Quark UBEC for my Neu 1515 1.5y/s brushless system ; 5A or 6A? which way should I go? - RC-Monster Forums

shawn197

Hello, y'all.
I have recently bought a Neu 1515 1.5y/s and hooked it up to my Monster Pro 125B. And I'm using Quark made 5A Pro-BEC on 6S lipo setup.
It worked fine and I was very happy with the system. But today when I went to a racing circuit nearby my house, My proud brushless Revo suddenly stopped working. So I took a look at it and found out that my UBEC went out of order. It seemed like a part of the rubber insulation had melted down and the electronic circuit board touched the metal part of my motor mount and...
Anyway... My question is that for the system that I have, which mode should I go with 5A or 6A? Would it have made some difference if I had set it up for 6A? Or 6S lipo are too much for the system that I have?

Quark Monster Pro 125B/Neu1515 1.5y/s (1500kv)/Quark Pro-BEC 5A/6s lipo/Ofna 51T mod1 spur/Mod1 17T pinion/ Gorillamaxx G3R Revo

shawn197 · **Another problem in My life. -** 02.22.2008, 01:01 PM

Can this brushless motor be fixed based on what you see on the video file attachment?

BrianG · 02.22.2008, 01:08 PM

Welcome to the forums!

First of all, you probably mean 5v or 6v (not amps), right?

Assuming so, 5v or 6v usually makes no difference, 6v just allows the servos to work at the max potential. Most of todays servos work fine at 6v (and some even higher). So, that's probably not as issue.

If the insulation actually melted, it usually means that the wires heated up a LOT, which tells me you are pulling more current than the wires are rated for the servo(s) you are using. More likely, the insulation simply wore down from rubbing on something until the wire touched the metal.

For up to 6s lipo, the Castle Creations UBEC would be a good choice. It will allow you to dial in whatever voltage you want and supplies a good amount of current. If you think you may go higher voltage in the future, the KoolFlight UBEC is a good choice. That one is good for up to 35v IIRC (8s lipo) and 3.5A. I've tested it and it provides a clean, noise-free output voltage (important for senstive receiver circuits) and stays cool even under heavy loads.

So, in short, your current battery voltage and BEC output voltage (5/6) probably was not a contributing factor in what happened to your Quark UBEC.

BrianG · 02.22.2008, 01:10 PM

Quote:

Originally Posted by shawn197

Can this brushless motor be fixed based on what you see on the video file attachment?

You have an issue with the motor itself too?

shawn197 · 02.22.2008, 01:18 PM

Hi, Brian.
Thank you for you kind reply. And you are right. I meant Voltage.
The motor you saw on the video footage is another brushless motor that I have.
I have two feigao brushless motors, but I think I killed both of them, one 3 weeks ago, and the other today. The motor you see on the footage is Feigao 540C 8XL 2 pole motor. The motor feels like it doesn't have any magnetic field. Can I simply change the rotor or spindle(I am not quite sure what to call it) to fix the motor? Or it's simply dead? I am really sad about what happened to the two motors... I am afraid that my Neu will go like that again...

shawn197 · 02.22.2008, 01:26 PM

Unfortunately, I bought another Pro-BEC from a local hobby store.
►Input Voltage Range : 11.1V~55V
►Amphere Rating : 5A : Continuous
8A : at 30Sec
10A : at 0.1Sec
►Ouput Volt Range(Programmable) : 5V +/- 0.2V
6V +/- 0.2V
►Ripple : 10mVp-p(@1A/15V)
13mVp-p(@1A/30V)
►Efficiency : 96.5%(@1A/15V)
►Dimension : 45 X 23 X 13 mm
►Weight : Under 23 gram

Do you think it's bad based on what you see on the spec?

BrianG · 02.22.2008, 01:29 PM

Are both those Feigao motors the same kv rating? Lower kv motors seems to have more of a magnetic feel. My Feigao 8XL felt way different than my 10XL. It is possible the magnet got weaker too. Excessive heat can deteriorate a magnet.

