J-P

My Feedback: (1)

I have been flying the OS BELT DRIVE for 3 years with great success, and while attending the European Championship in Belgium this year, I paid a special attention to a belt drive prototype installed on Danny van VLIET ASCENT.
I knew about the popular ADVERRUN CONTRA, but was immediately interested in this single drive prototype.
Having flown with the OS BELT DRIVE for more than 2200 flights, it was interesting to have the possibility to compare both engines.

I received two weeks ago a prototype lend by Robert HIRSCH to install on one of my planes, and perform a serie of flights and maybe more ...

The idea was to evaluate and compare objectively both belt drive engines.
Same plane , same FUTABA ESC, same TP 5000 PROLITE X batteries, same 22 x12 NURILA carbon prop.

JP
AMA 347801

Arnaud POYET

Very nice.

preston blake

I'd also find interesting a comparison between the single belt drive and the contra unit in an otherwise identical setup. Maybe we don't need the complexity of the "contra" units...just the benefit of different props and different torque curves.

big_G

Excuse my ignorance, but what are the advantages of a geared or belt driven prop?

wattsup

My Feedback: (1)

I'm not really sure but, I think Preston Blake had the answer to your question prior to your asking_ ie, " the benefit of different props and different torque curves".

J-P

My Feedback: (1)

Most of the time the airframe weight is a factor when choosing an engine.
By chance manufacturers improve their building technique, and when it's time to decide about which engine ... you have choice now.
I have been using all majors brands, and despite the weight, my favorite is the OS BELT DRIVE.
The new version I installed in a ZEBEC is the same as the first version, with a slightly increased belt size from 9 to 11 mm.

Regarding the weights, the best is to put the engine on a scale and to read …………
Most of the pics are by swk550 .... thanks

preston blake

JP, might you summarize the benefits of a belt drive over a direct drive such as the Plettenberg 30-10

OhD

1) High rpm motor is more efficient and lighter
2) Motor torque is lower so reaction torque on the airframe is lower

Jim O

Arnaud POYET

Hi.

Yes I agree with this.

In addition, the "natural" brake is better and the drive is more smooth than a direct motor.
Like JP, I've been trying this engine for some time.
It's a very good solution, very light and very powerful.
I use a 22x12 Lassi at 6300 at full throttle on the ground or a Falcon 21x14 at the same RPM.

Best regards

RuneG

Whats the weight off this new singel belt Adverrun?

J-P

My Feedback: (1)

The engine I received from Robert HIRSCH is one of 10 prototypes a few top pilots .. I'm not one of them ....are testing.

Without soft mounts and rear support, the weight of mine is 555 g.

The final weight of the engine including 4 soft mounts will be around 510 g, red anodized, and more sexy than the preproduction engine.

There is no adjustable tension device, belt is oversized compare to the OS BELT DRIVE, there are bearings where needed, and it looks maintenance free ....

It will soon hit the market - ask Mike MULLER at F3A Unlimited - after intensive flight tests.

Malcolm H

Hey Jim,
"Motor torque is lower so reaction torque on the airframe is lower"

You'll have to explain this one to me, surely its the gearing output torque that's reacted into the fuselage not the motor torque? Therefore for a given propeller torque the reaction torque is the same regardless of the type of drive.

Malcolm

OhD

Hi Malcolm,
I've been waiting to see if there was some smart guy out there that would catch me on that one. In the single prop drives being discussed here the "gear box" is mechanically coupled to the motor/airframe and you are correct. What I said applies to the Contra drive where one propeller torque reacts against the other propeller and the "gear box" output is not coupled to the airframe. But you already knew that.
If I hadn't made the statement though, and you hadn't replied, we wouldn't have been able to highlight one of the features of the Contra. By the way at our recent District championships, all pilots flew electric and about 30% had counter rotating props .

Jim

Malcolm H

luckymacy

LOL, it's already here - bell bottoms and contra drive biplanes!

Anybody owned a contra drive biplane and decided it wasn't that great after all and ditched it? I see a lot of bipes like the Biside for sale but not contra designed bipes.

