Official Nexa OV-10 Bronco 1800mm ARF Discussion Thread

[OV10]

Gents...I found a drawing to help make a dual battery dual ESC Parallel system cable

TwistedGrin

Thanx for posting the ol' standard TG.
The 4th one down is the most typical configuration going.

[TwistedGrin]

Gents,

Just posting up some personal observations regarding the ProFly OV10:

Recommended Servo arms are short:
I have observed in my early stages of assembly...the MotionRC recommended Hitec HS-85BB servo arms are so short...they don't meet the assembly manual recommended length of 16mm from center to outer hole of the servo arm.

Small servo arms only provide 12mm of travel:
On my assembly this translated to a total travel of 12mm on the Aileron surface. This is the assembly recommended travel....but even then the linkage hardware is a nats hair above the servo mounting plate.

Longer servo arms provide at least 20mm travel:
I was able to find a longer servo arm that fits on the Hitec HS-85BB servo head....it is the recommended 16mm length from center to an outer hole. This sets up the Aileron surface to travel at least to 20mm...thus a "High" rate is achievable over the low rate 12mm.

Additional stress on the servo with longer arms:
I hope the additional distance from center does not cause over tork of the HS-85BB Mighty Micro servo's.

You may not receive the (2) 500mm control rods required:
Next: In my kit there is no 500mm control rods needed for the rudders. I am having to make my own.

The shorter HS-85BB servo horns work for the flaps:
The flaps can use the servo horns that come with the HS-85BB servo's since we set the servo horn with enough bias angle (60degrees) for Neutral Flap position (UP)...the required rotation for flaps down to 20mm travel is achievable without any hardware interference.

Might look for a different size servo package:
I would check for a larger servo that would fit this airframes servo pockets that has a longer servo arm if I were to do this model over.

CA Hinge deployment - Your build technique depends on the materials:
One more detail to cover. In MotionRC's build video by James for his surface hinge deployments....he suggest to drop in some CA then push them into position. What he does not detail is the type of CA he is using.....must be a slow dry. If you use standard thin CA the bond will be nearly instantaneous you will certainly NOT be able to re-position the hinges after dropping on the CA. Therefore be sure to insert the hinge / control surface all the way as desired - then drop in the CA for the instantaneous bond!!

TwistedGrin

[TwistedGrin]

If you felt a disturbance in the Force last night - it was me as I allowed my pull string to the Elevator servo wire fall out....God Save the Queen, Bob's your Uncle and other terms of endearment flowed for quite awhile until I managed to find another means of pulling that servo wire through the vertical stab. I wanted to stay on the side of the servo lead orientation if possible.

I also deployed ball joint clevis's to the rudders, my control rods were pretty soft so I deployed carbon fiber tubes to prevent any bending to those rudder control rods. Also I am deploying larger servo arms all the way around except for the flaps.

TwistedGrin

[TwistedGrin]

Motor comparison,

In the original MotionRC video by James....he states he had the Admiral GP20 motors with 16x9 props power by dual 4s LiPo and cruising at 50% throttle. This would be nice.....but the GP20 motors are rated at 295Kv......so at 14.8v that's roughly 4366rpm:

Just for comparison here are some numbers......
Admiral GP20 296Kv x 14.8 = 4366 rpm
Admiral GPS 4220: 770kv x 14.8v = 11396 rpm
Admiral GPS 4220: 770Kv x 18.5v = 14245 rpm
E-Flite Power 52 590Kv x 22.2v = 13098 rpm

We all know the Watts / Amp loads vary with battery to prop sizes for thrust. But I can't figure out if I could throw a 16x9 on the E-Flite Power 52 590Kv x 14.8v = 8732 rpm and have a long running set up?

TwistedGrin

[OV10]

Motor comparison,

In the original MotionRC video by James....he states he had the Admiral GP20 motors with 16x9 props power by dual 4s LiPo and cruising at 50% throttle. This would be nice.....but the GP20 motors are rated at 295Kv......so at 14.8v that's roughly 4366rpm:

Just for comparison here are some numbers......
Admiral GP20 296Kv x 14.8 = 4366 rpm
Admiral GPS 4220: 770kv x 14.8v = 11396 rpm
Admiral GPS 4220: 770Kv x 18.5v = 14245 rpm
E-Flite Power 52 590Kv x 22.2v = 13098 rpm

We all know the Watts / Amp loads vary with battery to prop sizes for thrust. But I can't figure out if I could throw a 16x9 on the E-Flite Power 52 590Kv x 14.8v = 8732 rpm and have a long running set up?

TwistedGrin

I'm confused here TG. I can not find this video you are referring to where you say James is using the Admiral GP20 295kV (not 296) or 16x9 props
The only one I found is under the video's tab of the Bronco's product page which is listed as Step 6 Motors.
He clearly identifies the Admiral GP5 4220-770kV motors which are the ones recommended in the product overview page and those of course won't handle a 16 dia prop.

Regarding you quandary over your EF Power 52...…………. eCalc is a cheap tool @ $6/year.
I ran some quick numbers for ya.
The recommended prop to go with the GP5 on your Power 52 will be marginal in performance with just under 5 min run time using 4k mAh 4S.
Thrust/weight ration is .65 with operating temp of 100F and current demand of 30A
Put that 16x9 on the Power 52 and your run time dropped by half to 2.6 minutes on the same batteries.
Thrust/weight ration is 1.2 with operating temps jumping to 142F and current demand jumping to 71A

If you want to use a scale looking 3 blade like a MAS 16x10x3 then I would highly recommend a 6S power driven system.
Higher voltage always means more power efficiency for less current demands.
If you would like a recommendation for motors, I used the FL Spitfire 5055-390kV (6S) using that MAS prop on a 93" AMS A-26

I do believe you could have clearance issues with a 16 dia blade since this Bronco is a 1/6.8 scale bird whereas 15" is scale ( 102" is full-size)
I suggested way back in the beginning of this thread that the FMS Tigercat prop/motors would be a really nice marriage of power and scale fidelity of prop diameter at 14"

Hope ya found this info and suggestions helpful,
Best regards,

[TwistedGrin]

Thanks OV10....

