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YF-19 and SV-51 for radio control


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Wow, that looks incredible! What sort of propulsion are you using/planning? I flew a profile -19 for a while, but your version completely blows mine out of the water! (Here it is, all the same: http://www.rcgroups.com/forums/showpost.ph...mp;postcount=14 ;))

~Luke

Thank you for the compliments Luke. The 2nd proto used twin EDF-40's, but it was somewhat underpowered due to my crappy motors. Now I'm looking into alternatives, maybe even make my own propulsion system with the help of my brother.

It's going to take a while to make a "scale" YF-19 fly as good as my foamie F-16. Instability and drag are my worst enemies right now. One thing is for sure, I refuse to change the proportions to improve performance.

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Good show! How did the exhaust area work out? According to my CAD work, at 24" span, the perfect-scale exhaust is only 1.4"^2, which is less than 95% of the FSA?

~Luke

I haven't quite figured that one out yet, the earlier proto flew without its TVC vanes. Sadly, I will have to modify them a little :(

I was reading about custom CD-ROM motors at rcgroups, do you have any experience with that?

Here's another wiew of my WIP, the canopy is just taped in place. I plan on making a vacuum formed one, along with a decent interior.

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Edited by Argandona
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  • 2 weeks later...
  • 4 weeks later...

Would you by chance have the profile plans for the YF-19 and SV-51 that you made. I'd like to try and shrink them down and use Aero Ace gear in them with pusher props.

Also what material are you sculpting the SV-51 from and how are you sculpting it? Do you think a 10-12" wing span version could fly as a sculpt rather than a profile?

Last, you wouldn't know of anywhere that one could simply buy a sculpted foamie body that could be modified into a SV-51 or YF-21/22 would you?

By the way your SV is truly inspiring

Cheers

Yep, I've worked with a pair of custom wound CD-ROM motors... They work well, if you're OK with chewing your fingers up, as you wind the stator... :huh:

~Luke

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I'll see if I can dig up the plans for the profile ships. Pretty much, they're just traces of top/side views of the designs, though.

I'm using Dow's pink insulation foam; I initially block-cut the components using a hot-wire bow, and then just start shaping with sandpaper, keeping a careful eye on sectional symmetry.

Because of the volume of the airframe, I wouldn't count on a 12" span version to be light enough to really fly well. (It would also be quite a pain to carve, at that size.)

I can't think of any off-the-shelf airframes that are close enough to the SV to really convert convincingly. With a lot of work, an Su-27 might pass, but you may as well just build the whole thing from scratch. (You'd need new LEXs, wings, stabilizers, nacelles, canopy, plus the canards. That's almost the entire plane.) Same goes for the YF-21.

~Luke

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  • 2 weeks later...

Well, charging right along here... Look at the deflections the updated thrust-vector paddle design can achieve!

I've more than doubled the throws compared to my ship. The new linkages are also more reliable, making it almost impossible for them to disengage in flight, something that occured on mine a couple times. (They were a bit tricky to make, though... Nothing like tying knots in 1/64" thick wire. :blink: )

Anyway, I'm planning on finishing the airframe by tonight. We'll see. :rolleyes:

By the way, Jwinges: I take it back, a 12" 3D airframe carved out of foam wouldn't be too bad, weight-wise, according to some volume calcs. I did in CAD. Still a bit of a pain to do, of course.

~Luke

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Sean, I'm working on the gunpod mag. right now (saving 0.1 oz., in the process) and I'm wondering: Would you like me to engrave those little quadrilateral-shaped panels into the upper surface? I tested it on a spare piece I had, and it looks really good, but perhaps it's too much surface detail, given the rest of the aircraft is un-paneled? (I'm short a camera at the moment, but I'll post a pic. or two in a couple hours.)

Also, should I install the raised hexagonal panels on the nose, or do just supply you with the CAD patterns?

~Luke

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Another update, added the tipfins, and what-not.

Working on a gunpod, as well... Not sure if it's flightworthy, I'll probably attach it with magnets. First I need to make it fit the magazine, apparently my version has some a non-lineart-accurate set of cross-sections between the nacelles.

Lastly, Sean: Take a look, I threw together a mockup of the gunpod magazine with detailing. If you like it, I'll go and make a cleaner version, if you don't, I've got a blank ready to be installed.

~Luke

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Edited by IAD
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Those flight videos on Google are great. During the "Sorta Cobra"... looks like you had zero forward airspeed and still maintained altitude.

That is a great looking aircraft both in the air and on the ground.

Is it possible to make a vacuum form mold from your hand carved master? It may allow partial mass production since you have already validated the design.

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Those flight videos on Google are great. During the "Sorta Cobra"... looks like you had zero forward airspeed and still maintained altitude.

That is a great looking aircraft both in the air and on the ground.

Is it possible to make a vacuum form mold from your hand carved master? It may allow partial mass production since you have already validated the design.

Yep, I was pretty much sitting there, driving the nose with the thrust vector. Not bad, considering the tiny 7 oz. of thrust, or whatever it is...

The problem with vacuum-forming is... What do I form? Styrene sheet (0.02") would produce an airframe that weighs 11 oz. which is 5 oz. overweight. (The entire aircraft, loaded, is supposed to weigh 12 oz..) I've tried vacuum-forming foam sheet before... Don't talk to me about that! :blink: (It was rather traumatic, in the magnitude of failure. :rolleyes: ) I even tried matched-mold compression molding of the foam. Very touchy business.

Now, I am working on a 'secret project' which (if it works) could change my model-producing landscape forever, but that's for another day.

Sean: GAH! $600, for shipping!? :blink: *Passes out*

~Luke

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Yep, I was pretty much sitting there, driving the nose with the thrust vector. Not bad, considering the tiny 7 oz. of thrust, or whatever it is...~Luke

Not bad,??? You are too modest. I know that you need keep product secrets but doubt the aircraft has inherent control coupling or a stabilization augmentation system.

So that is an excellent design with superb flying skills since you do not have the luxury of being in the cockpit.

I hope that your current production ideas work. Best of luck.

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Well, the flight control system is mechanically interlinked so all the control surfaces respond cooperatively to my control inputs. (All off two servos, too!) So, at least the pilot workload is pretty low.

Unfortunately, production of the SV is pretty much off the table, due to copyright issues. A couple one-offs (sort of an oxymoron, isn't it?) is one thing, but I imagine there'd be trouble if I did a production run of the things.

~Luke

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Nothing that I know of... Maybe I wasn't true enough to the line-art? :blink:;)

Sean, here are the latest pictures... One of the now-finished control system, and one showing the deflections with the stick all the way to the left. Somehow, I think it will roll. :D

~Luke

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I don't know, it could be quite a bit of work... But, I might take a swing at it anyhow. (I'd also want to bring the ducting on mine up to spec., the intakes on your ship transition into the fan much more smoothly than on mine.)

~Luke

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