[4stripes]

Dynamically balanced the SK3 motor and CS9012 over the past couple days.
The 8mm shaft fit the adapter perfectly and some glue was needed for dynamic balancing of the fan.
Top quality motor for EDF. Fits Changesun 90mm 12 blade (with 8mm adapter). Perfect for 7S and 8S. 8S peak 3100watts/107amps settles to 2950watts/104amps. 7S settles to 2400watts/94amps. The CS fan must be of the stronger version or the risk of fan failure is high. The fan must be secured to the adapter with a sandpaper washer in between to prevent slippage at high power (which will throw off any dynamic balancing you may have performed). Do not run fan at high power unless it has been properly dynamically balanced.

This SK3 motor is a bargain!

PS I used locktite on the motor end cap (shaft end) to prevent the motor from unscrewing itself.

[Buckarooo]

Hi Eric, I found this site from your posts on RCG. Nice forum, some good info here. I registered. I have two of these motors on my list for my Citation. Good to here you like them. They look pretty good for the money and 8mm shafts.

Dean

[dashpuppy]

Post.... Movie....of..IT... running

[4stripes]

Why?
Perhaps when it flies in something.

[SARPLT]

Just ran this 90mm CS fan/ Turnigy SK3 motor combination in a test stand with older Turnigy 2X4000mah 25C batteries in series (8S) and got 2.9kg thrust at 89 amps and 2628 watts. For comparison I ran a 5 blade HET fan with a Typhoon 1680kv motor on the same battery power and got 2.8kg thrust at 82 amps and 2380 watts. Although both setups produced similar power, the CS was much quieter compared to the HET which was ear piercing. Given that the CS/Turnigy SK3 setup is available from HK for just over $80 (not including shipping/exchange), this seems to be a very reasonably priced EDF package. We will see how it holds up over the upcoming flying season in my CMP T45 Goshawk.

Cheers
Marty

[4stripes]

Marty something's not right with your numbers. Either your ESC isn't calibrated for throttle range or the batteries are sagging in voltage because you should be pulling over 100amps without any problem.
Cheers

[SARPLT]

Batteries were a little weak and sagging so hopefully fresh ones will give a little more thrust. When I calibrated the throttle I used the transmitter throttle stick travel only and did not adjust the throttle trim to minimum. I am not sure if this will make a difference. I wanted to ask you what setting you were using for motor timing. I did not play around with this and left it in auto which has defaulted to 18 degrees.

Marty

[4stripes]

Sounds like it is your batteries.
It's been a while since I tested it but I usually run the lowest timing that will give smooth operation. I've forgotten which ESC I used. For in runners I find the low PWM setting ( is usually fine.
I can't think of any of my motors that needed high timing.
Cheers

[4stripes]

Just built another SK3 CS combo for our FW F15. Same numbers (on 8S)
3100watts/106amps peak
2850watts/103amps towards the end of the batteries.
This time I added a heat sink for insurance and the temps stay reasonably cool.

[4stripes]

This setup is flying now in my FW F15 with 9s batteries. I'm limiting the power through the ESC using throttle end point adjustment. With full batteries 6s and 3s 5500mah Gens Ace the peak (limited) power is 3300watts at 94 amps. The motor stays very cool (120F) at this power and I'm sure it could be bumped higher without issue.