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07-13-2011 05:29 PM | ||
bensidus197217 |
Re: Well everyone will think I'm nuts? It's funny how some things can make such a difference. Sounds like your friends experiment worked well. I checked other websites too and nowhere did anyone recommend using three cell on a 500 I think most people are told to use batteries etc that can progress to 3D flying. Well 3D will never be for me and I do have a tendency to think outside the box when it comes to my hobbies. Thanks for your input Max. |
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07-13-2011 11:18 AM | ||
Max |
Re: Well everyone will think I'm nuts? Quote:
I had the same experience Monday night with a friend of mine that got this big trainer plane modded for electric from a friend. He had a pile of 3S 2200 mah batteries and didnt want to cough up the dough for 4S 4000mah batteries. So we hooked up my Eagletree datalogger and did a ground test using the 3S 2200mah batteries. We got a 27A draw at 100% throttle and 16A at 75% Throttle. Then we flew it with the datalogger with the intent of seeing how well it flew and what power it would need. It actually took of OK at 100% and then we flew the rest of the flight at 75% power. For this experiment, we timed the flight for exactly 5 minutes. The data logger showed we dropped abut 2A in load due to the unloading of the prop in the air. 75% cruise only pulled 14A. After we landed, we felt the battery- Barely warm! Recharge only took 1200mah back!! Then we repeated the experiment with a 4S 2600mah battery. We got a peak load of about 37A on take-off (100%) and then the remainder of the flight at 75% power was 19A. Upon landing, I did notice the battery was a bit warmer than the 2200mah pack. Imagine that???? We concluded that he could easily use the 3S 2200mah batteries. So just like you, we found that the reduction in cells translated to a lower power output, but that also meant we weren't killing the battery either |
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07-13-2011 10:23 AM | ||
bensidus197217 |
Re: Well everyone will think I'm nuts? I actually have a 17 tooth pinion I used some 30 size tail rotor blades and made them the same length as my old 500 ones they bolt right in. The only difference is the 30 size tail blades are wider so they work perfect. I get 10 minutes flight and put 2500 mha back into my 4000 mha batteries, nothing gets warm except the battery and it doesn't get as warm as my 6 cell used to. It flies very gentle is easy to operate because I find it is less reactive so I can catch up to it. I do believe it can go fast enough to get into trouble but I can catch it before it does. Flew for 40 minutes yesterday and loved it I'm also getting better on the controls. I use a Futaba 6EX radio I can give you my settings for pitch and throttle. The pitch numbers won't be the same but the ramp will help the throttle on the other hand could match mine. I will try to get a video of it in flight this weekend. |
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07-13-2011 10:12 AM | ||
Jimmy P |
Re: Well everyone will think I'm nuts? I am building my first T-Rex and it's a 500 , I haven't bought any batteries yet, I am thinking you could go up one tooth on the pinion to get a slightly faster tail speed as well as head speed, just don't over work it is all, by the way you say you fly I believe this would be your best fix. I am now thinking I don't need those expensive 6cell lipo's. |
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07-12-2011 09:18 AM | ||
Max |
Re: Well everyone will think I'm nuts? Hey Jim. If it flies good for you and you like it that way, that is all that matters. I would think you are nuts if you do things you dont like "just because other people are doing it that way".. |
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07-11-2011 07:04 PM | ||
bensidus197217 |
Re: Well everyone will think I'm nuts? A marker sounds like a good idea I will number them and place the rating on the side then put a dot on it for every charge and maybe a log book of charges and flight times. Yes tracking sounds like a plan. |
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07-11-2011 07:29 AM | ||
gi1mo2 |
Re: Well everyone will think I'm nuts? I bought a white paint marker, and indicate C rating and quality of battery on the side. That helps me with time I should expect out of the battery. I have helis and planes, and stick with those that take 3s 2200mAh and 6s 3000 mAh. I might have to change my preferences because I would like to get a float plane. Can't find one with those requirements... |
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07-11-2011 04:33 AM | ||
craneman32 |
Re: Well everyone will think I'm nuts? nice. I have a battery log book for that purpose. To know how many flights are on my batteries and if the performance is dropping on one of them. A good charger goes a long way. |
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07-10-2011 12:13 PM | ||
bensidus197217 |
Re: Well everyone will think I'm nuts? It does seem very easy on the electronics, I am going to increase the size of the tail rotor blades to help with the slower head speed. With three cells the headspeed is slowed down but a slight increase in pitch and it climbs fast enough for my tate. As matter of fact I flew it yesterday and it handle gusty wind conditions well. I was flying average four minutes before because otherwise my cheap chargers would take over two hours to charge one battery. Now that I have a good charger I found that four minutes only uses 1000mha out of a 4000mha battery so that means today I will extend my flight times to eight minutes and see how much mha needs to go back in. |
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07-09-2011 06:05 PM | ||
Drev |
Re: Well everyone will think I'm nuts? If your motor and electronics don't get hot and your flight times are decent stick with it. |
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