Well... I could safetly say I'm a complete newbie at pushing my Hobby Zone Super Cub to its limits. I'm okay with flying, turning, landing, and some loops/stalls. Recently, I just found out that my SuperCub could fly inverted! So I got excited to perform this trick but I accidently pulled the stick down (assuming it would go up) but It went straight down into the ground at full throttle for about 40+ feet since the elevators and rudder were inverted [:@]. The damage is pretty brutal considering it crashed into concrete. Broken fuselage, cowl, geargox, firewall, prop, spinner, and wing. [sm=confused_smile.gif]So I thought no biggie, only around a $50.00 damage. []

When I was preparing to transfer the internal parts to a new fuselage, I found out that instead of the 7 cell 8.4 volt 1000 mAH battery I currently use, I could fit 10AA rechargable batteries equivalent to 12 volt 2500 mAH into the plane using radio shack's battery mounts.

This would provide much more power and flight time but I was wondering, would the 480 hobbyzone motor take a 12 volt current? I know It allows an 8.4v battery and 9.6v battery but would 12 volts damage the motor or ESC/receiver/Servos? I have never done this before and I would very much like to, if it is no threat to my plane.


answers would be greatly appreciated

-Thanks for reading

I'm a newbie man....have a super cub too and I love it.....sounds like you've had yours abit longer than mine.....you have oviously mastered it....well except for the crash boo boo. Even though their parts are good priced, I'm suprised you got it back up in flying condition for $50....that's good news for me.......when I trash mine one of these days...lol. BTW....I went straight nose in full throttle from 50'+ the other night...but in the grass...and it hardly damaged anything. Ok....off my soap box and on to your question.....first of all....why do you even want to attemp to run the SC on a 12v system? Power I assume......I investigated the 9.6v option....btw...it cost the same as an 8.4v stock battery...about $30. I personally would not think that the motor could handle the 12v at least not for long without burning up. The only way to be sure is to get some numbers and hopefully a manufacture # off the engine and look up the exact specs on that 480 motor. I'm thinking you would get a good bit more power out of the 9.6v pack that is made for the SC. The only problem I have found with the 9.6v pack and the reason I did not buy it...(I bought an extra 8.4v pack) is that the ac charger supplied with the SC WILL charge the 9.6v pack BUT the car adaptor charger WILL NOT. I'm in civil engineering but have an electronics background from the air force....I was an instrument/autopilot technician on c-130s for 4 years. I think you will need to have another motor handy when you burn up the one you have if you go 12v....good luck though....

purpletdude

Yeah,

thanks for that reply.

Think I'll do some research, or just to a test run on another 480 motor.

Too bad I'm a bad googler



BTW, I use battery holders from Radio Shack...

It will run, but not for long. Go with a 9.6v pack.

I was unable to pull up the actual specs on the exact 480 motor that Hobby Zone uses in their SC, but I did find some more expensive equivalant motors from their E-Flite line. All the brushed 480 motors in that line show a voltage range of 8.4 to 9.6. So as stated above it will run but probably not for very long. The other thing to think about is that it will probably burn up your speed controller too. It might even start a small electrical fire & burn up a lot of stuff before you can get the battery unhooked. It sounds like it could be downright dangerous to me! Use the 9.6, it's not meant to be a speed demon anyway.

Sorry you had to learn the inverted lesson the hard way but now that you have, try not to forget that when flying inverted; "Down is up, & up is expensive!!"

The only way it would survive the higher voltage battery is if you put in a voltage regulator to bring down the voltage. Then you could use the extra capacity of the batteries for duration. You would still need to be able to charge the batteries but it sounds like you intend to do that on an individual basis instead of as a pack.

No, I don't know where to get a regulator that would work. It would need to be able to handle to input voltage and the current you will be passing thru it. Powering both the motor and the radio. Then, once the battery gets too weak to run the motor, the radio may also fail to work.

Even if the motor could take it, you don't want to do that.... Your standard NIMH rechargable battery is NOT meant to handle the kind of discharge rates a flight pack needs. Not to mention that at the number of cells and density you are talking about it would probably be too heavy for that plane.

Who mentioned NIMH?

I too assumed NiMH because of capacity, I have never seen AA NiCads with that much capacity (although they may exist ?)
Motor aside, higher voltage also means higher current. Can your ESC handle it and is the extra weight worth the trouble?

As I said, a voltage regulator would bring the voltage down and then the current would be OK. This regulator
http://www.smart-fly.com/Products/Regulator/1.htm
will take up to 13 volt input but the output is too low for you. Example provided to show that there is a solution but at a cost. Is it really worth it in terms of money and weight?

Using a regulator would work as far as lowering the voltage, but I can't think of any reason to use one, as opposed to just lowering the number cells. A linear regulator like the one in the link has horrible efficiency- The power it dissipates is equal to the voltage drop times the current. I.e., power and flight times would be the same (actually better due to the lower weight) for a system with fewer cells versus more cells and a linear regulator. A switching buck regulator would have much higher efficiency, but if you want one with high current capacity, it's expensive and could be heavy due to the large inductor. Also there is a RF interference to worry about from the high frequency (ranges from 100kHz up to 1MHz or more) and high current (radiates more RF energy.) Better to not use one and lower the number of cells, add weight by using cells with more capacity for increased current and/or flight times.

www.cheapbatterypacks.com has a extensive list of cells of all sizes and types. Although their max current suggestions are a little optimistic IMHO, you can get a good idea of what is out there for your app. Note that the really high capacity AA cells are NOT suitable for e-flight, they are are for transmitters and glow plane reciever packs.
Andy