Posts: 61
Joined: 3/7/2003 From: Orosi,
CA, USA Status: offline
Please note this review was not written by "bhunn3". I had to post this from my moms computer and forgot to change sign-in. The author, me, is "splais".
Introduction.
I am not a master builder, kit builder, or professional writer. I am an ARF assembler that would rather fly than build. If I could get someone else to do all the work for free, I would. I have assembled a couple of dozen ARF’s of all types and sizes from small to large; and cheap to expensive. This is the first ARF I have done with a “real” gasoline engine and the first with retracts. That being said, here goes.
Initial Impressions (after working on it for awhile).
This is a very nice plane. Built as well as any of the other three $400 ARF’s I have done. It appears well build, straight and strong. Many nice touches like pushrods already installed, lots of mounting blocks, etc, provided; comes with a 5” aluminum spinner that probably will only fit a Zinger prop. Already setup for either fixed or retractable gear without modification. The kit comes with the standard adequate hardware. The manual is very complete and full of neat information. If you use their recommended engine (US41) and retracts (Robart) all the instructions are there.
The covering, while looking nice, is not up to the standard I expect from this high a cost ARF. LOTS of ironing required and it seemed to require it to be done a couple of times. Conversely, the DP Ultimate and PacAero GeeBeeY I had both came with banjo tight Ultracoat covering that required very little maintenance. Monocoat seems to need a lot more work. All the many parts appear to fit perfectly without any sanding/fitting required.
It is not a completely scale plane; but I think it’s one of the best near-scale ARF’s out there. It also lends itself to upgrading if you want to spend the money. I personally thought some of the parts were a little cheesy (like the gear doors and exhaust stacks). But, all-in-all, it’s pretty good copy of the real thing.
Notes & Cautions.
[CAUTION: Hinge Points. If you are not familiar with Hinge Points it is very easy to screw them up three ways; (1) not enough glue, (2) to much glue, and (3) gluing your surfaces rigid I suggest you be very careful, practice and ask a lot of advice before installing. No matter what you do, do not install them and then forget then. You should check every so often to make sure the surfaces are still free until the glue sets up completely.]
[NOTE: Wing Hold Down Screws. Save yourself a lot of aggravation and replace the provided slotted nylon wing hold down screws with phillips head or socket head nylon or aluminum screws. And forget putting pieces of fuel tubing on them. Go to the hardware store and get a couple of small O-rings.]
[NOTE: Quick Disconnect Fittings between wing & fuselage.: The fittings are directional. If you mount the fitting on the red hose one way and the blue/purple hose the other way around. When the wing is disconnected you can plug the two ends of the fuselage and two ends of the wing into each other to keep dust out of the system when not in use.]
[CAUTION: Drilling Prop. Be very careful when drilling your prop if it has multiple hole mounting. You must get the notch in the spinner backplate, prop, prop hub holes all lined up or the prop will not fit properly because of the ridges on the side of the backplate.]
[CAUTION: Decals. Make sure you completely iron down the covering BEFORE applying the decals. You cannot do it after the decals are applied without easily screwing them up.]
[CAUTION: Decals. The instructions don’t mention it, but the Stars & Bars decals are two different sizes! The large ones are for the wing and the small ones are for the fuselage.]
[CAUTION: Canopy Paint Job. The canopy paint job is lousy. When I was installing the canopy and using tape to hold it down, it pulled a big junk of paint off the canopy. BE VERY CAREFUL WITH THE CANOPY PAINT JOB.
