Z Power Z20A motor is very efficient - I am a believer now

[ke6d]

I have been flying my Hurricane with the RCP H/18 on 13T pinion for quite sometimes already. The motor is a little bit hot at the end of the flight but I could live with it. With all the talk about how efficient the Z20A motor is, I was kinda skeptical at first, but then decided to get one to try out. If I could get motor to run cooler at the end of the flight, I probably would be very happy with the investment.

The motor arrived a couple weeks ago, but the rain had been pouring therefore I could not check it out. Anyway, I decided to take advantage of a a couple days of good weather in Northern Californion, take the Hurrincane out, and test flight the new motor.

The new Z20A 980Kv motor is running on a 14T pinion with a headspeed of 1900 (verified by a SkyTach tach). The RCP H/18 motor was running on a 13T pinion with a headspeed of around 2000-2100.

Attached are the plots of the H/18 motor and Z20A motor running for 6 min on a set of FP3200 EVO30. The Hurricane was flown with pretty much the same styles on both flights - I wanted to thrash the heli hard to see how the battery/ESC (Align 75A) are holding up.

Oh man, now I know where most of my good electrons go :)

Cheers,

Dan

[mjdee14]

Yup ! Looks like you were using a whole lot of Mah with the H18....

Did the reduction in HS seem noticable? Are running in non gov mode? hard to read the chart but looks like your rpm or whatever the yellow line is was fluctuating up and down like it was in non-gov mode.

But it does confirm what I have been seeing....the Z20 980 is a perfect motor for us non 3D flyers....cool running and easy on the lipos....with good flight times.

Thanks for the info Dan...


Mike D

[ke6d]

No, the reduction in headspeed is not noticeable anymore since now learn to manage the collective better. I was able to do some pretty big loops today (75 > 100 ft diameter) The main difference was wind. We had a 25 mph wind yesterday so I did not push it very hard. Today, the weather was perfect - sunny sky with 2 - 3 mph breeze.

I flew pretty much the same as the day I flew the H/18 motor a few weeks ago. As you noticed, at the end of the 6 min flight on the H/18 motors, the current draw was 3000 mA (Ouch!) At the end of today flight (also 6 min) only 1900 mA was used.

No, I don't run governor mode anymore. It is much easier to tune the TC for the HS I want. When you run governor mode, you are not supposed to run your TC curve more than 85% (The governor needs some head room to work correctly) I am currently either running 100, 98, 95, 98, 100 or 100% across so the governor mode won't do me any good.

The yellow line was the wattage. I did not record RPM since I already knew the HS. The H/18 is rated 1000W, yet the Eagle Tree recorded 1500W peak. Pretty scary I must say. No wonder the H/18 was so hot.

The reason that it fluctuated a lot because I did not fly level. I flipped, rolls, loops, inverted, stall turns, immelmans, climb outs. The only time that I hovered was at the beginning and flipped back to normal mode for landing at the end.

I can do pretty good acrobatics right now with the current motor/pinion/gears/and battery so I guess I will fly like this for a while.

I am happy now :)

Dan

[Zoobie]

Dan I am with you there. I was just never convinced by my Gaui motor, no matter how you put it a hot motor is just throwing energy/MAH/flightime to the wind. The motor is just inefficiant. The hotter the motor the more resistance and it is a vicious circle, after landing with my Z20a I knew all was well!!

[red_z06]

ke6d:

The power requirement goes up exponentially as the head speed goes up. In order to make a fair comparisson, you must match the head speed in both tests. Do you have a 15T pinion available to test on Z20? You will find out that the current draw will not be proportional to the head speed increase. For example, if the head speed goes up 10%, current draw can go up as much as 20% or more. After you get the close match on the head speed with the pinions, you then fine tune the head speed with the TC. Due to efficiency change on the ESC based on the %, you also hope the TC is within 5% between the two setups to do accurate testing. It is unfortunate that 13T is the smallest pinion available from Gaui. Typically, the current requirement skyrockets when the motor is operating beyond the rated power and much of the energy is lost through heat. Since you are already above the power rating on the Gaui motor, I suggest you perform identical headspeed hover test for accuracy. If you need a 15T pinion, I can lend you mine for testing.

Here is a link of Z20 14T and 15T test that show 20% increase in current draw going from 14T to 15T with the head speed around 2000. Based on the numbers I'm seeing, it is very possible that Gaui KV rating is way off. If the two motors have same kv rating and running within operating limits, they both should produce same head speed but show the difference in efficiency in current consumption.

