TRex 450SE on 3S A123

[Bill Sanford]

Originally Posted by kgfly

You can use any ESC which lets you disable the LVC or change it to a NiXx mode or set it to an explicit value for LiPo which should be 2.0V/cell. Effectively you want to disable the LVC. At the high end there the Kontronik Jazz and CasteCreations Phoenix 45, mid-range perhaps the HobbyWing Platinum 40, cheap end Turnigy K-Force 40 (I think this might be the Platinum 40 in other clothes and 20% cheaper) or HW Pentium 40 or Turnigy Plush 40. I wouldn't recommend the low end ones as they tend to have terrible soft-start.

If I was buying a new ESC for a T450 tomorrow I would try the HW Platinum 40 or Turnigy K-Force 40 just to see how they work out.

WOW, I can't believe this thread I started is still going strong after a year! I guess A123s are still tough to beat when you consider everything...

It's time for me to upgrade my ESC. I've been flying both my TRex 450s on 3s A123 with Phoenix 35s for close to two years now and although the Phoenix 35s have not failed me, I think I'm loosing performance because my Eagle Tree shows peaks of over 50 amps with a 13 tooth pinion and a HK2221-6 motor. I see the power sag quite a bit if I push the heli hard and I'm guessing the ESC is limiting the current. I have the current limiting set to insensitive. I'm afraid to disable it because I might kill the ESC due to the high current.

Above I see a few choices for ESCs. What about the Scorpion ESCs? Does anyone have any experience with these? I like the Phoenix ESCs and will likely end up with a Phoenix 45, but I'm just curious.

I have an old spare Phoenix 80 from a plank that I could install just to see if it fixes my power issue. No worries about overloading the ESC there...

The only problem with my Phoenix 80 is that it's an OLD one and has no governor software and can't be software updated. CC will "repair" (replace) it for 1/2 the price of a new Phoenix 80, so this may be an option, but it's quite big for a 450 sized heli.

So any other reasonably priced ESC recommendations?

Bill

[shaggybirdman]

Originally Posted by kgfly

That is because you are flying at very low headspeed relative to what most people fly. On 11t with the stock 3550KV motor you would be around 2200rpm compared to the 2800 to 3200 that is popular for aggressive flying. Since power is proportional to somewhere between the square and the cube of headspeed, running at such a low speed means the current draw is low and hence the voltage drop on the pack less accute.

Since you are getting 10 minute flights that is 6C average which is 14A or less. At that current the cells will hold close to 3V and with the LVC set for low = 2.6V/cell you have no problem. You will find that if you want to fly more aggressively you will want to move up to a 13t (or larger) pinion and then the loaded cell voltage will drop down such that the LVC does indeed become an issue.

not arguing that, but at my current skill level it works just fine. still learning my hovering orientations. no ff yet other than ditch maneuvers when things go bad. i'll never do 3d. it's cool ta watch, but not my cup o tea. i'll be doing sport/scale. i mite try a 12, and 13 tooth pinion just to see what flight times i get. yuppers the power is down, but i like the extra flight time to learn. i fly with 2 others, and we take turns flying. they fly for 5-6 min, and i fly for 10-11 min. almost twice the fliht time. i don't think they noticed as of yet

[kgfly]

shaggybirdman you are on to a good thing and I certainly was not criticising your choice, just trying to clarify why your experieve with LVC is different.

Bill The Scoprions have been a mixed bag IMO but improving all the time. Some models are more subject to spontaneously letting the smoke out than others, I believe the 60 was one of those, but it might have been fixed. Their governor was so so to begin but has been improving. A local person has been testing their latest governor software and reckons it is as good as Kontronic. Many have made that claim, none have proven it so far, but he has both so perhaps they are indeed getting close. None of the Scorpion ESCs are firmware upgradable so you would have to put off your purchase for a month or two and then figure out how to ensure you get new stock rather than old to get the new governor. I am not sure if they will distinguish it with a new part number or model name (eg Commander v2).

If you want to experiment, the HeFei King Kong 60 looks interesting but I have yet to see any user feedback. It has a built in FDR which looks pretty cool.

JustPlaneChris has given positive reports about his HobbyWing Platinum overall and IIRC said that the governor was OK but not Kontronik-class.