What I used, and What It Cost!!! [Jeesh - The first time I added this all up I got nauseous. Seriously, I probably well never build another giant scale plane. There is to much money involved in a plane that can crash at any moment for a dozen reasons. People that fly these things are either crazy or work for Microsoft. PS: I don’t work for MS]
Top Flight 1/5 ARF P-51 469.00 Desert Aircraft DA50R gasoline engine w/Slimline muffler 525.00 Desert Aircraft prop jig 20.00 Futaba 9CAP Tx & R149DP Rx 450.00 Hitec 5625 servos on elevator, rudder, flaps & ailerons (7) 350.00 Hitec 225MG servos on throttle, air valve & choke (3) 90.00 Hitec 425 servo on tailwheel 25.00 EMS Servo reverser Y servo extension 19.00 Misc servo extensions & Y 10.00 Robart air tank, hoses, connectors, air fill valve & pressure indicator 75.00 Robart retractable tailwheel 160.00 Sierra main gear retracts & air control valve 407.00 Supplied pushrods and control horns for elevator & rudder NC Supplied control horns for flaps & ailerons NC MK BB clevis and H9 titanium Pro-Link push rods for flaps & ailerons (4) 76.00 Blue Box Elite forces WWII Pilot 32.00 Dynamic Balsa 1/5 scale K14 gunsight 25.00 1600 NiMah batteries for ignition and Rx 25.00 MPI HD combination charge/on-off/status switch for Rx and ignition (2). 25.00 Tru Turn 5” 3-blade P-51 spinner 175.00 Mejlik 20x12 3-blade prop 60.00 Aerotech 4&7/8”” scale main wheels 95.00 Dubro 1&3/4” tailwheel 4.00 Aerotech Scale Options Kit (purchased but not used) 75.00 Cheveron Zinc Chromate paint 9.50 Testors Misc colors 5.00 Dubro Fuel Valve 15.00 3’ rubber fuel hose 2.00 30 minute epoxy 9.00 15 minute epoxy 9.00 thin CA 6.50 med CA 6.50 1 roll aluminum monocoat 20.00 Socket head screws #2x9/16 1.50 Socket head screws #2x7/16 1.50 Socket head screws #4x1/2 3.00
Total Investment: $3280.50
[cont'd in next post]
< Message edited by BHunn3 -- 11/1/2003 1:15:02 AM >
Posts: 61
Joined: 3/7/2003 From: Orosi,
CA, USA Status: offline
Wing Assembly.
The initial wing assembly (servo trays, flaps, control surfaces, control horns) was straight forward, without problems. Everything fit perfectly. I utilized the supplied control horns; replaced the control rods and clevis’. I am not using any of the kits supplied screws (hate those small flat blade screw heads). I used #2 x 9/16 socket head screws for servo mounting; #2 x 7/16 socket head screws for the doors; and #4 x 1/2 socket head screws for the control horns and cowl. Followed the instructions and drilled and CA hardened all screw holes.
[CAUTION: If you are not familiar with Hinge Points it is very easy to screw them up three ways; (1) not enough glue, (2) to much glue, and (3) gluing your surfaces rigid I suggest you be very careful, practice and ask a lot of advice before installing. No matter what you do, do not install them and then forget then. You should check every so often to make sure the surfaces are still free until the glue sets up completely.]
Gluing the wing halves together was straight forward and messy, as it always is. There are plenty of places to clamp the wing together, so had no problem. The fit was excellent. This is a big wing.
Attaching the wing to the fuselage required a little sanding at the rear of the wing for a good fit. The air scoop mounted without any problem at all and fit well. The front fairing piece was a different story. Required a lot of fitting to get it just right.
[NOTE: Wing Hold Down Screws. Save yourself a lot of aggravation and replace the provided slotted nylon wing hold down screws with phillips head or socket head nylon or aluminum screws. And forget putting pieces of fuel tubing on them. Go to the hardware store and get a couple of small O-rings.]
Fuselage Assembly.
Tailwheel gear doors were a very labor intensive job that took a lot of sanding an fitting to get right, and then extreme care in gluing the hinges. I still didn’t get it as nice looking as I had hoped, and they do not work well at all (bind); but it was my first attempt at gear doors. [note: the retract tailwheel has pulled one of the doors loose and I have given up and am removing the doors and painting the wheelwell in Zinc Chromate color.]
The horizontal stabilizer was spot on in alignment with the wing and all hinge slots were straight. Installation of the elevator and rudder was straight forward with no problems. I used Sig Easy Hinges instead of cutting my own out of the supplied material. The pushrod tubes for all rear control surfaces are already installed and ready to go. Just cut the covering off the ends. They were lined up properly.
