View Full Version : World Models' Sky Runner
09-13-2006, 04:09 AM
Anyone fly/own/seen one of these? This looks likew a really fun airplane to fly. Not sure if this is like a thermal plane, Warm Liner, or Slope Glider. Anyone with a few ideas??
09-13-2006, 12:10 PM
Hello Shane, Welcome to the Sailplane Forum!
I've never seen the Sky Runner so went to the World Models site and checked it out. http://theworldmodels.com/para/products/airplanedetails.php?airplaneid=148
From the specs and instruction manual I'd call this model a "Sport Aerobatic" powered glider. With a built-up wing and tail it won't withstand the Hotliner-type whistling dives but is likely pretty fast otherwise. It lists a semi-symmetrical airfoil so is apparently designed for aerobatics as opposed to thermal duration. That's not to say it won't thermal, just not as well as a "true" TD model. With 2 aileron servos you can add "flapperons" or "Spoilerons" which will help control landings better and maybe a bit of camber (slightly "down" flaps) for a slower glide in lift. I'd guess you could fly it off a slope also, providing the wind isn't too strong and there's a good landing spot. There's a reason Slope flyers call built-up models "Crunchies"!!
One suggestion that seems to apply to all ARF powered gliders is to replace the prop; They usually come with an inexpensive gray folder and you'll find these are very inefficent; Go to Hobby-Lobby.com and try a 6" x 3" CAM folder and you'll see a marked improvement. Also a "Water Break-in" will help extend the motor life and performance.
Overall it looks like a pretty nice little glider and should be fun to fly!
09-13-2006, 12:16 PM
The Sky Runner looks very similar to the ElectriFly Electro Streak. http://www.electrifly.com/largeelectrics/gpma1055.html
09-13-2006, 01:21 PM
Thanks for the input fellas! I'm not looking for blazing fast spped, just something alittle more peppy than the run of the mill glider. Any thoughts on the Electro Streak? You mentioned before "water break-in", what is that, and how is it done? Looking forward to more great inputs.
09-13-2006, 01:26 PM
One of our club members was flying one on Sunday morning with the North Coast Electric Flyers at Sagamore Park, Ohio. Beautiful flying plane right up to the point where it dug a divot in the grass and destroyed itself. Crash analysis was that the micro servo (HS-55) driving one of the ailerons may not have had enough "oomph" to push the control surface during extreme turns. Bad or weak servo? Too much plane?
the pilots quote follows:
World Models Sky Runner
AUW - 20 oz
Motor - Park 450 Outrunner (waiting for Don's motor for the upgrade)
ESC - CC 25
Battery - TP 2100
Prop - 9 x 6.5 CAM Folding
14 amps and about 130 watts/lb
It was a pretty easy build. The hatch cover and canopy are made from a cheap, thin plastic that I've already cracked. Everything fits where it should and balances right on with the TP2100. I hope to maiden it this morning at Sagamore. Don's motor upgrade and a slightly larger prop will be the next step after the maiden.
09-13-2006, 01:41 PM
Thanks for the info, I guess it would be best if I were to invest in a brushless setup. Also, thanks for the heads up on the HS-55, if I were to get this plane this is what I was going for in the ailerons. I do have some spare Tower Hobbies CS-12s laying around, think they'd work? As far as the canopy, could you try to put some fiberglass sheets on the underside to gived it more strength. Just a thought. Let me know how the maiden goes, if all goes weel I think I will petition the wife for the funds!!
09-13-2006, 05:33 PM
Hi shane, looks like you've been getting plenty of feedback so far! Regarding the HS 55's, I've never had a failure I could attribute to servo breakdown only, but I wouldn't use them in a model that could approach "Hotliner" speeds/flight loads, either. Check the torque figures for a few "Micros" and "Minis", most are under 18 oz-in for 4.8 volts. I believe the 55's are 16. If you can find a micro or mini that's over 20 oz-in it would be safer.
The water break-in sounds strange at first but once you try it you'll be a believer! Here's a link;
The ElectroStreak is a Great Planes design that's been around for years. It's an all balsa (A new ARF has a fiberglass fuselage) kit or ARF that has a wingspan of 44", 550 brushed motor (slightly larger than the Sky Runner motor) and is an Aerobatic Sport Glider, similar to the Sky Runner, as Jason mentioned. The GP ARF is part # is TE2130 and it's $99.99 from www.towerhobbies.com (http://www.towerhobbies.com)
If you decide to try the Sky Runner, I'd suggest you fly it with the stock motor at first (after the water break-in, of course!) then think about upgrading to a brushless. A "Speed 400" is by far the easiest motor size to upgrade, there's millions of choices. By then you'll have a good idea of the plane's performance and lots of practice with your radio and battery charger so the change won't be too drastic, just a much better climb!
09-14-2006, 07:56 AM
Now I am 80% sure I will be getting the Sky Runner vice the Electrostreak. I agree that running on the stocl set-up is the best way to go. I was also doing research on other opinions ofthe electrostreak on other forums on rcgroups, and they were saying the srteak was wayyy under powered stock. They said it pretty much launched and then shortly after crashed due to lack of airspeed. The thing I like better about the runner is that it comes with a gearing system which basically equates to (if i'm not mistaken), ability to turn a bigger prop?? Bigger props = more thrust ?? All I have to do is to convince the wife I need this plane! and also include that I need another receiver. Speaking of which, I was thinking of a berg 4 channel, any thoughts? Thanks again for all the inputs!
09-14-2006, 11:53 AM
Shane, I highly recommend the FMA Direct receivers. http://www.fmadirect.com/detail.htm?item=2098§ion=1
39.95 plus 9.95 for the crystal. Dual conversion and (in my experience on two different planes) bulletproof!!
09-14-2006, 01:09 PM
HI Shane, As far as receivers go, I haven't used the Berg so I can't say one way or the other. For my sailplanes and powered gliders I only use FMA Direct M5's or HiTec 555's, both dual-conversion FM's. I agree with Jim (Ribcracker), the FMA's are "Bulletproof". I've never had a "fly-away" due to signal loss. I believe Hitec has discontinued the 555.
It's true a geared motor will turn a larger prop than a direct drive motor. This is one of the advantages of electric, but also a source of much confusion; It increases the number of factors involved in selecting the optimum prop/battery/motor combination, and the gearing ratio is another whole variable in itself. Ultimately the result is more thrust if everything is right. I must have missed the gearbox photos when I looked at the instruction manual, my mistake, sorry about that.
If you replace the prop (and I still think you'll be better off doing so) use the same diameter and pitch they provide and swap it for a CAM Folder. The 6" x 3" I recommended was based on my (mistaken) assumption the motor was direct-drive. Make sure you measure the output shaft (prop shaft) of the gearbox and order the same shaft size with the CAM, on the Hobby Lobby site this is the number before the spinner size, like 3.2mm, etc.
With all the feedback and research you have increased the chances of being sucessful with this model greatly. If you stick to the recommendations of those who have flown this (or a similar) model you should be OK. After you've flown it with the stock drive system let us know how it works out!
05-26-2008, 03:46 PM
I just wanted to wake a sleeping thread. My buddy picked this model up during SEFF for wicked cheap.
Is anyone still flying this model. I took the controls a few times and had a great time with it. It seems that there needs to be some elevator mixed in with the throttle.
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