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Old Yesterday, 02:50 PM
EDF Jet Jam May 2014
Robert Belluomini's Avatar
United States, KY, Crestview Hills
Joined Dec 2000
6,416 Posts
Quote:
Originally Posted by v8truckin View Post
What's the price in that thing and rated amps? Looked but couldn't find it.
Sensors are here:
http://iisi-rc.com/IISI-RC/TXE.html
50-200 amp - 2-14S

Expansion sensors here:
http://iisi-rc.com/IISI-RC/EXP.html

Tx Mounted Cockpit Unit Here:
http://iisi-rc.com/IISI-RC/Products.html

All in English
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Old Yesterday, 02:54 PM
EDF Jet Jam May 2014
Robert Belluomini's Avatar
United States, KY, Crestview Hills
Joined Dec 2000
6,416 Posts
Quote:
Originally Posted by CoolerByTheLake View Post
No need to Translate Cooler all pages are in English, German or French
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Old Yesterday, 02:59 PM
Registered User
United States, WI, De Pere
Joined Aug 2010
167 Posts
I am running a jet fan with Het 700-68-1680kv. Batteries are Gen Ace 60-125
5000 8s set up. Combo runs great until I get to 3/4 throttle then the motor starts to pulse and loses rpm . Tried 3 different castle controllers and all three give me same results. I also tried Venom packs and the problem was still there.

I tried 7s and the problem was still there but not as bad. 6s the problem is gone.

I am stumped? Where do I start looking for the problem? Controllers are Castel and tried different timing settings and did not correct the problem
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Old Yesterday, 03:08 PM
Formerly "Heli Copter"
Jetsom's Avatar
United States, CA, Watsonville
Joined Apr 2009
421 Posts
Quote:
Originally Posted by goforit View Post
I am running a jet fan with Het 700-68-1680kv. Batteries are Gen Ace 60-125
5000 8s set up. Combo runs great until I get to 3/4 throttle then the motor starts to pulse and loses rpm . Tried 3 different castle controllers and all three give me same results. I also tried Venom packs and the problem was still there.

I tried 7s and the problem was still there but not as bad. 6s the problem is gone.

I am stumped? Where do I start looking for the problem? Controllers are Castel and tried different timing settings and did not correct the problem
Put a meter on it and watch the voltage drop. If the drop is more than .5 volts per cell, your batteries aren't keeping up with the amp load. As the cell count comes down, the load comes down, that's why you don't see it on 6S.
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Old Yesterday, 03:20 PM
Registered User
United States, WI, De Pere
Joined Aug 2010
167 Posts
Quote:
Originally Posted by Jetsom View Post
Put a meter on it and watch the voltage drop. If the drop is more than .5 volts per cell, your batteries aren't keeping up with the amp load. As the cell count comes down, the load comes down, that's why you don't see it on 6S.
Thank you !
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Old Yesterday, 06:22 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,493 Posts
You need to know your ESC settings first before you blame the packs, 0.5v drop is not a problem at the power level you are running, and it wont cause the fan to stutter and refuse to increase in rpm. Its only a problem if your LVC is set very high (and it would have to be 3.6-3.7v) and the soft cut is designed to pulse.

If your LVC is at a regular level around 3.2-3.5v per cell then it wont be the cause of the pulsing unless your packs are really sagging out, is it pulsing slow and steady or is it stuttering as you get past 3/4 and just wont go any faster?

In the later case it would be more likely some issue with the esc/motor combo, maybe a winding issue as you have tried 3 esc. I have done 3 exact fans in the last 2 weeks and they get run to WOT many times during final dynamic balancing, running with a Platinum PRO 120A esc set to 7.5deg timing, no problem at all to WOT. I have had the stuttering in the past with a couple of 28mm inrunners, its been winding issues, at very high power and rpm levels a mild short or incorrect winding will show itself with stuttering throttle, refusing to rev past a certain point.

Easy way to eliminate the cutout is to set it to hard cut, if it is the issue the system will cut power soon as the packs sag, if it doesn't and keeps stuttering then you could have a bad motor winding or esc issue. Next is to change esc brand, try something else just to be sure.
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Old Yesterday, 08:51 PM
Battery Puffer
Orange, California, United States
Joined Nov 2001
1,019 Posts
Having cracked motor wires will do this too. Make sure one of your connectors isn't hanging on by a thread.

Mark
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Old Yesterday, 09:41 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,493 Posts
Yes dry solder joints definitely can cause this and also worn or badly fitting plugs, have seen this before at the field, twisting the plugs inside each other fixed the stuttering, so all plugs were replaced.
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Old Yesterday, 11:28 PM
Registered User
United States, WI, De Pere
Joined Aug 2010
167 Posts
I replaced all the connectors tonight on the batteries , speed controllers and charger.

Ran a test on 7s and 8s. 7s runs great., no more slow down at full throttle.

8s was ran for aprx 3 minutes. Each full throttle burst was followed by aprx 45 seconds of 1/2 throttle.

I managed to get 3 10 second full throttle runs and no problem. On the 4th try
the pulsing started again but was not as bad. You would have not noticed it flying . I checked the cut off voltage after the test and it was set at 3.7 volts. Next test run cut off voltage to 3.0 with hard cut off and see what happens.



Thank you for you help
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Old Yesterday, 11:44 PM
efflux RC's Avatar
United States, CA, Santa Clarita
Joined Aug 2009
8,591 Posts
Most guys don't use hard cutoff for LVC. You don't want the jet shutting of during a maneuver. Many use soft cutoff. Some set set it to no cut off and pay care ful attention to the first few short flights, recording how much you ut back into the packs. then set your timer with some extra time for a go around if need be. This is how you should determine your timer setting anyway.
You should have (or get) a battery checker, to see how much you have remaining after the flight. 20-25% is considered decent.

3.7V cutoff is too high. The "normal" cutoff for LVC is 3.2V. Some take it down to 3.0.

I'd suggest setting it to 3.2V this gives you another half a volt per cell to play with, with out being hard on the packs.

With the right settings and some throttle management, you see about 4 minutes with those packs if they're in good shape.

Just my 2 cents.
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