What I find interesting is that some of the top fliers can go back and forth on the same day between a contra and non contra type plane without seeming to miss a beat. I have never flow contra so that makes me suspicious it's more hype than practical help but lesser skilled pilots than the F3A type flyer have told me that contra is easier, almost like cheating, and they'd never go back to non-contra in pattern. Reminds me of the folks who say they'd quit pattern before every going back to glow. So I guess if you have the muscle memory and recognition to move the rudder to compensate for the torque factor before it even gets a plane out of shape then it's not that big a deal not to use contra. Obviously so many of the very top pattern guys would tend to favor a plane that has bountiful power on a windy day (ie YS engine) than a contra drive option, all things being equal, so contra isn't the silver bullet. Someone we all know is about ready to debut his YS powered biplane to test it out for the upcoming Worlds and that'll shock some folks. Same person has bounced around with all different airframes and powerplants in pattern and flies great no matter what they are using.

wattsup

My Feedback: (1)

"Contra in one form or another are the current vogue"? It is a fact that "Contras in one form or another" have been flown successfully in many contests since June of 2010! Where have you been?

ltc

My Feedback: (3)

J-P

My Feedback: (1)

I think there is no difference between OS version I an II , except one of the belt has been enlarged from 9 to 11 mm

Regarding the brake, I followed OS / FUTABA recommendations and use 28 % with both RS 21 x 14 or Nurila 22 X 12 props.

ESC: OS OCA-1100HV
Acceleration: Lowest
Start power: Low
Advance timing: 0 degree
Air brake type: 15~25%

These are the exact settings I'm using for testing the AVERRUN SINGLE DRIVE

preston blake

I enjoy these discussions about the relative merits of different power/prop setups. I transitioned from an Osmose/Pletty/21x14 to an Inspire/V3 contra, then Agenda/V4 and now a Angelit/V4. For me the contra is about ease of speed control. I'm fortunate to have Joe Walker as a flying buddy and he alternates between a Fantasista/Pletty and an Agenda/V4. He flies both well but as I coach/critique his flights his speed control is better with the Agenda. I believe therefore that the contra's benifit is speed controll, not decreased left turning tendencies. Which then opens the question, might a single prop belt drive not offer the same advantages ? As a strong believer in the KISS principle, I'd prefer to get rid of the extra prop and mechanics required to drive it.

J-P

My Feedback: (1)

In order to compare the AVERRUN SINGLE DRIVE with the OS BELT DRIVE, I modified a plane to be able to install both engines.

With no time to wait for CNC cut parts from RS, I did the necessary parts with a dremel ....

I used 4 mm carbon plywood sandwich for the front and side supports, and a 1 mm carbon plate for the rear one.

Robert HIRSCH recommended me a rigid front and soft rear support, but I had to install the SINGLE DRIVE as the OS with four soft mounts on the front, and 2 at the rear.

Arnaud POYET who test flew the engine tried both, rigid and soft mounted, and didn't noticed any difference.

With the KONTRONIK wires on the opposite side of the OS, I extended by 10 cm the wires between the FUTABA ESC and the engine with PRC Silicone Wire 12 AWG.

Installation is complete ... next the ESC settings and first flights 😎😎

luckymacy

why not just go contra instead of all the install hassle without the contra drive benefits?

wattsup

My Feedback: (1)

To quote J-P from the first of this thread "I have been flying the OS BELT DRIVE for 3 years with great success".......I can't speak for him, but I believe this is his preference and unlike some, J-P has figured out what works fo him and is NOT just following the crowd.

MAVROS

Monkey see Monkey Do........blah blah blah

Its always about who has the shiny new gadget ......YS, ELECCTRIC, MONOPLANES,BIPLANES,CONTRA,SINGLE DRIVE.........BLAH BLAH BLAH
The sport is all about NOISSICERP aerobatics and no-one talks how to do a loop or a roll properly.....or how to compensate for that wind or energy management etc etc

If you are not skilful or talented ( like me) don't worry we have a fix for that.

OOPS did I go too far sorry

Hans Meij

Hi J-P,
Very interested in your experiences with the drive. Please let the info flow.
Have 3 OS drives. 2 V2 and one V1 converted to 11mm belt. Also very happy with belt drives.
Regards, Hans

preston blake

New technology is part of the fun...otherwise I'd still be flying my Veco 45 powered Kaos.