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Old Jan 08, 2010, 02:35 PM
And Repairs
TyFlies's Avatar
Grapevine, TX
Joined Jan 2009
262 Posts
Thanks - sorry about my confusion. Yes, I meant the plastic skid plate. I'll use the skid plate and some carbon rod or strip. Should finish this evening and hopefully trim it with some test tosses in the morning.
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Last edited by TyFlies; Jan 08, 2010 at 02:45 PM.
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Old Jan 08, 2010, 10:17 PM
Steve Chamberlin
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Bay Area, CA
Joined Oct 2009
121 Posts
I took my Alula for its third outing this morning, after repairing the nose and installing CF reinforcements. A couple of thoughts:

The grass was wet with dew, and within 10 minutes, the plane was soaked. It was literally dripping wet. After 15 minutes, I think water got in some place it shouldn't, and one of the servos went nuts. With all of the electronics on the bottom, how do you keep everything dry? Or do you just not fly if there's morning dew?

How easy or difficult should this plane be to fly, if it's properly balanced and with the right amount of control throws? I'd call myself an advanced beginner pilot, my only other plane is a Slow Stick which I've been flying for a few months and I'm extremely comfortable with. In comparison, I can barely control the Alula. When I "fly" it, I'm basically just trying to prevent a crash, rather than flying any intentional pattern. I still can't decide if this is how it's supposed to be, or if I'm not set up properly. Specific complaints:

- Stall behavior is very unforgiving. Stalls come on suddenly, and make the plane abruptly dive straight at the ground like a lawn dart. Impossible to recover unless the plane is more than 20-25 feet up.
- At low speeds, such as just before the glider comes down in the grass, the aileron controls seem to do practically nothing.
- Most of my launches are steep climbs followed immediately by a stall and nosedive that loses 50% of the altitude.
- Most of my launches also end up with the plane banking steeply left (I'm right handed)
- Did I mention that I am an constantly stalling and crashing.

Basically I throw it in the air, and just try to keep the wings semi-level when it comes down into the grass. The plane itself decides where it comes down, not me.

Are these typical growing pains for somebody moving up from an elevator-rudder trainer? Or would I have a better experience with another glider, perhaps? After three outings with the Alula, I've still yet to have any fun with it, really.
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Old Jan 09, 2010, 09:27 AM
Gravity sucks
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United States, WA, Richland
Joined Mar 2006
2,445 Posts
schamberlin,

It sounds like your setup is still not ideal. As stated before, planks are pretty unforgiving for cg placement. And the recommended position of the cg is just a recommendation. You have to play around with it a little and see what works best for you. I like mine right at the back end of the dimples, but others feel more comfortable farther forward. Your stalling problem might be caused by flying it too slowly or having too much reflex in the elevons. Too much reflex could also explain your straight up launches. Try giving it one click of down trim and see if that changes things. It is normal to lose some control authority as the plane slows down. Less airflow over the surfaces and all. On your launch, are you pushing the plane over at the top or letting it flop by itself? I like to push it just before I think it has topped out to make sure I still have some airspeed when it goes horizontal. Otherwise a stall is pretty much inevitable. Do you have any slopes where you can fly the Alula? It is easier to get the setup correct if mother nature helps with the lift. And, yes, this is part of the learning curve when transitioning from a RE ship to a plank. Worlds of difference in how they handle. Look at the videos on Michael Richters website and you can see how it should fly for you. Stick with it 'cause it can be loads of fun.

Mike
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Old Jan 09, 2010, 11:31 AM
Steve Chamberlin
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Bay Area, CA
Joined Oct 2009
121 Posts
Thanks SrWade. Yes, there are slope sites in the area, but I've been sticking to the flats until I'm more comfortable with the plane. Maybe that's a mistake, since I'm spending as much time launching and retrieving as flying. I also chose the Alula over the Weasel for its flatland capabilities, so part of wanting to make that work is just stubbornness.

The good: I went out again this morning, and had more success. At your suggestion, I gave it one tick of down elevator, but didn't change anything else. It seemed less stall-happy, but that's probably due to me getting better as much as anything with the plane's setup. Regardless, I was able to launch the plane, turn a wobbly half circle, and return it to me many times (but by no means every time). Four times I was able to catch it, and lots of other times I brought it down in the grass not too far from me. I only had two or three hard nose bonk crashes, which was a lot better than the last two outings.

