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600 size OH-58A Kiowa Project

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  • 600 size OH-58A Kiowa Project

    A few months ago, I picked up a blade 550X at a swap meet, and have been trying to figure out my next project. After some consideration, I bought a Funkey 600 size Jetranger fuselage for it, and stretched the 550 to a 600. However, I didn’t want to build your run of the mill Jetranger. Instead, I will be converting it to a Vietnam War OH-58A. Although most of these scouts were unarmed, a select few were equipped with a side mounted M134 minigun.

    Here is the overall to-do mod list for the moment:
    Scale cockpit with cockpit doors removed
    New tail fairing
    Move Tail rotor to left side
    Scale blade rotation
    New extended mainshaft
    Surface detailing and add minigun
    Paint

    Plenty of work to do here, so the build will probably be pretty slow. But, it will be an interesting project, and I’m hoping to have it airworthy for the summer season of flying events.

  • #2
    Excellent! This should be fun.

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    • #3
      This airframe flies so well!!, looking forward to the build

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      • #4
        Started off the modification to the airframe today as well as finishing up a few things with the mechanics. One of the great things about working with a blade 550x, is that the shaft doesn’t have a step machined into it like the Trex version. So, making your own mainshaft is simply drilling 2 holes in some 10mm rod. Right now, the head is sitting a bit on the high side, so I’ll go back and drill a lower hole later. Also got to test fit the scale blades. I just go these in yesterday from Helitec, and they are the only assymetrical blades that I know of that are designed for CCW rotation. Hoping that this will allow me to lower the headspeed enough where it begins to sound more realistic in flight.

        On the airframe side of things, I got the doors and intakes cut out, and the old fairing chopped off. The lack of doors really takes a lot of structure of the hatch, so it will definitely need some sort of reinforcement. I am really debating the next step for the tail boom as well. Most OH-58As few without the tail rotor driveshaft covers installed, so it would be more realistic to cut it off. However, that would mean a LOT of fiberglass work all the way down the boom... the driveshaft would make a great place to run the tail rotor pushrod though, hmm..

        On a final related note, I found a very cool reference for a lot of the cockpit detailing and layout; a copy of the original OH-58A pilot’s manual! Planning to start CADing up the panel and console tomorrow.

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        • #5
          What head speed are looking to get?

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          • #6
            Originally posted by JFandL View Post
            What head speed are looking to get?
            I’m planning on starting at 1700 and dropping it down from there. Of course, it all depends on how much tail authority I can maintain with the stock Blade 550 gearing.

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            • #7
              I was thinking around 1800 due to the tail but 1400 would be cool if you could get it.

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              • #8
                There might be another issue that prevents this altogether now.. When I was researching pinion choices, I foolishly assumed I could just use a TRex 5mm pinion. The Blade 550 uses a mod .8 main gear, so I need a mod .8 pinion. The only one that I can find out there is the stock blade 550X 6mm Pinion. I'm going to look more into this, but its looking like the Scorpion 4020 890kv I had set aside for this project might not work, and it may not be possible to drop headspeed with a simple pinion change down the road. Really starting to regret getting a Blade instead of getting a Trex 550 clone..

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                • #9
                  Well you can always build and test to make sure.

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                  • #10
                    Originally posted by JFandL View Post
                    Well you can always build and test to make sure.
                    Glad to say, I did manage to find some mod .8 pinions that will work! Turns out the outrage Fusion .50 used them, so I managed to scoop up a few. I now have 12, 13, 14, 15, and 17T pinions on standby. Plenty of room for headspeed adjustments :).

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                    • #11
                      Sounds like you got it covered no matter what the weight of the airframe turns out to be.

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                      • #12
                        Finally got back to this project this weekend. One of the main changes I wanted to make to the airframe was to remove the tail rotor driveshaft cover to replicate most OH-58s in Vietnam. The majority of aircraft flew with them removed for both the weight reduction and ease of maintenance.

                        First, I cut the driveshaft covers from the tailboom, leaving a large open gap in the top of the boom. Using some 1/32 balsa, I filled in the gap to create a solid base for fiberglassing. I then applied 2 ply of fiberglass cloth, and did a wet layup over the balsa wood.

