OV-10BZ Project
Test fit of version 1 prototype jet engine pod for the ICM 1/48 OV-10 kit.
Side view of the version 1 test fit.
Front view of the version 1 test fit.
I wish I had a good view of that target winch mechanism.
Should I built it with cargo door open? Note the gust lock which connects the door to the left boom. On the regular OV-10A this gust lock is located at the apex of the fiberglass door. Here it's below the door on a "towel rack".
Note the "roof" modification over the winch operator's head. This is unique to the OV-10B.
I don't know if this kit will need a brass spar, but I put one in just to be safe. The resin parts are pretty heavy.
No OV-10A or it's derivatives has a bulkhead between the cockpit and cargo bay. I don't think the OV-10D has one either, but I'm not sure. So the bulkhead is removed and the floor of the aft cockpit is cleaned up.
Making sure the fuselage sides don't collide with the brass spar.
1. Newly printed 230 gallon tank.
2. Fuselage sides and bottom showing sponson areas being filled in.
3. Cargo door being made into a form for vacuforming a clear one.
4. Notch cut into fuselage top side to make room for the brass spar.
EDIT: The original cargo door was crushed a bit in the vacuform machine. This made the result too fat, so I later decided not to use it. The final solution was to 3D print a new mold.
2. Fuselage sides and bottom showing sponson areas being filled in.
3. Cargo door being made into a form for vacuforming a clear one.
4. Notch cut into fuselage top side to make room for the brass spar.
EDIT: The original cargo door was crushed a bit in the vacuform machine. This made the result too fat, so I later decided not to use it. The final solution was to 3D print a new mold.
It's starting to look more like an OV-10 now. This photo shows the jet pod, the 230 gallon drop tank, and the vacuformed clear cargo door.
Attaching three sides of the fuselage here. Next step is to add a floor in the cargo bay. The basic OV-10A had a plywood floor, but it seems the OV-10B had a metal floor. After the floor is in I'll add ribs to the walls.
All four sides of the cargo bay.
I cannot figure out how to install kit main landing gear, or the brass landing gear, or the white metal landing gear. The parts don't seem to fit, or the fit is ambiguous and angles unknown. This is "plan D", print main landing gear legs. This is the first prototype part (one piece) being test fitted. I've made adjustments and will print the second prototype tomorrow.
OV-10 propellers at some time started wearing blue Hamilton Standard logos. If you want those you have to print your own. Here I printed the white/red/white bands, the blue HS logo, and the data stencils. The kit props should be in flat pitch (pitch angle zero). They are not, but they are fairly close and I don't feel like making my own.
I've painted the underside using MRP-104 Light Grey. The green color is MRP-208 Gelboliv. Here the engine pod is attached and I'm filling the gaps at the "feet". Next comes masking and then green color. I've painted the rudders separately using Tamiya TS-12 Orange, and this orange will also be used on wing tips, nose and engines.
Most of the paint is on now. Just need some touch-ups and some orange areas. I'll do the wheel wells later. The camera makes the orange look like red.
Left engine nacelle painted. It takes a lot of orange to cover both the grey and olive evenly. One more nacelle to go, then some touch-ups. Cockpit is next. Note that the pitot tube broke off (which was obviously going to happen), so I drilled it out and will go with an aftermarket part.
The main gear and external tank are installed, so now I'm trying to determine how much compression needs to be in the nose strut to give the airplane the correct nose-down "sitting angle".
I'm using some of the kit decals. I wasn't sure at first if I should paint the black walkway or use the decal. Both ways are a bit tricky because of the jet engine. I decided to use the kit decal. I printed some FRG flag decals for the vertical tails. The rest of the decals are on order from Peddinghaus Decals.
Waiting on decals now. I haven't decided yet if I'm going to use the vacuformed cargo door I already made or make a new one from a 3D printed form. Since I'll probably be waiting a long time for decals I should start working on a new door. EDIT: work on a mold for the new door is in progress.
