YF-19 and SV-51 for radio control

[IAD]

Yep, the motors are only 12mm in diameter... The fans themselves are 40mm.

~Luke

[HWR MKII]

Be sure to run some good FCFs on her. (FCF= Functional check flight)

[IAD]

Don't worry, always do. Lots of them. Range checks, control direction, motor interference, etc. Finals are done on Wednesday, and the weather's nice for flying.

~Luke

[robodragon]

This is awsome. Please tell me that you will be selling the kits minus the controller and servos. I think you could do well selling thease.

[HWR MKII]

Nope he wont. This was a special request i made almost 2 years ago. Luke has my biggest thanks for this too. Theres an RC club here that i just want to take it to an let them look. Even if i dont fly it at that time i think alot will have to clean bricks out of their shorts.

[IAD]

Yep, Sean's correct. These things are a TON of work for me to fabricate. (Was it really two years ago!? Wow. :eek: )

Now, I'm working on building a CNC milling machine and 3D digitizer, which could change things a bit, but that's still a good year or more away from becoming a reality, and even then, there's the hot, humid breath of the copyright/licensing lawyers breathing down one's neck...

~Luke

[IAD]

Wow, better motors + better ducting really pays off...

I modified the ducting arrangement to have constant cross-section, to minimize losses... Dropped it in the airframe, and ran a thrust-test.

Test results: 5 oz. of thrust, at 6.44 A. With the two motors, we'll be looking at 10 oz. of thrust, for 12.88 amps. (Thrust will actually be a bit lower, because of voltage drop under load, but... Close to 10 oz.)

On my ship, TOTAL thrust (both motors) was only 7.6 oz, at 11.33 A!

This thing should really go places in a hurry!

~Luke

[HWR MKII]

Wow. You may actually land this one in a controlled manner then.

Honestly though you managed to get yours onto the ground with no serious damage and thats a good sign. The airframe seems to want to flatten out as it falls.

I can only imagine what this one will do with almost 3 more Oz of thrust comapred to yours. I cant wait to see the vids of this one.

[IAD]

HAHA.

Really, though, I think this thing will be extremely easy to land... I mean, I've done it about 5+ times now with mine... Just every time, it's been by accident.

It does seem to land on it's feet, though.

~Luke

Edited May 19, 2007 by IAD

[Splash]

Still no rush Luke but i was thinking it would be cool to have it for WF next month.

Still no rush. I want this thing to fly right not sit on a shelf and look pretty.

Where's the nearest r/c field to WF, now that the one across the river is closed for development? I'd be a great sub-event to hold a sci-fi/anime fly-in to tie-in with the Fest! Maybe I'll test the waters for interest, for 2008.

Being my own critic, it wouldn't be much of an event if one pilot shows up to perform for 6 people spread out over a 5 hour slot.

Edited May 20, 2007 by Splash

[maxi]

hi man. I´ve been tracking your post from a time ago and I think what you´ve done is very impresive. Is there any chance for you to share the plans for building this baby?? I´ll understand if you don´t. I would love to do some like that and my flight isntructor would be amazed!!!jajaja. greetings man, and keep working.

[IAD]

Well, sort of tricky, since there aren't really any plans. I wish I had accurate section data, but as it is, all the shaping is done by eyeball.

Anyhow, I hope to fly the second ship tomorrow. I just finished the ducting, and I have a little more wiring to do, but after that (and double/triple checks of everything), it's show time!

~Luke

[IAD]

Well, heading out. Batteries charged, 10 oz. of thrust, 12.5 oz. AUW.

~Luke

[IAD]

Well, not entirely successful... I logged about 6-7 minutes of flight, but had a fairly bad encounter with the dirt... Broke a carbon fiber rod in the fin, and really chewed up an intake. But, I'm about 75% done with repairs already, so things aren't so bad.

I got killed by the flaperons, they've got enough power to override everything else at a certain airspeed, so they're getting switched back to elevons. (That 'certain airspeed' just so happens to be launch and landing speed, so...... Not good. )

The good news is... The new motors are a good deal more powerful, which allowed me to perform a very nice Russian-style standing flip. Overall, the aircraft performs quite well, so once I reconfigure the elevon/flaperon mixing, it should be able to put on quite a show. Got to watch the full-throttle usage, though, the battery was pretty warm on landing.

~Luke

[HWR MKII]

YOU FLIPPED IT? Awesome! Not that i plan on trying that the frst time out but its nice to know it can do it.

Too bad there isnt a vid of it.

[IAD]

I've actually have a video, but it's not zoomed in, so it's a bit hard to see. If you'd like, I'll get it posted when I have a chance.

Yes, though. It does the flip quite nicely. By the way, the flip wasn't related to the hard landing... Ironically, it was a simple descending turn that lead to that. It just happened to hit the "flaperons overpower canards + elevators" speed, and I couldn't arrest the decent. So, back to the original (horribly inefficient, but effective) elevons on the wings.

