Oct 14, 2002, 02:43 PM
Flying...Pushing Air Down
sr71fan's Avatar



I guess you missed my previous (many months ago) thread on this conversion. Here's the boom pivot joint. The threads going through the short tube are the pull-pull lines for elevator.


All-up 4.4 ounces.

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Oct 14, 2002, 02:46 PM
Flying...Pushing Air Down
sr71fan's Avatar


Oct 14, 2002, 02:55 PM
Flying...Pushing Air Down
sr71fan's Avatar

Outdoors Too!

The airplane has a pretty high wing loading, which makes it a little bit fast in the gym (but figure 8s are easy), and comfortable outdoors in the wind.

Photo by Jason Nowell.

Nov 24, 2002, 07:04 AM
AMA 697691 / FAA 13675
Here is a re-cap of why my next micro project will be converting the Harbor Freight Sky Runner to R/C using the RFFS100 module.

It has many things that I am looking for that will help bring more people into micro flight. My goal here is a simple to convert, simple to fly, and durable indoor flyer.
  • safe pusher configuration
  • rubber nose for crashing
  • charging station
  • On/Off switch
  • cheap $10-$13 ARF
  • big wingspan for 2oz
  • durable foam construction

I'm thinking of replacing half of the wooden dowel fuselage with a carbon tube. This should reduce some weight and allow for a sliding CG correction which makes component placement less critical. I would also use the Selman "self centering" actuators for elevator and aileron(s). It should be a fun conversion.

Here is a photo of the stock Sky Runner next to my converted Wattage Lightning using conventional R/C gear and an AF Firefly motor. The Lightning weighs 3oz using a 2-cell Lithium pack and it flies very easily indoors with little effort or skill needed.

The Sky Runner has a similar wingarea but is only 2/3 the weight. Using an RFFS100 module, I feel that it can be kept to around 2oz. I think the easiest conversion controls will be elevator and maybe a single aileron.

I'll keep you posted on the mods. as they materialize and, as always, I welcome suggestions.

Click here for a larger image.
Latest blog entry: Greg's Web Hangar
Nov 24, 2002, 07:47 PM
Team 30 Micro EDF
Mike Taylor's Avatar
I've finished a SkyRunner/RFFS conversion. Haven't flown it yet, but maybe tomorrow. It weighs 1 3/4 oz. or 51 grams AUW. That includes a belly wheel, charging jack and on/charge switch, radio, two Selman actuators and CF control rods. It actually weighs less than the stock FF version! The battery/switch and plug assembly you rip out weighs 3/4 ounce.
Nov 24, 2002, 09:21 PM
Registered User
Mr.RC-CAM's Avatar
I am nearly done with my Sky Runner conversion using rudder only pulse propor control. AUW is about 2.2 ounces with a 4-cell 150mAH NiMH pack. I replaced the boom with a CF rod and a N20 motor was installed.

However, I am still dorking around with the motor choice. What are you using? How many cells do you intend to fly with?

Nov 24, 2002, 10:36 PM
Team 30 Micro EDF
Mike Taylor's Avatar
I put a KP-00 motor with U80 prop, and 1 x 170 mah LiPoly battery, RFFS RX, and 2 Selman actuators on mine. I also have some other KP 2- 3- and 4-bladed props to play with. The 1 3/4 oz. weight includes the battery.

If I had any CF tubing, I would have replaced the wooden boom as well. Every bit you can save back there makes balancing easier. As it is, I had to mount everything as far forward as possible.

I was only able to get the CG at ~ 40 - 45% without ballast. I think that is pretty far back, but the stock toy balances at ~ 65 - 70%, and it glides just fine like that, so I will try it before I decide to add balast.

I wanted to put a 230 mah LiPoly in the nose to help bring the CG forward, but I had shorted out the only spare I had and it won't take a charge so I put in a 170 instead (1cell, 4.2 v, 170 mah, 4 grams w/ connections).