Here is the first step in producing a new mold for the clear vacuformed cargo door. I'm trying to learn FreeCAD since the old-style CAD that I've been using is not enough to make this part well. This is as far as I can get in FreeCAD right now, so I printed it, and I'll finish it by hand.
Here, from left to right, are my first attempt at vacuforming a clear cargo door, the newest 3D printed mold, and for reference the cargo door from the 1/32 scale KH kit. The original attempt is not very good.
New vacuformed door. This one is much closer to correct size and shape. The door will be open 90 degrees to the left, so the slight difference in size will not be noticed. Masking it is going to be pain 🙁
To make the masks:
1) Draw the masks in Gimp; one mm equals 11.8 pixels (assuming 300 dpi)
2) Use Cameo cutting machine to cut the masks into Tamiya masking paper
3) Test fit and make adjustments to drawings
4) Repeat
1) Draw the masks in Gimp; one mm equals 11.8 pixels (assuming 300 dpi)
2) Use Cameo cutting machine to cut the masks into Tamiya masking paper
3) Test fit and make adjustments to drawings
4) Repeat
Decals arrived! I hope there are enough of the correct size markings to do the job. The framing on the cargo door/fairing is painted, and the winch operator's seat is almost done - I just need to find some seat belts.
This is the final markings I've decided on.
I "finished" the day before the show. The model is not competitive due to the decals, but I just wanted the build to be seen. I really should remove the decals on top of the wings and make my own to replace them.
Коментарі
69 7 September 2022, 03:45
Jorge Medinacool work!!! I also into 3d printing and opens a wide range of modifications that are super interesting like yours!
12 September 2022, 19:23
David CulpYes, Jorge, it really makes any project possible. I always 3D print something now, for every project.
13 September 2022, 02:57
Robert PodkońskiInteresting! I have never known about this version of Bronco.
13 September 2022, 06:58
David CulpThe instructions have you install the landing gear struts early in the build, but I refuse to do that. I'll make it work another way.
26 September 2022, 00:02
JohnIt's really coming together nicely! Landing gear is my bugaboo and what usually requires summoning the last reserves of interest to push though to the end.
26 September 2022, 01:16
David CulpThanks everybody! Getting close to the finish line now. I have some decals on special order from Europe, so that may take some time. Since nobody makes OV-10BZ decals I ordered some generic crosses and numbers from Peddinghaus Decals.
1 October 2022, 21:25
JohnHaving stared at two fuel tanks exactly like the one in pic 4 for months, I would swear that it's a repurposed F-84F drop tank. Did the Luftwaffe do that sort of thing?
2 October 2022, 00:45
David CulpThe story I heard was that it's a hand-me-down from the F-102. The F-102 started out with these 230 gal "subsonic tanks", as these were called, and later switched to supersonic tanks.
2 October 2022, 00:58
David CulpOne thing to note: The jet engine pod makes a great handle for picking up the airplane!
3 October 2022, 01:52
JohnLooking sharp 👍 If they used surplus F-102 tanks, maybe they could have used a surplus F-102 engine and had a supersonic OV-10, briefly at least.
16 October 2022, 03:37
Michael KohlI like your build and watch closely the techniques you apply.
Concerning the orange, I consider it helpful to use a white base paint to avoid the problem with bad coverage.
Of course it is always difficult to judge from pics, but I have the impression that the glow orange used by the Bundeswehr has quite a different hue.
16 October 2022, 08:56
NeilAs you know David, I've just built the old Testors Bronco, so have an idea of this kit... I absolutely agree with Robert 👍 and... I'm so intrigued by you guys who utilize 3D printing also. The subject/results look fantastic!
16 October 2022, 09:44
David CulpI have a collection of every photo I could find of the OV-10B(Z), and it's amazing how many different hues there are. The orange can be any hue from faded yellow to a darker red-orange. I think it depends on the photography and the age of the paint. In fact, a lot of things involving this aircraft seemed to change over time: The shape of the jet engine pod, the green paint, the light grey paint, the markings, the antennas, the placement of the orange paint, etc. There is an OV-10B currently flying that has been recently re-painted, but some of its paint doesn't match the original, so it's only partly useful as a reference.
