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Post by jjonyoung on Aug 19, 2009 5:09:52 GMT 1
Has anyone used this LIPO before. I want a LIPO battery that I can use on a stock Cub. Can anyone tell me if they think this is going to burn out my motor or if its even going to upgrade my performance. I am not currently using LIPOS but wanted to switch over. I have new connectors and soddering equipment. Am I going to need anything else for my conversion like, ESC! The LIPO is.... Turnigy 2200mAh 3S 20C Lipo Pack www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=8932Let me know what you all think... Jon |
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Post by duck9191 on Aug 19, 2009 5:36:20 GMT 1
you will have to modd the battery box to get it to fit. you will notice quite an improvement over stock, your gaining a few extra volts of power and added capacity will make your flight times longer. you need to remove the little black jumper from the rx/esc, it will raise the low voltage cut of level so that its a bit more acceptable for lipos. also going to a 10x6 prop will help to make sure you dont burn out the motor.
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Post by Dillzio on Aug 19, 2009 10:56:13 GMT 1
I think the weakest link is the speed controller, not the motor, isn't it?
Seems to me a lot more stories about blown stock receivers/ESCs going around than reports of blown motors.
That battery seems OK, but the zippy 2200 is a lot lighter.
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duck
Squadron leader
R/C Addict
Posts: 219
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Post by duck on Aug 19, 2009 15:43:21 GMT 1
Yes it will work, Yes the Zippy is lighter, yes you will Definately need to modify the battery box.
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Post by duck9191 on Aug 20, 2009 4:43:13 GMT 1
the motor just takes longer to die, that much current though the brushes and it will over heat, burn the brushes and com. speed control failure is a bit more hit or miss, some times the fet will take the extra stress just fine and other times it dosent. one thing you can do is open the box up and add a heat sink to the drive fet, the black thing with 3 metal post. you can get them at most electronics part stores.
easiest way to avoid any problems is to use a 10x6 prop, the extra rmps from the extra voltage will more then make up for the loss in pitch and it will draw less current.
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Post by Dillzio on Aug 20, 2009 7:16:36 GMT 1
the motor just takes longer to die, that much current though the brushes and it will over heat, burn the brushes and com. speed control failure is a bit more hit or miss, some times the fet will take the extra stress just fine and other times it dosent. one thing you can do is open the box up and add a heat sink to the drive fet, the black thing with 3 metal post. you can get them at most electronics part stores. easiest way to avoid any problems is to use a 10x6 prop, the extra rmps from the extra voltage will more then make up for the loss in pitch and it will draw less current. That's a fantastic idea! I think I know the component you're talking about, it burnt out on my ESC. It's just next to where the Z-port hooks up, I know cos it singed my Z-port plug too. So, refresh my memory. A heat sink is just a excellent conductor of heat with a large surface area to dissipate the heat over right? How are they connected, do you use a special cement or something? |
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Post by Dillzio on Aug 20, 2009 8:08:04 GMT 1
Ah, I just looked it up. It's attached with heat sink paste, about $3 for a very small tube. Also a "mini U heatsink" or a "micro U heatsink", they're made to strap on to the power transistors.
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Post by duck9191 on Aug 20, 2009 16:37:04 GMT 1
yep, the past is highly conductive to heat and holds heat sink fairly well after its cured. i think its a tos-92 pacakaging for the fet in the rx, but any small general pourpos one will work. i dont know if you guys have any chain electronics stores like we do here in the states, but you should be able to find on online fairly cheap.
just remeber though, it isnt a cure all, the fet can only take so much current even with a heatsink before it fails. a 10x6 or 10x7 prop will make sure it dosent fail and help your motor last more then a few dozen flights.
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Post by chops1sc on Aug 20, 2009 20:21:16 GMT 1
This is my first post!
I couldnt help but comment on this subject. My friend and I are both gonna make the jump to lipo with our SC's. I am aware of the need to prop down and remove the jumper and all that good stuff. Here is my question. (i hope its not in the wrong place)
I used to modify my Radioshack Xmods by stacking fets on the stock board. Would this be possible/feasable with the SC board? I haven't opened the ESC to see inside. This conversation just reminded me of those good ol' days!
Thanks!
P.S.: sorry if this is already talked about in the ESC section, I just felt I needed to ask on this thread.
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Post by flydiver on Aug 20, 2009 22:54:22 GMT 1
Good luck on that question. Many of the folks here don't even know what a FET is let alone where to find one.
The ESC is proprietary. Don't know if that is a limitation to modifying the ESC.
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Post by duck9191 on Aug 21, 2009 2:21:17 GMT 1
you could stack them, or use a fet with similar opperating charceristics but better current handeling. in the end though its still a poor speed controll, the money and time spent finding the fets isnt really worth it unless you plan on staying stock.
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Post by Dillzio on Aug 21, 2009 7:53:18 GMT 1
In the original spitfires, you could only open them to about 80% throttle before the throttle would strike a thin metal pin. If ever they REALLY needed full throttle, they could push up the throttle lever hard enough to break the pin, thus giving them access to the full throttle. After breaking the pin, it had to be replaced by a flight engineer who would also check over the engine to make sure it was OK after revving so high.
Perhaps we could steal this idea, and tape a bit of elastic over our throttle sliders at the 80% mark, or perhaps paint in a "red zone" like on a car's tachometer. That way we can perhaps save our ESCs, and still have enough reserve power to outrun a BF-109 if we get separated over the channel.
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