You know what they say, The cheaper the motor the bigger the packs! And that's just to match a better motors power on less packs, but hey when ya don't care bout performance but how many watts you get to say you have what else can ya do?

I guess there might be 2-3 70mm airframes that can handle heavy packs but I found that the limit for most of the larger ones is 500-600gr of battery.

Well, if stuff like Tam is doing is to get huge Power/Watts (thrust) out, to put into a larger (90mm) airframe, then it isn't such an issue to have 'large packs'. Even if a 90mm was used it would still need that power input.

If it is for 70mm use, then that is far more marginal and the % of people doing that would be very low. (2%?). More of an academic pursuit than of truly great use - or maybe for the hunt for record speed.

Well not so long ago some were sticking 70mm watt suckers into an airframe, say 2000-2500w, run some 3200 6s packs and then fly it like a drag car, one fast pass then tool it back to the line at 1/4 throttle, do that 4 times and you are finished As I have always said, I want to fly my jets like a jet, WOT for a good 3 mins or more if I can, with around a min of half throttle in the mix, imagine a 70mm fan pulling 108 amps on a 3200 pack, thats like 1.7mins WOT

"Well, if stuff like Tam is doing is to get huge Power/Watts (thrust) out, to put into a larger (90mm) airframe, then it isn't such an issue to have 'large packs'. Even if a 90mm was used it would still need that power input.

If it is for 70mm use, then that is far more marginal and the % of people doing that would be very low. (2%?). More of an academic pursuit than of truly great use - or maybe for the hunt for record speed."


Yeah your dead on the money! Cause if your in the realm of probably gonna take more anyway, then now if more would be needed, it adds options to swap around for some mah to add too. And for example the f100 makes this easier cause really were calling it 90 but. A: it's not big 90 by 90 standards, and if you take today's power into account it's really no longer a 90 but more a large 70. So looking at it as a 70 airframe your just not gonna power it like a typical 70 but more a high power 70 that's approaching anemic 90 power levels. As a 90 back then it'd be a 7-8s at most, now today's power 6 range, so if you can only have 6 why make it turn a big fan slow when you can crank up a 70 with that for less motor cell and fan weight. The max power in is determined by cells you use period, they can only provide so much, so to have that but she'd weight where ya can is just free power. And the better the motor the more of that your carrying goes to good use. No reason a good system has to do one or the other, if it's good it's good, it can go fast and fly long cause it has most power and efficiency it can have without compromise. It isn't gas so we don't have to sacrifice low or mid just to get top end. If it uses every ounce you put in without needless weight to either survive or just hit a high number at sacrifice of needless weight, then yes you can have both if we're smart about it.

Originally Posted by Extreme_RC

I run the Minifan rotor at 56K+ with the old ARC2858 setup, and with the new 1W40 its running at 63K without issue, of course balance must be perfect. When I did destructive testing I had to take it well over 70K to explode it, saw over 3.5kg thrust on the stand before it blew, and it took 2 runs to blow it, very tough rotor.

What esc and amps were you seeing and what cell count were you using to get 56k? Any data log on this? Also what set up did you use to get "well over 70K" to explode the rotor? Any video and or data log?

Question for those running this fan with Castle esc's. Does the rpm it reads on the data log represent the actual rpms of the fan? If not is there a way to calculate it?

yes it does, after setting the pole count and kv in the castle viewer it reads rpm of the motor/rotor

How do you set those? Is there a seperate menu somewhere?

Originally Posted by houstonderk

How do you set those? Is there a seperate menu somewhere?

yes when you download the data from the castlelink program it launches another program called castle viewer and within that viewer you select edit and set pole count/kv to match the motor your using, this sets the rpm calculation so that it reports the correct rpm in the log

Sweet, thanks! Learn something new everyday.

Originally Posted by Super Matt

What esc and amps were you seeing and what cell count were you using to get 56k? Any data log on this? Also what set up did you use to get "well over 70K" to explode the rotor? Any video and or data log?