James's comments are in his flight video from the Joe Nall event where he states the motor, prop and battery combo.

I intend to run either 5s or 6s on my set up....so I am looking for a good matching prop combo to go with it....thanks for running those number in e-Calc. Ya running the Power52's on 4s would not work very well at all.

I might just try out some 15x7's on the 5s twin battery set up and a 12x8's on the 6s set up .....

TwistedGrin

[didier n]

I will use the FL Spitfire 5055-390kV motors on 5s swinging a 14" 3 blade varioprop. This gives me the opportunity to set the pitch myself if it's not enough i can still go 6s ....

[OV10]

I will use the FL Spitfire 5055-390kV motors on 5s swinging a 14" 3 blade varioprop. This gives me the opportunity to set the pitch myself if it's not enough i can still go 6s ....

I don't believe that the 5S is gonna do it because turning a 14" prop at 7215 rpm just isn't enough. That motor was designed to use 6S swinging 16 inch blades at 8658 rpm.
Examples of rpm ranges for 14 inch props that have been time tested for performance and reliability are the FMS 1400 P-40B, FMS 1700 F7F and the FMS 1500 P-47.
All three planes use the same 14" prop blades which is 14x8.
The P-40 uses the 4S 4258-kV650 which turns 9620.
The Tigercat uses the 6S 4250-kV460 which turns 10,212
The Razorback uses the 6S 4258-kV460 which turns 10,212

Prior to FMS finally getting in the performance groove they used the 4250-kV580 on 4S which turned 8584 rpm which was okay but was highly criticized and modified over the years due to the less than stellar performance.

So as you can see the Spitty motor on 6S is still approx. 1000-1500 rpm below the range that is required for the 14" blade performance and on par with the old lackluster 4S 580kV days.

I'll also remind that the Spitty motor was designed for a 16x10x4.

The amount of pitch that is going to be required of that Variomoser to achieve the appropriate thrust factors will more than likely have that thrust erased due to extreme prop turbulence.
It will be interesting to see what you find if you do as expressed.
Best regards,

[didier n]

I don't believe that the 5S is gonna do it because turning a 14" prop at 7215 rpm just isn't enough. That motor was designed to use 6S swinging 16 inch blades at 8658 rpm.
Examples of rpm ranges for 14 inch props that have been time tested for performance and reliability are the FMS 1400 P-40B, FMS 1700 F7F and the FMS 1500 P-47.
All three planes use the same 14" prop blades which is 14x8.
The P-40 uses the 4S 4258-kV650 which turns 9620.
The Tigercat uses the 6S 4250-kV460 which turns 10,212
The Razorback uses the 6S 4258-kV460 which turns 10,212

Prior to FMS finally getting in the performance groove they used the 4250-kV580 on 4S which turned 8584 rpm which was okay but was highly criticized and modified over the years due to the less than stellar performance.

So as you can see the Spitty motor on 6S is still approx. 1000-1500 rpm below the range that is required for the 14" blade performance and on par with the old lackluster 4S 580kV days.

I'll also remind that the Spitty motor was designed for a 16x10x4.

The amount of pitch that is going to be required of that Variomoser to achieve the appropriate thrust factors will more than likely have that thrust erased due to extreme prop turbulence.
It will be interesting to see what you find if you do as expressed.
Best regards,

Interesting explanation, i will surely let you guys know the outcome... as said, i can always go 6s if needed.... We have a FL spit flying at the club, and i found it performing outstanding on 6s... with the standard 16 x10 prop.... so if my theory is correct when going down in size, i can increase pitch... I've also seen germans running 14 x14 prop's and getting nice results...time will tell

[wperry38]

would you guys please share with me how much weight you are putting in the nose to get the c/g at 85.
thank you
bill perry

[fjkelley@cox.net]

I am using/flying with two 5s, 5,500 MaH LiPo's. I added zero nose-weight.

Old Dawg

[sam51401]

Flap question
I used the stock CA hinges and HS225MG's and like to hear what deflection other are achieving as mine seem stiff and im concerned about stalling the servo when moving past the TO deflection. Thinking of redoing them and using pinned hinges to allow freer movement.

[wperry38]

I am using/flying with two 5s, 5,500 MaH LiPo's. I added zero nose-weight.

Old Dawg

thanks for the reply i am using 2 4s 4000 mah looks like i will need about 8 oz in nose
BP

[wperry38]

thanks for the reply i am using 2 4s 4000 mah looks like i will need about 8 oz in nose
BP

anyone else using the 4s 4000

[TwistedGrin]

Just a note: XOAR PJN 15x7 prop fits the MotionRC stock OV-10 prop spinners.....I don't think any larger XOAR PJN prop will fit

TwistedGrin

[WrightBrosRC]

It's been a long day...

[WrightBrosRC]

This is the video from yesterday's flight. The cargo drop went well, mostly...

[didier n]

The LG i will be using, still needs some modifications, and i'll have to cut into the fuselage to get it all in when retracted.... Electron retracts, 100° now let's find some decent wheels...

[MikeT]

I'm very close. Was missing the 4mm insert in the elevator so I pulled the hole drilled than tapped it.Otherwise it went together great.I just need to figure out how to transport it. LOL.

Mike

[Twowingtj]

Looks good Mike!