Hobbywing Seaking 180 GO BOOM

[ray schrauwen]

Something here:

Originally Posted by Carl Petersen
Lucien,

From time to time the subject of paralleling BEC outputs from two speed controllers, twin motor setup, to increase the current available comes up. What's your take on that?

Scorpion has done testing on their 4-cell ESC's with linear BEC circuits, and found that they can be put together in parallel with no ill effects. When you stop and think about it, the BEC's inside the ESC already have several voltage regulator chips in parallel to begin with. The BEC Circuits in the 4-cell ESC's are comprised of 2, 3 or 4 seperate voltage regulator IC's that put out one amp of current each. These chips are all connected in parallel with one another right on the PC board, and they all work well together. That is because Scorpion uses high quality voltage regulator chips with very tight output tolerances.

If you take 2 ESC's, and put them in parallel through a Y-Harness, you are basically connecting one group of voltage regulators to another. If they are all at the same voltage, then the output of one will not fight the other, since both are at the same voltage. Where you would run into problems is if you took two different ESC's and hooked them together, you could have the potential for a difference in voltage, and this could lead to a high amount of current flowing from one BEC into the other, and that would not be good.

The only down side to this is that if one of the ESC's fails, and the BEC circuit goes down with it, it can pull the remaining good BEC down as well. This situation can be avioded if you place a Schottky rectifier diode in line in the output between each of the BEC circuits. Schottky diodes are preferred, because they only have a 0.4 volt drop across them, as opposed to silicon diodes that have a 0.7 volt drop. All of the new Scorpion ESC's use 6.0 volt regulators in them now, so even with a Schottky diode in line, you still get 5.6 volts to the receiver, which is enough to ensure that you do not get a brown-out in a Spektrum receiver. Just make sure that the diodes are rated for at least 3 amps of continuous current and you will be fine. This way, if one BEC were to fail, the diodes would prevent current from flowing back into the dead BEC and allow the other one to continue functioning.

Talking about ESC's that have switching type BEC circuits, you should NEVER put these types in parallel with one another. The Switching type BEC's rely on a closed loop feedback system, where the output voltage is constantly monitored and pulse width of the switching circuit is constantly changing to adapt to the changing load on the system. This happens thousands of times per second, so that it can rapidly rrespond to a change in current when a servo moves or the load changes.

If you hook two switching type BEC's together, if one of them increases it's output voltage, the other one can see this as too much voltage and reduce it's output. Since the two outputs are tied together, you end up with a tug-of-war between the two BEC circuits where one adjusts, then the other one adjusts to compensate, then the first one re-adjusts, and this goes back and forth, throwing both of them out of whack.

If you intend on using a switching type BEC, you always want to use a single unit that is capable of handling all the required current demands.

That is my take on the situation, and hopefully you agree with it.

Thanks!

Lucien

more in the same RCG thread...

[ray schrauwen]

Also:

Originally Posted by Innov8tive
I am not sure which ESC you were running, but one thing that many people do not take into account is how much load the BEC circuit puts on the speed controller. With the newer digital servos, the current coming from the BEC circuit is quite high, and the heat generated by the BEC circuit is often greater than the heat generated by the FET transistors in the ESC. Most ESC's are around 95 to 98% efficient at full throttle, so for every 100 watts of energy that transfers through them, you only get 2 to 5 watts of heat. Running at reduced throttle settings is less efficient, and the loss in the controller can go up to 10 or 15% depending on the PWM frequency and the design of the ESC itself.

Typically, a heli with 325mm blades will pull around 10-12 amps in a steady hover and average around 20 to 25 amps in 3D flight, so in general sport flying you run about 130 watts of power through the ESC and in hard 3D you run an average of around 250 watts of power. If you had the throttle set at 100% with proper gearing, just flying around you dissipate 7-10 watts of heat through the ESC, and in hard 3D up to 25 watts of power.