Oh well, they'll help it flip better, anyway.

~Luke

[neptunesurvey]

Please do. I have to see this.

[IAD]

No video yet... But, Sean, here are the intake options...

[maxi]

EYEBALL!!!!!!WOW MAN!!! that´s very awesome. I´m trying to do something like that but a VF-1 model. I hope I succes like you have done. wish me luck.

[HWR MKII]

Definitely the balsa.

[IAD]

Yes, I was quite impressed with now nicely the balsa did the compound curves there...

I'll keep you posted.

~Luke

[IAD]

Two intakes finished. Installation, then thrust-test.

~Luke

[IAD]

Sawtooth intake lips look really neat.

(Note: intakes are not glued onto the airframe yet.)

~Luke

[HWR MKII]

Honestly if you hadnt told me i dont think i would have ever noticed it had been crashed in the first place.

[IAD]

Yep, it'll be fine, don't worry.

~Luke

[IAD]

Got the control system 'rewired', and significantly improved the overall precision, while I had it all apart. The fin is reinstalled as well, so pretty much everything's settled. Still trying to get around to compressing that video clip.

~Luke

[HWR MKII]

Cool im glad its all worked out. No rush on the vid. Just youtube it when you can.

[IAD]

Will do. I'm really sorry about this taking so long. These unanticipated issues really hammered me.

~Luke

[jwinges]

Hey IAD

do you think the new Transformers starscream microflyer would work as a starting point for a YF-21?

At radio shack

http://www.radioshack.com/product/index.js...rentPage=family

Reviews

http://www.rcgroups.com/forums/showthread.php?t=695754

Supossedly it comes in at about 18.5g total. That includes the small prop motors. It seems like there are already some beginnings of ducts. Are there any small and light fan units that put out around 20g of thrust?

[IAD]

Not that small, or that light... The EDF40's I'm using are pretty much as small as you can get, off-the-shelf, and they weigh about 28g per, not counting a 6g speed control, and a hefty battery, to feed them. (88 g battery, for two of them, and that's about as light as you can go.)

~Luke

[IAD]

Clip of the second SV.

Let's see if that works. (Uhg, it works, but YouTube resolution is HORRIBLE..... Oh well.)

~Luke

Edited June 20, 2007 by IAD

[IAD]

Ok, here we are, post repairs/upgrades:

I've reinforced the nose, replaced the intakes, increased control surface precision, added speed-control cooling, and reshaped the nose, to look more SV-ish. Still have to put the pointy spikes back on a couple of the fins, but that's a minor detail. (Don't mind the 'patchy' look of the covering. It's all smooth, I spent a couple days feather-sanding the overlaps, it's just the new tissue I picked up is slightly off-white.)

Weight gain was roughly 0.25 oz., but I hope to lose 0.1+ oz by reducing wire length.

~Luke

Edited June 20, 2007 by IAD

[IAD]

Going for test-flights tomorrow, if the wind dies down. (If, only if... Big "if".)

~Luke

[IAD]

Perfomed a flight early this morning.

ABSOLUTELY SUCCESSFUL!

Pulled three rolls, a loop, and a flip. The longest flight was 7 minutes, but that was with a couple other short hops, so total time on a charge was about 10 minutes, with power to spare. Thanks to the upgrade work, it has very precise control response, very easy to fly the traffic pattern with. It even glides nicely.

The structural upgrades paid off, the reinforced intake sawtooth ripped up hunks of grass on landing, but didn't stress/break at all.

The only items that need addressing are the balance point (I needed to add a pocket comb inside the nose to get it to fly nicely) and nailing down why one motor occasionally goes out of sync. (Throttling all the way down resyncs the motors, but sometimes, that isn't an option. It happened twice, and that's too much for me.)

However, I'd say that's the last flight I'll have to perform on this ship. Aerodynamically/flight-performance-wise, it is already superb.

(And yes, there's a video. )

~Luke

[IAD]

Ok, video being uploaded now.

Not the super footage, but still, here it is

http://home.comcast.net/~louisosweldlurky/SVCompressed3.AVI

(Divx compression, right-click and Save As.)

YouTube:

Notes:

The aircraft is NOT jumpy/twitchy, however the camcorder definitely is.

The 'kulbit' maneuver looks like a loop in the footage, but not in real life, where it appears much more 'rotational'. (Has to do with how the camera tracked the aircraft. That, and no horizon reference. Oh well.)

Yes, the exit out of the kulbit was very sloppy, but not as bad (dangrous) as it looks. In hindsight, the trick is to push the nose down 45 deg., instead of trying to climb out after finishing the maneuver. Also it didn't help that the aircraft was still nose-light.

~Luke

Edited July 6, 2007 by IAD