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5S vs 2 x 3S lipos for Trex 500

Old 04-19-2010, 10:52 PM
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Default 5S vs 2 x 3S lipos for Trex 500

I have been running two 3S lipos for my 500 heli - well i was thinking of going to one 5S lipo - is this "interchangeable"?....i.e can i just use the 5S vs the two 3S in series(?) and be fine? .... i think i read somewhere if i did this that the heli would be calmed just a little more (not as much punch - which is fine with me for now)- plus the two batteries are giving me canopy fitting issues.
Old 04-20-2010, 03:44 AM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

going from two 3s in series to one 5s pack, you'll see a marked decrease in headspeed.   you will have to change the current pinion to a higher tooth count to make up for it.   Also expect a higher amp draw,  so make sure your esc is able to handle the extra draw.

with a lower headspeed your heli will be less responsive and it may cause bobbing.  500 loves headspeed.
Old 04-20-2010, 08:21 AM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

actually i was trying to decrease head speed til i got to be a hotshot flyer.....i still dont get to put in the time i would like to fly the way i would like....so this is the esc i am using ....do you think i will be fine here http://www.hobbycity.com/hobbyking/s...idProduct=3727
Old 04-20-2010, 11:46 AM
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Default RE: 5S vs 2 x 3S lipos for Trex 500



lowering the cell count on the lipo pack is not a good way to reduce your headspeed.  lowering the pinion teeth is a much better way.  </p>
Old 04-20-2010, 11:51 AM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

yeah i know ...but a less count pinion is hard to find ...trust me i have tried....that would have been my first option.
Old 04-20-2010, 01:07 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

like I said before, the trex500 loves headspeed.  with a drastically reduced headspeed, its going to give you problems.   the high headspeed is normal for this helicopter. you will just have to get used to it. 

I'm sure there are folks that have tried what you're about to do but its not recommended.  let me know how it turns out.
Old 04-20-2010, 01:12 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

Lowering the cell count is not going to hurt the helicopter. There are plenty out there that do 3D with 5 cell packs. There are two things that you need to be aware of. First, you may need to use a larger pinion (one more tooth or so) and secondly the lipo packs need to have a higher mAh rating. For 5 cell, something like 2500-3000 depending on what kind of flying you want to do.
Old 04-20-2010, 01:25 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500


ORIGINAL: Cleared2Engage

Lowering the cell count is not going to hurt the helicopter. There are plenty out there that do 3D with 5 cell packs. There are two things that you need to be aware of. First, you may need to use a larger pinion (one more tooth or so) and secondly the lipo packs need to have a higher mAh rating. For 5 cell, something like 2500-3000 depending on what kind of flying you want to do.
Ihave already pointed this out. He wants to lower the cell count but leave the pinion count the same. which will give him problems. With a higher amp draw his electronics is going to suffer. especially in the heat.

My other suggestion to the OP is getting another motor that is not as powerful as his current one.
Old 04-20-2010, 05:29 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

I'm aware of what you pointed out, I just wanted to elaborate on some of it. For instance, lowering cell count and needing to increase mAh ratings. As far as amp draw, an 80 amp esc is more than up to the task.
RC-jj, straight from the manual it says to use a 14 tooth pinion and around a 2700 mAh 5 cell battery for a 2400 rpm hover. These are just baseline settings and can be deviated from depending on likes and personal flying style. A 13 tooth can be used but you may have to kick up the throttle curve just a bit, not much. What pinion do you have in there now?
Old 04-20-2010, 08:54 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

i have the 13T pinion right now.
Old 04-20-2010, 09:07 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

I don't think your helicopter will fall out of the sky with 13 teeth and 5 cells. You should be fine.
Old 04-20-2010, 09:29 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

cleared2engage...that was funny ...."fall out of the sky" ...hopefully if it does i wont be standing under it ...thanks for all your advice.

ciao
Old 04-21-2010, 03:29 AM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

I apologize if my post was offensive Clear2Engage.  was not my intention.  Some folks will do what they want to do, and only ask advise for assurances. 

I dont sugar coat my responses. I tell it like it is.  I'm in no way an expert in everything heli related but I have vast experiences with many different helicopters and can easily setup any heli in a very short time.  Its my passion.

Its true the heli will not fall out of the sky.  In fact It may work just fine.   But It just wont fly right with a low headspeed for which this heli is intended. 

Old 04-21-2010, 11:35 AM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

No offense taken, Noob. I was trying to offer a different perspective based on my experiences. If you want to see one of my experiments on head speed and pitch, check out this link. I turned my 450 into a FP heli. http://www.youtube.com/watch?v=ZkFy4Yk_5QE
Helicopters are like politics, everyone has a different opinion of how things should be done.
Old 04-21-2010, 01:58 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500


ORIGINAL: Cleared2Engage

No offense taken, Noob. I was trying to offer a different perspective based on my experiences. If you want to see one of my experiments on head speed and pitch, check out this link. I turned my 450 into a FP heli. http://www.youtube.com/watch?v=ZkFy4Yk_5QE
Helicopters are like politics, everyone has a different opinion of how things should be done.
that's cool man. good experiment too. I have always flown my heli's balls to the walls, but that doesnt mean everybody should too. different strokes for different folks.
Old 04-21-2010, 02:02 PM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

As has already been said, no right or wrong way to do this, just avoid having a heli that acts like a nodding dog.
Her that shall be obeyed uses 5S / 15T pinion on her 500, if I use it I just shove a 6S battery in and it's erm lively.
Best way to calm down a 500 is to use a 400mm flybar (600E fits perfectly - don't use a 440mm off a 600N)
Old 07-22-2010, 02:19 AM
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Default RE: 5S vs 2 x 3S lipos for Trex 500

I was flying my TreX 500 using 5S when it first came out. The heli was doing fine but i had a 15T pinion in it to get the best head speed, and the pack was 3300mah. But after sometime i replaced it and used 6S packs with 13T as this gave it better power in 3D. I would prefer using 6S packs... it best for this little heli as it has good power and stability. Running the heli in 13T 5S packs will be okay.. although the heli is kinda slow and retarded.. and align design for this 3D helis like really fast head speed. so running low will just make the heli bobble...

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