Thread: New Product Change Sun 10 blade 70mm
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Old Jul 23, 2012, 12:21 AM
PeterVRC is offline
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Australia, VIC, Melbourne
Joined Nov 2006
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So here is a L2855 versus HET 2W30..... for 6S use.

"2855".... the 55 obviously does not truly (or honestly) mean "55mm". The magnets are only 28mm long. Windings the same.
The HET is a 50mm can, with about 46mm magnets/windings.

So how are they going to compare in abilities..... ummm, the L2855 cannot possibly be a true match in this fight.
Or can it....

On the bench the 2200kv HET gives fractionally better thrust in the CS10, than the 2100kv L2855. Pretty well the exact amount that the 100kv would cause it to have more.
Both draw close to the same currents... pretty well in line with their output differences too. (working in around 1200W areas)

So we have a $12 28mm motor... with a 28mm magnet length. Achieving the same output (and input approx) as a $75 28mm motor, that has a 46mm magnet length.
A very impressive result for a $12 motor......
But......

Of course a smaller motor can't be as good as a bigger motor, can it?
Well it can... for a short time....
The HET does its job CRUISING... it doesn't even know it was working. I bet it would last ongoing until the day the bearings reached their MTBF hours.
The L2855 runs overly hot, and I have fried two of them in very short times... one or two flights.....
And really, you could not be surprised by that.... 28mm magnets versus 46mm.... the L2855 is being over-worked big time!!

Keep the L2855 under 1000W and it can cope with that sort of load pretty well - though it is still over-stressed really. But at least it will last for a better ratio to its $ value. If run down at around 900W - surprisingly about what the wishy-washy specs listed say - and it becomes a much longer term capable motor.

This basically means it is no good for 6S in a CS10. Because the 2100kv means it will attempt to drive it to RPM that need 1200W area. To only run out to 900W area it would need to be 1900kv area rating. And there is no L2855 of those specs.
So the 2100kv and 2300kv are optimal for 5S use.
If you want the 900W ability of it, use the 2300kv on 5S. If you don't need the thrust and want a bit more flight time, use the 2100kv on 5S.

If you want to run 6S.... buy a decent motor! LOL
From 2000 KV to 2300 KV....
2200kv is already getting into fair power needs, and by 2300kv you really need very good batteries and will have low flight times.

I have only found ONE "great value" motor for 6S. The Turnigy XK2850-2060kv. $32. Which is for a very good quality and ability inrunner. (not a cheap 'junkie' motor). But they don't have them anymore! BAH
At 2060kv it is a bit down on power and more in the "good thrust and ecomomical for flight time" area. But you get no choice... that is all they ever had (2060kv).

To tailor the motor KV to exactly what you want, Leopard have a wide range covering all KV's needed. Otherwise with HET you are stuck at 2200kv - which is fine if that suits your needs too. Both brands are much the same price areas.
2200kv will give you very close to 2.0Kg thrust. 2100kv around 1.8Kg. 2060kv around 1.7Kg

...
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Last edited by PeterVRC; Jul 23, 2012 at 12:30 AM.
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