Here is a list of ESCs rated for 40A and over that you might find useful

  Brand      Model         Voltage  Amps/Burst  BEC   Soft  Gov   Dimensions (mm)  Weight  USD$
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  Align      BL60G           25V     60    70   S,3A  good  bad    65 x 28 x 12     55 g    93
  Align      BL75G           25V     75   100   no    good  bad    72 x 28 x 11     54 g    91
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  Kontronik  Jazz 40-6-18    25V     40         S,2A  good  fab    52 x 26 x 8      33 g   166
  Kontronik  Jazz 55-6-18    25V     55         S,2A  good  fab    52 x 25 x 11     38 g   185
  Kontronik  Jazz 80-6-18    25V     80         S,2A  good  fab    52 x 25 x 11     38 g   249
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  Kontronik  Jive 80+ LV     25V     80         S,5A  good  fab    62 x 32 x 15     84 g   300
  Kontronik  Jive 80+ HV     50V     80         S,5A  good  fab    62 x 32 x 15     84 g   400
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  CasteCre   Phoenix 60      25V     60         L,2A  good  so so  60 x 27 x 12     58 g   119
  CasteCre   Phoenix 80      25V     80   120   L,3A  good  so so  67 x 27 x 12     60 g   136
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  HeFei      King Kong 60    25V     60    70   S,4A  ?     ?      71 x 27 x 15     48 g    94
  HeFei      King Kong 80    25V     80    90   S,4A  ?     ?      71 x 27 x 15     49 g   105 
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  HobbyWing  Platinum 40     26V     40    60   S,3A  ?     ?      59 x 27 x 12     38 g    57
  HobbyWing  Platinum 60     26V     60    90   S,3A  ?     ?      70 x 34 x 16     68 g    80
  HobbyWing  Platinum 80     26V     80   120   S,3A  ?     ?      70 x 34 x 16     77 g    99
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  MSH        MSH 80          25V     80         S,4A  good  ?      77 x 28 x 14     56 g   110
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  Scorpion   Commander       26V     45         S,4A  good  so so  75 x 30 x 10     41 g   120
  Scorpion   Commander       26V     60         S,4A  good  so so  68 x 30 x 13     65 g   135
  Scorpion   Commander       26V     90         S,4A  good  so so  68 x 30 x 14     66 g   160
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  Turnigy    K-Force         26V     40    57   S,3A  ?     ?      59 x 27 x 12     38 g    37
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  Turnigy    Plush           26V     40    55   S,3A  bad   bad    55 x 28 x 13     33 g    34
  Turnigy    Plush           26V     60    80   S,3A  bad   bad    80 x 31 x 14     60 g    44
  Turnigy    Plush           26V     80    90   S,3A  bad   bad    88 x 31 x 14     91 g    52
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----
  YGE        YGE 80          26V     80         ?,3A  good  good   70 x 25 x 11     55 g   190
  ---------  ------------  -------  ----------  ----  ----  ----  ---------------  ------  ----

 Notes:
  1) For the BEC column, L = linear, S = switched
  2) Soft(start) and Gov are rated based on dominant comments from users

SBECs as add-ons
----------------

 Brand     Model      Input    Output   Amps  Dimensions (mm)  Weight  USD$
 --------  ---------  -------  -------  ----  ---------------  ------  ----
 Generic              2s - 5s   5V/6V    3.0                     6 g    15
 D.E.      SportBec   3s - 8s   5V/6V    3.5                    13 g    30
 C.C       CCBec      3s - 8s   5V/6V    5.0                    13 g    26
 --------  ---------  -------  -------  ----  ---------------  ------  ----

[Mac_Heli]

Originally Posted by Bill Sanford

I think I'm loosing performance because my Eagle Tree shows peaks of over 50 amps with a 13 tooth pinion and a HK2221-6 motor. I see the power sag quite a bit if I push the heli hard and I'm guessing the ESC is limiting the current. I have the current limiting set to insensitive. I'm afraid to disable it because I might kill the ESC due to the high current.
Bill

After sooooo many A123/2221-6 flights, I'm outgrowing this setup as well... I've been flying the new hyperion 35A w/ switched BEC, and I have no issues, but the power sag is there too. I recently upgraded to a 14T and the additional HS helps, but the sag still there plus now flight times are shorter 4-4:20 (on a 13T flights were at 5min).

So I've been looking for ways to fix this power issue, and my first step was a new pack. It made a small difference, but it is not it.
I just tried the pinion, but no luck...
UPS shows that my castle link will be here tomorrow, so I'll try gov mode on my repaired CC45, hopefully that will do.
If not, I did notice that the scorpion magnets aren't as strong as they were when I first got it (I think)... I remember it was really hard to turn the head to the side of the motor when installing the blade holder at the end of the day... so motor would be next.
If none works, than I'll have an excuse to try the new hyperion lipos on the 450 .

