500 size Apache Gunship Build

[F106DeltaDart]

Over the past couple of months I've started working on another scale Heli to join my AH-6 Little Bird, a 500 size AH-64A Apache Gunship. This is all based off of the old (discontinued) RC Aerodyne scale fuselage kit. This includes a custom main gear to fit inside the narrow fuselage, and frames that lower the tail boom to the scale location. I am also using the RC Aerodyne raised tail kit, that allows me to use a torque tube drive setup. In addition, I will be using the scale 4 blade head and offset tail rotor kits from CNC helicopter. I am also planning on a fully detailed cockpit.

One of the first mods to the airframe was to move the tail rotor fairing to the correct side. The kit included the tail rotor on the left side, while it is located on the right in the full scale version. To do this, I cut out the fairing with a Drexel cutoff wheel, and glued in a styrene backing. The gaps were filled with bondo and sanded to blend the surface. The fairing was then painstakingly reconstructed from styrene on the correct side.



The next thing was to add in a few missing panel lines. Thin panel line tape was applied to all of these missing lines:



These were then painted over with thick auto body primer, and then the tape was removed to leave the panel lines. In addition, various handles were added across the airframe by bending thin steel rods. Here is the current configuration with test fitting the mechanics in the fuselage.

Next up will be more airframe detailing including more handles/antennas/sensors, and a start on the cockpit detail.

 

[makattack]

Very nice!

I love the detailing so far, and it's quite an ambitious project. I was at my flying field a few years ago when a member pulled up with this gem of a scale zulu cobra or viper(?):

https://goo.gl/photos/WoZA8kN41NEgdkD66

Unfortunately, I couldn't stay to watch him setup and maiden it, but really wished I could have! I hope to see it again, but haven't yet.

 

[F106DeltaDart]

Thanks, that Cobra looks awesome! It is really rare to see a Viper modeled for sure! I have a Whiskey model on the bench as a future project.

 

[F106DeltaDart]

Made a bit more progress this weekend in the Apache. I got the landing gear attached and added on more airframe details, as well as starting the cockpit detail. I added some more of the various handles around the helicopter, and the antennas and fences behind the rotor mast.




Quick test fit of the weapons wings.

Some of the cockpit detail so far. The seats, pilot, and instrument panels were all 3D printed and painted with autobody primer to smooth out the surfaces.





Next I'm hoping to make the flare dispensers, start on the rivet detail, and move forward with the cockpit and window installation.

 

[ElectriSean]

Beautiful work

 

[F106DeltaDart]

Thanks Sean! One of the more difficult issues that I am trying to figure out is battery placement and ESC cooling with the full cockpit tub installed. Also need to do a bit of trimming on the mechanics so that the canopy actually fits with the mechanics installed.

 

[ranger351]

Looking good! I may have missed them in another post but could you add some pics of the AH-6? Would love to see that one!

 

[F106DeltaDart]

Absolutely, here are a few photos and a video of the AH-6 flying. It is easily one of my favorite models to fly .

 

[F106DeltaDart]

Another update on the Apache. I've been busy adding rivets. LOTs of rivets..

 

[F106DeltaDart]

More rivets.. almost ready to start painting. Next I have to add the flare canister, a few more smal, surface details, and attach the weapons. I am also trying to figure out how I will provide some cooling to the electronics. I am thinking that I might use some small computer fans behind the engine intakes to blow air into the mechanics.

 

[Tench745]

I love detailed scale builds. What are you using to do the rivets? Could you get a picture with a known object for size reference?

 

[AkimboGlueGuns]

Pretty schnazy heli! I love it when people model cockpits.

Also, nice F-80! Is that an EDF?

 

[F106DeltaDart]

Thanks guys, the rivets were done with the Starwood scale models rivet kit, which includes a glue solution with a syringe that has different tips for various sizes of rivets. Tench, here is a photo of the fuselage next to my radio, the fuselage is about 41" long from the nose to tail.

I didn't get much done tonight, but I did manage to paint the panels and add the wire cutters on the landing gear. I'm also working on adding the laser warning receivers. I added the one on the boom, but need to make 2 more that will go up by the mast. Hopefully I can get a bit farther on finishing the surface details tomorrow.

