Has anyone flown with C.G. behind the recommended position, and if so how did it handle? I have gone back through the old posts and can't find where anyone has played with the C.G. range. I'm running exactly on the most rearward point (5.0 inches), and it really seems nose heavy.

On the landing gear Q&A on these last few posts; From the begginng of this project I wanted my model to sit up with a higher stance, and I like the Sig tailwheel because it looks more "scale" and does not put any force on the rudder hinges.

If you order a replacement, or custom, landing gear from TNT you need to specify that it is for the ARF and not the kit. I called TNT and asked for a landing gear that would make the model sit two inches taller, and that's what they sent. Couldn't ask for better service, and the gear arrived five days after I called. I believe the price with shipping was $51.

The distance between the wheels is about 1/2" wider than stock and this gear is 1/8" thick. I did not weigh the TNT gear, but it is appreciably heaver than the stock unit, and is probably why my C.G. came out level with the battery in the stock location.

Mike

Mike, where did you get the spare tail wheel assemblies from. I too like that set-up also. I tried Tower and they said the were not available as a replacment part. I'm going to use a Sullivan type for this SkyBolt ARC unless I find one that comes with the ARF. Lastly, Is there any law that says a SkyBolt must be done in the standard color scheme normally applied ? [ like all-over black with flouro pink ] [ just so I can see the thing better ] MM

DUH, Gee...... Stupid MM here, You know guys, if I just stop to read some of the previous posts maybe I'll answer my own questions. [concerning the tail wheel assemblies] Guess I'll go back to my orange juice now How embarrassing.... MM

Where did you get an ARC Skybolt?

hi guys
Just an answer to a couple of posts lately
I have been flying the ARF Skybolt with all the stock components for the last two months now. Mounted with an OS 91 Surpass II and a 15x6 topflight propeller, I am able get awsome pull and power.
The rpm range is currently 2000 on the idle to 7500 on the WOT. Not the fastest plane, but very acrobatic and it does hover and knife edges, spins, harriers and all the standard acrobatic manoeuvers like hammerhead, split S, slow rolls and so on...

I shall admit the center of gravity is nothing close to the factory recommendation. In fact it is set at 135mm from leading edge of top wing, and it is just fine.
The control throws in the manual are fine for the low rate, I increased the travel for the high rate a bit, but not much...

I can't tell how heavy is my plane, as I don't have a scale... But it is all built as per the manual. Instead of standard servos I have digital ones and I use a 1200mAh 6v NiMH battery, but this is not necessary.

My Super Skybolt is pretty much like yours, with an OS 91 Surpass II and digital servos. You might want to try a Graupner 14x7 prop as it won't bog down the engine as much as the 15x6. As far as the CG goes, I believe that Great Planes is doing the Super Skybolt a disservice by publishing such a forward CG in its manual. My battery and receiver are in their stock location as per the manual with no lead up front and the plane flys beautifully. I learned this as I gradually removed the lead from the nose (the last 2 ounces actually just fell off). This is a model I would definitely replace if something happened to it. I can't say that about any other plane I own.

OK guys report from this morning. to recap: stock ARF, sig tail wheel, 2 elevator servos, pilot , battery on back of motor mount, OS .91FX 2 stroke, slimline pitts muffler, stock spinner, no lead!

7lb 9 oz
CG at -5 inches from leading edge of top wing

15/8 prop; clearence ok but cut grass, could barely idol low enough to keep plane from moving on ground, flew well with great verticle, little fast at back throttle sweet spot.
14/6 prop; did not cut grass too much, idled well without pulling plane, flew well great verticle but seemed little less than 15/8, still fast at full throttle but slows nicley at the back throttle sweat spot, more scale speed seemed like to me.

I will try 13/8 in the morning. This prop is supposed to maximise horse power of the motor and run at the highest rpm of recommended props 11,500. 2000 rpm over the 15/8

the rated rpm of my motor is like 15000 rpm and no recommended props over 11500rpm whats the true horse power....who knows

The OS Max representative suggests propping the 91FX to run at about 9,000 on the ground. We've got a number of them running at the field that like the 15x6 and the 14x8 best.

A couple of us did a prop testing session just yesterday. Swapped through a handful of props, one right after the other. Flew the test mule with one, swapped it out, cranked, set needle, flew the next one. Consensus on the test mule was that the Master Airscrew K 14x8 did the best in the 14"ers. And all the 15x6s seemed about equal. 16x6 was too much fan. and anything over the 15x6 was too much load on the engine.

BTW, test mule was a 4star that was heavier than your average 4star and most certainly heavier than 7lb 9oz

And everyone was surprised at how the MA K-model did. After all, it looks nothing like a modern prop "should". It's amazing what actual testing will show.

I must have received a copy of your E-mail from O.S.!!!

Yeah they told me the same thing.

On mine I had to prop it down to a MA 14x6 to get best RPM's ( around 9400 ) and pulling power.

When I tried an MA 15x6 the engine would load down too much in the verticals.

While a wider prop would have been nicer, I'm QUITE happy with the pulling power for the Skybolt.

We tried a couple of different brands of 15x6 and all of them got around 9,300. The two different 14x8s gave 9,200 for one and 9,150 for the other. Our vertical test was to run about 300' level and pull max elevator into a vertical line and count. With the heavy airplane, vertical isn't forever. The 15x6s went up for a count of just under 10. The 14x8s went for a count of about 8.

