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Dec 27, 2012, 11:12 PM
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Quote:
Originally Posted by Jetnfast
A 35-70C pack should be plenty for the stock setup if that is what you are running. Also you mentioned you tried a second set and that seems to rule out the batteries as the direct source of your problem. Is the fan balanced? Have you checked all your solder joints with your connectors. Based on the info you posted, it sounds like you have some resistance between your batteries and motor which the most likely cause is a bad or cold solder joint.
Yes it's all stock setup except the ESC - I'm using a Turnigy Dlux 100A. The stock fan sounds balanced. All the solder joints seem secure; I guess the only thing is that the 4MM connectors between the motor and the ESC don't seem extra tight - they're certainly not loose, but just not super tight the way I'm used to seeing them. Would this cause what I'm describing?

It seems the high/low sound is indicating Low Voltage Cutoff, but I'm not sure how the cutoff could be reached so soon, especially when all the batteries still had at least 3.75V upon landing. Will use a wattmeter later to check current, but it also seems unlikely that the stock setup would draw enough to trouble a 100A ESC?

Kevin
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Dec 27, 2012, 11:15 PM
Registered User
Quote:
Originally Posted by swarick
Got a Habu 32 for Xmas and was reviewing this thread to find servos used. I noticed quite a few people have used the HITEC servos. I want to run a 2 cell LiFe pack rather than separate BEC. do the small HITECs handle the higher voltage OK?

Rick
The only issue with the Hitec 85MG or the 5085MG (if you want digital) is on the elevator. The Hitecs have only one mounting screw so you have to drill new holes and getting to the elevator servo mounting area is a bit of a PITA unless you have a long drill (or short for that matter). Otherwise you have to drill the new mounting hole at a bit of an angle.
Dec 28, 2012, 08:00 AM
Michael

Current Draw Measured?


Have you measured the current draw using, e.g., a wattmeter?

I had a problem with a Turnigy ESC once when near the current limit. To protect itself, it reduced power to the motor giving the appearance of LVC activated; batteries were still well over 80%.

I upgraded the ESC and the problem went away. I find a wattmeter one of my most frequently used tools when setting up any model and when troubleshooting electrical problems.

Michael
Quote:
Originally Posted by kchen95
Yes it's all stock setup except the ESC - I'm using a Turnigy Dlux 100A. The stock fan sounds balanced. All the solder joints seem secure; I guess the only thing is that the 4MM connectors between the motor and the ESC don't seem extra tight - they're certainly not loose, but just not super tight the way I'm used to seeing them. Would this cause what I'm describing?

It seems the high/low sound is indicating Low Voltage Cutoff, but I'm not sure how the cutoff could be reached so soon, especially when all the batteries still had at least 3.75V upon landing. Will use a wattmeter later to check current, but it also seems unlikely that the stock setup would draw enough to trouble a 100A ESC?

Kevin
Dec 28, 2012, 08:13 AM
Another one on the way...
ysolomon's Avatar
BTW, I used two dlux 100A ESCs in my ProJet A-10, and was never too crazy about them... For example, I couldn't simply "Y" the control line to have both controlled by a single Throttle channel. They would just quit at some relatively low power level, and then jump to maximum, and then quit. Very strange. Can you try to use another ESC just to see if the problem goes away? This does sound more like an ESC problem than anything else. You probably already have $800+ into the plane anyway, might as well trust it to a good ESC...
Dec 28, 2012, 08:50 AM
Registered User
Jetnfast's Avatar
What ysolomon suggests is a good idea, trying another ESC in addition to what I suggested of checking all the connectors. You mentioned the somewhat loose but not tight bullets. Bottom line, there should be any play in the connection. If there is then I would use some pliers or a similar tool to expand the "cage" in the male bullet so it fits tighter, assuming you have the cage style bullets and not the castle creations type. That's an easy solution if that is indeed the source. Worst case you can rule out the connectors and then whittle it down to the next potentional cause, the ESC. I wouldn't fly the jet again until I determined what the problem. Bench run it and use your watt meter and you will eventually solve the problem.

Just curious what type of connectors are you running on your batt and ESC connection?
Dec 28, 2012, 09:15 AM
Registered User
Quote:
Originally Posted by Jetnfast
What ysolomon suggests is a good idea, trying another ESC in addition to what I suggested of checking all the connectors. You mentioned the somewhat loose but not tight bullets. Bottom line, there should be any play in the connection. If there is then I would use some pliers or a similar tool to expand the "cage" in the male bullet so it fits tighter, assuming you have the cage style bullets and not the castle creations type. That's an easy solution if that is indeed the source. Worst case you can rule out the connectors and then whittle it down to the next potentional cause, the ESC. I wouldn't fly the jet again until I determined what the problem. Bench run it and use your watt meter and you will eventually solve the problem.

Just curious what type of connectors are you running on your batt and ESC connection?
Ok tks for all the input. Finally figured out how to use the wattmeter with two lipo's in series Will go check now and see how it goes - also have another ESC to test as well.

