OhD

All good info Brian. That holding the middle spinner is the hard part. I ended up putting a large washer on the brass puller and using a large wheel puller to pull the whole thing forward. it took a bunch of force so I will do the polishing. I would have been dead in the water if I were 90 miles from home.

Jim O

Bubblehead575

Is there an update on when the V4's will be coming available?

Brenner

Yes,

Right now we are in discussions with Kontronik to have them supply modified Pyro motors for us.

We are also in the queue for CNCing our first batch of fifty parts, so we should be building and starting to ship Drives during the month of December.

In the interim, I am going to arrange for www.f3aunlimited.com to start taking preorders. This should happen in the next few weeks.

When it happens, I will announce it here on RCU, and I'm sure that Mike Mueller will also announce it on the f3aunlimited website.

Brenner ...

TonyF

My Feedback: (92)

Brenner sent me a V4 and a Kontronik Pyro 650 motor. I installed it in my Episode which previously had a V3/Neu. It was pretty simple to retrofit since I used his mounting plate with the V3 installation with the bulkhead in front of the unit. About a 3/8" spacer and cutting the motor shaft put it in the model. I was able to get 5 flights in yesterday. I didn't weigh anything but this is quite a bit lighter then the V3/Neu. The unit is just beautifully engineered and fabricated. And it is really simpler then the V3.

The V4 is very smooth in the air. Quieter then the V3. The power is maybe a bit better then the V3/Neu but I have the Pyro 650. The Pyro 600 is higher Kv and should make more. But I honestly wouldn't know what to do with more power. I very rarely have to use full.

Brenner

The V4 Manual is finished.

See attached for a first draft.

Brenner ...

jankulus

Nice work with the drive Brenner!

Has anyone tested the energy consumption on V4 yet?
I mean how many MAh`s per for example P-17 sequence it consumes from the battery?

Regards,
Jan

Brenner

Hey Jan,

The energy consumption is no different than with the V3.

It depends on the flying style, how big the maneuvers are, and how far out they are being flown. Typically, I am using from 2800mah to 3800mah.

This is using motors that generate about the same power as the V3 Drive. I have been testing some really hot motors that draw up to 4000W, and the energy consumption with these jumps up considerably. With some of these motors I've been seeing more than 4500mah, but for the purposes of testing I fly 6000mah packs, so I was pushing the limits. (These packs also let me fly longer as well, over 10 minutes..))

Brenner ...

jankulus

Thanks a lot!

Standing by to see it available!

Cheers!

Jeff Worsham

My Feedback: (28)

Brenner,
Having never run a contra, I have to say your manual answers all my questions about theory of operation, mounting, use, and maintenance. How is the manufacture-ability of V4 vs V3? Any issues which might affect drive availability or spare parts moving forward?
Thanks,
Jeff

g_mkoch

I'm curious, how does the battery consumption of the V4 Pyro compares to a standard single prop outrunner (Pletty, Q80XS)?

HerbK

Very nice job on the manual Brenner. Your explanations and diagrams are very clear Having run one of the prototype V-4's for a while you covered all of the issues very well. I would emphasize that tightening of the pinion gear bolt is very important to be sure the Colette is set on the motor shaft. I thought I had it tight enough before you had the torque measurement but on one occasion I noticed that it slipped a little during flight. I re-tightened it at the field and had no problem. Also your hint about removing the Colette is important as it can get stuck and needs to be rapped to release it as mentioned in your manual. Re greasing and assembly of the drive are easier then on the V3 also the grease reservoir really helps as I went over 100 flights and the gears still had nice grease on them. Looking forward to buying one of the V4's to put back in the plane.

Herb

Brenner

Hey Jeff,

The manufacturability of the V4 is actually quite a bit better than the V3 Drive. This was one of the reason why we developed the V4 concept in the first place. The V4 has fewer parts, and we have developed roller burnishing methods to size the critical bearing bore dimensions, and the collapsible collet diameters.

The CNC machine that we are using to make our parts is brand new, so it holds tolerances very well. It is actually capable of holding +/-0.005mm (+/-0.0002") but we don't specify our parts that tight. The tightest tolerance we specify for CNC machining is +/-0.01mm, and then we use roller burnishing to get critical dimension tolerances down to +/-0.005mm. This means we are able to reliably hold a Cpk = 2.0 on all critical characteristics in the design. (Cpk=2 means that the part tolerance is twice the manufacturing process capability..)

As far as spare parts are concerned, moving forward we should have the same parts availability for the V4 as we have now for the V3. Right now we are challenged because we are committed to supporting our V3 Drive with spare parts, and at the same time we need to find money to invest in manufacturing our first batch of parts for the V4, and since we haven't actually sold any V4 drives yet, we are essentially using the revenue stream from one Drive to support two Drives.

However, this is a temporary problem that we have solved by reducing the size of our first batch of V4 parts. This makes parts quite a bit more expensive, but as soon as we start shipping V4 Drives, the additional revenue stream will let us manufacture more economical batch sizes.

Brenner ...

Brenner

I don't think the battery consumption is dramatically different from a single prop setup. However, it's difficult to make an accurate comparison because of all the different factors that can affect battery consumption.