Now if you look at the BEC circuit, you have around 11 volts available that you are stepping down to 5 volts, this means that 6 volts is being dropped across the BEC circuit. If your average servo draw is 2 amps, then you are gettin 12 watts of heat from the BEC circuit alone! If you have a buzzing servo, or a gyro with too much gain that causes the tail servo to constantly adjust, then that servo alone can pull over 2 amps of current, doubling the current through the BEC and pushing it to 25 watts of power just from the BEC circuit. When you combine this with the dead air inside a scale fuselage, the ESC is going to get hot!

By running a seperate switching type BEC, all this servo load is taken away from the BEC in the speed controller and this allows it to run much cooler. Another thing that can be done is to get a small 30mm cooling fan from a computer CPU heatsink and run it on the ESC. These things typically only pull arounf 0.05 to 0.10 amps of current, which is virtually nothing, and they can be connected directly to a 3-cell Li-Po battery, since they are designed to run on 12 volts. This will work wonders pulling the heat off the ESC and allow it to dissipate into the air.

Al of this can work together to make your ESC run way cooler and much happier!

A 55 or 60 amp Scorpion ESC would be adequate for this installation, but I would still recommend using a small cooling fan to stir the air around the ESC.


Lucien

[ray schrauwen]

I have an external BEC that I can use. How do you use this spark arrestor that you described?

I just clip one end to the battery + and the other to the Esc while the other lead is already connected, wait 10 sec. then plug it in. The clip will have to come off before the plug goes in.

I like that pic someone posted that had a resistor soldered permanent, looked neat.

[scooterP]

I'm seriously beginning to think that this esc had a defect. I have another one that I have put 2 times as many runs on now as the first one on the same setup without issue. It's ashamed that you can't get any warranty replacement on these chinese esc's......but you get what you pay for I guess. It's a roll of the dice.

[scooterP]

Well, I almost hate to admit it, but I have had yet another HW 180A esc self incinerate. It did it in the same fashion as the first one that I had. It wouldn't be so bad if I were running flat out and something happened, but this is happening right after I put the boat in the pond!!!!! I also was running this one with a seperate BEC and I made sure to un pin the + lead coming from the esc to the reciever.

I had ran this esc with my 8XL and a 640 prop for at least 15 times before this failure occured. The only thing that I had changed before it occured was the reciever, and using an external BEC....I had been using a Hitec 3ch FM reciever when the first one blew. It caused that reciever to loose the throttle channel, so I went back to one of my old AM recievers until I could order another Hitec 3ch.

What's weird is the first day with the new Hitec, the range was worse than with an AM reciever, and the throttle would pulse when I reached what looked like the range limit.

Went out to the pond the next day, put batteries in and put the boat in the water. When I hit the throttle the motor seemed to cog once or twice then the magic smoke appeared......and things started to cook.

The only thing I can come up with is either the motor is causing the failure or the reciever has something to do with it. I just don't know at this point. I haven't had the ESC under water or anything. It could have had a few drops on it here and there, but I thought their "waterproofing" would surely keep out a few odd drops......

I sent in pics to HobbyWing and they are replacing the esc for the cost of shipping, but honestly I'm scared to try it again. I think I will put my 9XL in and run with it to rule out the motor, but for some reason I think my reciever might have had something to do with it. Anyone have any ideas on this?

I'm honestly thinking of taking a break from boats after this run of bad luck....or whatever it is. I can go back to flying helis and get out cheaper than this!!!!

[ray schrauwen]

Is your motor a feigao or cheap knock off. I would guess you should try your motor on a cheap $23 Super simple esc. If it works you are cursed with 180's

If it doesn't work your motor fried it. I doubt you rx caused this but it is posible. try it on something else like a servo.

Standard defaulkt timing on the 180 is 15 degrees. O.k. for 4 pole + motors but, a 2 pole will pull lots more amps at this setting.

[cybercrxt]

Has that motor been overheated? Sure sounds like it. I really cannot stand the Feigao motors. I have owned a couple, and wasn't impressed with the long term durability.

[scooterP]

I bought the motor used and it didn't appear to have been overheated. I actually had put in new bearings that I had laying around in my toolbox. The old ones weren't worn out, but I thought since I had them I would use them.

