View Full Version : Keith Sparks OV-10 Bronco build

08-30-2005, 03:44 PM
Well this is mostly done, but I have to show off.

Keith Sparks has a new model on the block. An OV-10 Bronco. As you know Keith spends a lot of time making sure they look right (scale lines) and that they fly well on electic power.

I have flown Keiths OV-10 (one of them - he built three for his upcoming magazine article) and it flies like a trainer.

I don't want to re-create the work I have done over on the "other" site, so see here for the build....

It is covered, and the cockpit is done. One of my modeling buddies is a master modeler and did the painting for me.

Test flight soon!!!!


08-30-2005, 03:45 PM
Here is a Pic of one of Keith's models......see the thread for his really dolled up one!

08-30-2005, 03:50 PM
Here are a couple of close-ups of my cockpit (no canopy installed for clarity).

I wish I could take credit for the painting, but alas it is not my work. Doug Cohen my friend did the work for me. He is a Master figure painter and sculpter. You will easily see why in the pics.

Completed pics to follow soon!!!:D:D:D

08-30-2005, 03:51 PM
Mine will get a California Department of Forestry paint scheme. I love red and white airplanes.

09-01-2005, 04:45 PM
Not one comment....Hmmmmmmmmmmmm Nobody likes?

09-01-2005, 06:05 PM
Noooo! I love the looks of the plane, and the red and white will look awesome! At this point, I can only dream of the day that I'll have enough time to build up a balsa kit from the beginning. Two kids involved in everything under the sun keeps me hopping. Soooo for now, it's easy, quick building foamys, if I want to see them in the air before my kids graduate! LOL. Please keep us up to date with pics, and the finished product. Thanks for sharing.

09-01-2005, 06:12 PM
Thanks Rick - I was beggining to think I was alone!

09-03-2005, 09:53 PM
Well it is almost done. The markings are on and I did the amp tests. It is about 21-22amps total...

Anyway the cowls are getting their black paint now......

09-19-2005, 11:19 PM
Great looking Bronco. I built two of the Hobby Hangar versions years ago when they first came out. I strained one thru a tree three weeks before I was supposed to demo it at KRC so the second one was a quick build to get it ready in time. Both flew well, but with todays gear they would be soooo much better. I sold mine at Mid Am a few years ago, but seeing this makes me want another one. I may just have to get one of the short kits and knock out another. I like this size too as it won't fill the back of my truck. I've got plans for Rich's 80 inch version, but I don't know if I'll ever get around to doing that giant version. Have you seen the laser cut kit from Tanks?

09-19-2005, 11:41 PM
Thanks Greg! I guess I should send you some snapshots for your column!

It flies great as well. It will get the brushless system it deserves hopefully in the not too distant future.

I have not seen the laser cut from Tanks....what is that?


09-20-2005, 12:03 AM
By all means send photos and info any time you're doing something cool. I can't get them all in, but I've tried to show specific techniques and ideas that guys have used to show how things are done. High res digital is great, send them to [email protected]

Here's a link to the Tank site for the laser short kit. You still have to order the plans and plastics from Keith, but if you don't want to cut the wood this might appeal to someone. I haven't actually seen one of the kits so I can't speak to its quality etc.

09-20-2005, 12:40 AM
Hi Mike,

You have done a neat job on your OV-10. Keep up with your posts as they are real informative. I am building the same plane with the same color scheme, but it has been a real slow build for me. I started mine in 2001 and it is now about 85% finished. In the meantime a number of other electric and gas planes got in the way!!! I would be very interested in your statistics on your plane, (motors, weight, batteries, escs, etc.) Perhaps you have written about this elsewhere. Mine currently is a slimer with 2-25 OS FX glow engines but now after having so much fun with electrics over the past 2 years I may convert it over. I have the Spring Air retractable gear in mine, flaps of my own design, lighting including a strobe lite, the rear of the fuse opens up by air to drop parachutes, etc.). As you can guess it will be a bit heavy! I have a Hobbico Twinstar that I have been flying, about the same wingspan and area, and I will add weight to that to get an idea of how the OV-10 will fly. Again, any information you have on weight, electric motors, batteries, etc. would be appreciated because, with the new brushless motors and Lipolys we are using, an electric would be more reliable. I will enclose a few pictures of my plane. Thanks for all of your posts.


09-20-2005, 04:16 PM
Bill it looks fantastic! My build was quite a process too. I have a Ryan p-38 on the bench (and it has been) for about 3 years now. I need to finish it!!!


09-20-2005, 04:20 PM
I haven't actually seen one of the kits so I can't speak to its quality etc.

Greg - yes I used one of the beta cuts to build my kit! I just know him as the guy with the laser cutter! :D.

My digital camera is a 2mp, great for web stuff, but likely not enough for your needs. I will have Keith snap some of the group at DEAF this year!


09-30-2005, 01:01 AM
Hey Mike,

Could you list all the vital statistics on your OV-10 electric? As I mentioned above I am seriously thinking of switching from glow to electric on mine. Give me some numbers so I can compare mine, which is 90% finished, to yours with electric power. As you can tell from Post 12 mine will be on the heavy side but yet I think electric may be the way to go for me. Let me know what motors you are using, what props, watts, rpms, batteries, etc. Also overall weight , one or two esc's, etc. etc. We need that kind of information so we don't have to reproduce all you have done. Thanks. You have done a great job on your OV-10.


09-30-2005, 02:59 PM
Bill here you go:

-AUW - 55oz with the 8 cell NiMh 1800 pack. Weight drops a bit on the 2s 5000mA LiPoly, but so do volts and amps.
-Speed 400 motors GWS gearbox with "c" gearing
-GWS HD (direct drive) 9x7.5 props
-190W total (both motors) and about 21.5amps total (10.8 per motor)

Keiths designs all have a unique quality - they "fly" when they appear not to have enough airspeed. You have full control and they are happy right down to stall speed. That is why I am getting away with a 55/watt per pound power system.

