Eagle Tree graphs 450 heli with 3S A123/HK2221-6

[t2o]

Spec:
Trex 450 clone (stretched w/Outrage G5 Boom)
Motor- HK2221-6
Blade- 350mm Outrage woodies
Pinion- 13T
Pack- 3S A123
Receiver AR7000
Servo HS65HB @ 6 volts
Gyro CSM SL560/S9257@ 5 volts (Align Step Down Regulator)
ESC Castle Creation Phoenix 45 Separate BEC (Head Speed Mode 2700 RPM)
Eagle Tree Elogger w/Brushless RPM Sensor
10 degrees pitch collective // 8 degrees pitch cyclic
Flight weight 935 Grams (ouch!)

That is my heli and here are my first graphs. The flight consisted of the hardest workout my meager skills could muster. I did 100% climbs while doing my best imitation of "Crack flight" The climbs were to about 100' and I was giving it full aileron for as long as I could while keeping the heli from going inverted, then back to the other full aileron all the while at 100% collective. Basically doing big zigzags up ,up and away then back down and do it again till the pack was flat. This wouldn't impress anyone, I am sure, but it was definitely working the heli. The pack got as hot as I have ever felt it. The motor and the ESC, however did not really even feel warm.

The first graph is with the pack cold and charged the night before. The second was the same pack, re-charged at 8 amps and flown immediately after it came off the charger. The difference is huge while looking at the graphs but in reality, in flight performance change was too small for me to feel.

The change in head speed is quite small and I think this is a good combination. Flight times were down as I would expect with the heli being so heavy. As soon as I get a chance I will log more with some carbon 325 blades at 3000 rpm. This is fun stuff.

[TRex888]

Cool.

Flight time of only 3.5 mins?

Can you post your settings for the CC45 in 2700rpm HS mode?

Thank you in advance.

I'm running the standard 325 mm blades, but want to try governor mode with 14T at 2900/3000 rpm. Your HS governor looks very good (no need for me to upgrade to Jazz).

[t2o]

Actually the flights were a little longer. I cut out the pre-crack-flight stuff and posted only the meat a potatoes of the log. I hovered around a bit before working it just to make sure the heli was good to go. When I get home I will post the ESC print out and try to get some realistic flight times with this set up before I change blades.

[ktm520]

Originally Posted by TRex888

Can you post your settings for the CC45 in 2700rpm HS mode?

i'm running the same setup mechanically, but my electronics are different.
https://www.helifreak.com/showpost.p...2&postcount=31

i've got two flights so far, the first at 2600 and the second at 2500. at 2600 and gov gain at 7, the tail had a slight wag. for the second flight i reduced the gain to 6 and this eliminated the wag. again, this was just initial test flights, but the setup was spot on besides the slight wag. i'm still impressed how much power the -6 has. at 2500, i could bog the head for a split second if i slammed the collective up, but the hs would recover while at FULL COLLECTIVE, amazing. if smooth on the collective, the setup worked very well at 2500 and had plenty of power for mild 3d. but, my heli is 75g lighter than t2o's.

i think you all are running one tooth high on the pinion. the 12 i'm running was perfect for 2600 and should also work at 2700. for 2900-3000, a 13 should do the job. give it a try as it will reduce the current draw and provide longer flights.

[t2o]

Here is a print out of my ESC setup.

I too had trouble getting the wag out after going to head speed mode. I never completely got it to stop, a Gov Gain of 5 is a compromise at best.

I have spoken to Castle and it is aparenlty a timing issue between the gyro and the ESC. Just going down on Gov Gain is not always the answer, sometimes going up makes it better. It will only, ever, be a perfect match at one head speed. The bigger the gap between your headspeeds, the more likely that a gyro wag will happen at one of them.

What I was told, is to pick the head speed that I would like the ESC play "nicely" with the tail gyro, and fine tune the gov gain in one step increments first going up 1 and then down 1, up 2 and then down 2, untill the gyro is smooth.

If your gyro was set up and worked good in fixed end point , no amount of gyro tweaking will help the Gov created wag

I have not done this Tweaking with the Gov Gain but I will. I believe the Scorpion and the A123's will hold the head speed even tighter with a higher Gov gain.

I am going to eventually try the smaller pinion as well as the bigger ones. for right now I want to determine the range of head speeds for the 13 tooth.

