rjtw

Well, as "The Coolest F3ADrive on the Planet" is too unwieldy, keep it simple: ContraDrive.

If you choose my idea, Iwill gladly accept one unit as adequate compensation in return forall IPrights flowing herefrom

Rick

servari

Hi,

I live the 8 th one a lot because of the round shape that reminds a turning wheel. Besides, wouldn't it be cool to have your catch phrase:"our wheels are always turning" written on the sticker, and maybe something indicating where the contra drive was designed (Like USA for example)?

vincent ...

serious power

To continue the theme I was thinking; 'N'3rd Drive ,but it does not work at all.
I think I should just say it ;
Newton Drive

serious power

Dsnow

I made this suggestion to Brenner some time ago but he did not bite:

Contra Drive Innovation by Brenner Sharp => CDI BS

I don't think he liked the BS part.

Dave

Brenner

I've used the BS acronym before in past projects. It hasn't worked out well...

J Lachowski

My Feedback: (46)

BeSharp Contra Drive Systems

Brenner

That's what I told everyone that BS stood for, but no one believed me ...

J Lachowski

My Feedback: (46)

or you could do it musically:

B# Contra Drive Systems

Strat2003

My Feedback: (1)

Unfortunately, B# doesn't exist!

J Lachowski

My Feedback: (46)

Depends on the key you are playing in. B# same as C.

servari

Hi,

Some pics from props with balancer. I used front spinner to set rear prop on the balance.
Rear prop is all right ! a tiny bit for front prop!

Vincent ..

Brenner

Mike and I are thinking about leaving access to the inside of the blades through the hub so that they can be balanced by the user, but if we do that then we have to worry about moisture condensing inside causing a much worse imbalance.

Another thing we might do is used a colored paint spot to show where the hubs can be drilled if anyone ever wants to get access to the inside of the blades, but then we have to worry about shavings and other particulates getting inside also causing an unbalance.

Brenner ...

Brenner

Mike and I put the first flight in on the version 2 Contra Drive today, and it flew
perfectly. My setup was as follows:

22x20 prop
10.15:1 gear ratio with my Hacker 14XL
20C 5050 mah flight pack that was about a year old
The temperature was about 2 deg C
Carf Integral at about 5 kg RTF

The plane was definitely faster than when I ran the same pack with a 22X18 last year.
Based on this one flight I think the switch from a 22x18 to a 22x20 is like
switching from a 22x12 to a 21x14 with a single prop setup. I was very pleased.

In addition, the plane was definitely quieter to my ear. Last year when I flew
with my version 1 Drive the sound would turn into a sharp "bark" as soon as the
plane was moving fast enough on the takeoff roll, but now the bark is gone, and
the sound in the air is now quite pleasant in my view. I attribute this change
to the higher pitched prop and the increased spacing between the props.

r/cdawg

Hi Brenner,

From the pictures it looks like you might have been flying at the Watervliet airport. I travel sw Michigan quite a bit for work and have been known to stop in and put a few flights in there occasionally.

dawg

Brenner

Yes, we were flying at Watervliet airport. The ground is still pretty soggy. I filled my wheel pants up with mud...

Jeff-RCU

My Feedback: (4)

Brenner,
I'm going to be in Watervliet this weekend. If your flying saturday, I'd like to stop by and see it in action.

Brenner

Hey Jeff,

It all depends on the weather. Right now it's still pretty cold here in SW Michigan. If It warms up in to the 50's, and we get some sun, then Mike and I will definitely be out there.

Brenner ...

gmr1948

Hi,

Any update on delivery date?

Gary

Brenner

Hey Gary,

Right now we are about ready to release all of the CNC parts to manufacturing. We are still negotiating delivery dates, because our stuff has lower priority than other jobs that are going through the system. (It costs way too much to pay for priority ...) However, our expectation is that we will receive delivery of all CNC parts sometime between April 1st, and May 1st. As soon as we get these parts we will start to assemble drives and ship them out to people who have placed pre-orders with us.

Our current plan is run a batch of fifty Drives through the system, and after we fill all our outstanding orders we will offer the remainder for sale to interested parties. If we receive more than fifty pre-orders we will try to increase our manufacturing batch size to suit, but if it's too late to do this we will stop taking orders for this batch. My understanding is that as long as parts are still in process, we can increase our batch size if we don't need another manufacturing setup.

Brenner ...

gmr1948

Brenner,

When will customer specific choices need to be made? (gear ratio, motor type, prop size, color)

Gary

Brenner

Hey Gary,

Everything accept color can be changed up until the last minute. We need to know what colors to tell the anodizer to use, so we need to know color by the last week of April.

Brenner ...

serious power

Hi,
We have had our first flights with the contra.
It's early days but I thought I should post a brief report.
I got out on Sunday in a bitter 15/20k North wind.
The flights that I have had with the contra ,13 or 14 now,are my first in 5 months so I do not want to draw to many conclusions to soon.
I used the 22x20 props and the 10.33 gear set.
I put it in the Ventura.
It's mounted on 3 8mmx10mm lord mounts- softest coumpound they(Fibbet)have.
The spinner just sits there,not even a shimmer,as the props spool up.On a hard surface it sounds like a big ,in line,4 cylinder motor cycle engine.A very pleasant sound.In the air it sounds just as I remember Seba's ,so that's the same sound/noise but with a lot more performance.It compares very well with my Plettys.Stronger in the verticals.
I will do noise tests in the next week or so.
The motor ,a Neu F3A,ran very cool but it is still cold here 8/10c.
The YGE 90A controller seems very good, with no spark and no extra connection.
Horizontal speed is very good and the verticals have to be seen to be believed.The height it is getting to in the 'M' is something else.
It is tracking well.The rudder is a lot more sensitive and also the elevator but to a lesser extent.Biplanes are more stable in pitch and roll anyway.
Stall turns seem great,I'm rusty, and I had no difficulty with any of the 20 or so that I did.
Spin entries are good.
The pull over the top of humpty bumps,the 'P' and up the half sq,, loop on corner is great and very 'true'.
I have to learn to stay off the rudder during pushes and pulls.
The downwind loop with 8 pt roll is easier, it carves out over the top back into wind very well.
I use a mode for 8 pt/slow rolls wherein I have only just a little top rudder and elevator to spare. Now I have twice as much as I need.
I think I will/will have to move the cg forward. Some,previously discussed, equal but opposite 'stabilising' forces are gone as is the gyroscopic 'stability'.A more forward CG can be a good thing so if it transpires that a contra driven plane can wear that there will be other benefits as a result.It's looking that way.
The integrated 1/2 outside loop 1/2 roll in the 'M' also seems easier.
Everything seems fine with the drive itself.
All in all a very good experience so far.
As I get more time on it I will post the detail re what I find and maybe add a photo.

Brian

TonyF

My Feedback: (92)

I have just posted my experience with the Contra unit in my Onas in the "regular" pattern forum. Mine are very similar. I didn't measure any weights, I just started off with the battery further back to make up for the slightly higher weight of the Contra. But after 20 flights or so I found myself moving the battery back to it's original position. I do believe with the Contra a more forward CG is better. And I also found much better rudder authority. I decreased my "normal" rudder throw and increased expo.

There is very little doubt in my mind that this is the future of pattern flying. The model is so much better and much more symmetrical feeling. Here are the pics of my Onas.

Doug Cronkhite

My Feedback: (34)

Tony, are you coming to Riverside in a couple weeks? I'd love to see it fly.