I will upgrade this setup to long can s400 motors run 3s LiPoly and increase amps to about 30. That will increase my weight a bit too, but should provide a touch more power. Eventually I will put a brushless power system in it.

I have only flown it twice now, but both times were amazing, it just looks fantastic in the air. It climbs well and glides like a glider! Very impressive desgin.


09-30-2005, 03:02 PM
BTW for your system with .25's and AUW in the 6lb range I would go with the Hacker a30 series motor. Length determined by how much power you need. 200-300w per side would be excellent.



09-30-2005, 03:13 PM
Thanks for the information. It will save me a lot of time and I can start my conversion in a more sensible manner. I know it will fly with the two OS 25 FXs as I have a Profile P-38 and a Hobbico Twin Star that I have been using the two motors on. Over the long haul, though, electric seems more reliable on twins and then of course there is the advantage of not having to clean up all the goo afterwards! Thanks again.


Mike Parsons
10-26-2005, 04:34 PM
In the interest of saving time. Where can I get a kit? Is it a full kit or short kit and laser cut? I am thinking of a winter build and this may be it :)

10-26-2005, 04:59 PM
Mike it would make for a nice winter build...

You will want the short kit from here:
www.tanks-hangar.com (http://www.tanks-hangar.com/)
And you must get the plastic kit from Keith Sparks (designer). It will appear in the January Model Airplane News.
Sparky2 @ att.net (take out the spaces)

It is a fantastic flyer. Very basic build for a twin Military aircraft. Flies just like my old PT60 trainer in fact!

Snap some pics along the way for us!


Mike Parsons
10-26-2005, 05:03 PM
Thanks! I certainly will document the build


10-26-2005, 09:22 PM
Wonderful plane!!!

10-26-2005, 10:29 PM
Thanks sikorsky - it was great fun to build and even more fun to fly!


12-27-2005, 09:59 PM
Hey there guys,

This is my first post and also my first attempt at building an RC plane. I've done lots of models and am fairly good with my hands so I thought "why not...

I picked the OV-10 because I always thought it was a really cool aircraft and I wanted something challenging. I've been doing lots of research and have noticed the no one seems to have put rudders on this plane. Is there a reason for this?

I plan to document my build for my dad who lives in Mexico, so I will put the link to the site once I get it going in these forums.

Wish me luck...


12-27-2005, 10:03 PM
I've been doing lots of research and have noticed the no one seems to have put rudders on this plane. Is there a reason for this?

ACtually it is quite simple. The rudders add two more servos and linkages. It is cost and weight. Combine that with the steerable nose wheel that is 3 servos.

Just that.

This OV10 is super easy to fly and a fairly simple build (except the rudders!) but you will need some stick time on a good trainer before you fly this one.

Welcome to RC and Watt Flyer!


12-27-2005, 10:26 PM
I see your point... Here are perhaps some some silly questions...

Why would you use 2 servos for the ailerons? Could you not use just 1 servo to control both ailerons? This would reduce both weight and cost?

Thanks for the welcome...


12-27-2005, 10:34 PM
Yes you certainly can! The with a single servo in the center of the wing is much more difficult to setup, that is why two are recommended. But you could cut that to one and then use bellcranks.


12-28-2005, 01:31 AM
Mike, I am a new member to wattflyer and a beginner at rc flying, but I`ve got to tell you that I read every post you made on your OV-10 build and it was like reading a good book ,couldn`t stop till finished , you guys are an inspiration to a beginner like me and I hope I can only be half as good as some of you are I`m really glad I found this site and I`m looking forward to reading and learning even more. Beautiful plane and great job!


12-28-2005, 04:43 AM
Thanks Lee this plane was a blast to build, and it flies even better!

It is good to have friends that set you up with great projects like this!


12-28-2005, 02:27 PM
Great looking Bronco Mike!

12-28-2005, 03:47 PM
Thanks Tom - you guys should see Keiths next plane.....

How about this?


12-28-2005, 03:54 PM
Nice! Mike, where did you get the pilots for your OV-10, did you scratch them? If so, what materials did you use?

12-28-2005, 04:08 PM
The Pilots are included in the plastics kit. As is the canopy. Doug my friend who is a world renowned artist painted them for me. Amazing eh?

Nice to have talented friends.


03-18-2006, 04:35 PM
I've picked up Bob Ruff's OV10 but I need some help to get it airborne.
1. What is the CG as stated in the stock setup?
2. How are the separate nose gear and rudder servos connected/coordinated? with a Y connector or with some computer radio setup?

03-18-2006, 11:56 PM
wdahlstrom -

Is the OV10 you picked up one of Keith Sparks design?

Yes, normally you just use a Y cable for nose steering and rudders.


04-03-2006, 02:36 AM
Well it's been a while since I posted anything. Ithought I would just drop in a little update.

Still building the Bronco. I'm really having a blast doing it, even if I've made some big mistakes, that I was thankfully able to fix... I still wonder if it will take off or not :) I'm thinking that the first flight will be a throw as opposed to a landing gear one. The only disappointment if going to have to wait as I'm headed to sea for 46 days and will not ba able to work on it.

This week I'm hoping to finish building the wing. Next week will be the booms, tail, and with luck the fusilage. Sigh, I which I could take a vacation and finish her up.

I purchased the motors, Eflight 400 brushless, with 6.6:1 gear boxes. I also ordered the GWS 3 bladed props.

Well that's all for now.

05-25-2006, 09:23 PM
I just ordered this Bronco - planning to build it as light as I can and use 21 Esskay 400's
Anyone looked at this ARF?