EDF Durafly Sea Vixen

corsair_pilot

corsair_pilot

Member
Hi guys,
Still trying to get my head around electric motors etc.
This comes with a 70m edf. 70mm with 2950kv 2836 Brushless Outrunner Motor.
I'm wanting to get something that will add more punch. Is adding more blades, and a higher KV going to do that?
I can get a 4S unit (same battery as standard), but 10blade alloy 3000kv motor. (1200Watt)
Or I can go to 6s 10 blade alloy with 2200kv motor. (1900Watt)
I just want to add a bit of punch!
 
callsign4223

callsign4223

Staff member
Here is some quick math for you. Completely ignoring the blade count here.

On a 3s battery the current motor runs at 32745 rpm. That's kv*11.1(3s voltage)

The 4s setup would be 44400 rpm

The 6s setup would be 48840 rpm

So you can see, the rpm jump alone is very significant, going from 3s to 4s you are getting ~25% more rpm.

(edit)I didn't even notice that the original setup is 4s. Going from 43660 RPM to 44400 won't make much difference I think. How many blades is the original EDF?
 
Tony

Tony

Staff member
The more blades, the more pressure the edf will create. The more voltage, the faster it will spin the motor. However, the lower the KV, the more "punch" you will get. Low kv equals torque, high kv equals rpm.

If you go with that 6s setup, remember that you will have to go to a lower mah battery to fit in the plane and save weight. You will also have to make sure your electronics will handle it.

EDF Jets are not "punchy", they are fast. With a prop job, you can punch the throttle and it will pull out of a situation at the last second. With an EDF, you must think a few seconds ahead. The EDF will never be what a prop is. You can spend thousands on motors and EDF units and never be happy if you are trying to match them to a prop.
 
corsair_pilot

corsair_pilot

Member
Ah ok, so all I'm going to do is increase my speed, but not necessarily my torque... Wasn't expecting it to be like a prop, but was curious.

Ok next question on the Vixen, and anything where 'y' harnesses are used... how do I set up the trim properly in the radio? At centre on the servos, they L&R servos seem out compared to eachother.
I was going to set up like I would a helicopter, get to 90 degree, adjust push/pull rods so that everything appears level, and then adjust with radio from there. But how do I get to adjust them individually?
 
Tony

Tony

Staff member
If your using a Y harness, you can't adjust them independently unless they are programmable and you have the box. You need some EZ links or whatever they are called from Dubro where you just slide your control rod through it.
 
corsair_pilot

corsair_pilot

Member
Just curious, I'm looking at putting a small camera on this. I was thinking of putting it on the horizontal stab just in front of the elevator.
Is this going to cause me any control issues with the elevator?
The camera is small, and I was planning on using hook and loop tape to velcro it into place. This way it makes it easier for me to move the camera to different vehicles. Or should I look at using something else to hold it in place?
 
corsair_pilot

corsair_pilot

Member
Cool sweet thanks Tony!!
I'll give it a go and see what happens.
Thinking I may get a few of the little cheap cameras, see how they go, end up with one just under the nose, and then a forward and rearward facing camera, one top and one bottom of the horizontal stab. That's the plan for later anyway. will get one first and give it a shot
 
Tony

Tony

Staff member
I'm sure my elevator is a quite a bit larger as well. And the vibration you saw in teh video was a bent motor shaft from a lawn dart.
 
corsair_pilot

corsair_pilot

Member
Ah I see...
Like you said, all I can do is give it a go... I can't see it making a huge difference to the control surface, there will be a bit of turbulent air hitting the control surface cos of the camera, but it shouldn't make a huge change.
Well i'll just wait for the camera to arrive and then i can give it a go and see what happens
 
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