hehehe....Ramon, I think you've grasped it!

What I AM Saying, jrf, is that a Saito 91 can easily use a 12 X 8 prop for sport flying. You take the same plane, and you put a Saito 120 or OS 120 in it and you're suddenly into an 18 X 6 range on the prop, and if you reduce the prop size you have to increase the pitch to something like a 14 X 12 or something in the vicinity of that, and that means your airspeed is up because of the pitch, and that prop is still a full 2 inches bigger than the other one and a full three inches if you go with something like a 15... You're increasing the drive forces just by having a larger prop, and you're increasing the reach for speed by the prop when you increase the pitch so that you can reduce the diameter. When that engine winds out it has to have a prop that will limit it at the right point. Now, yes, one could reduce the throttle throw...but then why is that big engine mounted there if you can't use it all?
To me, it's just that saying they have about the right tool for the job. Yes, we all like to have one or two models that we think of as our "wild thing" model, but most of the time, a big engine just complicates the heck out of things. Okay, okay, yeah, it's impressive, too. Got me there!

Jim

Jim, didja see the Liberty sport in the bones? Check out what I said about the WACO.
Bill

Oh, that was the Liberty Sport in the bones?? I thought the top wing of that "Waco" was WAY too flat! Duh.

Sorry, I had been called out just then and had to leave right away. Now that I read the blurb, I know it's your Liberty Sport. That's great news about the cutter being interested in cutting Wacos for you. I have some questions as to whether Pica is going to be willing to sign off on it, or whether you'll be able to call it that. Maybe a "replication of a Pica kit" ?? Still sounds to me like there's something waiting there in the wings to take a bite out of you.

I'm not up on copyrights and such, and I've often wondered how the kit-cutters handle that part of things.

Jim

I don't know. Pica is no longer in business. The cutter is reasonably sure that the copyright has expired and I suppose I need to get an attorney that specializes in copyright law to look at that. (If I were still in Nashville it would be easier...there are lots of ambulance chasers that specialize in that) It may be just a dream, but I think it is worth finding out.

This discussion has gotten a little out of hand. I am going to state my position as clearly as I can and then go back to building.

Given your prop size assumptions, you are correct in your conclusions. But I do have to quibble with your assumptions. According to the Horizon website, the range of acceptable prop sizes for a Saito 91 is 12x8 - 15x6. The most commonly used prop on that engine is a 14x6. Again, from the Horizon website, the acceptable prop sizes for a Saito 120 are 14x8 - 16x10. The most commonly used prop on that engine is a 15x8.

Now if you take the 91/14x6 out of your average sport plane and put a 120/15x8 in it, it will undoubtedly be faster, but you will certainly not have ground clearance problems. Since the airplane was designed to accomodate a 91FS it already has adequate clearance for a 15" prop. Switching the 120 to a 16x6 will slow it down to just about the same speed as the 91 and the prop tip will still only be 1/2" closer to the ground than the airplane was specifically designed to handle. If that is a problem, put on larger wheels.

With the 16x6 the airplane won't be faster, but it will have much better acceleration and vertical penetration. In other words, more reserve power to smooth out your maneuvers and, if needed, to get you out of trouble.

The point of all this, I think, is that using a larger engine requires common sense and planning. The effect on airspeed and ground clearance must be considered. (And the effect on weight, balance and wing loading as well.) When all of these are considered and normal throttle discipline is observed, adding 50% more power to an airplane can be very rewarding.

And as you implied in post #72, replacing your 91FS with a G-62 is probably not a good idea.

Jim

Well looks like I was premature (again) Cox has indeed bought the intire Pica line-up, and will be debuting at least 4 of them at Toledo. The YMF may very well be one of them. Cox will not sell the rights to any of the PICA offerings, so looks like we have to wait and see.
Bill

I'd check with the cutters in reference to Ziroli. He sells plans and kits, and obviously expects that they will be cutting some kits.. Did Pica ever sell just plans? If they did, they could not stop people having the kits cut. Just a thought....

Jim

Just change the shape of some cut-outs in formers and ribs, modify a few details and call it what-ever kind of Waco you want. Pica, Cox or who ever only own rights to a specific set of plans drawn in a specific way. They do not own the rights to the design or appearance of a Waco aircraft. So go for it, call it a Wah-ko if you are scared of lawyers. If you cut kits to sell you'll have to generate a set of plans and instructions so it'll be your design anyway.

What about using one of the larger 2 strokes in the .75 to .91 range for the super skybolt arf. Also is anyone considering a smoke system?

Anyone received the kit yet?

I wonder if the ARF and the kit are the same dimentions / RE: cowl and wheel pants etc. If someone finds specs on this please post. So far I only find fuse length and wing span. Of course its early on. ( like a kid waitin for Christmas !)

