RE: OV-10 Bronco 81
 

Well, another Uravitch Bronco has flown.

The maiden on the new Bronco is done!

There were no surprises. The Bronco flew just like all Uravitch Broncos. Plenty of power and speed out of the power systems and after about 5 minutes of 2/3 throttle flight and very good 1/2 flap landing, the batteries still had 4.0 volts per cell. The electric guys at the field said I probably had at least enough battery left for another 5 minutes+.

The trim was about dead on. I needed 1 click of right aileron and one click of down elevator to fly hands off. I had one issue with the canopy fogging up due to all of the rain we had this week. I had vented the canopy but it still steamed up when the sun hit all of that plastic surface. That problem will go away with dryer air.

RE: OV-10 Bronco 81
 

Hey congrats gsmith! Looks like you set up a great power system for that great looking bronco.

RE: OV-10 Bronco 81
 

Congratulations.....that is a fine looking machine....even with the IFR canopy!

RE: OV-10 Bronco 81
 

Thanks guys. The photographer gave me a hard time about the canopy. He said:

" Thank goodness his pilot was instrument certified, or he would have never made it back to base due to some "cockpit fog"

Phil"

RE: OV-10 Bronco 81
 

AmishWarlord as far as Centry Jets go I used them on my KMP makeover, I wish they had a beefier knuckle, but have had few problems over the last 4 years I've had them,.SP did not have anything ready when I needed them so I had to go with Bruce's units. One thing that bugged me was paying $825.00 on a set of retracts and replacing all of the pop rivits with bolts and lock nuts ....Don

RE: OV-10 Bronco 81
 

Gsmith6879, congrats on the maiden, it's nice to get that over with. She is a beauty. You're right, they all seem to fly well, it has to be one of the best flying twins around. Welcome to the VMO2 squadron!

RE: OV-10 Bronco 81
 

Hey Ron here is a link to my reworked KMP, there is a bit of work to get the boxiness out of it as well as redoing the canopy and retracts, after all of that I glassed it. I am flying mine on 2 Power 110's from EFlite with CC PH.85 HV's on 8s 5000 spinning 16x10 3 Bld. props. I saved all my templates for the changes so it would speed up the proceees a little.If you can find one they have good bones just needs a little Scale Work, it is post 109...Don

http://www.rcuniverse.com/forum/m_33..._5/key_/tm.htm

RE: OV-10 Bronco 81
 

Looks great in the air! Can you describe your power system in the OV-10? I'm putting together the 81" arf and I'm planning on 2 Scorpion 4025-16's and CC HV80 ESC's using 10s 6000 lipo's. What is your amp draw and what size prop's you are using?

Thanks,

Wayne

RE: OV-10 Bronco 81
 

I'm a novice on electric flight so I spent a lot of time researching, asking questions, and then testing my power systems. But I am sure more experienced electric power guys could have done a lot better. Here is what I have and how it performed during my tests.

Motors:
Common Sense E-90-3
325KV
64 amps max
rated at 2213 watts on 10 cells (I'm using 8 cells)

ESC:
HobbyWing 70A Platinum-70A-HV

Battery:
8 cell (2 - 4 cells in series) Zippy 30C 5000mah

Props:
Master Airscrew 14 x 9 3 blade

Performance info from testing:

Thrust in Pounds
Prop Amps Watts RPM Prop Calculated Measured Combined MPH Notes
MAS 14 x 9 - 3 Blade 47.44 1482.3 8700 1.35 9.78 11.2 22.4 74.1
MAS 16 x 8 - 3 Blade 63.51 1946.6 8200 1.35 12.67 62.1 Amps too high
Bam 17 x 6 - 2 Blade 55.85 1678.8 8200 1.3 12.75 13.6 27.2 46.6
JFX 14 x 8 - 3 blade E 50.1 1562.4 8600 1.4 11.98 65.2
Xoar 16 x 8 - 2 Blade 60.95 1897.5 8300 1.4 12.99 13.5 27 62.9 Amps too high
JFX 15 x 10 2 Blade E Will test this week

The calculated thrust came from Pe Reivers Power/Thrust calculator. The measured thrust was running both motors hooked up to a digital fish scale. The calculated and measured thrust is for one motor. The combined is for both motors. The trick is to pick the best prop for both thrust and speed. I have a 15 x 10 2 blade coming that may be the best of all tested but I really like the scale 3 blade look so may stay with the 14 x 9 3 blade.

RE: OV-10 Bronco 81
 

Great Looking Bronco Gaines!!!

I need to get my rear in gear on my C-53 project. I've been working on the horizontal stab and elevator for months now - was just supposed to take a couple days[X(]

Keep up the good work and all the information you post for us to learn from..