16 October 2022, 16:18
Mark DReally cool work! Great subject. I too want to build this one for a while, didn't want to take the hassle with the older testors kit, ICM has a good base for it.
21 October 2022, 21:03
DutchAbsolutely beautiful workmanship! Love the ingenuity in making the needed parts.
27 October 2022, 21:57
David CulpThanks, Mates. I wish there was an easier way to make this airplane so that more people could build an OV-10BZ, but I can't think of one. The jet engine is the easy part.
28 October 2022, 01:00
Bernd GrünOutstanding research and build. I'm impressed and take a seat. Congrats, David. 👍
10 November 2022, 11:52
Michael KohlWhich insignias are you going to use? Inspired by your build I was looking for information and material to build it in scale 1:72 and was very surprised to read that the planes were actually never operated by the Luftwaffe herself, but by a civil contractor. Consequently - as your profile pics show nicely - they had a civil registration and no crosses. Very much to my surprise was the registration all numbers. I always thought, that all number-registrations indicate glider planes (without engines). Hm.
In scale 1:72 a decal sheet is available, but only for one of the repainted versions that feature crosses.
10 November 2022, 15:07
David CulpI just added an image (number 33) that shows the markings I'm going for. I don't know the history of markings in the Bundeswehr, so I just picked one. I'm a bit delayed now, but one thing I'm doing is experimenting with decal techniques. I applied the cross to the top of one wing using microset and microsol, and it layed down nicely but the carrier film was too visible, so I removed it. Once I decide on a good technique then I'll finish the decals using the Peddinghaus generic crosses and numbers.
10 November 2022, 18:56
Ricardo BarrosoWhat an amazing work. I don't know how I missed this. Congratulations😄 I'm seeing with all of my attention!
12 November 2022, 19:04
DickVery nice build David, and a very original Bronco with the 3D printed jet on top! Also great paint job and choice of version.
3D printing makes life for us modelers much more interesting these days.. I'm building a 1:72 Boeing 747SP, fully 3D printed in parts by a friend of mine.
Keep up the good work👍🏻!
20 November 2022, 00:55
David CulpI just ordered a set of resin propellers from Quickboost. If all goes well I might remove the kit propellers and install the Quickboost ones. The new Quickboost props have separate blades, and I'm guessing that these can be installed at any pitch angle. We'll see. The operation comes with some risk though.
14 December 2022, 17:51
Mark SherwoodNice build, very nice scheme too. That jet engine looks familiar, He 162 anyone? Or is it just the configuration?🤔👍
14 January 2023, 19:37
David CulpIt's a J-85 engine, and to me it looks a bit like the J-85 installation on the C-123K, including the cover that can be moved to block the intake. One difference is that on the OV-10BZ the engines all use the same fuel.
14 January 2023, 20:53
Mark DI thought JATO were take-offs with rockets (like used for demo fat Albert and mirage IV for example, not for assistance by a jet engine?) Anyway not want to get a long discussion here, it's a nice addition to the silhouette of the Bronco 👌
16 January 2023, 05:37
Mark SherwoodNo, mate I meant the JATO'S on the Provider which David mentioned (J85 engines, C123K) 👍
16 January 2023, 05:42
David CulpI'm calling it finished now. I wish I'd had a specific decal sheet for this build. The 3D printing was the easy part.
20 August 2023, 20:06
David CulpThanks everyone. Here's link to the files I used for the printing, cutting, and decals: daveshangar.org/photo/OV-10B/OV-10BZ-v3.0.zip
Let me know if the link doesn't work.
20 August 2023, 21:15
Michael KohlCongrats for this excellent result on this very unusual variant of the Bronco and a big Thank you for sharing the files. Much appreciated.
21 August 2023, 06:55
Album info
Prototyping some 3D printed parts for a 1/48 scale ICM OV-10A conversion to OV-10BZ (with the jet on top). I thought this would be a back-burner build, but I made so much progress the last couple of days that I should have it done soon enough.
