whalleyB0Y's First Build (HK F22 Raptor Twin 70mm EDF) - Page 14 - RC Groups
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Nov 09, 2012, 07:00 PM
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WhalleyB0Y's Avatar
Some more replacement parts arrived today so I was busy in shop assembling the fan units.

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Nov 10, 2012, 07:58 PM
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WhalleyB0Y's Avatar
I got around to running the fans up today so I can get some numbers. The fans appeared to be running incredibly smooth but one of the them was producing sparks from the rotor at high speed? When I look at the rotor it appears that the maybe the motor has moved off center so the rotor rubs. I managed to stop it before any damage but maybe I should examine the motor mount again and see whats up? This seems to be a reaccuring problem that I could really use help with guys...
On the bright side the current and temps stayed very low so I might consider changing the controller timing from low to medium and trying again. And it should be safe to run both controllers in parallel on a single pair of 10awg wire.

Both fans produced similar results as expexcted:

59 amps peak / 45 amps avg.
1059 watts peak / 800 watts avg.
49,000 rpm max
80* F avg temp

getting 3 mins runtime on 3300mAh.
Nov 10, 2012, 08:25 PM
it wasn't me flying that plane
Hover or die's Avatar
Man Whalley,
I know you are about to pull your hair out....
Now sparks from the rotor area....could you see a place where it rubbed a little before shutting down?sparks means either something electrical or metal part rubbing together and those were sent to you assembled?
Try to hang in there you deserve a good running ship friend.....
I know you feel like you are losing your mind.....
It has to get better.............Chris
Nov 10, 2012, 08:41 PM
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WhalleyB0Y's Avatar
Yea, I am pulling my hair out now.
This unit came assembled and balanced and it did feel pretty smooth running on the bench. My thrust tubes are transparent and I visibly saw the sparks coming off the rotor tips against the shroud. The shroud which was new now has a slightly rubbed out area. This is supposively normal? Well it is not anywhere as bad as the last one but maybe only because I stopped the test before it got worse?
Now I got the rotor and spinner removed and I find a stripped motor mount screw. Grrr! How the heck do I get this out now?

I managed to talk to a couple guys who fly jets out here. They said jet guys are pretty scarce out here because there is nowhere to fly them. Apparently everyone that is flying jets is running turbines because they cause less trouble and the size of aircraft is better suited for grass runways. He then told me nobody uses edf fans and nobody ever gets together to talk jets so they wouldn't be able to help. So I am on my own with the troubleshooting.
Nov 10, 2012, 11:20 PM
A-4 nut!!
skyhawk's Avatar
The big electric Byrons rock on grass! Actually - any of the old ICDF stuff is easily converted. If it was .77 to .91 powered and flew from grass - the electric stuff is even better.

I find it hard to believe the you have sparks comming from the rotor. It's a plastic shroud and a plastic rotor??????????

Not that your not telling the truth - it's just that plastic on plastic doesn't = sparking
Nov 11, 2012, 12:16 AM
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WhalleyB0Y's Avatar
I thought maybe because WeMo isn't plastic like cheaper fans but made of glass filled nylon but I guess that wouldn't make much sense to spark either. None of the other fans had produced any sparking even when the rotor clearly was rubbing. I went straight to the motor screws to see if there was any rubbing but there was none. The rotor itself and the motor mount aren't damaged at all. A tape of some type is wrapped around the motor inside the housing so it seems unlikely that the motor has budged.

I guess the only thing I can really do here is to try and get it on video so I can produce a demonstration of this problem.
Nov 11, 2012, 02:52 AM
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Jacques.Eloff's Avatar
Can't you send the fan unit back for a replacement?
Nov 11, 2012, 07:31 AM
it wasn't me flying that plane
Hover or die's Avatar
The sparks probably were comng from the motor and just looked like it was the rotor..
When you screw the the housing down to test the setup does it seem like it causes binding as in it might be hard to get the screws in?
Someone had to e cranking down on the motor mount screws to cause one to strip out like that.....
Im very surprised the fella doing the assembling of the fans has not come in here to see if he can help you troubleshoot this problem...
If the same place assembled the fan as before it might be time to cut your losses...
Im not sure if Gary offers balancing but i can assure you that if he does the unit will run right when you test it...
I just hope you get it figured out without having to spend more...You deserve a flying jet...
One other thing....with the wheels you have you should be able to fly off of smooth grass runways..as long as youcan get your speed up before trying to rotate..another thought is the bungee..you could save weight and fly at your regular field....just a thought..
Take care and good luck............chris
Nov 11, 2012, 11:28 AM
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WhalleyB0Y's Avatar
Here is another idea Chris, one that is borrowed from Gary...

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The wheels I have on now should be large enough to take off from the grass field at the flying club. Should I gain confidence from the shaker flight then I can resume flying at my regular paved location.

So you figure maybe the motor mount screws are threaded in too deep and rubbing on something internal to the motor? The one screw is stripped and is not coming out. The other came out fine and looks perfect.

I put it back together so I can try running it again, starting slow until I see a problem.
Nov 11, 2012, 12:32 PM
it wasn't me flying that plane
Hover or die's Avatar
Man that is one trick doley setup!
Also try winding up with the rotor off the motor shaft and you wll be able to tell if the stripped screw is the problem..

Look at it like this,,,,those metal threads off the screw had to go somewhere,,im thinking it may be stuck inside the motor due to the magnets and causing sparks ect..
If you have a small pair of vice grips you may be able to get a bite on the screw head and pull and turn at the same time and possibly get lucky getting that little b***h out of there...
Good luck and take your time.............Chris
Nov 11, 2012, 01:13 PM
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WhalleyB0Y's Avatar
Originally Posted by Hover or die
Man that is one trick doley setup!
Also try winding up with the rotor off the motor shaft and you wll be able to tell if the stripped screw is the problem..
Thats a good idea, I will try it. Do you think it is safe for the motor to run up without a rotor? Remember that the sparks occurred only at full throttle.
Nov 11, 2012, 02:19 PM
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WhalleyB0Y's Avatar
Ok here it is guys, the video playback of whats going on.

First off I had ramped it up with no rotor and I got no sparks at all. Then I put the rotor on and this is the result...

It was probably a good idea to make this video because I was able to slow it down and zoom in on the picture to see where the sparks where coming from...

My 2950kv edf spark show (2 min 34 sec)

So Skyhawk and Hover, I stand corrected. It isn't the rotor rubbing that is producing the sparks. Either way I am still having big problems here and don't know how to fix it.

Lol Skyhawk can I invite you over for beer or something?!
Nov 11, 2012, 02:40 PM
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Nov 11, 2012, 02:45 PM
Mile High EDF
420flyboy's Avatar
That made your heatsink move , wow
Nov 11, 2012, 05:35 PM
it wasn't me flying that plane
Hover or die's Avatar
Man you need to email the fella that balanced and set that fan up and link him the video....
When your rotor winds up it pulls forward harder and harder on the shaft as rpm increases..my vote is that once you reach high rpm the magnet/parts thats built around the shaft are coming a little foreward(as is normal) and rubbing the bottom of the stripped out screw...
Right or not i would not run it up again as the motor has probably about had it with internal damage...
They need to replace this setup....period!
At this point i wouldnt be surprised if they used the wrong threaded screw and just stripped everything tightening it in place....
Man i feel your pain....
I promise you edf is so much more fun than this.....will turn you into a horrible adrenelin junkie

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