[Bill Sanford]

I'm in the process of strapping my old Phoenix 80 to the side of my older TRex 450se. I'll let you know if my Phoenix 35 ESC is the bottleneck. I'm guessing it is because the A123 cells are capable of giving a lot more than 50 amps if pushed hard... I think the Phoenix 35 is just limiting the current to protect itself.

Considering that my peaks are over 50 amps with the Phoenix 35, I'm surprised I haven't cooked one yet!!



Bill

[kgfly]

At 50A and above, 10awg wire will help. You might also consider the cell-to-cell connections and whether they should be enhanced too.

[shaggybirdman]

Originally Posted by kgfly

shaggybirdman you are on to a good thing and I certainly was not criticising your choice, just trying to clarify why your experieve with LVC is different.

not a prob. i would like more punch (full throttle climb outs are very slow vs 3s lipo), but i do like the 10 min flights. i wish my 450 could lift a 4s A123. i mite try it, but balancing it out would add even more weight.

[Bill Sanford]

Originally Posted by kgfly

At 50A and above, 10awg wire will help. You might also consider the cell-to-cell connections and whether they should be enhanced too.

Cell to cell connections are good as is the wire. it's #12, but very short and not likely the issue here.

Thanks for the suggestions.

Bill

[brunobl]

shaggybirdman,

i'm using the stock 35 amp align esc set to the lowest voltage cut off, and get 10-11 min flights using a 11 tooth pinion all day long o 3s. not sure why your esc won't do it.

kgfly,

On 11t with the stock 3550KV motor you would be around 2200rpm compared to the 2800 to 3200 that is popular for aggressive flying. Since power is proportional to somewhere between the square and the cube of headspeed, running at such a low speed means the current draw is low and hence the voltage drop on the pack less accute.

From the above, I see just where I stand on this. Interestingly, my 450SE V2 kit came with not one, but two pinions - both 13T.

It would be easiest now to just exchange the pinion for an 11T one, but I'm tempted to get another ESC, so I can fly on either the A123s or Lipos and get the higher HS when on the Lipos without changing back/forth between pinions.

Thanks to all who addressed the issue.

[concept1]

i have been running the stock align 35 esc and 13t pinion with the Scorpion 2221-6 motor. 3s A123 i do get a very slight occational twitch in the motor but only in a hover. it has not been bad enough to replace the esc though. I have one of the older versions of the 35 amp so not sure if the newer versions is more of a issue with LVC. I get a solid 4.5-5 minute flight, the twitch could be the LVC but it doesn't change from a new pack to the end of the flight. performance has been better then I expected so I just fly it!

[shaggybirdman]

brunobl

with the 11 tooth pinion it will have a ton of pop with a lipo. with the A123's it will be slugish. it depends on how you fly. for me still learning my hovering orientations the 11 and A123 3s is the ticket.

concept1

with my esc it will pulse the throttle when it reaches lvc. does yours only do it after you have been flying for 5 min or so? if so it mite be lvc kicking in.

[Mac_Heli]

I installed the CC45 today, and went for a quick test flight with gov mode on high and right of the bat the headspeed felt weird, lagging behind the stick... (first time I ever use gov mode) After 10 seconds, some sort of glitch and the heli went straight to a tree. It was there, laying on the grass, lifeless... but intact. Aside from twisting the paddles back and bending a link from servo to swash back into place, nothing else happened... I'm still shocked, my crashes are usually at high headspeed, and a lot of stuff bends or breaks....
So fearing another glitch, I installed the round magnet thing, rerouted some wires and did some testing on the bench and it still does it (weird headspeed). After a couple of Coronas I realized this is gov mode and the throttle should be flat, so after messing with the eagletree I ended up with ST1 @ 60% with 3000 rpm and ST2 with 66% 3300 rpm without the blades (I have a 14T on). Does this sound right? How about all those settings from the castle link software? I left all the gov stuff at default, should I up the gain at least?
I don't like to Fly Under the Influence, so further testing should happen tomorrow morning...

[Bill Sanford]

OK, I got my Phoenix 80 strapped to the side of my TRex 450 and tried it out with a 3s A123 pack. It seemed good! I wasn't able to get out to a decent place to fly, but I did do some long full collective climbs in my driveway and it seems like it's holding power much better than with the Phoenix 35.

I should get out this weekend to really give it a good workout and see how it performs. My initial impression so far is that it's definitely time to replace the Phoenix 35s in my two TRex 450s both running HK2221-6 and 3sA123.

