View Single Post
Old Oct 01, 2012, 06:19 AM
OlliW is offline
Find More Posts by OlliW
Joined Sep 2009
2,918 Posts
moin Olli ... do you think Ralf would agree ( regarding the 3x00 ... ) ??
yes, he would for THESE 3x00... LOL... (they are just too weak for pulling 34er blades at this rpm and rather will run hot, that's at least what had been reported)

and hey, E2, you have them all... but only on the desk, not in a heli...

I think it was Ralph though who highly recommended the swanghobby, not sure anyone else tried them

2mm pinions are fairly easy to come by
yes, but for the 3x00 KV you would need 7T or even 6T... which is very tiny for a 2mm spindle... not much flesh anymore
so, its better to start form a low KV motor and increase the pinion than vice versa (and the gear noise will also be lower then)

@KJ: it is a know issue that asian motors can have very varying performance as well as KV rating... so it easily could be that your C10s or the batch they came from had been just few 10% to weak
(as I said, if my lama would be closer to 250g, which is I guess quite normal, my setup also would barely lift, but in my case I did the test that it is not limited because the motors wouldn't produce enough power, but just that they couldn't generate the rpm, so going to a 9T pinion would probably been a good thing, but I was too lazy... since my bird is only about 200g LOL)

@All: by the way, fixed wing flyers have a rule of thumb for the motor wattage, which is something like 3 Watts per gram or so. The detailed number is not relevant here (and I might have gotten it wrong), the point is the insight which is underlying this rule: The max power is mainly limited by how fast heat can be "absorbed" and transported to the outside, hence the more massive a motor the more power it can handle...

This simple rule tells you that if you need more power than a C10/Turnigy 1811, there is not other way than to go to heavier motors... such as the roxxy or swanghobby... TNSTAFL
OlliW is offline Find More Posts by OlliW
Last edited by OlliW; Oct 01, 2012 at 06:27 AM.
Reply With Quote