The rain and wind finally left eastern Nebraska and provided a great day for the first flight of my new Dave Guerin built electric PL Partner. Statistics:
10 lbs 15 oz
2000 mah NiMH receiver pack
Futaba 9Z radio with dual JR elevator servos
Thunder Power TP 5300 lithium pack
Hacker C50 14XL Competition motor
Hacker Acro 90 Comp ESC
Jerry Budd motor mount
APC 22 x 12 prop
5700 RPM at 67 amps full throttle

The aircraft was set up with zero/zero wing/stab incidence for the first flight so it was no surprise that a bit of up elevator trim was needed. I now have two turns worth of positive incidence in the wing adjusters and the up elevator trim is nearly gone. There is no detectable pitching in either knife edge and verticals are straight as an arrow. I currently have the CG right on the center of the wing tube. During these first flights, I tried to keep the current draw around 5C or below as recommended by Thunder Power for the first flights on a new pack. Even at a hair above half throttle, vertical performance was stunning. A great flying plane.

Mike Moritko

Mike:
You can save quite a bit of weight by replacing your 2000 pack with maybe a 930 li-po pack. I did some tests on my e-plane with 5 digital servos ( 2-9411 2-3421 1-8411) and was replacing about 35mah per 8 min flight from my radio pack. This is vs 200-250mah for a 10 min flight on my glow plane. I can routinely fly 4 flights on my electric Genesis and when I recharge the pack put in about 140mah. the vibration is just not there anymore to make the servos work hard and draw lots of power.

4mm bullets?

You'll save a ton of weight by going to a very small lipo rx pack and a regulator. Plus you'll gain no self discharge, always constant voltage, and your choice of voltage.

Another 14XL. I'm still waiting for someone in North America to try the 13XL. I would if I was going to run a C50. 57A on a 22x12 isn't what I consider ideal electric power.

Why did you change wing incidence instead of stab incidence? If I understand correctly, the difference would primarily be resultant thrust angle, as wing:elevator angle will end up in the same place. There also might be a change in fuselage flight angle. Maybe. I'm just hoping to bring out discussion in this weak area of my knowledge.

Another Adam snipe.

Funny comment. Still waiting for someone in NA to try it. haha. Why, why are you waiting for this? Explain? Why do you care? So you can come into a thread and snipe a quick comment to berate it?
FYI............
Tony Frack tried the 13xl along time ago. I don't recall his comments about it (or, it's just not my place to say) , but he still ran the 14xl until he decided to take a break.

So exactly what is the ideal power to you adam?
It sure seems that here in NA that it isn't the motor you run? Maybe it works up north and that's fine. But here in NA it may be different. Although I hear the new plett is pretty good and I am anxious to see one.
I don't run the Hacker and we all know that, but I do admit that the 14xl is a great motor. And a proven contest winner.

Back to the thread. Beautiful Partner!!!!!!!!!!!!
I think it's a great looking and flying plane!!
I'm not sure I would want to lose weight. I find that as slow as the electrics fly, light can be a disadvantage in the wind. I would rather have my electrics at 11lbs. They penetrate better.
I run a 730 3 cell in my ship. I get, well, as I found due to forgetting to charge, 8 and a 1/2 flights on a 2 cell 730. Now I fly 5 flights then recharge. All digitals and I put back in around 300 mah.