Kevin
Dec 28, 2012, 10:18 AM
Registered User
DamonH's Avatar
Quote:
Originally Posted by Sit-N-Fly
The only issue with the Hitec 85MG or the 5085MG (if you want digital) is on the elevator. The Hitecs have only one mounting screw so you have to drill new holes and getting to the elevator servo mounting area is a bit of a PITA unless you have a long drill (or short for that matter). Otherwise you have to drill the new mounting hole at a bit of an angle.
What servo is better suited for the elevators? Thanks.
Dec 28, 2012, 10:38 AM
Registered User
Jetnfast's Avatar
Quote:
Originally Posted by DamonH
What servo is better suited for the elevators? Thanks.
I am using HS-85s. HS-82s will also work. These have plenty of torque and speed. The digital variant 5085 also will work as mentioned above. Drilling new holes to make it fit is not that big of a deal IMHO.
Dec 28, 2012, 10:39 AM
Registered User
Quote:
Originally Posted by Jetnfast
What ysolomon suggests is a good idea, trying another ESC in addition to what I suggested of checking all the connectors. You mentioned the somewhat loose but not tight bullets. Bottom line, there should be any play in the connection. If there is then I would use some pliers or a similar tool to expand the "cage" in the male bullet so it fits tighter, assuming you have the cage style bullets and not the castle creations type. That's an easy solution if that is indeed the source. Worst case you can rule out the connectors and then whittle it down to the next potentional cause, the ESC. I wouldn't fly the jet again until I determined what the problem. Bench run it and use your watt meter and you will eventually solve the problem.

Just curious what type of connectors are you running on your batt and ESC connection?
OK just came back from running a bunch of bench tests - btw my connectors are the 4MM red bullet connectors.

Right now, my best guess is that the ESC went into LVC because of overheating. For the first test, I ran the wattmeter with the canopy open, it registered peak current of 75A (which really shouldn't burden a 100A ESC?), ran full throttle for about 40 seconds and alternated between various throttle settings for another 2 minutes, and everything was fine but ESC felt hot at the end. After waiting for about three minutes, I spooled up the system without the wattmeter and with the canopy closed. It went into LVC-like behavior after about two minutes. After resting for another three minutes, I did a wattmeter test again with the canopy open (but ESC not yet completely cool down), and this time it went into LVC after 2.5 minutes. After a temporary stoppage (without unplugging anything) of 1 minute, I spool it up to max and it was fine again.

So, does that sound like a heating issue? If so, without doing some significant modifications, is throttle management plus short flights the solution for now?

Kevin
Dec 28, 2012, 10:42 AM
Registered User
DamonH's Avatar
Quote:
Originally Posted by Jetnfast
I am using HS-85s. HS-82s will also work. These have plenty of torque and speed. The digital variant 5085 also will work as mentioned above. Drilling new holes to make it fit is not that big of a deal IMHO.
Yeah I have HS5085 all around (havent installed elevator servos yet). I was just asking cause he mentioned the mounting issue with the 85's being a single screw mount. Was wondering if there was a recommended servo with the dual screw mount.
Dec 28, 2012, 10:48 AM
Registered User
Jetnfast's Avatar
Quote:
Originally Posted by kchen95
OK just came back from running a bunch of bench tests - btw my connectors are the 4MM red bullet connectors.

Right now, my best guess is that the ESC went into LVC because of overheating. For the first test, I ran the wattmeter with the canopy open, it registered peak current of 75A (which really shouldn't burden a 100A ESC?), ran full throttle for about 40 seconds and alternated between various throttle settings for another 2 minutes, and everything was fine but ESC felt hot at the end. After waiting for about three minutes, I spooled up the system without the wattmeter and with the canopy closed. It went into LVC-like behavior after about two minutes. After resting for another three minutes, I did a wattmeter test again with the canopy open (but ESC not yet completely cool down), and this time it went into LVC after 2.5 minutes. After a temporary stoppage (without unplugging anything) of 1 minute, I spool it up to max and it was fine again.

So, does that sound like a heating issue? If so, without doing some significant modifications, is throttle management plus short flights the solution for now?

Kevin
Did you pull the power system from the model to do your run up? If not, realize you have limited to zero airflow over your ESC depending on the location if it was installed at the time you did your test. Where do you have it installed anyhow? Regardless of the location, make sure it has some cooling airflow on the ground and see if that helps. There are lots of posts on the subject of ESC location in this thread as well.

Depending on the ESC, they usually specify the amount of airflow needed during operation to keep it cool.
Dec 28, 2012, 11:00 AM
Registered User
Good point - I did the tests with the entire system installed, so airflow was non-existent. The ESC is velcroed to the wall right behind the battery tray, so it actually touches the batteries (2 in series). I guess that's not exactly a location conducive to airflow either? I simply placed it there because that's where the manual indicates. Should I slide the ESC further back, towards the intake?

Kevin
Dec 28, 2012, 11:19 AM
Mile High EDF
420flyboy's Avatar
Stuff it between the ducts , where they come together , the fan will pull air over it and keep it cool.
IMHO it's the air flow and that Dlux esc , I've used those with varying results , use nothing but castle now and haven't had one problem

The hobbywing 100A is a better esc if you are on a budget, than the dlux 100a .
Dec 28, 2012, 11:48 AM
Registered User
Got it tks. May decide to pony up for a Castle ESC. This is just too nice a jet to risk on something like this

Kevin
Dec 28, 2012, 02:00 PM
Registered User
Jetnfast's Avatar
Quote:
Originally Posted by kchen95
Got it tks. May decide to pony up for a Castle ESC. This is just too nice a jet to risk on something like this

Kevin
I have seen them on sale recently as well. I think Neumotors was selling ICE 100's cheap, or you could check the classifieds to find a good deal!


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