I have a Gaui 1100kv motor on one ship and Neu 1509H/2y/F on another that I'm building. I will probably perform a similar test to see just how much better the Neu is over Gaui.

[concept1]

yes please test with a larger pinion! I also run the H/18 and love the performance, but I have been considering a Z power motor, unfortunatly I haven't seen anyone really compare the H/18 to the Z. Also how does the performance compare? I am running a flat 100% curve with the revco gearing 21t, about the same as a stock 13t. my h18 is warm but not hot and i get 4.5 minutes out of evo 2500mah packs the packs are not hardly even warm when I'm done. with the stock gearing the packs were warm but not hot, tp2170's were hot, to hot. I compare my H/18 to a raptor 50 with a muscle pipe, pretty equal in power, the Hurri might have a slight edge. the one benifit i see in your setup is it would probalby be better with 8s A123 then the H/18.

[ke6d]

OK. I have a 15T pinion that came with the XES kit when I purchased it last October. According to the headspeed calculation, the Z20A 980Kv at 15T has slightly higher headspeed than the RCP H/18 1100Kv at 13T. I will put the pinion in this weekend and test it out next week.

I will post the results here for comparison.

Dan

[ke6d]

I changed the autorotation gear (19T -> 20T) instead of the pinion (14T -> 15T) to get the headspeed that I like to test. After that, my Hurricane headspeed was between 2000 - 2100 rpm. Over all, hovering takes 2 -3 Amp more than when I was using the 19T autorotation gear. The Hurricane is now much more responsive. I was able to pull 45 - 50 A on certain maneuvers (It used to draw 60 - 75A when I was flying with the RCP H/18 motor)

The draw back was my flight time on a set of TP EX v2 3200 mA shortened by almost a minute.

Since I am currently working on my inverted circuit and backward circuit with a loop/roll/stall turn from time to time, I decided to put the 19T autorotation gear back onto my Hurricane in favor the extra flight time.

The amazing thing was, even though I was pushing the motor pretty hard, it was just barely warm at the end of the 6 min flight.

Cheers,

Dan

[bearwood]

I think my Gaui motor is not a normal one, yes it runs hot but I get 7 mins comfortable hover time from it. Put around 1800 back into 2200 el-cheapo 3s packs.

I bought a Z20 1470 as I could not find a 980. That was a mistake as it fightened the crap out of me when the Heli lifted off and tried to beat the Space Shuttle into orbit. Changed down to 14 tooth gear but still way too fast for me. Flight time, hover only now down to 4mins 30sec and have to put 2100 back into packs.:thumbdown: I don't think I am flying this motor at its most efficient speed (whatever that may be)

I'm changing back to Gaui motor till I can get my hands on a 980Kv or my flying skills improve enough to use the 1470 maybe with another gear combination to get the headspeed down a bit more.

[red_z06]

bearwood:

Since you gained 50% more motor RPM, you need to gear accordingly. All you have to do is to replace the 42T 1st spur gear with 61T (same as main gear). This should put your head speed where it belongs and give you back the flight time.

[bearwood]

red_z06
Thats just too cool and it will have the benefit of pushing the motor forward giving me more clearance to the frames. woohoo:thumbup:

Problem is am I at work and its perfect flying wx at the moment. No rain, no wind and only 30 degrees C. Will have to wait til tommorrow and it will probably rain then.

I should have figured this myself as I was contemplating the 68 tooth gear from readyheli:arggg:. I sure noticed the power increase and the extra noise from the blades. Your help is appreciated.

Eddy

[red_z06]

This motor is even higher kv than yours at 1820. So, in addition to 61T 1st spur, the motor pinion needs to be lower at probably around 13T

Going with 61T 1st spur has an added benefit. You will only have to keep 61T gears as your spare. :)

NeuMotors 1509H/2Y/F

[bearwood]

red
Fitted the 61tooth and ran with a 14tooth pinion as I don't have a 13tooth yet. Away managed to get a quick hover flight in between showers and flight time back up around 7mins. Motor was so cool to touch it was almost unbelievable.
As a side note I had to widen the slot where the gear sits to accomadate its extra width over the 42 tooth gear. Mostly on the lower face and not too much.

Is there a reason your skid struts are facing rearwards in the photo?