The canopy instructions in the manual have proved to be completely inadequate and wrong. The canopy blew off (all 8 screws poped right off) within 5 minutes, the first time the engine was run. The wood is to soft and the screws to small. If you follow the instructions, the canopy is installed to late in the process. By the time you get to it you cannot reach the inside to reinforce the mounting screws. I would suggest installing the canopy as the very first fuselage step. Drill your hole, go inside and put small reinforcing blocks on them, install screws, remove, CA reinforce. Then you can remove the canopy until needed later. Or, make it easy, forget the screw and use RC56 canopy glue.
[CAUTION: Canopy Paint Job. The canopy paint job is lousy. When I was installing the canopy and using tape to hold it down, it pulled a big junk of paint off the canopy. BE VERY CAREFUL WITH THE CANOPY PAINT JOB.
The canopy paint job is very weak. It will come off at the slightest stress. I have a big ugly 2 inch repair on mine. If you have to tape the canopy down, make sure you do not tape over the painted portions. Put something between the paint and sticky tape. Once it starts to peel off, it's hard to stop.
The servo trays fit nicely and the fuel tank install is described elsewhere. Because I needed to move the fuel tank rearward about 2”, I moved the forward servo tray back one former to just in front of the cockpit.
It’s kind of hard to explain but I set the fuel tank up so that it pivots on the first former behind the firewall. I extended the support blocks ¼” to serve as the pivot. The tank plate is held in place with a wedge block (see picture). It all worked out very nice, in deed.
Main Retractable Landing Gear.
The Sierra retractable landing gear was a near drop-in. Fit nicely and mounted up easily. There is a small problem mounting the cover plates. The way the gear is designed, one edge of the mounting bracket sticks up high enough to prevent proper installation of the cover plate. This is amplified by the fact that the screw holes in the plate are not recessed enough.. It must be noted that I received the first developmental set of these gear. I have spoken to Sierra about the problem and it will probably be fixed in later manufacturing runs I hope. In any event it was not hard to get around. I CA’d in a couple of wood strips (see photo) and just monocoat covered the entire unit. If I need to work on it, it will be easy to remove the covering and do whatever I need to do.
Retractable Tailwheel.
The retractable tailwheel unit was very easy to install with no problems at all. Dropped right in, drill four holes, hook everything up.
Air Bottle, valve, fittings & Hoses.
The air bottle mounted easily in the recommended location. The actuation valve was mounted in the recommended location. For ease of access and installation I mounted the fill valve and pressure gauge above the wing. All the hoses and fittings went together nicely without any problems.
[NOTE: on Quick Disconnect Fittings between wing & fuselage.: The fittings are directional. If you mount the fitting on the red hose one way and the blue/purple hose the other way around. When the wing is disconnected you can plug the two ends of the fuselage and two ends of the wing into each other to keep dust out of the system when not in use.]
[cont'd in next post]
< Message edited by BHunn3 -- 10/21/2003 1:43:48 PM >
Posts: 61
Joined: 3/7/2003 From: Orosi,
CA, USA Status: offline
Engine Install.
After much research I choose the Desert Aircraft DA50R gasoline engine. It is a beautiful, light, narrow, and powerful engine in it’s size. It is equipped with a Slimline inverted Pitts muffler designed especially for it.
This engine is small in overall size for a 50cc and fit within the cowl nicely. No hole was required in the firewall for the rear mounted carburetor. It is 7.5” from firewall to cowl face. The DA50 required 3” engine standoffs and a 1” wood block to get the spacing perfect. As you can see from the photos, you must cut out the entire bottom of the cowl, two holes for muffler clearance on the left side and a couple of small holes to reach the carburetor needles. There are no holes on the right side at all. Doesn’t look to bad. I could not figure out any way to mount the ignition battery and CDI unit outside the firewall. Just no room. I have mounted both these items with a certain amount of pain-in-the-butt work on the inner side of the firewall. In order to do this you must be willing to relocate the gas tank rearward a couple on inches (still well forward of CG) and enlarge the existing firewall hole for the sparkplug wire exit, fuel lines and CDI connection.
The throttle linkage is behind the engine and is in a location that needs the tank to be moved out of the way. But with the tank moved already, it allow a pretty straight shot from carb to servo. I utilized the supplied Nyrod with a neat little 2-56 Sullivan quick disconnect ball link at the carb.
The plane comes with a pretty nice aluminum 5” spinner that will hold a Zinger 22x10-12 prop. Don’t know about anything else. I am using a Tru Turn P-51 spinner and Mejlik 20x12 3-blade prop for visual effect and some scale appearance.