Yeah of course it was tested, almost 2 years ago now. I set up the ARC2858-1 in my Extreme ALLOY 70mm Wemo fan on 6s, 87 amps to hold 2.5kg thrust and it could do it sustained. At the time velocity was promoting their 70mm fan and motor as doing 2.5kg thrust as well, difference was theirs pulled 108A on 6s to do it and could only do it as burst, not sustained. Mine did it with 20A less.

I used one of my LIGHTNING 80A ESC's in this setup, tough ESC running at over 80A continuous and no airflow over it for the test. In a model the ESC ran ok inside the inlet ducting, and if outside we used the Platinum PRO 100A.

EXTREME RC AUSTRALIA - Extreme ALLOY 70mm Fan with Efflux (1 min 18 sec)

I used the same fan unit for destructive testing, ran it up on 8s packs with a LIGHTNING 100A-HV ESC, it was on a flat sled test stand facing a brick wall and no way I was going to stand next to it with a camera.

First run I took it up till the stand showed 3kg thrust, it was pulling 2470 watts and spinning at 65,220rpm.
Second run I took it to WOT and it showed 3.6kg thrust, was pulling 3320 watts and the E-meter clocked out around 73K or so, Hyperion couldnt keep up with the fan.

Ran this test again and once it hit WOT it went booom. I have a feeling if I had clearanced the rotor some more it might have held on for a few runs, but the point was not to see if it would fly on 8s, it was to find the rotors failure point. Unfortunately I didnt hit log on the meter before doing it, but end of the day its a mute point as there is no way anyone would run the Minifan up to this level as its a dangerous practice and I do not advise nor condone it. Test fans at your own risk.

Originally Posted by anlucas

I guess there might be 2-3 70mm airframes that can handle heavy packs but I found that the limit for most of the larger ones is 500-600gr of battery.

I agree Andrew. Even my huge WingsMaker J11-B (41" Wingspan) with Twin BL-32/CS-10/Delta-V's fitted with Two 6S Nano-Tech 3300mAh/45-90C at 565grams each, is pretty much Maxed out for battery size, even with the enlarged battery tray!

I flew my Hawk today with the 4S extreme alloy setup. Sounds sweet as I love it.

Originally Posted by Extreme_RC

Yeah of course it was tested, almost 2 years ago now. I set up the ARC2858-1 in my Extreme ALLOY 70mm Wemo fan on 6s, 87 amps to hold 2.5kg thrust and it could do it sustained. At the time velocity was promoting their 70mm fan and motor as doing 2.5kg thrust as well, difference was theirs pulled 108A on 6s to do it and could only do it as burst, not sustained. Mine did it with 20A less.

I used one of my LIGHTNING 80A ESC's in this setup, tough ESC running at over 80A continuous and no airflow over it for the test. In a model the ESC ran ok inside the inlet ducting, and if outside we used the Platinum PRO 100A.

http://www.youtube.com/watch?v=ETAQ80LdD3c

I used the same fan unit for destructive testing, ran it up on 8s packs with a LIGHTNING 100A-HV ESC, it was on a flat sled test stand facing a brick wall and no way I was going to stand next to it with a camera.

First run I took it up till the stand showed 3kg thrust, it was pulling 2470 watts and spinning at 65,220rpm.
Second run I took it to WOT and it showed 3.6kg thrust, was pulling 3320 watts and the E-meter clocked out around 73K or so, Hyperion couldnt keep up with the fan.

Ran this test again and once it hit WOT it went booom. I have a feeling if I had clearanced the rotor some more it might have held on for a few runs, but the point was not to see if it would fly on 8s, it was to find the rotors failure point. Unfortunately I didnt hit log on the meter before doing it, but end of the day its a mute point as there is no way anyone would run the Minifan up to this level as its a dangerous practice and I do not advise nor condone it. Test fans at your own risk.

Ok. And I believe in the EDF tooth fairy.