Good luck with the Partner!!!!!!
Chris

Thanks for the comments. Regarding the bullet connectors, yes...they are 4mm. I have larger ones but they're quite heavy. I've used the 4mm bullets on all my C50 motors for quite some time and have had good success with them. The Partner is the first model in which I've used an external arming connector for the motor....a nice convenience I'd recommend to others. While some folks have decided to utilize lithium cells and regulators for receiver/servo power, I'm still quite comfortable using NiMH, which I've used with 100 percent reliability since perhaps 1990. Pack voltage holds up well under load and weight isn't an issue for my Partner. Based upon what I read, lithium cells and regulators seem to provide good reliability for those using them; however, the combination does represent two potential failure points.....the battery pack and the regulator, while a single (but admittedly heavier) Nicad or NiMH pack represents only one. Consequently, I've decided to stick with that which has given me good and reliable service for many years. I think it's great that pattern flyers now have several motor choices....both outrunner and geared. It really comes down to personal preference as there are several good combinations that can produce winning results. The 13 wind Hacker C50 is a good motor for those who don't want to run a larger (i.e., 22 x 12) prop. I don't own one, but unless I'm mistaken, I believe the C50 13XL is Chip Hyde's favorite of the Hacker geared lineup. Wolfgang and Roland Matt used the 13XL when they first tried electrics and had good success. However, more recently, they have switched to the Hacker 14XL C50 competition motors and ESCs. I have a 12XL on an Extreme Flight Yak that turns a 20 x 13 APC at 6000 RPM while drawing 68 amps at wide open throttle. It goes like a rocket and climbs like there's no tomorrow. It's all a matter matching the motor, prop and battery pack....there are many combinations that will work. One of the primary reasons I continue to use the Hacker C50 motors, which have been ultra reliable for me, is the sound of the gearbox. The motor is quite quiet in the air, but the gear box does provide me with some audible feedback which helps establish the position of the throttle. I do not, however, have anything against any other motor type for those who prefer something else. I probably should not have even mentioned adjusting the wing incidence as I wasn't really trimming for good pattern performance, but experimenting to see how sensitive the Partner is to changes in wing incidence. I didn't have an allen key in my flight box that fit the stab adjusters so I decided to see how changing the wing's incidence would affect knife edge and the slight up trim needed to compensate for the zero/zero setup. As it turned out, a few turns of the wing adjuster screws made little difference. I won't begin the actual trimming sequence until the LiPo packs are broken in and I can use them as I would during a normal pattern flight. At that time, I'll assess the Partner's performance relative to knife edge flight, as well as vertical ups and downs, and then make adjustments accordingly.

Mike

Mike, I'll have to say, that was a nice, informative email!!

I happen to run the axi and I will agree, it's too quiet. I could use the gearbox whine sometimes. Maybe I should mount an aluminum can to the prop to get some noise!! haha
As for lithium and regulators. Well, after losing two planes, well three, (but who's counting) this year I have settled now for a 3 cell pack and the jaccio switch regulator combo. If a cell goes bad I still have 2 cells, which is enough to fly and land.
The jaccio fails open so you still have control if it fails. I'm sure you know this though.
I have a friend that runs two 2 cell lithiums and two switches. This works for him but I feel comfortable with my setup. I don't see any need for you to change as you are within weight and are comfortable.

Sure is a nice plane!!!

Chris

Hi Adam,

I've been meaning to continue your discussion but have been super busy. A long time ago someone asserted that stab incidence was not critical and I had a big problem with that. It was pointed out that all the stab did was set the wing at the proper angle of attack. It kind of made sense. I countered with the fact you would get trim drag if the elevators didn't trim to exact neutral and was told it is insignificant.
Now some recent experience. My Impact required uptrim to fly level and went to the canopy on vertical lines. I started adding positive incidence to the wing which required less uptrim in the elevator. It had the effect of adding downthrust and it made the tail fly higher. After a number of cut and tries the plane goes straight up and down and is flying with a tiny bit of downtrim. A purist would adjust the stab slightly but the downtrim is almost imperceptable so I won't mess with it.

I am now thinking of going back and working on my Composite-Arf Extra which never did good vertical lines. On it, I will adjust the thrust line as it is difficult to change the wing incidence.

Jim O

Jim,
It's been pointed out to me that my jaccio switch regulator may overheat running a 3cell lithium. Do you know if it will?

Thanks in advance for an answer!!!


Also, thanks Jon Carter for pointing out that if a cell in my pack fails I will still lose the whole pack. I didn't think about it obviously. I will switch to two packs and switches like you in the future!!!!

Chris

Hi Chris,

A three cell pack is not a good idea. You will dissipate more power in the regulator and that does mean more heat. In our electrics the average current is pretty low so you may get away with it but I'd switch to a two cell pack. I've been running Lithiums for years and have never seen a failure. From what I can see they wear out slowly and the mode is high internal resistance which results in fewer flights per charge and longer time to charge. In Li-Ions this seems to happen in about two years if you use them or not. I don't know about Li-Polys yet.

Jim O

Thanks for the answer. I'll switch back to a 2 cell lipoly. Actually, 2 and 2 switches probably.
FYI, Several of us watched my NMP pack fail after takeoff at the gardnerville contest. Battery voltage was 8.04 under load before takeoff. I was on my 1st pass back after takeoff when it failed. One cell reads 0 the other still good. So it does happen with li ion's. I have the pieces to prove it[]. I was pretty bummed as I have swore by these packs since they came out. I won't use them again unfortunately..

Thanks again for the answer. Sorry to hijack the thread!
Chris