Tom

RE: OV-10 Bronco 81
 

Gaines, like what you did with the canopy and nose that is what it is supposed to look like and if it is flying ok with the 3 Bld. setup go with it , those numbers look fine. When you recharged the batteries how much did you put back in them? ...Don

RE: OV-10 Bronco 81
 

Don,

Thanks for the compliment on the canopy. If you know Broncos you know the nose is off on Rich's design. His looks OK but I just wanted to try to get it closer.

I had a "hiccup" when I recharged. The power supply I used couldn't handle all 4 batteries at a higher rate so my charger shut down and I lost the info. I'm estimating they used only about 1300-1500mah during the 5 minute flight. I took off at full throttle but pulled back and flew most of the flight at just above 1/2. All 4 packs had 4.0 volts per cell remaining after the flight. So I didn't come close to the 3.5 cutoff. I will post the real numbers after the next flights.

Gaines

RE: OV-10 Bronco 81
 

Tom,

The C-53 sounds like a unique project. Are you posting it anywhere?

Gaines

RE: OV-10 Bronco 81
 

Hey it happens but from what you have said you're going to be fine in your setup. Now don't go and get teary eyed on me but thought about you while I was in Ft. Worth in Jan. I got to go see the Home of the Yankee Air Pirates. When you love Broncos like we do it's pretty cool to go fondle ,oops did I say fondle one of these Ponys, the FAC Museum was really cool. They have can we say 2 1/2 OV-10s as well 2 Oscar Dueceas as well as other airframes. I picked up a few momentos Coffee Cup, Pins ,a cool shirt,Yankee Patch, Jamies hits on CD. Man I was like a kid in a candy store. I thought I would find Ed's Office, Ed only kidding. He He . Keep up the outsanding work...Don

RE: OV-10 Bronco 81
 

Gaines,

Great looking Bronco, where did you find the stickers for that nice looking plane?

Paul

RE: OV-10 Bronco 81
 

Don,

Been there. Just down the road from me. I have a huge file of digital photos of the only privately owned Bronco in the US. He was there for Bronco Fest V in 2003. I have hats and T-shirts as well. Well worth the trip down I-35.

Gaines

RE: OV-10 Bronco 81
 

Paul,

The graphics were from a number of resources and done in CAD. Then copied to a graphics file my local sign guy could use. It is a combination of cut vinyl and print on vinyl. He does some great work but will only do local stuff.

If anyone wants the cad file or some form that your local guy can use PM me and I will email to you.

Gaines

RE: OV-10 Bronco 81
 

Gaines,

Thanks for the info. So as I understand the info, with the master airscrew 14/9 3 blade, you are pulling 47 amps, 1482 watts at 8700rpm and 8 cells. Is that correct? What would be your guesstimate for the speed at full throttle? Did you feel that you had enough power with your set up? I too want to run the 3 blade props. Where did you get the spinners?


Wayne

[/quote]

I'm a novice on electric flight so I spent a lot of time researching, asking questions, and then testing my power systems. But I am sure more experienced electric power guys could have done a lot better. Here is what I have and how it performed during my tests.

Motors:
Common Sense E-90-3
325KV
64 amps max
rated at 2213 watts on 10 cells (I'm using 8 cells)

ESC:
HobbyWing 70A Platinum-70A-HV

Battery:
8 cell (2 - 4 cells in series) Zippy 30C 5000mah

Props:
Master Airscrew 14 x 9 3 blade

Performance info from testing:

Thrust in Pounds
Prop Amps Watts RPM Prop Calculated Measured Combined MPH Notes
MAS 14 x 9 - 3 Blade 47.44 1482.3 8700 1.35 9.78 11.2 22.4 74.1
MAS 16 x 8 - 3 Blade 63.51 1946.6 8200 1.35 12.67 62.1 Amps too high
Bam 17 x 6 - 2 Blade 55.85 1678.8 8200 1.3 12.75 13.6 27.2 46.6
JFX 14 x 8 - 3 blade E 50.1 1562.4 8600 1.4 11.98 65.2
Xoar 16 x 8 - 2 Blade 60.95 1897.5 8300 1.4 12.99 13.5 27 62.9 Amps too high
JFX 15 x 10 2 Blade E Will test this week

The calculated thrust came from Pe Reivers Power/Thrust calculator. The measured thrust was running both motors hooked up to a digital fish scale. The calculated and measured thrust is for one motor. The combined is for both motors. The trick is to pick the best prop for both thrust and speed. I have a 15 x 10 2 blade coming that may be the best of all tested but I really like the scale 3 blade look so may stay with the 14 x 9 3 blade.





[/quote]

RE: OV-10 Bronco 81
 

I'm a novice on electric flight so I spent a lot of time researching, asking questions, and then testing my power systems. But I am sure more experienced electric power guys could have done a lot better. Here is what I have and how it performed during my tests.

