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Posted by flipsideflyer | 07-05-2018 @ 05:52 PM | 10,676 Views
Like many other R/C airplane designs on the market today, this particular model was only available for a short period of time. That’s unfortunate. This plane makes an excellent platform for the venerable, old-but- reliable Zenoah G-62. Having a couple of G-62’s sitting around with nothing to do, I randomly picked the Hangar 9 Inverza 62 for one of my building (assembly?) projects. As of this writing, I’ve logged nearly thirty flights and couldn’t be happier. In fact, it’s one of the sweetest flying giant scale planes I have yet to fly. It’ll climb vertical with ease; handles all the maneuvers that I know how to throw at it and it lands and takes off like a trainer. An added bonus is that its flight characteristics, both upright and inverted, are nearly identical. As I said, it’s truly a sweet flying airplane!

Here is a summary of the modifications I made to accommodate the G-62 engine and to allow me to continue flying from sod and/or unimproved runways.

1. Removed 1 ½ inches from the front of the motor box. First, however, I transferred the original equipment manufacturer (OEM) engine thrust lines from the kit-installed firewall to the outside of the motor box before actually shortening the box. These lines served as a reference for the new firewall installed later. I used a box-cutter to remove the 1 ½ inches from the nose of the box...yeah, it’s soft ply!

2. Cut and installed eight (8) small, triangular pieces of ply to fill in the structure on both the left and right sides of the motor box. Then added a 1/8” sheet of ply over the top of them in order to beef up the sides of the motor box. I then installed a 3/8” ply firewall, adjusted to match the original thrust line, added hardwood triangular stock to all the stress points, pinned and fiber glassed the firewall at the side rails and fuel proofed the section of the fuselage, motor box, etc.

3. Because I don’t run a tuned exhaust, I have no need for the “tunnel style” landing gear. Instead; I can benefit from a stronger gear-mounting platform. TNT manufactures a “flat style” gear that serves as a perfect replacement. To beef up the mounting, I installed a 3/8” ply platform on top of the OEM aluminum rails. The ply platform runs from side to side and from the front bulkhead to the second bulkhead. In order to install the new platform, it was necessary to first split it down the middle (using a squiggly cut) and notching the sides to clear the OEM hardware. I epoxy-glued the entire platform in place, including along the squiggly center cut.

4. Once the epoxy glue had set, I installed a rectangular piece of 1/8” ply to fill the gap between the aluminum rails on the bottom of the platform, again using epoxy glue. I then used foil-backed duct tape to cover the entire gear area...including the small openings and running across the entire platform under the landing gear. Then I drilled the necessary holes and bolted on the TNT gear.

I’m using high-voltage electronics for all except the engine ignition....JR8911HV for surfaces; JR8711HV for throttle and JR RS1222 RCVR. The engine ignition utilizes a 4.8 NiMH 2200 mAh battery while the rest of the equipment utilizes a pair of 2S 2200 mAh LiPo batteries. Once the airplane was fully assembled and with the ignition battery located inside the motor box, I used the LiPo batteries to finalize the CG. In my case the LiPo battery location was ~1 inch behind the spar tube. With the batteries in these locations, NO (as in “zero”) additional weight was needed to obtain the perfect CG. Weight with batteries and no fuel is 18 lbs.

The final touch was adding a nylon “carry strap” around the spar tube to facilitate loading and unloading from my van. I leave the strap in place when flying as it’s in a location that doesn’t interfere with anything inside.

Several miscellaneous tips:

a) Elevator servos: use a long (20mm X 3mm) screw in place of control arm screw to hold servo in place while installing.

b) Rudder: install the control horn BEFORE putting the rudder on the plane. Also, make a decision on tail wheel steering and install any needed hardware BEFORE installing the rudder. Oil the rudder hinges to prevent epoxy from entering and jamming the hinges following rudder installation.

Posted by flipsideflyer | 03-20-2017 @ 08:46 AM | 8,747 Views
I’m a big fan of the large Haigh-Style tailwheel assembly manufactured by Ohio Superstar Products. I find them easy to install, they provide good dampening and are extremely durable.My only issue...and I may be the only R/C’er in the world faced with this problem, is the amount of built in swivel.

The way that the wheel assembly is manufactured allows it to pivot 90 degrees left or right of centerline. While this design provides 180 degrees of travel, I seldom, IF EVER, need that amount! In fact, about 30 degrees total travel provides total control on the ground, both on paved and grassy surfaces.

Another issue with the design is that the tailwheel will sometimes hang up at 90 degrees whenever full left or right rudder is employed. Although the wheel will pivot back to center upon landing, the added (unsymmetrical) load on the rudder servo during flight makes for some interesting maneuvers!

Okay, so here is my fix. I’ve installed a pair of “stops” that restrict the total left and right travel to approximately 35 degrees in either direction.
  • Rummage through your spare supply of music wire to find a size that looks appropriate for the job and that you have a drill bit to match.
  • Using the wheel collar that came with the tailwheel assembly as a guide, either scribe or mark with a pencil the outer diameter of the collar on the top (flat side) of the bracket. This is somewhat important because the collar must be able to fit between the pair of pins that you’re about to install.
  • Drill one hole outside the circumference of the collar and as far forward to the edge of the straight side as possible. The hole should be drilled all the way through the first side and only HALF or less of the way into the second side of the slot. This allows the pins to be held in place by simply swaging the top of the holes.
  • Measure the total depth of the holes and reduce the measurement by a small amount. The pins need to be slightly recessed in their respective holes to allow for swaging.
  • Drop the pins into place and swage (dimple) the top edge of the holes.
  • Reassemble the tailwheel and note that the pins now use the collar set screw as a “stop.”
If you find that you’ve either misjudged the distance between the pins or if they tend to hang up slightly on the collar, just grind the outer dimension of the collar to make things work smoothly.

Perhaps someday Ohio Superstar will consider altering their design by milling a curved slot vs. a straight slot for the collar. In the meantime, this solution has worked great for me and I hope it does the same for you.