 

[F106DeltaDart]

Pretty schnazy heli! I love it when people model cockpits.

Also, nice F-80! Is that an EDF?

Thanks! Hoping to get the cockpit finished up soon. I love building detailed cockpit, but I tend to give them more attention on my Helis since they are generally much more prominent than on planes. Also, the jet is a T-33, the two seat version of the F-80. It is going to be my first 10S model, running a 90mm EDF, 1600mm span. It is going to be a very special build to me, as my dad actually flew in one when he was in the Air Force. I'll definitely post a thread when I get around to starting that project!

 

[AkimboGlueGuns]

D'oh

Should've spotted the two place canopy

 

[F106DeltaDart]

Today I worked on the setup for the mechanics. The main objective was to substitute the stock align shaft to move the rotorhead lower similar to the real Apache. I did not however, realize how much of a pain this would be. The rotorhead that I bought for this project was a custom scale Apache from CNCHelicopter, which I now would not recommend.. The first issue was that the ball links on the head took a lot of force to move, not free to move as they should. So, I decided to change out all the linkages to Align hardware. While removing one of the ball links, the screw snapped clean off, inside the threaded hole. Trying to remove this lead to the discovery of more issues, including cracked parts, and poor tolerances. So, I elected to use the Align four blade head instead. I had to cut down the tip on the DFC mainshaft to get it to fit, and shrink all of the pitch links, but I finally have something that looks a bit more reasonable. Here are a few photos and a comparison of the old head position and the new. Also, couldn't resist a test fit with the blades attached..
Old position:

New position:

 

[Konrad]

Stiff ball links, in my day (Schluter, Gorham Model Products [GMP] and Kalt) we would polish the spheres of the ball joint with 1200 grit.

Have you been able to contact "CNC Helicopter" about the manufacturing issues you fond with the head? We all make mistakes, I’m curious to see if "CNC Helicopter" is a stand up firm.

I assume you will be flying this like an FAI ship rather than a Bumble Bee on acid (AKA 3D).

All the best,
Konrad

 

[F106DeltaDart]

Their return policy is only within 10 days of receiving the item, period. And even then, they only refund 90%, and make you pay for return shipping. They won't be getting my business again for sure.. Good tip on the ball links though. Since I had plenty of the Align versions as spares, I just elected to use them since I trust them on rotorheads and have had good experiences with them. And yes, there will be no 3D flight in the future for this machine, just scale flying. It's too much risk to both the aircraft and my investment, and there is no way that the airframe and thinner blades would take the G very well anyways. Besides, it would just look ridiculous with all of the scale work I've put into it. Best to fly it like the real McCoy.

 

[Konrad]

Sorry to learn about CNC Helicopter's policy. Have you actually asked? Often times these policies are written by and for the legal departments to limit the firms liability. In practice honorable firms often will address customer's concerns outside of the posted notice.

I thought the Apache could fly inverted or at least perform a loop (this is about the limit of my 3D skills).

As you mentioned blades, could you go into some detail as the shape of those tips. (I recall that you are now working at Bell) When I was last in school the hingeless rotor was just being explored.

All the best,
Konrad

 

[F106DeltaDart]

The email is out, waiting on a response. As for the Apache's performance, the answer is yes and no. It can loop and roll no problem. Inverted, not exactly. I doubt they can actually pull more than a degree or two of negative pitch, so they can go there transiently, but not sustain inverted flight. There are no full scale helicopters that have that capability as far as I know. Once the rotor is very negatively loaded, you are most likely to end with a boom strike.

The blade tip design on the real Apache is two fold. It allows the rotor to be more efficient in high speed forward flight, where the advancing blade may reach Mach 1. Like a fixed wing, the swept tip delays the rotor from hitting its critical Mach number, avoiding much higher drag. The second, is that the swept tip suppresses rotor noise in cruise by the same method. The reason for tip on the model rotor is mostly just for looks. They were one of the only scale sized 500 class blades out there.