Thanks,
Bill

Are they out yet? I heard not until after the 31st...

Jim

Mainer Jim,
No , dont think they are out to general public. Usually someone gets their hands on a new plane before they start shipping orders. ( And ship dates tend to go a little longer than ETA). Either way , it wont be too long before we get a first hand evaluation. Im sure RCU will be the first place to get info.

Bill

Looks like they are showing mid-june for orders on tower now...maybe preorders done before now will still get end of may Kieth

Yep, I kinda figured it would go beyond the ETA, they almost always do.

Jim

I have a YS 91 and 110. I am thinking I will see what the finshed weight is and go with the appropriate motor. The 110 is clearly more powerful but the 91 will probably fly is better than most engines can>

Tom

Tom, My original kit version flew extremely well with a YS 91. The Kit was about a pound heavier, plus I had the added weight of a Smoker. All in all, it was a very heavy plane, but the YS 91 pulled it beautifully.

If you haven't seen it yet, here is the infamous video of the Skybolt Kit with a YS 91AC and Smoke:

http://www.minnartist.net/Skybolt/Vi...t_high_res.wmv

That's the video that made me get my Skybolt Minn! Still haven't had the guts to put it into a flat spin yet....yet.

Nothing to it Randy, Just remember to start high (Very high) and end high so you can let it nose down, pick up speed and pull out GRADUALLY. A fast pull-out can result in a snap.

IF you watch the video, you'll see how I pull out

Just in case anyone is intersted in a bit of history I've built both the Sig Skybolt and the Smith Miniplane. I will tell you that both were fun to build but very demanding and nit picky in their construction. Between cabane construction and the ABS plastic turtledeck on the Skybolt it was enough to make you want to pull your hair out. In the end the Skybolt was hands down the better flyer. Smith Miniplane showed signs of being short coupled and just didn't groove the way the Skybolt did. Skybolt had a OS 61 FSR with Slimline pitts and was purely a delight to fly. Takeoffs and landings were picture perfect and quick but easily controllable for someone comfortable with tailwheel handling. Smith miniplane by contrast was always hunting and searching it seemed to me.
I"ve never flown the GP Skybolt but if its similiar in its character to the Sig model then I would be very happy with it. I've got a new Saito 100 that has no home and I feel it would be an excellant match for this new GP Skybolt arf. Any of the Supertigere 75-90 would certainly be winners. Any 4stroke 91-110 should do the trick nicely also. I think you will find this airframe pretty much open for power plant options. My feeling is never add an ounce of weight to the nose of a model if you can use the same space for a few extra cc's. I find this a disturbing trend among arf manufactures like GP. I was really hot to go on a Chipmunk till I found out you had to bolt half a junk yard to the firewall to get it to balance. To me there is just something taboo about adding weight for balance purposes. At least when your talking about a pound and half!

I have been eyeballing this since it was first anounced. I have never seen one fly or a skybolt period fly other than the video in this thread. How does it fly compared to an ultimate about the same size? I had the global .40 with a o.s. .61 in it and it was probably one of my favorite planes to toss around in any weather condition. When I get back stateside(KOREA, right now) this will definately be on the short list. NIpilot where abouts in N.I.? I grew up in and around CDA, Postfalls, Kellog. Thanks in advance.
Stangevil29

I have never had my hands on an Ultimate, but seen many fly. The Skybolt flys nothing like the Ultimate. The Skybolt flys like a pattern ship. Sleek, clean, and fast with a Magnum 120. Very precise maneuvers, crisp and clean aerobatics, and did I mention fast? It takes a while to slow down on landing, and lands fairly slowly once you get a handle on the low speed carachteristics. I flew mine in a 20 MPH crosswind this weekend, and would not hesitate to do so again. You will not be disappointed. Mine flies at half throttle most of the time.

I got my Skybolt today...looks great, everything is perfect. A Saito 100 will be the powerplant for mine. I can hardly wait to get started on it.

I see by the post from iflywhenican that the Superskybolts are starting to arrive.
I should be receiving mine next Tues. It'll probably take me a couple of weeks
to get mine in the air because of time restrictions. I'll be waiting to see how the
assembly's are going and what powerplants are going in them. I have a Magnum 91x
that needs a home on my shelf that will fit the bill. I'm curious how it will fit the cowl.
Since this is my first bipe I'm open for any helpful suggestions.

I have never owned a bipe and I have been in the hobby for over 30 years. I think the time has come for me to make the move. I have an OS 91 4-stroke available that should be a good choice.

For the readers that have had bipe experience, I have a question about field set-up. To assemble the bipe at the flying site, does it take just a few minutes to get the wings assembled and all connects hooked up or is this a 20-30 minute project?

Thanks,

Ed