If you use Dave Gierke's method of estimating thrust (load) the 14x8s would put about 15% more load on the engine we were using.

Good info on the props there. I found similar results. I ran mine in the back yard with a 14x6 APC pattern prop, and was getting 10,200rpm with it when leaned out. I am guessing 9800rpm or so running a couple of clicks rich, which is were I like to be.

Here are a coupls of pics of mine. It is ready for it's maiden Monday.

Do you have a vid of it flying?[]

BIG QUESTION FOR YOU GUYS, please answer kindly,

i just gave 1 of my 3 skybolt kits to a couple of friends that i fly with. i gave it to them because i know that when i sold my framed up version some 15 years back, one of my buddies said "yeah i wanted it, but never had the cash"...............so i feel good about giving things to others...............but i did ask that they had at least an FS.91 for it.
now i'm told they are going to install an OS fs .70..............Doh!!
i told Marion (he's the guy i know best and gave the kit to) that a .70 is not enough.....Marion tells me, "probably so, but Bobby just wants to putt around and make an occasional loop"..............Doh!! again (Bobby is who Marion gave the kit to, as i they are closer to each other).

i just can't see the OS .70 doing the job, but give your input please.

It will fly it, but I don't know if he'll get it to loop

I flew my original kit-version with an old style OS 90 and it flew well but was lacking power

It should have just enough power to take it to the scene of the crash.

What engine?
FS or Fx 91?

yeah a four stroke .70...............
think what i'll do is get mine in the air in the next month and fly it at half throttle and show them how my OS .91 FS surpass II w/pump is just enough power...........
i mean hey, i gave it to my buddy Marion as a gester for all his helping me when returning to the hobby, and i pretty much knew he would give it to his friend, but i just hate to see someone build such a beautiful bird and then stick the equivelant of a "house fly" for power on it.......not to mention all the lead it will probably take to get it to balance.

Fx 91

Hi again guy's well i finally got my Skybolt almost finished ,( i hate it when work[:'(] interfears with play ) any way i installed the skywriter smoke pump first try not much smoke at all that was with a O.S. FS-91SII-P with the stock muffler and stock nipple location which is a little far from the engine so i guess it's loosing the heat needed .So i went and got some of the small copper 1/8" diameter tubeing and wraped it around the muffler about 6 or 7 wraps and used fiberglass tape like the kind used on wood burner doors and wraped the copper tube then wraped the insulation with coper doorbell wire and then covered that with the metal duct tape like they use on a furnace now she is smoking pretty good i have yet to maiden the plane because i just couldnt bring myself to fly it without the SMOKE i am going to try and fly it thursday i will try to get some video of the maiden flight.

P.S. : I used two of the DoBro fueler valves one for the fuel and one for the smoke tank filling .
after running the plane a little it would shut off and run eratic !!! Brand new motor then i found the problem is the fueler valve letting AIR to be sucked into the fuel line as long as i put my finger over the fueler valve it ran fine as soon as i removed the finger i could see the AIR BUBBLES start to come and the engine would start to run rough again.

Is it best to just use a pluged fueling line or can this problem be fixed and How do i do it ??

Get rid of those fuelers. I've had nothing but trouble with them. Want some more?

The rings wear and become lodged in the lines, etc.

Use a T connector and fuel dot instead. Much safer.

---

I recently put a slightly larger muffler on an O.S. 1.20 after I was having similiar problems with it's smoker, just as you are.

I tried the wrap technique but I was not quite pleased with the results. The muffler still tended to cool too much in flight.

Instead I coiled copper tubing INSIDE the muffler, to act as a heat mass and at the same time act to provide far more surface area for the oil to heat up from.

It worked great! The output from the engine keeps the copper HOT and it does not cool down in flight.

Thanks for the info after i posted about the fueler valves on my skybolt i went back into my shop and the first plane i see when i come in the door is my FUNTANA 90 which i havent been flying du to issues that i am haveing with the SATIO 100 after a couple of close call dead sticks it has just been sitting i never expected the fueler valve because they were all new so guess what new stuff can be crap also i removed the fueler valve from it and will test fly next week but im sure the valve was the problem because now it idles fine and no AIR in the lines.

Thanks again.

Ditto on the fueler valves. Hang them on the wall.

I am building a Super Skybolt ARF. I mix it up with my Midwest Extra kit. The Extra gets priority. I am in no hurry. It is so pleasant this way. Here are the specs on my Skybolt: Saito 91, Futaba 9001's all around except throttle which is a Hitec 81. Battery - Fromeco 2600 mAh LiPo regulated to 6.0V with a MAXX products miracle switch. The first two pictures show the Extra which is slowly but surely coming together. Back to the Skybolt - I plan on fitting a DuBro tank instead of the one that came with the Skybolt. It is almost the same size, and I prefer having a cap which surrounds the opening at the front of the tank. I am nervous of the ARF tank splitting over time. If you look carefully at the wing joiner, there is an 1/8" dowel near the tip. There is one at the other end too. This held the two pieces in alignment as I laminated them together with epoxy. No worries about sliding out of alignment. One more thing - I will mount the engine inverted and use an Electrodynamics on-board glow system with a 3400 mAh single NiMh cell. I'll run a flexible exhaust header.

Look's Good keep up the good work [] i wish i had the time to do a scratch or a kit build but i cant seem to find the time .
and when i do i like to fly my planes and heli's i'll post my ground smoke test here later on My Super Skybolt .