Motors:
Common Sense E-90-3
325KV
64 amps max
rated at 2213 watts on 10 cells (I'm using 8 cells)

ESC:
HobbyWing 70A Platinum-70A-HV

Battery:
8 cell (2 - 4 cells in series) Zippy 30C 5000mah

Props:
Master Airscrew 14 x 9 3 blade

Performance info from testing:

Thrust in Pounds
Prop Amps Watts RPM Prop Calculated Measured Combined MPH Notes
MAS 14 x 9 - 3 Blade 47.44 1482.3 8700 1.35 9.78 11.2 22.4 74.1
MAS 16 x 8 - 3 Blade 63.51 1946.6 8200 1.35 12.67 62.1 Amps too high
Bam 17 x 6 - 2 Blade 55.85 1678.8 8200 1.3 12.75 13.6 27.2 46.6
JFX 14 x 8 - 3 blade E 50.1 1562.4 8600 1.4 11.98 65.2
Xoar 16 x 8 - 2 Blade 60.95 1897.5 8300 1.4 12.99 13.5 27 62.9 Amps too high
JFX 15 x 10 2 Blade E Will test this week

The calculated thrust came from Pe Reivers Power/Thrust calculator. The measured thrust was running both motors hooked up to a digital fish scale. The calculated and measured thrust is for one motor. The combined is for both motors. The trick is to pick the best prop for both thrust and speed. I have a 15 x 10 2 blade coming that may be the best of all tested but I really like the scale 3 blade look so may stay with the 14 x 9 3 blade.





[/quote]

[/quote]
Wayne,

The data table got scrambled by the website. The numbers you quote are correct. The calculated airspeed was 74.1 mph. I think that was about right at full throttle. Plenty of thrust and speed to fly the Bronco. I felt that at just above 1/2 throttle it was at scale speed. The 14 x 9 Master Airscrews are not the best performing prop in the mix but for scale appearances they worked very well.

The spinners are stock 2 1/4" Tru Turn 3 blade spinners from Tower. http://www3.towerhobbies.com/cgi-bin...&P=SM&I=LXHME9

The 2 1/4" spinner that Rich uses is a bit small. I'm reworking the cowl mold to use a more scale 2 3/4" spinner. Also from Tru Turn. http://www3.towerhobbies.com/cgi-bin...2&I=LXLW27&P=K

Gaines

RE: OV-10 Bronco 81
 

Gaines

I keep forgetting to ask you on RCSB to show how your battery compartment through the top of the wing turn out. Can you post some pic's, how easy is it to install and remove the battery?


Doug

RE: OV-10 Bronco 81
 

Doug,

The battery hatches are pretty simple but seem to work well. They are made from a combination of FG composite for the hump fairing into the nacelle and reinforced balsa sheet on the wing. The hole had to be large enough to accommodate the 8-10 cell packs I thought I might use and to get my big hands into the opening to plug up the wires.

Photo #1 - Is a close-up of the hatch installed on the wing.
Photo #2 - Show the bottom of the hatch construction.
Photo #3 - I use 4 rare earth magnets to secure the rear of the hatch and ply tabs to hold the front. I was concerned that air could get under the front of the hatch during flight.
Photo #4 - Shows the insertion of my 8 cell battery pack.
Photo #5 - The battery pack is secured in position with HD Velcro.
Photo #6 - There is just enough room to handle and connect the wires before flight.
Photo #7 - The hatch has been reinstalled ready for flight.

Gaines

RE: OV-10 Bronco 81
 

Thanks Gaines for post the pics that work out very well! I'm in the middle of reworking my Bronco to save some weight after adding a set of retracts. I have the batteries in the fuselage and extensions leads with dean connectors running through the wing to the esc's. I'll save a few ounces by removing the extensions leads and cutting some weight on other areas should get me back to my target weight.

RE: OV-10 Bronco 81
 

Oh, not very unique :) It's just a Top Flite DC-3 Kit. I picked it up at a good price back in 2010. Was supposed to start building last year - oops, then just got going this February.

Since I like to make my projects "personal" I found a C-53 Skytrooper here in California. Since they were primarily troop transport and paratroopers, and I skydive, I liked the idea. Then I found out this C-53 flew for the US Geological Survey - and I"M a Geologist:D

So, that's how I decided to do the 53 instead of the DC-3 or C-47.

I have not started posting yet; I do have a bunch of build photos and different little stuff I have been working on (modifying plans, making mistakes, etc.). So I may get something up soon - but it may be over on Scale Builder under the Top Flight Kits.

RE: OV-10 Bronco 81
 

Tom,

I will be watching RCSB.

Gaines

RE: OV-10 Bronco 81
 

Gaines,

That is a neat installation for your batteries. I was under the impression that it took about 2 lbs. in the nose to balance the OV-10. I was planning on using the batteries in the nose instead of adding lead to balance. It look's like your batteries are on the C/G or very close. Are your batteries tied together, or does each motor have it's own batteries seprately?

Wayne