Brenner

I have also seen Hacker C50 motors with slipped rotors as well, but not with Contra Drives. This was back when I was flying single prop setups. (a long time ago ..)

The problem with both the Neu and the Hacker motors is that they both use standard N grade magnets, which start to demagnetize at 80C.

I've attached a chart that shows the maximum operating temperature for various grades of magnets.

The magnets used in the Kontronik Pyro motors are grade NSH, which makes them good for 150C . The windings are also rated for 300C, and we use a bearing grease in the rear motor bearing that is rated for 250C.

This means that these motors can run a lot hotter than pattern flyers are accustomed to seeing their motors run, and since the design of the external rotor eliminates any risk of a slipped rotor, these motors should generally be noticeably more robust than your typical pattern motor.

Also, I asked the engineers at Kontronik what the maximum allowable case temperature for their motors was, and they told me I shouldn't exceed 100C, which is at least 20C higher than typical f3a pattern motors.

Brenner ...

I

Henning

Hi,


I did some temp. measurements with the new aluminium front plate installed and it looks like it helps. I will need more flights to see consistent measurements. Just after landing the alu.plate was nice and warm. As I fly in low winter temperatures it is only the difference between the outside temperature of the motor can and the inside temperatures of the windings that makes sense to measure. With the fibreglass front plate I had a consistent 10 degrees C higher readings on the windings. With the alu. plate the difference was only 6 degrees C. I will need more flights and the next time i will add thermal paste between the motor front/screws and the alu. plate for better heat transfer. I will use Arctic Silver 5.
http://www.arcticsilver.com/as5.htm





Br,
Henning

DaveL322

Hi All,

After speaking with APC at the 2016 US NATs, this past fall, I sent a bunch of prop data to APC. APC did some modeling/design calculations for a new set of props - target was to match load of Falcon 23x20F / 23x22R and have better efficiency. Design calculations estimate 23.3x20.5F and 22.8x22.5R. The props would be made from the newer CF/nylon matrix (lighter than the fiberglass/nylon matrix) and be priced at $49 each ($98 for a set). Weight is estimated to be ~175 grams (6 ounces) - so approximately 3 ounces heavier than the various 20-23" diameter CF props currently available. I'd anticipate the APC props would be quieter (no resonance from a carbon skin) and more durable, and very likely more efficient with a good ratio of top end speed vs downline braking.

If the props were to go into production, how many Contra flyers would be interested in running them?

vbortone

My Feedback: (2)

Hi Dave,

I am interested. Thanks,

Brenner

Me too...

jgg215

Also interested

John Gayer

pippy

Dave, would they suit the V4 drives better than the V3? Or would they suit both?

DaveL322

Hi Pippy,

I switched to the V4 drive before trying the 23" Falcon props, but, based on the data I have collected from both the V3 and V4, I think they would be suited equally to either drive. With the V3 and V4, I generally don't change props / gears / settings when conditions change. For me, the larger props have enough braking to fly a relaxed pace in nice conditions, and enough speed to handle windier conditions.

Henning

How will the extra weight affect flight performance and the life of the motor bearings compared to
2 x 50 grams props?


Br,
Henning

Brenner

Hey Henning,

It will be important to set your ESC for a slow acceleration from zero throttle. This is where the added mass will have the most effect, and a slow acceleration is especially important because there are two heavy props, not just one.

There will also be high gyroscopic moments during snap rolls, but these will all be absorbed by the bearings in the rear hub, so the airframe won't see any of this. However, the bearings in the rear hub will see these moments, but since they are momentary, and the bearings in question are pretty robust, I'm not expecting to see any problems.

Brenner ...

DaveL322

Henning,

Specific to flight performance -
I have run the Brenner CF 20" props back to back with the APC 20" props. With a small shift in the motor batteries to keep the CG the same, I don't notice any difference in the way the plane flies (aside from being a little heavier).

underdw

My Feedback: (2)

I've been using 22x18F, 22x20R for years with enough bliss such that I haven't experimented with props much.
Would energy usage go up with the larger props being discussed here, or would it be similar with appropriately lower throttle usage?
Dave, I'd probably try the APC props.

Brenner

Hey Dan,

I've been using the 23" Falcon props on my Allure, and with this plane I find that I am using quite a bit more throttle management than I was when I was using the 22" Contra props, and this has resulted in the same, or less, draw from my packs.

I am typically taking about 3200mah - 3600mah for Masters and P17.

However, I also know that all of this probably highly airframe dependent, and if you run the 23" props hard, they are definitely going to pull more from your packs.

Brenner ...

EHFAI

Dan, I agree with Brenner, the static amp draw will increase significantly with the larger props but throttle management results in less total mAh used. Need to be aware of the draw possibilities flying a big F17 in the wind though!

EHFAI

The larger super light props may make passing the noise test a concern. I've measured the noise of my Allure / V4 Contra (ANSI Type II meter, same fully charged pack for each test, and the F3A protocol). In comparison to the 23" Falcons, the 22" Contras measure 1dB less and the 20.5" Contras 2dB less. A nylon filled (APC) prop might be expected to be quieter, but Brenner is aware of the design criteria necessary to keep noise down. However, I'd love to try a set of the new APC props if they become available.