[t2o]

Here are some normal flight logs with the gyro gain set to 14 or "normal." The tail was a little twitchy at 2500 rpm but really smoothed out at higher head speeds in stunt mode. At first I thought there was no improvement in maintaining head speed at the higher gain but after looking closely at the graphs the line indication head speed does appear to be much tighter.

These flight times are longer with the hot pack going almost 6 minutes and this is no doubt a result of me just flying the heli around instead doing one pitch pop after another.

Note the little red line on the bottom of the second graph and the corresponding data box below the graph. This is my total servo current, it only maxed at .63 amps and averaged .17 amps. I got this data by hooking my servo current sensor in-line with my BEC feeding the whole system. This reading is the total draw from everything in the system less the motor, it is the receiver, gyro, and servos. I had heard tails that the S9257 digital tail servos can draw up to 3 amps alone, this was why I separated and did not use the BEC on the CC45. After getting this reading I think the CC45 On-Board BEC can handle it; It does not have the option to run the servos at 6 volts though so I am not sure if the weight saved by removing the external BEC is worth the price.

Cold Pack easy forward flight




Hot Pack right off charger

[TRex888]

Interesting stuff t2o. Keep the data coming.

I'm put off by the need to fine tune on the CC45 gov mode so I haven't committed to moving awaying from100% fixed throttle yet, but your graphs shows excellent HS holding for normal flying even at 2700 rpm.

I put on some 335 woodies last night and drop down to 12T to an average HS of 2800 rpm. The heli felt less bogy during flips, loops and tic tocs. Max pitch was about the same. Flights time may have been just a tad longer (I didn't fly them to 0mAh which I sometimes do). But there was more prescence to the heli with the extra 2cm of disc diameter and it felt less twitchy.

Graph is general flying around (without canopy), pitch pumping and climb outs to 100+ feet, and a few piros.

[t2o]

Trex888, I leave a y connector hooked up to the heli for set-up. This way I don't need to unplug the ESC every time I want to make a change; I just plug the PC into the loose end of the y connector. Yes the tweaking is something else to do, but once you get that done all your throttle mixes and curves are history.

I could run 90% flat and then added a throttle mix to take me up to 100% when aileron and/or elevator and/or right tail was input, The head speed would be pretty stable but setting up each one of these mixes takes time. In the long run I find the Gov to be a big time saver for me.

[ktm520]

t2o, have you tried running a smaller pinion? why i ask is that i have messed with the gov setup on the cc a lot with lipos and i've noticed that trying to run to low of a hs with too big a pinion can cause wag induced by the gov.

got a couple more flights in with the 3s A123. at 2500 w/ a 12t, i've tried the gain at 6, 7, and 8, and 7 ended up being the optimal setting. 8 cause wag and 6 was slow to respond. i'm using a logictech 2100t w/ 9257.

i strongly suggest dropping to a 12t pinion for 2700 hs, which calculates out to a max of 3100 at 8.8v. this should be plenty of headroom to maintain hs. my heli is lighter than yours, but i tried 2700 with the 12t and it work well.

[t2o]

KTM520,

Yes, I am coming to the same conclusion. With the 13t anything below 2600 RPM seems unworkable with the Gyro no matter where I set the Gov gain. 2600 and up and the gov-gain can be as high as 15 with only a little nervousness from the gyro.

Before I change the pinion, I want to add more pitch to the setup and see if I can stall the motor at 2700. Then I am going to bolt on some carbon 325's and compare performance to the 350 woodies.

Basically, I want to try every thing I have with this pinion and then do the same with the 12t.

[phillipda]

Well done with the Data guys, Very interesting.

I am using a 12t on my setup with a HS of 2700 getting 7 minutes of flight. Works well for me, but for some reason when I punch the throttle hard the tail kicks out a bit. It does not kick out as bad at 2800 hs. Maybe I don't have a setting right somewhere in my CC ESC.

[t2o]

phillipda,
Can you post your esc settings? The set up I have now does not do the tail "step out" thing, but I did have trouble with it at one time.

It seems to me that I had set the gyro gain low, trying to get rid of the Governor induced wag. Once I realized it wasn't a gyro problem and started messing with the Gov gain, putting the Gyro gain back to where it should be, the "step-out" trouble ended. I want to check out your speed change rate and Gov-gain settings.