The bad: Dew on the grass was still a huge problem. After two throws the plane was soaked. I had to hold it wingtip-down for 5-10 seconds after each throw, to let a stream of water drain off. I taped completely over the servos, and temporarily taped over the access hole in the belly skid too, but it seemed to do a better job of keeping water in than out. After 15 minutes, one of the servos started malfunctioning again (third time this has happened), centering too high and putting the plane into a loop with every launch. This seems to happen when it gets wet. That cut things short, so I didn't have as much time to practice as I would have liked.

I think the problems I've been having with stalling are due to just not flying fast enough. That sounds stupidly obvious, but what I mean is that my Alula will not fly at the speed and glide angle I expected from watching other planes. It really needs to keep moving pretty fast, and at a noticeable downward angle. Cruising along more slowly at a near-level angle results in a fatal stall almost every time.

Also, the reduced control authority at lower speeds seems to increase the likelihood of an accidental stall. If I accidentally get into a too-steep dive, the plane picks up speed, and just a little bit of up elevator will make it pitch way up and probably stall. But if I accidentally get into a too-steep climb and impending stall, the plane loses speed, so that even full down elevator has little effect and I can't prevent the oncoming stall.

I will check out the videos on the Dream Flight site again, good idea. My launches are typically so brief that by the time I have the transmitter in my right hand, it's already topped out. I do try to push it over to level flight, but I'm not always successful.
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Old Jan 09, 2010, 11:51 AM
Steve Chamberlin
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Bay Area, CA
Joined Oct 2009
121 Posts
Alula stalls

I'll try to get some video of me flying. But for comparison, take a look at this video of some other guy's first Alula flight:

http://video.google.com/videoplay?do...JHXDg&q=alula#

There are three small hiccups at 5, 16, and 18 seconds into the video where the plane rises up, almost stops, then starts coming down again. I believe any of those three would have created a major still with my Alula, with the plane quickly pitching 90 degrees and coming straight down.
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Old Jan 09, 2010, 02:09 PM
Registered User
france Colmar
Joined Oct 2009
33 Posts
Check if you are well balance from side to side.
For your stall problem (from video) may be you try to always go up....
this kind of plane is like bycicle... you need a bit speed to drive it... just let it a bit down from horizontal axis to have some speed and you will enjoy it...
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Old Jan 09, 2010, 02:16 PM
weisenflymanheimer
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Crested Butte, Colorado
Joined Dec 2007
1,188 Posts
on 48" wings we set the elevator throw @ 25% low rate the aileron much higher even on the high rate too .

you probably have to much elevator throw
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Old Jan 09, 2010, 05:01 PM
a.k.a. Matt Nelson
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North Tustin, CA
Joined Oct 2008
1,752 Posts
Maidened mine today. First gentle toss nose-dived immediately to the ground. "Ah yes. I remember that from trimming my combat wing...". I gave it a healthy amount of up trim and tossed it again - airborne, but all over the place. At least I could get it up in the air and start figuring out the trim.

I spent an hour or so tossing, trimming, tossing, trimming. I had a lot of expo initially, but got rid of most of it as I found better trim. I also reduced my throws way down - these things are crazy sensitive to elevator. I got it to the point where it kind of launched OK (tends toward a big loop so I need to jump on the stick quickly), and cruised OK. Never got more than 30s or so out of a flight - but that's OK.

I still need to tweak it - it needs more aileron authority and perhaps even less elevator.

I've attached a picture of it after it's last landing of the day. Those of you who have flown at ElDorado Park in Long Beach will immediately recognize the conditions... Why do all my ground landings seem to find gopher mounds?
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Old Jan 09, 2010, 06:12 PM
Registered User
R/CDragonfly's Avatar
Kailua, Hi
Joined Jun 2004
114 Posts
Hi Shamberlin,
You will find it much easier to trim your elevator at the slope. Trim it to fly fast and when you throw it at the flatland it won't pull up so hard and give you a little time to push over at the top and prevent a stall. If the plane is too nose heavy, the faster it flies the harder it will pull up and the speed of a hand launch will make it loop or stall. Keep your turns very flat or the Alula won't fly long from a hand toss. Also control your speed with your elevator very carefully.
My fuselage broke like yours and I squeezed goop into it and it feels strong.
Last week I flew mine in about 5 to 7 MPH wind at a slope and found that the Alula can DS! It just did it in about 8 foot circles very fast. WILD!
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Old Jan 09, 2010, 06:21 PM
Twisted and Confused
flyonline's Avatar
Joined May 2003
4,295 Posts
I've got mine balance just on the back of the dimples and have the elev movements at about 3mm each way.