Brenner

I noticed this 1db difference at the 2016 Nats.

The 23" props were enough to give me problems with the sound check, whereas I've always been able to pass with the 22" props. However, fortunately for me, there was no sound check in masters at the 2016 Nats, but this can easily change in 2017.

Earl is working on some possible fixes for the Falcon 23" props, and Mike Gaishin and I are going to cut molds this winter for our own set of 23" props.

We plan on putting more carbon fiber in the hub area and along the leading edge of the blades, so they will probably be 5g to 10g heavier, (for a set..) but we are going to try and make them as quiet as possible.

Brenner ...

Henning

Was this with full throttle or do you have the ATV reduced and or a Throttle Tech sensor?


I have not done any sound checks yet but will be surprised if if don´t pass the sound check with the V4/Pyro 600 and Falcon 23”x20F and 23”x22R. My Throttle tech sensor is set to 37 and I have reduced the ATV to 90% in addition with the Mezon 95 ESC. In the air I have enough power to fly my Naruke Ascent BiP through the F17 with amp readings at max 74A in the air. The average consumption is 3200-3300mAh which is just within the limit flying with 4150mAh packs from Hacker (900 grams).




Br,
Henning

DaveL322

To echo a bit,

Yep, the 23" props definitely increased peak amps static and in air. However, for flights of equal size/distance/pace, the 23" props are more efficient. If Throttle Tech were used to match the amps of the 23" props to your current setup, I suspect the 23" props would still be more efficient.

Thanks for the feedback!

PeterP

I thought I would share some of my recent experiences on various updates I have made with my Brenner V3 setup.

I am still flying the V3 Contra (3rd season) and it is still going strong with no evidence of wear on the Brenner drive (500-600+ flights). I had a recent issue with the NEU motor which also took out my Spin 90 ESC so I made the decision to give the new Hacker C54 a try (advertised 1280 KV) which is similar to the NEU. This resulted in purchasing a new manifold and pinion gear assembly and mount to get it working. I must say I am really impressed with the quality of the Hacker and the way it delivers its power. The performance seems slightly better, smoother throttle transition, running significantly cooler than the NEU and a saving of 40 grams in weight. In addition I would say that power consumption has reduced slightly with this setup. I have also upgraded to Jeti Mezon 95 Opto lite which I purchased for my V4 and I am really impressed with this combination. There isn’t any real weight penalty with this ESC but the idle RPM can be set as low as 150 RPM if you want that. The braking performance seems better as I had to reduce the amount of brake I was using previously. Not sure if that was a result of the Hacker C54 or the Mezon ESC. In design the Mezon appears to be at another level when you compare the circuit design btw the Spin. Overall I think there are significant benefits over the SPIN with the ability to recall flight min/max values at the end of the flight or view live data on the ground with the programmer box attached.

I did a bit of a search on the net and came across a new product called a JLog-S32. It basically converts Jeti EX data stream to Futaba FASSTest the following link provides some interesting reading. http://j-log.eu/s32/s32-en/jlog2-6-s32-en/ so my Jeti Mezon now feeds data Volts, current, capacity, temp, rpm directly into my Futaba 18MZ for real-time display. This unit only weighs a few grams and will be an invaluable tool to monitor the performance of my setup. The beauty is don’t need to wire an inline current sensor to give you this feature. (If you fly with a Jeti radio you obviously don’t need this item)
The Jlog also the ability to log all this information on a micro SD card for further analysis. All information is time and date stamped so you can recall information to a particular point in time. The Jlog has to ability to translate to most other telemetry protocols if you fly some other brand of radio.

underdw

My Feedback: (2)

Thanks for the post Peter. I have a couple of V3 drives that I love and run flawlessly.....except that the Neu motors fry about every 2 years.
Did you just buy the manifold Brenner makes for the C50? Anything else one would need for the conversion? Do you know of a US source for the motor without gearbox?
Dan

PeterP

Hi Dan. all you need is the C50 manifold and the pinion gear assembly for the Hacker as it needs to be shorter to make the conversion. I was using a Hyde mount previously with the NEU so I also had to deal with that to fit it to my model without making any mounting changes to the model. The motor is a little shorter a little wider so you need to modify the rear mount slightly. It may seem like a bit of work but well worth the effort. This combination is the best I have flown. I am using the 10.15 gearing and 22x20 front and rear. Great performance and ideal speed envelope from light wind to heavy wind.

PeterP

Here is the link for the C54 Hacker motor to suit the Brenner V3 drive http://www.hacker-motor-shop.com/e-v...&c=8123&p=8123. I would have thought F3A unlimited would sell them other you can buy directly from Germany. Another option is to buy down under from https://www.precisionaeroproducts.com.au. The current exchange rate favours you guys so that could make it viable.

Jason Arnold

I have everything BUT the C54 in stock at the moment. Should have the C54 available in three to four weeks.

Cheers,
Jason.

rgreen24

My Feedback: (6)

Can you post some pics of the jlog in your plane, how you hook it up and where you can purchase it. I also fly an 18mz and this information would be very helpful to have - I am also runnng the Mezon

ltc

My Feedback: (3)

I would suggest trying here
http://www.espritmodel.com/jlog-2-6-...y-gateway.aspx

Additional info here
http://j-log.eu/jlog2-en/