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My Feedback: (3)

Hello there,

I have bought 2 PowerExpanders to install on my Giant scale planes and ultimately on my turbine jets. I had the chance to test the one installed in my 40% Carden Extra 330 and unfortunately it didn't work properly,so I had to remove it and fly without the PowerExpander. This is what happened:

A)My planes set up:

1) Elevators: 2x Futaba 9206 on each elevator half (wires hooked together and one servo lead going all the way to RX (right elevator hooked on channel 2 and left on channel 7 using a Pmix to activate both.)
2) Ailerons : 2x Futaba 6206 on each aileron (wires hooked together and one servo lead going all the way to RX (right aileron hooked on channel 1 and left on channel 6 using a Flaperon to activate both.)
3) Rudder : 2x JR8611 installed with a floating bell crank system (servos are not fighting each others) (one servo hooked on channel 4 and the second on channel 8 using a Pmix to activate both.)
4) Throttle: 1 Futaba 3001 hooked on channel 3
5) Smoke: TME smoke pump hooked on channel 5
6) Choke: 1 Futaba 3001 hooked on channel 9
7) RX : 1 Futaba 149 DP 40 Mhz
8) Batteries: 2 x NiMh 2500 mA
9) All leads were connected to PowerExpander as per above references and each battery on Power output as per instructions.


B) What happened.
When I installed the system in my workshop Elevator halves and wings were not in place, the rest of functions were working properly although I haven't tried to move the rudder to check if it was moving properly.
At the field, I wanted to do a range test to check that everything was working smoothly. When I switched on the power and tried to test if all servos were working properly I was very surprised to see that elevator halves were acting heretically and not in synchronization (left elevator would have a bouncing effect going up and down 2 or 3 times after moving elevator stick up one time giving a very weird aspect).
Furthermore, Rudder servos although they are separate (each on one channel) were also acting heretic but not as obvious as elevators (from time to time).
One thing that was also surprising is that when elevator stick was pulled all the way (full up and holding it that way) both elevator would go to full up and stayed as long as stick was in this position. When stick was released the left elevator would go bouncing up and down 2 to 3 times.
Did not notice this behavior on ailerons although they have exactly same set up as elevators (but I cannot be 100% sure that ailerons were acting faultlessly view I was very upset from the way elevators were functioning that I didn't pay more attention to the rest of functions.

I had no choice but to remove completely PowerExpander and hook all servos back to respective channels and flew the plane without it and without any problem.
I was so pleased of having installed the power expander on my plane and I had a really neat installation to show off with but was very disappointed with the results later on at the field in front of all the guys.

Can anyone help in this respect. Did I go wrong at some stage during installation or my unit has some sort of defect? Appreciate if anyone had similar experience or any advise on how to proceed.

Thanks. Regards.
Dany

rrritchey

Hi Dany,
I will keep an eye on this thread. Let me know if using the other PowerExpander makes any difference.

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My Feedback: (3)

Thanks Robert,

Will do first chance I get and revert with results.
Dany

mikko97

Greetings. I have been following this thread, and I have also been experiencing the same problem with glitching limited exclusively to the left elevator half of my Lanier Yak. I just recently purchased a smart fly power expander and super reg. I use a 9 channer Multiplex receiver and I have Futaba high torque servos for my elevators. I am using a servo reverser which is attached to channel 2 on the smart power expander. I check my linkeages and tried using another servo and I still get the same effect. Please advise.

Thanks.

Geoff

rrritchey

Hi Geoff,
I wish I had an answer but these are the only two issues like this I have heard of, and just recently obviously. Is the glitching servo on the servo reverser? Have you tried direct connections just to rule out the reverser if it is? Does it glitch when you just move that servo or when you are moving other things. If it does it when you are moving other things can you tell me which channel if you can isolate. Does the servo glitch if you move the channel on the receiver that is physically on either side of the glitching channel? If you want, you can send in the PowerExpander for us to look at.

mikko97

Hi Robert,

I had the chance to work on some of the recommendations that you mention on the forum, and I found out there maybe a compatibility issue with the smart fly power expander and the EMS servo reverser that I am currently using on my plane. I did a direct connection without using a servo reverser, and I had no glitching on channel 2 or 7. I used the same EMS servo reverser and placed the right elevator half on the lead, which has the reverser. I found out that the right elevator half had the same glitching problem. The left elevator half was working fine. I also decided to change the servo reverser with a new EMS reverser. The same problem of glitching of the elevator half connected to the EMS servo reverser lead was observed. Hooking the servo reverser lead directly to my receiver, I notice the same glitching problem. Glitching only occurs while the engine is running and this problem occurs with or without manipulating the elevator control stick. I used the same servo reverser on another giant scale plane of mine, which is hook up directly to the receiver, and I have no problems with glitching. All other control surfaces are stable. Do your recommend that I switch over to another brand of servo reverser Y harness?

Thanks for your prompt reply.


Geoff

rrritchey

Hi Geoff,
I would recommend you use one of our Equalizer IIs or a Matchbox. Most of the servo reversers out there are "analog" and have serveral problems. First they drift with temperature which is not a good thing, especially here in Arizona where we go from the 50's in winter to 110s in summer. This is very noticable here. In addition they are very sensitive to noise, which is why you probably are seeing the glitches you are. Servos normally ignore small noise issues. The Equalizer and Matchbox are both fully "digital" and will not have these problems.
Please let me know if you have any further questions.

mikko97

I will certainly purchase the Equalizer II or Matchbox that you recommended. I will keep you posted once I receive your product. Thanks for your help.

Geoff

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My Feedback: (3)

Hi Robert,

Exactly one year after i posted my thread/problem. a couple of weeks ago while i was surfing on the net, i came accross JR HD switches with 18 ga cables and Dean plugs that would accomodate smart fly Power expanders. It hit me here and then to note that i had used normal thin wires soldered to the Dean Plugs and maybe, due to high current output the thin cables may not be able to deliver enough current to move all the servos, consequently, this would give the impression that batteries are weak and moving herratically.
I have already ordered a couple of above switches and will do some testings as soon as possible.
Meantime, appreciate your comments on above theory.
Best regards.
Dany

rrritchey

Hi Dany,
Yes, we do make the SuperSwitchHD that has 18ga wire and Deans plugs on both sides. With 22ga wire or smaller you are going to get some voltage drop in the wire, but mostly any standard R/C plugs you have in line, before you get to the PowerExpander. If you did measurements you would find that the biggest voltage drops are caused by the standard R/C connector, not the wire. Using better connectors helps a lot, either Deans Ultra Plugs or even their smaller Mini-plugs. Let me know if I missed your question.