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        Discussion Hobby King Skyfun - speed thread

#1 J.E. Johnson Dec 23, 2009 10:39 PM

Hobby King Skyfun - speed thread
 
1 Attachment(s)
Hello all....

I am starting a thread on the SKYFUN flying delta which is available from hobbycity to see what everyone has been doing with theirs.

I bought one a while back and just got around to putting it together.

I didn't bother with the supplied power system, I put a HET 3W motor driving a 4.75 by 4.75 prop on the back, a Pentium 40A speed controller, polyquest 4S 2250 lipo to see what would happen.

I have flown it a few times and todays flight is on the YOUTUBE link below.

My first impressions are:

The thrust angle is wrong, I need to add some upthrust. The change in trim from full power to no power is around 5 clicks.

The plane is nice and stable, very easy to fly.

The speed is okay but I want to know how to make it go much faster!

I lost the plane today when the clear canopy blew off. The battery and all electrics followed it out and so the plane just fluttered down like a leaf. No damage at all except the clear canopy separated and I lost one of the fins.

It's a bitter sweet crash... I know it was not pilot error but I have lost the receiver, fin and the battery. Everything else got found after a search.

I did actually find the battery but as you can imagine it was in no state to re use after a vertical drop from altitude....

As an aside can anyone doppler the video to check the speed for me?

The video is quite shaky and hard to watch but I had a new camera man today.

I am new to high speed foamies so be patient with me! I know there are some big stryker threads etc but there is almost too much information to wade through.

skyfun.wmv (2 min 20 sec)

#2 djacob7 Dec 24, 2009 12:38 PM

Looks like a fast setup alright.
Did you mean HET 300W?

#3 J.E. Johnson Dec 24, 2009 03:46 PM

Quote:

Originally Posted by djacob7 (Post 13896601)
Looks like a fast setup alright.
Did you mean HET 300W?


No, the HET EDF 3W

http://www.highendrc.com/index_eprod...products_id=28

It's meant to be for ducted fans.

#4 djacob7 Dec 24, 2009 05:11 PM

LOL, I thought that the "3W" was its power!
Looks like a powerful motor at 450W.

#5 J.E. Johnson Dec 24, 2009 05:39 PM

Quote:

Originally Posted by djacob7 (Post 13898289)
LOL, I thought that the "3W" was its power!
Looks like a powerful motor at 450W.

I hadn't thought of it that way. 3 watts wouldn't cut it at all.

I contacted hobby city to see if I could buy a fin by itself and they said they would get back to me.

I don't mind making another one but if I do that I have to make two so that they match.

#6 PulseFusion Dec 25, 2009 10:11 PM

That big blue aussie sky is unmistakable ;)

#7 epoweredrc Dec 25, 2009 10:17 PM

How fast do you want to go? it looks fast to me, sorry about the ejection that stinks hope you get back in the air soon

#8 J.E. Johnson Dec 25, 2009 10:37 PM

Yes we are very lucky with the weather here... I got quite sunburnt looking for all the parts after the crash though...

How fast do I want to go? I am not sure really. The first few times I took this out it seemed quite fast but now it seems normal and my other planes seem slow.

I asked Don (of DonsRC)if he could doppler the video for me and this was his reply:

The first high speed pass about 60 seconds in (left to right) was about 93mph, the pass after than right to left was 99mph. That is based on a 68F air temp.

Don



That comes out at 160 kilometres per hour so I guess my first goal is 200 kph.

I have been trying to track down a fin and I have emailed several places but the one I found on eBay for example wanted 14USD plus 20 USD postage. I only paid 60 USD for the plane in the first place.

I will give it a few days and then just make some from balsa.

An interesting note is that I found the clear canopy which caused the whole issue when I went back to the field for another look. It had a spot of glue at the front and another spot at the rear but that is all that was holding it on.

#9 epoweredrc Dec 26, 2009 12:28 AM

I was going to post something about the doppler. i wondered if that was something anyone could download and figure out how to use or just some people had it. I never heard of it untill a threat a few days ago someone was clmaing x amount speed they said naw so somone did it.

I just got a Donsrc wicked jr motor for my hommade delta, fingers crossed will be fair nuff weather to test it out tommorrow.

#10 Ebolavoodoo Dec 26, 2009 10:20 PM

Reminds me of a Stryker. At 450 watts, about twice as much as a stock stryker motor. Plenty of ummmmmph. Earth magnets work wonders. Keep em coming!

Jerry

#11 J.E. Johnson Dec 26, 2009 11:22 PM

Quote:

Originally Posted by Ebolavoodoo (Post 13910749)
Reminds me of a Stryker. At 450 watts, about twice as much as a stock stryker motor. Plenty of ummmmmph. Earth magnets work wonders. Keep em coming!

Jerry

It reminded me of a stryker too. That's where it all started. I have been unable to find a stryker for sale in Australia so I tried this.

I have new fins on their way and an eagletree logger so I will be able to get better speed info.

I have worked out how to attach all the parts better this time.... No more premature evacuations.

#12 J.E. Johnson Dec 27, 2009 03:30 AM

4 Attachment(s)
I started to get the plane ready again tonight. The fins on it's way and should be here in a week.

Although I will make sure the canopy is properly attached next time I thought it wise to make sure this could never happen again.

I have attached velcro hold downs on the ESC and the battery. When I get a new receiver I will be sure to do the same for it as well.

I am so impressed with this little plane for the price. Now that I know what it can do I will give it a decent paint job and put some carbon in the wings.

#13 Murman Dec 27, 2009 07:55 AM

Quote:

Originally Posted by epoweredrc (Post 13905402)
I was going to post something about the doppler. i wondered if that was something anyone could download and figure out how to use or just some people had it.

The Doppler program is in this
thread. You will also need some way to extract the wav file from the video or you can just record the sound of your plane with a voice recorder and convert that to a wave file. It's a pretty simple to use program once you figure out how to use it.

#14 Nicoflyer Jan 01, 2010 09:23 AM

Hi I've done the same with my Skyfun.
I used a Neu 1107 2.5Y motor and a 2200mah 4s with a 4.7x4.25 APC prop @ 600 watts.
Here a link to my video
skyfun on steroids (1 min 45 sec)

#15 J.E. Johnson Jan 01, 2010 05:09 PM

Quote:

Originally Posted by Nicoflyer (Post 13953030)
Hi I've done the same with my Skyfun.
I used a Neu 1107 2.5Y motor and a 2200mah 4s with a 4.7x4.25 APC prop @ 600 watts.
Here a link to my video http://www.youtube.com/watch?v=BrqMUNNtLTE


Nice job! I was starting to think I was the only one!


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