[CAUTION: Be very careful when drilling your prop if it has multiple hole mounting. You must get the notch in the spinner backplate, prop, prop hub holes all lined up or the prop will not fit properly because of the ridges on the side of the backplate.]
Radio/Electronics Install.
There is plenty of space in the fuselage to mount the ignition circuit and receiver circuit and keep about 12” of separation. There is limited space on the firewall. Because of this I mounted the CDI unit and ignition battery on the inside of the firewall. I mounted the ignition switch just aft of the cowl in one of the black checks. All of the radio gear is aft of the first servo tray and mounted in the stock location. However I did move the receiver to the bottom of the cockpit floor. I also ran a tube down the fuselage to run the receiver antenna in instead of running it outside the fuselage. The receiver switch is mounted above the wing and about 14” aft of the ignition switch. Both of the switches are the new MPI switch that have the little green-yellow-red battery indicator light, charge receptacle and on-off switch in one integrated unit. Very sweet.
Scale Stuff.
The supplied very semi-scale cockpit kit actually fits pretty well once you get it all cut out and trimmed up. Read the instructions carefully about what to cut and not cut. I painted the entire cockpit area Zinc chromate and the instrument panel flat black. I also painted and installed the Dynamic Balsa 1/5 scale K14 gunsight. Initially it looked cheap and poorly made, instructions were poor. However, when it was finished it looked pretty nice. I made some dummy radio gear to mount behind the seat. The pilot I used was the 1/5 scale Blue Box Elite Forces WWII pilot. It is a very scale pilot. However I don’t play with dolls and he came in about 20 pieces. I had to dress him and put all his equipment on him. Took about an hour just to get him setup. You need to cut his legs off at the knees (ouch) for him to fit. I also cut the rudder pedals off the dash piece of the cockpit.
I found some round stickers to emulate the red-yellow-green signal lights on the bottom of the right wing tip. I was going to upgraded the wing guns and engine exhaust manifold to Aerotech 1/5 scale items vice the supplied parts. But after looking at them I decided it was just not worth the effort as I had already prepared the stock exhaust stacks. I did replace the supplied wheels with Aerotech scale aluminum hub wheels.
I used Windex (dries faster) to install the decals instead of the recommended soapy water and had not a single bubble. Amazing, first time that ever happened, I must be getting better.
[CAUTION: Decals. Make sure you completely iron down the covering BEFORE applying the decals. You cannot do it after the decals are applied without easily screwing them up.]
[CAUTION: Decals. The instructions don’t mention it, but the Stars & Bars decals are two different sizes! The large ones are for the wing and the small ones are for the fuselage.]
Just for info, the supplied dummy exhaust manifold is totally bogus. You have to glue a square wood block about six inches long to the plastic exhaust and then proceed to grind, sand, chew, whatever, ½ of the 1” square block away so that it fits flush to the cowl. I was talking a lot under my breath about how stupid TF is during this little operation.
[cont'd in next post]
< Message edited by BHunn3 -- 10/21/2003 2:52:08 PM >
Posts: 61
Joined: 3/7/2003 From: Orosi,
CA, USA Status: offline
Setup & Programming.
CG. I figure I kind of lucked out here. I did not check anything until I was almost done. I have now done my final CG checks and have found that the CG is just slightly nose heavy. I think I will be able to have it spot on or at least within recommended range without adding any weight at all.
I was concerned that the location of the elevator and rudder pushrods and servo spacing would not allow for a long enough servo arm. This was not a worry. A short servo arm that allowed everything to line up had more than the recommended high rate throws.
The throw required to activate the air valve for the retracts is very short. Even with a short servo arm, I am only using about 12% of available travel.
If you use everything available and install as recommended by Top Flight you will need 8 or 9 channels, at least 8 of which are programmable. I have a Futaba 9CAP. Here is my setup.
Ch1 R-aileron Ch2 elevator on reversing Y Ch3 throttle throttle kill switch Sw-F Ch4 rudder Ch5 retractable main & tail wheel Sw-E Ch6 L-aileron Ch7 flaps on a Y Sw-C Ch8 steerable tailwheel Sw-H Ch9 engine choke (optional) Sw-G
With proper elevator servo orientation a standard Y will operate the flaps. I have them programmed to Sw-C with two position (half and full) activation.
