The Death of my Alfa Sabre... [Archive]

Kilo60

Oct 17, 2007, 01:13 AM

:o

Well after 30 or so unevenful handlaunches I guess the law of averages finally caught up to me...

My Sabre went in hard nose first full throttle on JS and 4s all the way. Tore the fuse in half so bad it crushed ripped and twisted it to shreds... No gluing option here. :(

Maybe it was too widy (10mph w/ gusts slightly higher), maybe it was my stuborness to continue to hand launch solo... but at any rate, it left my hand like always then rolled hard right... Before I could get my hand on the aileron stick she rolled so hard right she impacted nose first.

Somehow, I always got the feeling that I was one bad handlaunch away from total devestation w/ this bird...

Nothing left but to build another I guess... or wait for the A-4. ;)

Is there any special way to launch these birds w/o a repeat of my last crash?

I'm thinking of adding some slight "up" REFLEX to the ailerons next time to keep it a little more stable.

Usually, I'm flying my 3d ships and I just let them go with an underhand release. The thrust to weight ratio just takes them safely straight up.

bmiller

Oct 17, 2007, 01:38 AM

Sorry for your loss...
I've flown mine in over 20mph winds. Bumpy flight but nothing unusual.
10mph is nothing, especially with 4S JS power.
Possibly you launched at a slight angle to the wind?

FresnoJay

Oct 17, 2007, 01:47 AM

Kilo, For this reason when I do hand launch solo I always have my Aileron hand on the stick and bumb up the throttle using my chin or nose this way I have immediate control and correct it. This has actually save a few planes launching them this way. Had a few do nose dives or rolls in which I was already in place to take corrective action. Sorry for the loss of the bird those Alfa's are beautiful birds.

Jason

Wilson Co

Oct 17, 2007, 08:14 AM

Kilo-

Sorry for the loss... It's a right of passage. You gotta get back up in the air!

As bmiller said these things can fly in high winds. I have flown my Mig where it would literally gust and blow the plane side ways like 10' LOL. That's in the winter when I fly over the frozen lake...

ronin4740

Oct 17, 2007, 10:28 AM

Sorry to hear about the demise of your Sabre. I know all too well how a bad hand launch can cost you a plane - it's cost me almost a full bottle of CA for a Synapse at this point...

If the electronics survived perhaps you might consider transplanting them into a Mig or a Sabre with drop tank/wheels or an A-4 with wheels?

The simplicity and ease of ROG with the Mig makes getting it in the air a non-event once it's trimmed. I did a tailwind launch yesterday at the field as the sun was right on the horizon and I didn't want to ROG right into it. Wind speed was about 5 mph on the ground and the Mig handled it fine. Only difference was that it didn't climb on it's own as it usually does.

Anyway, hope you get another Alfa in the air soon!

metroidrc

Oct 17, 2007, 10:31 AM

Kilo, I have a vid of a bad hand launch that I did on my Sabre as well, so I feel your pain. Its just alot harder to hand launch because of the lower wing, and your hand in the rear of the fuse. I would say you could even throw it up a little higher just to be safe. I always give it a very light toss also, don't really throw it. It should have enough power for recovery. I believe that I did launch it from holding the top one time and it was ok. I'm rebuilding my old Sabre now with a new paint job and some new electronics. Don't give up! These are great flying planes, and if you treat them right, they will treat you to a nice show! :)

Ed Waldrep

Oct 17, 2007, 11:48 AM

As much as these birds cost and (as far as I know) no spare fuselages available, I'd experiment with a carbon rod in the bottom of the fuselage from the wing leading edge forward to the nose. If you nose in, the rod would flex and absorb the impact. Leave a short gap up front so you have a crumple zone, so maybe only the nose ring is lost but hopefully the foam of the fuselage will at worst only crinkle a bit but not break.

I added a rod to my second stryker and shortly after hit nose first pretty hard...no broken or distorted foam this time like the first one (yeah you can glue it back but the foam gets distorted upward and never looks the same). I've had three nose first crashes with the Stryker and the rod has taken all the punishment, it's broken off a couple of inches back now, but the nose, while slightly crinkled is still intact. Depron may be a bit different but heck for a 1/4 or so weight penalty it might save a 160 dollar foam jet.

I with the far east manufacturers would discover heat molded depron, the jets would be cheaper but perhaps not as well designed as the European stuff.

OLD JET LAG

Oct 17, 2007, 02:21 PM

Spare fuselages are available over here.
You can't compare a jet with a prop job. At launch there is little air passing over the wings of a jet, just the wind. At launch the thrust is just pushing the model against the CoG so the angle of release is quite critical. Also, even with a 10mph head wind the intake can stall resulting in little air going into the fan. By far the safest launch is ROG. The Mig is OK off short grass but the Sabre needs wheeled drop tanks. A rudder is very useful at launch as its the only control to use if a wing drops. Using aileron to pick up a wing only makes the situation worse, making the aircraft roll in the opposit direction to that required due to aileron drag.