[phillipda]

Hi T20, I can't remember what I have it setup at this moment. i think i will have to plug my programing kit into my ESC to find out what I have set.

I will do this tomorrow. and get back to you.

[ktm520]

phillipda, the tail kicking out under full collective can be caused by a number of things. gyro setup and hs decay (bogging) are the main two causes. bogging causes a drop in hs and tail rotor speed which causes a reduction of tail authority. it takes a really good gryo and tail servo to control tail kick. what gyro/tail servo are you running?

assuming you have a good gryo setup, bogging can be caused by poor collective management or in the case of the cc35 not enough gov gain. you should have the correct pinion for 2700hs. also, too much pitch can cause bogging.

imo, 2700hs is right on the line of having enough tail speed for good tail authority. i'm running 2500, but i'm running the G5 62mm tail blades to increase tail authority. also, outrage makes a 12t drive pulley for the G5 that will increase the tail speed (stock trex is 11t). another option is changing back to the old 450xl autorotation gear set, but i would not run much more than 2700hs. at 2700, the 12t drive pulley would raise the ts 1100 rpm and the xl gear set 5900 rpm (a little extreme, but would definately solve any tail authority issues).

in my experience, it is really hard to get a tail not to kick under full collective if running lower hs and especially if you are not smooth on the collective. i really need more info on your setup to make any recommendation. i don't consider a small amount of kick under full collective abnormal. when sportflying and mild/hard 3d, you are rarely at full collective. typically, the only time you will have problems is when doing pitch pumps or (again) poor collective management. i've grown out of the pitch pumping phase and rarely do them anymore other than to test my tail or gov setup. if your tail kicks out a lot, like 45 degrees, then you probably have a problem. but, a slight kick of only like 5 deg, is not that big of a problem imo and you may spend countless hours of testing to get rid of it with no sucess. did i mention poor collective management?

main blade length?
tail blades?
gyro/tail servo?
cc gov parameter settings?
max collective pitch?

[t2o]

Some more graphs finally. I thought I would never get to fly! This is still the 13T pinion. The first graphs are with the 350mm woodies,2700 rpm, just like before but with 12 degrees of pitch. Finally the motor gives in a little and I must be careful not to stall the head. Yes just like ktm520's last post would predict, the tail was kicking out, if I just jammed the stick. The climb rate was much better though, if I was just a wee bit careful.










Second pack, HOT, much better.









New set up. I bolted on the carbon 325 and went for the ceiling on RPM. I set the CC at 2700,3000,3300. I will have better graphs on this later with more time spent at each speed. Obviously 3300 is too much for the 13T but notice the longer flight times. I thought the heli was great with this set-up and I liked it even better than the 350mm woodies.

[phillipda]

Hi T20, Thanks for the time and effort with the graphs.

I am still to connect my ESC to my programing kit to get that info your after.
I am busy in my spare time building a new heli. a Hurricane 550. As soon I get a chance I will post the info.

Meanwhile, here's a video of my hovering in the backyard.

Trex 450SE V2 on 3-cell A123 cells (7 min 17 sec)

[ktm520]

t2o, i got similar results changing the 350's out for align pro 335's. heli didn't seem to loose any stability, had more climbout power, and faster cyclic. this was at 2500 hs. current consumption reduced 300mah for a 6 min flight.

[t2o]

More graphs with 13 tooth pinion, 325MM carbon blades, ~12 degree's of collective and ~ 8 degree's cyclic.

This setup works pretty good for me. The heli is still very heavy and even though the acceleration is good cyclic commands are slow and care must be taken; changing direction requires more space than a normal 450.

Even 12 degrees of pitch doesn't stall the head very badly alone but feed in some cyclic and I must be careful. The big stalls you see in the graphs are all from doing tumbles? and rolls while banging the collective to 100%. It stalled so badly on the cold pack that I ended up doing my first piro-tumble.The heli lost tail command and it started to piro in the middle of the tumble. Thanks to a lot of luck and a big increase in confidence (lately) I didn't panic and just flew out of it. Cool! Not long ago that would have been all she wrote.

This is about all I can do with the 13t pinion. I need to get some carbon 350mm blades, I think those would be awsome at about 2700 rpm and a good match for this combination. Next I will go to a 12t pinion and post those graphs.

3000 rpm headspeed mode cold pack







3000 rpm head speed mode, warm pack






2800 rpm. warm pack