What speeds were you spinning those Feigaos? They tend to heat up quite a bit at speeds over 35k rpm, so you might want to look at that. If the coils haven't melted (or partially melted), you can replace the magnet (assuming that it is the problem). Either find one from the same type of motor from someone here, or see about getting a brand new replacement. Mike should be able to help you out if that's the case.

BrianG · 02.22.2008, 01:37 PM

Quote:

Originally Posted by shawn197

Unfortunately, I bought another Pro-BEC from a local hobby store.
►Input Voltage Range : 11.1V~55V
►Amphere Rating : 5A : Continuous
8A : at 30Sec
10A : at 0.1Sec
►Ouput Volt Range(Programmable) : 5V +/- 0.2V
6V +/- 0.2V
►Ripple : 10mVp-p(@1A/15V)
13mVp-p(@1A/30V)
►Efficiency : 96.5%(@1A/15V)
►Dimension : 45 X 23 X 13 mm
►Weight : Under 23 gram

Do you think it's bad based on what you see on the spec?

That's actually a really good UBEC based on the specs; very high input voltage range and a very decent current output. Ripple voltage is a bit high, but not too bad. It'll probably be higher with higher current loads. You could add a 10v 1000uF (or higher) capacitor to an unused receiver port to help with that "noise" if it becomes a problem. You can see how to hook up this capacitor here. Some receivers can be sensitive to noise. The efficiency is probably max, and will be closer to 85% under normal running, but that's still very good. What UBEC is this? You have a link?

shawn197 · 02.22.2008, 01:37 PM

I am sure I heat it up too high because when it went out of order, the bolt on the slipper got loose. However, not knowing it, I pushed the throttle to make it come back. The next thing I know was it stopped revving. What it does it now when I hook it up to my ESC, is the rotor jerks when I push the throttle trigger without rotating normally.

BrianG · 02.22.2008, 01:39 PM

It does this with both motors? Are you sure the ESC output is good? Also, check connections, especially the motor to ESC wire connections. Sounds like one or two of the motor phases aren't firing...

shawn197 · 02.22.2008, 01:41 PM

It's made by Quark. I can get a picture of it but think it's not out in the USA.
If you go to www.sky-technology.co.kr then the page will ask you to choose between Korean and English. If you click on Korean. It will lead you to Korean page.
I can try to copy screen the page for you.

shawn197 · 02.22.2008, 01:49 PM

The thing is that I have two quark brushless ESCs. One is Monster pro 125B. The other is SSB-mk2 which is not out in the USA. The monster pro seems to be working because it's making signal melody. But the other I haven't checked it out why it's not making a sound. However, the two motors were hooked up to different ESCs. I hope I will be able to fix 540C 8XL. I can be careless about the other one. Because I don't know what this motor is because it came with the used E-revo I bought.

shawn197 · 01:54 PM

This is the motor that I killed today, but I don't know about the spec of this motor.

BrianG · 02.22.2008, 01:51 PM

Looks like a nice unit! And from what I can see of the circuit, they use parallel ICs. Should be perfect. Quark makes really nice ESCs, no reason to think their BECs wouldn't be the same...

BTW: This is the page: http://sky-technology.co.kr/product_...2&set_number=4

shawn197 · **This is the ESC for my E-maxx -** 02.22.2008, 02:00 PM

This is the ESC for my E-maxx

Input voltage : Ni-cd(mh) 4-18 , Lipo 1-6 셀
►continuous voltage : 100A (@Full throttle, 25 ℃)
►internal resistance : brushless mode - 0.00045Ω
► brush(DC) mode - 0.00015Ω
►Motor Limit: Limitless (540 Brushless + Brushed )
►BEC: (Switching BEC type ) 5.5V/3A
* Linear BEC can be used without a limit on cell count
►size : 45mm X 30mm
►weight : 58 grams ( 와이어 제외 )