I've also dialed in a tiny (one click) of down trim that I have on a switch that I launch with, then click over to the up trim state immediately after flattening out as I had trouble getting a good launch without it. I can also use this as a 'come home' switch if I hit sink or a strong wind.

ANY moisture on the surface of the wing will kill lift straight away as there are many drops screwing up the nice clean air flow which kills efficiency - this is true of any plane from a $$$$$$$ mouldy to the cheapest foamy. And you risk the danger of damaging your electrics, not worth it surely?

Keep persevering, they really are a cool little plane.

Steve
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Old Jan 10, 2010, 06:27 PM
Steve Chamberlin
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Bay Area, CA
Joined Oct 2009
121 Posts
getting better

Thanks for the suggestions. I'm making some progress... I changed the elevator trim to be a bit more down, which seems to have helped. Now the plane launches at a shallower angle, but retains more speed and actually attains a higher final altitude than before. I threw for about 30 minutes, and didn't have any disastrous stalling incidents, and only a couple of hard crashes onto the nose. CF reinforcements to the nose seem to be working to prevent any damage. I'm still not having too much luck steering the plane where I want it, but I feel like I'm improving at least.

I'm at 20% dual rate for elevator, 60% for ailerons. That translates to about +/- 2mm of travel for elevator and +/- 7mm for ailerons. I've also got 50% expo on both.

I haven't been able to experiment with moving the CG around yet. Removing the belly skid, shifting the weight, and retaping everything is like a 10 minute exercise. Next time I go, I'll try taping a penny on the top with painter's tape until I get something I like, which I can adjust much more quickly. Then I'll measure the final CG point, and try to replicate it by moving the nose weight around without the penny.
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Old Jan 10, 2010, 07:06 PM
Twisted and Confused
flyonline's Avatar
Joined May 2003
4,295 Posts
Sounds much better! Just watched your video, and yes that looks like way too much up elevator. At 0 trim, mine flies with the nose just pointing down, notice how yours is always nose up. Flying with up elevator doesn't always give you the best flight times/glide path. If you're constantly flying right at the edge of the stall (as you were) then efficiency isn't good as you will sometimes go into the stall (as you noted) and lose all that lift and it will take more energy/height to recover (the nose dropping).

A coin moved around is a great way to trim, remember though that it will need to be moved in tiny increments!!!! Do you guys have blu tak in the US? That can easily hold a coin on the bottom of the plastic skid, or as you say some tape.

With regards to the plane always turning at launch, does it do it under a normal javelin launch, or only with a SAL? It may just be your technique, e.g. rolling your arm/dropping your wrist as you let go.

A tip I always use for trimming/cg-ing planks. A forward CG flies badly, a rearward CG flies only once

Steve
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Last edited by flyonline; Jan 10, 2010 at 07:13 PM.
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Old Jan 10, 2010, 08:24 PM
Steve Chamberlin
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Bay Area, CA
Joined Oct 2009
121 Posts
Just want to clarify: that video isn't me or my plane. It's a random video I used to make a point about stalling. One of these days I'll get a video of myself.
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Old Jan 10, 2010, 09:11 PM
Twisted and Confused
flyonline's Avatar
Joined May 2003
4,295 Posts
Quote:
Originally Posted by schamberlin View Post
Just want to clarify: that video isn't me or my plane. It's a random video I used to make a point about stalling. One of these days I'll get a video of myself.
Ooops, my bad sorry
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Old Jan 10, 2010, 10:02 PM
Throw it like you hate it
RCPC's Avatar
United States, CA, Castro Valley
Joined Apr 2007
3,060 Posts
Quote:
Originally Posted by pivlrs View Post
I've attached a picture of it after it's last landing of the day. Those of you who have flown at ElDorado Park in Long Beach will immediately recognize the conditions... Why do all my ground landings seem to find gopher mounds?
Hah! i did the same thing when i brought mine out to eldo. it went from a nice clean, white plane to brown in a split second. bring yours out to the Erikson Memorial. we will throw them around at lunch and after the contest. i love the paint scheme!
cheers
paul
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