I didn't overheat the 8XL motor while I had it. My 9XL motor is the one that Hobby King sells. All of the runs with this setup I had always checked for any excess heat, but never more than warm on the esc or the motor. I'm running 2 cooling pickups for the motor and esc. Both systems independent.

I think the timing was set to 7.5 when I checked it with my program card. On my next one I will go with zero and see how it runs. The 9XL will turn the 640 prop while only generating 93amps according to FeCalc.....

I was using the 180a esc because my setup on 8XL was supposed to be pulling anywhere between 120 and 130 amp. I had also went through a couple of the cheap Flyermate 200a esc's, but the issues I had with them was totally different. One got water to it and fried a chip on the board that recieves the signal for the rx. The second I think could not withstand the amperage and finally just quit working.

I bought this HW esc because I had read good things about it. I can also say that it is one of the smoothest throttling esc's that I have ever used.....and that includes CC esc's that I have used on electric helis and cars.

[Brod]

Well, I almost hate to admit it, but I have had yet another HW 180A esc self incinerate. It did it in the same fashion as the first one that I had. It wouldn't be so bad if I were running flat out and something happened, but this is happening right after I put the boat in the pond!!!!! I also was running this one with a seperate BEC and I made sure to un pin the + lead coming from the esc to the reciever.

I had ran this esc with my 8XL and a 640 prop for at least 15 times before this failure occured. The only thing that I had changed before it occured was the reciever, and using an external BEC....I had been using a Hitec 3ch FM reciever when the first one blew. It caused that reciever to loose the throttle channel, so I went back to one of my old AM recievers until I could order another Hitec 3ch.

What's weird is the first day with the new Hitec, the range was worse than with an AM reciever, and the throttle would pulse when I reached what looked like the range limit.

Went out to the pond the next day, put batteries in and put the boat in the water. When I hit the throttle the motor seemed to cog once or twice then the magic smoke appeared......and things started to cook.

The only thing I can come up with is either the motor is causing the failure or the reciever has something to do with it. I just don't know at this point. I haven't had the ESC under water or anything. It could have had a few drops on it here and there, but I thought their "waterproofing" would surely keep out a few odd drops......

I sent in pics to HobbyWing and they are replacing the esc for the cost of shipping, but honestly I'm scared to try it again. I think I will put my 9XL in and run with it to rule out the motor, but for some reason I think my reciever might have had something to do with it. Anyone have any ideas on this?

I'm honestly thinking of taking a break from boats after this run of bad luck....or whatever it is. I can go back to flying helis and get out cheaper than this!!!!

I can see were your coming from,i fly helis too and nothing like the problems with these FE boats,
we run mainly gas boats now,after burning 2 180's,both escs took the out the lipos as well.
I am just about finished building a HOR 32" cat with an Etti and Medusa motor,if this burns its goodbuy forever for FE boats for me too.

[scooterP]

Man I tell ya. I got into boats last summer when a new friend asked me to take a look at his. He figured since I flew planes and helis and dabbled with nitro trucks that I would be able to get his Villian going again. I got hooked by messing with the Villian....went out and bought an SV27.....and the rest...you know the story.
I had taken a break from helis because of aggravation and expense.....but lately the boats........

[ray schrauwen]

Ihave seen the HK feigao copy motors loose their magnet strength after one run.

[scooterP]

Ihave seen the HK feigao copy motors loose their magnet strength after one run.

I have had that happen when I got a little froggy one day and ran one of my 9xl knock offs on 6s. It ran 61, but only did it from one end of the pond to the other......then no magnet..

[scooterP]

I am on my third esc now, but with much better luck. I changed out my 8xl to a 9xl that I had and so far though many runs I have no issues at all. I never thought a motor could cause an esc to blow like mine did, but I guess stranger things have happened.
Can anyone tell me what issue a motor could have that would cause the esc to literally blow up like mine did?
Thanks

[ray schrauwen]

It is key to have the proper magnetic field when under power I believe. If not, then bad things happen. This and/or if the windings have been heated significantly to damage the insulating properties of the wire, possible short circuit? Partial short circuit?

[electric]

I have fried a motor before. Need someone else to give you the reason, but the result is the motor demag's and then there is this huge amp draw and then poof!