OV10 Bronco by Planeprint

davidk · April 24, 2024, 03:02:40 PM

Time to start the Bronco.

Michael · April 24, 2024, 05:25:36 PM

Wingspan?

davidk · April 24, 2024, 06:47:19 PM

Wingspan 1400mm / 55.1 inches. Printable in 2 versions, A or D, and with or without the sponsons on the sides of the fuselage. I've printed the short nose A version with the sponsons.

davidk · April 24, 2024, 11:21:38 PM

The rear 2 sections of the main fuselage are made up of 4 printed parts... tops and bottoms.
The gold piece is a crossbar brace. The carbon fibre tubes run through the fuselage and through this crossbar.
There are a lot of alignment tabs between these 2 sections.

davidk · April 27, 2024, 12:36:25 PM

Twin booms done. The parts are so similar that it's tough to tell left from right. Planeprint designs an "L" and "R" into parts.

davidk · April 27, 2024, 07:45:42 PM

Really nice hinging system.

Michael · April 27, 2024, 08:29:00 PM

Impressive design and engineering.

davidk · April 29, 2024, 02:05:29 PM

Very good structure on this OV10. There's a cross-brace in the fuselage and the front landing gear is supported by 2 6mm CF tubes crossing over sections.

davidk · May 13, 2024, 12:31:45 AM

Outer wings are done, so it's on to the landing gear. Since the brass threaded inserts worked so well for the L-39, they're going into the Bronco.
I've got a bit more to work with so I'm using a 3mm x 6mm threaded insert this time.
But, there's always something.
Pushing that long an insert through melting plastic allowed that melting plastic to feed into the open end of the insert. Completely filled the 3mm interior.
So, I did what anyone else with this problem would have done... I left to watch a movie. The Beekeeper with Jason Statham... excellent.
When I came back, I took a 3mm long set screw and screwed it into the threaded insert flush with the end. Now, while melting, the plastic has no where to go but around the insert.
Remove the 3mm set screw and all is clear.

davidk · May 17, 2024, 05:30:28 PM

The rudder servos Planeprint recommends are small 4.8g Hitech HS-40. I think they're too small but there's only enough room for these so they'll have to do. The servo cover screws into 4 posts, but there's no way to get those posts situated perfectly. So, Planeprint instructions are to screw the posts onto the servo cover, then add a drop of CA to the bottom of the posts and put the cover in place. When dry, take off the cover and secure the posts with more CA. Then the servo is attached to the servo cover with double sided tape. Worked out well.

davidk · May 17, 2024, 05:39:51 PM

The OV10 has inner and outer flaps... which are on either side of the motor fuselage. A 6mm CF tube is glued into the inner flap. That tube then runs through the motor fuselage. A small connector is glued into the open end of the CF tube. This connector fits into a slot on the outer flap but is not glued... it's this part that actuates the outer flap.
A servo is put in place inside the motor fuselage. A control horn is snapped into place around the CF tube and the servo is connected to the control horn. I don't think there would be any way to get the left and right flaps aligned enough to use a "Y" cable and 1 channel, so 2 channels will be used and the flaps can be adjusted.

davidk · May 22, 2024, 12:45:11 PM

The motor mount parts screw and glue together to form a support cage. I put one together and fitted it to the fuselage and found that the motor was sticking out a bit far... about 8mm. I checked my motor against the suggested motor and found I might have selected the wrong one. I have four on my desk... 2 Turnigy 3548 and 2 Turnigy 3542 - the specs call for a 3542... and I'm shaking my head. Then I realized that with the prop adapter on, the 3542 was actually longer by about 2mm. Sheesh. So, I go back to the Planeprint site just to double check and find that Rene has posted what he calls a "Free Tuning Part" There are a few better tuned parts for the Bronco and I had all of them... but he'd just posted a new one this week. A motor mount that is 8mm shorter than the original. Yikes.
These are the parts and the difference in sizes. Motors mounted and installed.

davidk · May 23, 2024, 12:45:53 AM

I don't know how Rene figures this stuff out. These parts are the Battery Tray and supports and are the last pieces being glued into place. The supporting pieces are screwed onto the battery tray and then glued into the fuselage. This process ensures the supports are exactly where they need to be. Then the battery tray can be easily removed. This entire structure is also tied into the main fuselage support and into the front gear parts. As parts are added the plane as a whole gets stronger.

davidk · May 23, 2024, 04:05:29 PM

A 1mm x 5mm carbon fiber strip running the length of the elevator is glued in place. Planeprint allows for the size of the strip and also builds in 2 channels for thin CA.

Gil.E · May 23, 2024, 08:47:35 PM

Hi David,
This is really nice. The surface quality of the foaming LW-PLA, design sophistication, and precision are amazing!

Things have changed quite allot since the beginning back in 2015.

This last model in the series of models you printed and built over the winter pushed me over to get back into printing and building again. Thanks (I hope

) for the inspiration.