail and parts you really didn't add all that much weight. . I really don't think there will be much of a noticeable difference in how ours fly, particularly since we both like to fly warbirds "scale". Yours will just look better :cool:
 

willsonman

Builder Extraordinare
Mentor
Yeah, Carl. It bodes well for all the modifications. Again, planning ahead to use weight smartly, you can pile on some fun details without sacrificing much performance. Each subject is different, of course, but you always have options and you weigh the cost of each one. I'm super pumped about this project being revealed to the guys at Horizon. I'm fairly confident that they will be impressed that my build is so comprehensive and only requiring a one pound sacrifice.
 

willsonman

Builder Extraordinare
Mentor
Final touches on the cradle. I added a storage box and it has ample room for what I need to put in there.
IMG_E8054.JPG IMG_E8055.JPG

Final cleaning and there was STILL polishing compound coming off. Seriously, this stuff gets everywhere. Cleaned with a de-greaser, then window cleaner, dried with a clean cloth, then application of Sheila Shine.
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willsonman

Builder Extraordinare
Mentor
Update: today is my birthday.

With that out of the way... I have a maiden flight report to give.

The initial takeoff attempt was odd. I suddenly lost power with the motor glitching. Looked through the cowl and saw that a motor lead had come out of the Castle ESC. Pulled the cowl off and noticed the tanes for the bullet plug were crushed a bit so I opened them up and it was a nice and snug fit.

Second attempt was a success. She took off nice and level and needed a bit of up elevator. A good sign. There was also need of some right roll to trim her out but she was fine after that. Landing was uneventful with full flaps and the taxi back was a nice scale touch.

I want to note that the prop was making an odd vibration and sound at full throttle. I’ve had this happen before when there is a pressure cavity between a prop and dummy radial. After switching to an APC prop I determined that the Flight prop was not balanced. So, I need to properly balance the prop before the next flight.

Carl used an IR thermometer to measure surface temps in the sun. On average, they were about 10 degrees below the surface of his stock airplane. I do think I will eventually add a BEC as well. The higher voltage of the castle ESC seems to be problematic on the smaller servos for the pylons and the landing light. For now I can in plug them but it is something to note.
 

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