With the V4 Drive there are several motor choices, and they each trade-off battery consumption with maximum power. I've run a Pyro 650-78 motor, and finished flights in AMA Masters (similar to f3a P) using only 2500mah. I've also run a Pyro 650-103 motor, and consumed more than 5000mah for the same flight. (The Pyro 650-103 is pretty much unflyable though ...)

I think there is enough flexibility in the design and the setup to allow a pilot to configure a system that exactly matches his needs, whatever they be. for example, Jason Shulman likes to fly small, tight, and slow, and for this he prefers the Pyro 650-78 motor, whereas Dave Lockhart prefers to have huge amounts of power available for him to call on if needed. (I'm sending him a Pyro 650-103. If this isn't enough power, there's nothing more I can do for him..)

Brenner ...

underdw

My Feedback: (2)

Hi Brenner,
Might I suggest funding your initial V4 manufacturing by taking deposits from customers? Your reputation and support have built you a loyal, trusting base of customers.
Dan

Brenner

Hey Dan,

Yes, I agree. This is something that we will do as soon as we ship our first batch. However, for now we have the first batch covered.

Brenner ...

PeterP

Hi Brenner,

The delivery of power, speed and braking of my V3 drive using 10.15 gearing and 22x22R + 22x20F is very well suited to my flying style. Will the V4 combination you have selected have a similar feel in the air? What motor option will you be supplying as standard as part of your initial batches.

Brenner

Hey Peter,

Our plan is to supply the Pyro 600 motor as standard, but we can easily supply any of the Pyro 650 motors as well.

I think the Pyro 650-83 will also be a good choice for a lot of people. This motor will probably be the best match for your V3 setup.

With the stock setup I think you will notice more power at full throttle, but the Drive will also be noticeably more quiet, and the throttle response will be more linear.

I am currently flying with a completely linear throttle curve on my V4 setup, and what I am seeing is better speed control in the midrange of the throttle curve. Anywhere in a maneuver I can push my throttle up a click, or down a click, and I get the same speed response from the plane. Also, when I am climbing across the top of large maneuvers, I can push the stick forward, and the Drive still has enough headroom to accelerate quickly.

Brenner ...

Brenner

This is an ad that f3aunlimited.com is planning to run in the January issue of Kfactor magazine. (Kfactor is the monthly magazine published by the NSRCA ..)

Brenner ...

Jason Arnold

Hi Brenner,

What soft mounting system are you suggesting for the V4?

Cheers,
Jason.

Brenner

Hey Jason,

We are recommending the Budd Mount System. The rubber in these mounts is soft, but the stiffness of the mount is non-linear in that it stiffens up when the Drive is deflected.

This means that high rpm vibrations are isolated, but the drive is still mounted firmly in the plane.

The V4 will come with a complete set of mounts and carbon fiber mounting plates for this system.

Brenner ...

PS-> Here's a picture of the V4 on a scale. Proof that the total weight, including Drive, Spinners, and Props, is 600g

servari

Hey guys,

has the pyro 600 you use a 1200 kv ?

Brenner

We are using the Kontronik Pyro 600 with about a 950 rpm/v kv.

This is a small helicopter motor that has been designed to really take a beating. The magnets are rated for 150C, and Kontronik says that the windings are good for 300C

As far as the motor design itself is concerned, there is a big centrifugal fan in the rear of the rotor that pulls cold air in at the front, blows it over the windings and the magnets, and then pushes it out the rear. This fan is several times the size of the fans that you typically see in inrunner motors.

Based on the testing I have done, my prediction is that on a 40C (104F) day, the maximum case/rotor temperature shouldn't exceed about 80C, which should be significantly under what the motor is actually robust to.

In addition, what I do is position my ESC directly under the rear of the motor so that the fan also keeps my ESC cool.

Brenner ...

servari

Hey Brenner,

It's a good news.
Do you know How many RPM you reach with the Pyro 600 at full throttle with APC carbon props ?

Brenner

Actually, I don't. The 20" carbon fiber props haven't been a good choice for the V4 because they allow the Drive to over-rev, and the speed is insane due to the high pitch.

I flew them one time, and I think the speed must have been more than 130 mph. (210 kph) (maybe even 150 mph. Either way, it way too fast ..)

Rather than reduce the diameter of the props, I think the V4 would do better with larger diameter props. I think a sweet spot would be somewhere between 23" and 24"

For now, what I've found is that the 22x22 rear, with a 22x20 front works very well. This setup is whisper quiet, the vertical is completely unlimited, the acceleration is powerful, and it has very excellent speed range.

A 22x20 rear with a 22x18 front also works, but at full throttle this setup also tends to over-rev. (not as much as the 20" props ..) It's usually better to ATV the throttle back a little with these props to avoid this.

I definitely think the future for Contra Drives is going to be with larger diameter props. Probably 24" to start. I that a 24x22 rear, and a 24x20 front, would be fantastic.

Brenner ...

servari

Hey Brenner,

Thanks for the informations.
On the TonyF's pics, I can see 10S pack. Is it the norm or is it possible to use the drive with 8S pack ?