The elevator servos are attached to the Rx with a reversing Y that allows two servo activation off one channel.
The tailwheel is steerable off Ch8. In order for the Robart retractable tailwheel to work properly you must link about 10% left tailwheel to the landing gear switch in order for the tailwheel to clear the fuselage former when going up. I have also programmed the tailwheel on Sw-H so that I can lock it centered for takeoff, flight, and landing. Then unlock it for taxiing, kind of neat. It is programmed to work with the rudder when taxiing.
If necessary, and you can’t figure some other way to do it. You can run a cable parallel to the throttle cable and put the engine choke on a servo mounted next to the throttle servo. If you do this, the only channel left is ch9 on whatever switch you want.
Sierra recommends no more air pressure than necessary (80-100#) I have found that I can get 4-5 good complete cycles with 80# pressure. I am using a small Coleman 12v tire pump ($14) to charge the system.
Sub-par Products. Products I purchased or that came with the kit that I determined to be sub-par and what I replaced them with.
Bad part / Good part Hughes RC “Fuel Jewel” / Dubro Fuel Valve Robart Air Control Valve / Sierra Air Control Valve Robart Fill Valve / Sierra Fill Valve Canopy Screws / RC56 All small slotted & phillips screws / Socket head screws
Final Comments.
This was my first Top Flight ARF. I was pleasantly surprised. For a first-run design, the plane came out exceptionally well. Overall weight – 20.6 pounds. There are a number of labor intensive minor things required in assembling a gasoline powered, retractable, giant scale aircraft; but all-in-all, it went together with no major problems or flaws. This is one beautiful airplane.
Hits. Overall quality & fit of parts Ease of assembly Instruction Manual “Wow” factor
Misses.
Canopy paint job & installation Fake Exhaust Manifold Tailwheel doors Fit of front wing fairing Covering job
Nice touches.
Factory supplied spinner Pre-installed pushrod housings Hints & Tips in the instructions
< Message edited by BHunn3 -- 10/29/2003 8:01:57 AM >
Posts: 61
Joined: 3/7/2003 From: Orosi,
CA, USA Status: offline
Well, here she is all done (sort of). With any luck she will have her maiden flight on Saturday.
A few final comments. I have run the DA50 three times in the yard. You need the choke. It will not start by hand without it. The engine only has about 15 minutes of actual run time on her. It is turning about 6200 rpm with the 20x12 3-blade prop. I'm still on the factory recommended starting settings.
I have completely re-ironed this plane twice now and it still has extensive wrinkles in her. It seems like they just pop up every few days no matter what. I know some like it; but I am beginning to like monocoat less and less.
I have cycled the landing gear numerous times and it seems to be working fine. All systems are go. so Saturday, here we come.
I had failed to discuss one issue because I was not sure what I wanted to do. That was how to resolve the choke issue. I had already mounted the engine and did not want to demount it. The DA50 needs a choke.
Because of the design and angles, a choke servo was the best option and that was what I ended up doing tonight. Took about an hour to complete. I mounted a Hitec 225MG next to the throttle servo and ran another Nyrod parallel to the throttle Nyrod. Used the same type Sullivan Quick Ball Link on the choke arm I used on the throttle. It works very nice. There is a lot pressure on the servo because of the ball and spring tensioner on the choke arm. At some point I am going to have to demount the engine and remove them.
< Message edited by BHunn3 -- 10/24/2003 2:56:21 AM >
Posts: 1179
Joined: 10/1/2003 From: Fresno, CA, USA Status: offline
Thanks a million for the complete and informative posts!! The narrative is very detailed and the photos are quite useful.
Have been kicking the idea of doing the TF P51 around, and your experience has given me both pause ('cuz of the $$$ ) and hope (because a great looking product is possible ).
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Top Flight P-51 ARF 1/5 Scale Review(SHE FLEW!!!) - 
RE: Top Flight 1/5 Scale ARF P-51 - 
RE: Top Flight P-51 ARF 1/5 Scale Review - 
) and hope (because a great looking product is possible 
). 