LuckyDuc

Oct 17, 2007, 05:02 PM

Kilo60

Oct 17, 2007, 06:29 PM

Kilo60

Oct 17, 2007, 06:32 PM

Bummer about the crash. :(

I had a bad launch on my 28th flight. I managed to put it back together and it still flies great. Looks a bit more weathered though ;)

I feel very confident about my hand launching skills, BUT it only takes one bad launch to ruin your day. Especially with EDFs

Yes Luc,

It actually went in exactly like your posted Maiden Video... where that fellow at the field threw it for you. Only at full 4s throttle!!! :eek:

I'm really going to check the lateral balance next time as I believe mine was slightly heavier along the right side due to the ESC being heavier (on right side of fuse tray) than the HS56 servo (on Left side of fuse Tray). Can anyone suggest a good way to check lateral balance with a propless A/C?

Luckily all electronics survived, even the fan unit, stator poped free though (nothing CA can't address).

As fun as this Jet was/is...
it's hard for me to motivate myself to drop another $160, on an EDF Alfa, that could very easily succomb to another bad hand launch. :(

LuckyDuc

Oct 17, 2007, 06:52 PM

As fun as this Jet was/is...
it's hard for me to motivate myself to drop another $160, on an EDF Alfa, that could very easily succomb to another bad hand launch. :(

I know the feeling. I really like mine, but I'm not sure I would spend another $160 for one... considering I only got 28 flights on mine before a bad launch crunched her. $6/flight is not what I call good value. I like to get over 100 flights on an airframe before I justify buying another kit.

ronin4740

Oct 17, 2007, 06:59 PM

The Alfa A-4 which I have on back order will get wheels so she can take off from the paved runway at the club field. I'm planning on grass landings though... There's a lot of nose to crunch and I have yet to get to the point where I grease more landings than not...

Kilo60

Oct 18, 2007, 12:47 AM

I really think that the biggest problem with the Sabre is the high CG (batt on upper portion of A/C) causing some nasty wing rock/tip stalling at slow speeds. Add in the fact that the control surfaces aren't all that productive, compare to a prop plane and a less than perfect level throw and it really makes for some hair raising hand launches at times.

I wish there was a way to mount your batt under the ducting as this would really make things more stable with a lower CG (closer to the wing area/lifting surface)...???

metroidrc

Oct 18, 2007, 06:34 AM

I suppose you could build your own battery compartment underneath but it may add alot of drag. One of the things that you can do is cut the wood tray and rest the battery right on top of the duct(protected of course). That would eliminate some of the instability. Overall hand launches were slightly annoying but with enough power it always climbed out. I also have an A4 on order and looking forward to it!

Josh

FresnoJay

Oct 18, 2007, 11:57 AM

Kilo, Yes I throw whimpy handed as I am right handed. Even though my left doesn't have as much control or force its more than enough to get a model going. No bad launches yet (knock on wood).

Jason

rvincent

Oct 18, 2007, 12:46 PM

Wimpy handed!!!?

You hosers just need to be left handed is all :D

FresnoJay

Oct 18, 2007, 03:17 PM

But left handed would mean issues with the aileron and elevator on the right stick ;) :D . Its all good as long as they get in the air :p .

Jason

rvincent

Oct 18, 2007, 03:33 PM

Well if you throw like I do with your left hand, your right hand is already on the right stick with the aileron and elevator ;)

metroidrc

Oct 18, 2007, 05:48 PM

I only had one hand launch problem and it was because I threw it too hard. Its a light toss straight ahead.

D Yoakum

Oct 18, 2007, 10:59 PM

I also throw Left handed, Lately I.ve been throwing it up with a underhanded toss. A tip that I got from another E zoner it works great! Don't give it up. D Yoakum

Kilo60

Oct 18, 2007, 11:56 PM

I also throw Left handed, Lately I.ve been throwing it up with a underhanded toss. A tip that I got from another E zoner it works great! Don't give it up. D Yoakum

Are you tossing it this way at a high AOA...??? :confused:

Seems like it would tend to stall more easily.

D Yoakum

Oct 19, 2007, 09:57 AM

I just grip it just behind the canopy and and give it a straight arm toss and release it somewhere between waist and chest high at about an 30 degree angle. I can get both hands on the radio slightly faster than with a overhead toss. The first time was pretty nerving I didn't expect it to work however I have a new in box (NIB) saber at home so it gave me some extra confidence! D Yoakum.

Kilo60

Oct 21, 2007, 08:28 PM

Does anyone know if RedFive is still making those Alfa F-86 nose cone/gun port protectors? I haven't seen him on these boards for quite some time now and I hope he hasn't scrapped the moulds.

They are definately a must have item!!!!!!!

I sent him a P.M. a couple of days ago and so far no joy. :(

metroidrc

Oct 21, 2007, 09:35 PM

he is, I was supposed to buy one two weeks ago but I haven't had a chance yet. I really should buy one...

D Yoakum

Oct 22, 2007, 12:10 AM

I think that I was one of the first ones to get one. Without it my Saber would been gone a long time ago. He also makes a body shell that goes from the nose to just past the gun port looks great and really toughens up the the whole frount of the plane. I hope he is still making them!

vonJaerschky

Apr 12, 2008, 07:14 PM

A bit of an old thread, but having read this for the first time I think I will mix the rudder stick to the ailerons for my upcoming F-86 maiden. I'm right handed, so that way I will be able to at least have my finger on the left stick of the transmitter and have some aileron control when the airplane leaves my hand.