Eagle Tree graphs with the Phoenix 80 should be in interesting considering that even with the Phoenix 35 I was pulling over 50 amp peaks... :o

Bill

[kgfly]

I have been battling tail problems on my T450 for months now. Well today in desperation I changed my CC45 from governor mode (SetRPM) to non-governor mode (Fixed end point) and voila, the problems disappeared. I am very dissappointed. I had read about some people having exactly this problem but only on bigger helis. Well it sure bit me

It seems on my heli, the CC governor has a bad interaction with the tail so that although it does a fair job on the headspeed, it is driving the motor in such a way that there is a persisant wag. No amount of fiddling with gyro settings can cure this problem. I do think that perhaps it results from a complex interaction between the governor and gyro control loops but I couldn't tune it out.

I am thinking of selling off the CC45 and trying something else, perhaps a Platinum40 or K-Series40, at least they have integrated SBECs unlike the lousy and useless linear BEC in the CC45!

[concept1]

on my align 35, I get no LVC pulsation, only a very slight occasional Tick or twitch in the motor and only on hover. it does it at first liftoff and throughout the whole flight, but not under load, only when I hover otherwise it flies just fine. Like I said before I just fly it, it really doesn't bother me since I very rairly hover!!!!!

[t2o]

Originally Posted by kgfly

I have been battling tail problems on my T450 for months now. Well today in desperation I changed my CC45 from governor mode (SetRPM) to non-governor mode (Fixed end point) and voila, the problems disappeared. I am very dissappointed. I had read about some people having exactly this problem but only on bigger helis. Well it sure bit me

It seems on my heli, the CC governor has a bad interaction with the tail so that although it does a fair job on the headspeed, it is driving the motor in such a way that there is a persisant wag. No amount of fiddling with gyro settings can cure this problem. I do think that perhaps it results from a complex interaction between the governor and gyro control loops but I couldn't tune it out.

I am thinking of selling off the CC45 and trying something else, perhaps a Platinum40 or K-Series40, at least they have integrated SBECs unlike the lousy and useless linear BEC in the CC45!

I had this same trouble and spoke with CC about it. The Gov gain might need to lowered for small helis but for what ever Gov Gain you decide on, they suggested changing the head speed in small increments, say 25~50 rpm at a time untill the wag stops. This worked for me. Now in normal mode I get a little wag but when I go to Idleup it is smooth. If you change the Gov Gain you will need to do this again. Might be worth a try.

[kgfly]

Hey thanks t2o, that is very useful and I will see about giving it a try out of interest. I have found flying in fixed endpoint mode with a v-curve works pretty well for me anyway.

[Mac_Heli]

Which BEC for 3sA123?

Another test flight, another crash... Somehow the heli went full negative collective from 6ft high. The 35A Hyperion SBEC was working fine, but since I installed the CC45/SportBEC, the heli is glitchy as it can be. I just checked the specs on the SportBEC and the minimum input voltage is 3s lipo, not 3sA123. Since I'm pushing 3300rpm the input voltage must be dropping enough to kill the BEC and reset the receiver, which would explain this last crash.
Which BEC are you guys using on 3sA123?

[Bill Sanford]

Well I flew my TRex 450 with 3s A123 using a Phoenix 80 this weekend. Bottom line is that it is just marginally better than with using the Phoenix 35.

I forgot the Eagle Tree at home so I don't have hard data, but the power level was only marginally improved with the bigger ESC.

It seems that the biggest improvement in power this time out was due to the fact that it wasn't freezing cold like it's been here since last fall for the first time this weekend. The A123 cells like warmer weather and perform much better when the ambient temps aren't in the arctic range...

Thank God summer is finally here in northern Minnesota!!



Bill

[kgfly]

Originally Posted by Mac_Heli

Which BEC for 3sA123?

Another test flight, another crash... Somehow the heli went full negative collective from 6ft high. The 35A Hyperion SBEC was working fine, but since I installed the CC45/SportBEC, the heli is glitchy as it can be. I just checked the specs on the SportBEC and the minimum input voltage is 3s lipo, not 3sA123. Since I'm pushing 3300rpm the input voltage must be dropping enough to kill the BEC and reset the receiver, which would explain this last crash.
Which BEC are you guys using on 3sA123?

Ouch! The D.E. ParkBec (1.25A) is rated down to 6V, the CasteCreations CC BEC (5A) is rated down to 5V and there are plenty of generic SBECs rated for 2S lipo for use as standalone Rx supplies.