                        After a bit of trimming and sanding, I now have a round boom with no drive shaft fairings! Still have to do some priming and sanding to get the finish smooth though. Next will be the tailcone fairing and bearing blocks for the false drive shaft, which will conceal my tail rotor push rod.

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                        • #13
                          Really cool! I was a crewmember on 58s with 6th Cav during 1976-1977 and have great memories of that time. Following this build and hope to see it at Dalton this coming year
                          Roy Mayoral

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                          • #14
                            Originally posted by Heli143 View Post
                            Really cool! I was a crewmember on 58s with 6th Cav during 1976-1977 and have great memories of that time. Following this build and hope to see it at Dalton this coming year
                            Thank you for your service! I actually just got back to working on this build recently. Plan will be to have it at Dalton this year if all goes well! If you have any photos of your bird, especially if you ever had the gun installed, I would love to see them!

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                            • #15
                              I need to dig thru my old pics.
                              Roy Mayoral

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                              • #16
                                Finally pulled this bird down from the project shelf again after starting and finishing many other project since then, and after having moved from my small apartment to a house.

                                First order of business was to sand out and eliminate all the original paint and surface detail. This took a while as much of the original surface detail is actually thin tape underneath the clear coat. I filled in these lines everywhere except for the rear door seam lines.

                                I also removed both the engine bay doors and fabricated new ones to match the original OH-58A cowlings. The doors themselves were made from styrene with 3D printed vent detail behind them. I also 3D printed a new pilot air vent for the nose. The model was then coated in primer, and rivet detail applied to the rear section.

                                One of my major gripes with the Funkey Jetranger fuselage was always the placement of the hatch seams. I could never stand how it sliced through the middle of the rear door and fuselage along no existing lines. Most other manufacturers try to hide a hatch by making it follow a seam line. So, I decided to redo it, and move the hatch seam above the rear door. Still working on the mating surfaces between them, but it’s already an improvement In my eyes.

                                Next is more work on the hatch seam, and adding the tail rotor drive shaft to the boom.

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                                • #17
                                  Getting back to this project yet again. Seems like I end up working on every 6 months or so. First thing is, I finally chose which aircraft I wanted to model it after. I knew I wanted to replicate one that carried the mini gun, so that severely reduced my options. I did however find some great photos of one machine, OH-58A 68-16936 of the 3/17th Air Cav, A Troop, “Silver Spurs”. It appears to have an ammo box mounted to the side of the copilots armored seat to hold extra smoke grenades. There was just one problem.. I couldn’t make out the text on the upper cowling..

                                  Like any good scale modeler, I started a deep dive for reference photos. All searches turned up empty. I contacted Veterans who were in the unit, and no one remembered the name. I even contacted the Army Aviation Museum, who redirected me to Army Records at Redstone. Many emails were exchanged over several months, and I had to file a Freedom of Information Act request to get them to look for records of that airframe. And they told me that the records were missing for that airframe..

                                  In the process of this search, I learned a great about the history of the real 936. It survived the Vietnam War and served in the New Mexico National Guard until the mid 90s. The airframe is currently listed for auction. The cutout for the mini gun mount is still visible in the rear door. I became set on modeling this airframe, but I still needed to figure out that marking, or at least make up something..

                                  Finally, I had a breakthrough. My brother, a software engineer, has able to apply filters to un-distort the text visible in the photo. With some photoshop and squinting, we were able to discern that it reads “Chef’s Special”. With the markings solved, I finally moved back to actual work on the airframe.


                                  936 in Vietnam:
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                                  936 Today:


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                                  • #18
                                    One of the first things I wanted to tackle getting back to this, was to correct the tail boom angle. The OH-58 has a few degrees of up angle in tailboom relative to the floor of the cockpit. The stock Funkey Jetranger fuselage has these parallel, and doesn’t look quite right. So, I got out the dremel and removed the tailboom. Both surfaces were sanded flat, and the appropriate angle was added at the seam.

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ID:	345975 Before re-attaching the tail, there is some further work required. I will be relocating the H-stab to the scale position (farther forward) and to a scale scale angle of incidence. I will also use this opportunity to fabricate the tailcone extension, and mount for the Vertical fin.
                                    Attached Files

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