If you haven't looked at these cells, check them out. They are really light and packs lots of power... A 230 will run a 14" Lightning for ~20 minutes or more (22:34 on one outdoor flight). The 230 mah LiPoly cell weighs only 6 grams wired up.

I used the switch that came with the plane, and an earphone jack for the charger, and mounted these two to a 1/64" plywood base that covers part of the hole in the belly. The plastic piece you pull should get tossed since it is too heavy at ~4 or 5 grams.

I intend this to be a motor glider, with emphasis on the 'glider' part. I live at the foot of a low hill, and there are trees that form a slope wave in front of my porch. I could fly forever on a 230 mah cell!

This is also going to be a testbed for the motor since it is almost twice the weigh (1 3/4 oz.) of the other planes I fly with the KP-00s. If it has enough poop, a KP-00 will go in a more elaborate built-up stick and tissue 'walnut' scale plane. If not, the pull-off blister protecting the motor on the SkyRunner allows for testing a lot of prop and motor combos very quickly and easily!
Nov 25, 2002, 09:31 AM
AMA 697691 / FAA 13675
It sounds like you guys are doing a great job!

I haven't taken out the stock battery yet but it looked pretty large. I suspected that CG would be a pain, that was the reason for the carbon tube replacing half of the fuselage. You could simply slide into the right CG.

Although the KP-00 motor will work just fine here, once again, the E-Chargers enclosed gearbox would be very cool in the existing pod.


Remember that with the extra weight, you also have a much larger wingspan. The KP-00 motor should be more than enough power for the Sky Runner.

Latest blog entry: Greg's Web Hangar
Nov 28, 2002, 05:01 AM
Blade Butcher
smitty240's Avatar
The HF planes are on sale in the stores in the Virginia area until 12/24.
Nov 28, 2002, 12:20 PM
Team 30 Micro EDF
Mike Taylor's Avatar

The stock motor, batteries, wiring and the plastic 'power center' on this weigh 3/4 ounce! With the micro gear, Kp-00 and Lipolys, it lost weogh going from FF to R/C! I also broke down and bought some e-chargers to experiment with. They are awfully cute.

Wing loading (~4 oz/^ft) is lighter than the Lightning (~5.2 oz/^ft) or the e-Charger (5/8 oz., 16.5 ^", 5.8 oz/^ft.). I also stood it on its nose on the scale and measured the thrust (5/8 oz) @ ~30% of the weight. I see no problems in getting this flying. All I need now is a calm day (haven't had one in 2 weeks).
Nov 28, 2002, 01:04 PM
AMA 697691 / FAA 13675
Hi Mike,

Thanks for the information. I'm excited to get this conversion project started and now feel confident that it will make an excellent durable indoor trainer.

Have a Happy Thanksgiving!
Latest blog entry: Greg's Web Hangar
Nov 30, 2002, 02:24 PM
Registered User
Wow. I never noticed this thread before. As soon as I pick up an RFFS system, I'll have to add this plane to my list of possibles. We have two that run FF, and I've almost lost the first one about 5 times (got a 4 minute flight out of it that took it "cross-neighborhood". I'd never seen an FF plane rid thermals like that before, but I met some new neighbors that day!) For us, a 30 second charge on new batteries produces motor run times of about a minute and fifteen seconds. I love these things. We've crashed it numerous times and it's still in one piece. Now look what you guys have done! By the time I get my RFFS system, I'll have a garage full of these things!

Nick R.
Dec 01, 2002, 07:28 AM
AMA 697691 / FAA 13675
LOL, Nick!

Yes, you have to be careful not to charge these FF planes too long or you'll get a good workout!

Latest blog entry: Greg's Web Hangar
Dec 04, 2002, 11:57 AM
Registered User
Stewart Pid's Avatar
How about using the wing from a sky runner on the Lightning? Would the motor handle the larger wingspan?
Dec 04, 2002, 01:40 PM
AMA 697691 / FAA 13675
Yes, you could do that, but, at the cost of an already great scale look and flyer.

The KP-00 motor has plenty of power since most of the flight is at reduced throttle.
Latest blog entry: Greg's Web Hangar

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