Hobby Hanger OV-10

[LJH]

Has anyone done a E-convertion to the Hobby Hanger OV-10 designed by Rich Uravitch. I have always like the OV-10 and it looks like it might be a good candidate for a E-conversion.


Cheers,
Jim

[KOMET 44]

Jim look in the picture archives here on the e-zone.i know i saw one there. stefanP

Ghost rider requesting a fly by.............

[John Zook]

Jim: I'm not sure how much if any mods being done to the airframe. Somewhere I have a magazine article . As far as motors Astro 05 geared was the system of choice, so geared endos or Mayhems would be a decent alternative.
I've been lconcidering this plane for a while now. I read that it is a nice flyer w/ electric power BTW the wingspan can be increased
some for lighter wingloading....the instructions are in the kit...parts too. Good luck if you decide to build one.
John Z.

[Greg Gimlick]

I reviewed one for RC Report when they first came out. I built mine stock with no changes from the original plan, but if you're not bound by magazine ethics there is a lot of room for lightening it up. I flew mine for about 4 years on Astro 05's and 16 cells. Gary Wright did one with Endos or MM, I can't remember which and he made his a lot lighter.

The OV-10 is a good flying plane and draws a lot of attention in the air. The kit can be lightened a lot though.

[GWRIGHT]

I originally used two endoplasmas, geared 4.6 with 11X10's on 20 cells in series. WAY overpowered. Went to 11X8.5's, then 11X7's, then to two atomic force motors. Rich is here in melbourne and says the original was 6.5 lbs with two 25's and fixed gear. My electric was extremely lightened in structure, plus I added spring air retracts. With 20 cells (that's 2 and a half pounds of batteries bythe way) it was 7.5 lbs ready to fly. I ripped out the nosegear in an off-field landing, and haven't patched it up yet. I will someday,.. and the plan is to put two endo's back in it as it was originally (it would climb 60~70 degrees on takeoff with that setup), but I plan on using two ESC's so it's two individual setups,.. with the two throttle channels mixed. I had some problems running the two endos in series on 20 cells (had 800 watts input power that way), even though they take 400 watts on 10 cells singularly just fine. I think that one sometimes "sees" more than it should in the series setup for some reason. With two atomic force's and 11X7's it was down to only 550 or so watts, which was still sufficient, but I did like that turbine-like whine of the endo's and 11X10's as it whizzed by at very high speeds. With two ESC's i could explore single engine flat spins ,.. which I think would be neat.

[LJH]

Stephan,
I will take a look. Thanks for the heads up.

John,
Exactly what I was thinking in the power department . After seeing what the Endo and 4.8:1 gearing on 10 cells can do in my E3D all these planes are looking easier to do conversions. The fact that the kit includes parts to add a bay on the wing is cool. Power wise there would be no trouble but I am not sure of how a 25-30oz/sq.ft. plane would fly. That seems awfully high? or is that ok for a plane of this size?

Cheers,
Jim

[GWRIGHT]

I did stretch the wing a bit. I added slightly larger bays that he recommends, and it's 59" span if I remember correctly. I did the math once and it worked out to something around 30~32 ounces per square foot. It flies beautifully and has absolutely no bad habits when slowed down. It will stall and just mush forward at a high sink rate,.. no "tippiness" whatsoever. That really surprised me. By the way,..Rich now has an ARF version of the plane. I don't know if it's advertised on his website yet or not, but I've seen him fly one of the ARF's (on glow), and he even modified one for retracts. He has norvel 25's in them and they go like stink. The arf has the normal wing without the added bays, and although it'd be heavier than a true E conversion,.. I think you could strap on the motors and go with it. It would be a bit higher on the wing loading due to weight, and the wing size, but after seeing how mine flies, it wouldn't be a problem,.. just a bit higher landing speeds.

[LJH]

Gary,
Thanks for the info on the OV-10. I think I am going to have to build one over this winter. I have been dieing to do a plane with retracts and the fact that the Hobby Hanger's OV-10 can take them makes it look even more promising . I did a search on the E-zone last night and I believe that I read that the ribs are lite-ply? Is this true? Wonder if I could get the guys to cut the ribs out of Balsa? They seem like a great buch of guys. and I just recieved my Pond Side this morning and the Laser work is very nice. A little off subject here but the other day I was flying the E3D up at my favorite field and a older gentalman comes over to me and look at the plane. Asks what kind of power I have in it, and I tell him. He then goes on to tell me that he has been flying R/C longer then I have been alive (I am 35) and that you cant have a powerfull electric that has any duration. I am goggiling to myself as I prepair the plane for flight. I set her down apply the throttle and off she goes, break free of the ground pull vertical for 50' or so slow the plane pull off one of my better torque rolls that I have done and proceed to fly till my 8min alarm goes off. I land the plane the Gentalman comes over again and say "I've never seen a electric plane do that before" . It was pretty cool.

Cheers,
Jim

[GWRIGHT]

The ribs aren't all liteply,.. just a few of them, around the areas that are cutout for the nacelles. I didn't change any of that. I replaced the rear spars (1/4" hardwood) with 1/4" balsa. I replaced all the 1/16" wing sheeting with hand selected very light wood (that alone saved 1/2 lb,.. yes,.. 1/2 lb according to my digital scales comparing the woods). I removed all the doublers and such in the nacelles and fuselage and used a simple sheet of 1/8" birch ply ran across them for the retract mounts, with only 1/4" square bracing on each side. It is enough,.. but I'm VERY carefull about landings. The one off-field landing I had did some damage to the nosegear retract,.. I should;ve left the gear up,.. but hindsight is always 20/20. I made the fuselage look like "swiss cheese" with a forstener bit,.. same with the nacelles. I used 7 HS81 servos,.. one on each aileron, one on elevator, one on each rudder, one for retract valve and one for nosegear steering. Reciever pack was 720mah nimh, and then 20 panasonic 3000's for the motors. Some old astro ESC that I got at a swap-meet really cheap,.. it said 50 amps, and some astranomical amount of cells on the ratings.

[GWRIGHT]

LJH, I forgot to mention it in the above post,..but if you want to show them real duration, try a magnetic mayhem with a 14X10 on the front of the E3D and 10 3000 nimh cells. It won't hover with that,..but you'd be surprised at how well it does fly with it,.. hover is the only thing you give up,.. and at 20 amps full throttle ,.. you end up with extremely long flights. One fellow in Tampa is flying that setup after we talked at a recent electric event over there. He emailed recently and said most flights with his E3D,.. learning basic aerobatics,..i.e. loops rolls, stall turns,.. are lasting 20 minutes or more with Saft 3000's,.. which indicates an average of about 10 amps. The big props really buy you a lot in the efficiency department.

[LJH]

20minutes.....Holy Cow. But I have to say that I am really enjoying the hovering part, and I am starting to get better at it. Starting to do it at lower altitudes (I should get another kit comeing my way ) I think I have to pick up a 14X7 next time I buy props, almost out of the 4.75X4.75 for the Twister. When the ESC goes into thermal shut down I guess it does not take the BEC with it? That would be BAD . Thanks for all the info on the OV-10.

Cheers,
Jim

[GWRIGHT]

Be very carefull with the 14X7. It draws mucho current. When the ESC thermals, it shuts down the motor, radio is fine,..at least that's been my experience, but i'm allready running the BEC way above their specs,.. 10 cells, and 4 servos.