#35 Model Airplane Building Clinic >> DJAerotech Chrysalis 2m Electric Sailplane

[Stevephoon]

Well, did I mention that the motor was crazy strong??? The second flight I was pushing it a bit. Then.... tail flutter .... No control .... Into a tree..

If I had just thought fast enough, the spoilers may have helped. They were real effective on the maiden. The main damage is to the wing. Of course every section has issues. Not sure how to repair this much damage. So, my next question is for Don. Do you have a wing only kit? Even just the laser cut parts for the wing would be OK.

This is how it went at the flying field today. Someone disconnected their rudder in flight. (He got down OK, second flight on a new plane as well) Then two other planes went down hard and looked like mine.... Of course I was blamed for starting the trend.


Steve

Sorry, no picts of it in a tree... Just the wing damage after I got back.

[Don Stackhouse]

OUCH !!!

Well, that is fixable, and we could send you some ribs for that, but with the spar damage it's probably safer to build a new one. That right inboard panel is twisted pretty bad, and I'd be worried about other hidden damage that could show up later, usually at the worst possible time.

We do sell separate wing kits and fuselage+tail kits, each are $50. You can order them through the website.

We did it originally to help repair situations like yours, but a lot of folks like to order a full kit for one version, and a fuselage+tail kit for the other, so they can have both the pure sailplane and the electric version, using the same wing.

Very sorry to hear about your airplane-eating tree experience, but you will get it back in the air soon.

[vicrider]

oh crap! sorry to see that. I hope your first flight gave a good enough impression that you will go ahead and rebuild it.

[Dimeflyer]

That is a ruph ending to a flight , sory to see that guy hope you can get the kit for the wing and have it in the air again !!
George

[Don Stackhouse]

I stopped by Joe's tonight to drop off some tooling for a new project, and mentioned we might be getting an order for a wing kit. I don't know if we have any wing kits packed up at the moment, but I believe we have all the materials to put one together for you.

[Bill G]

Originally Posted by Stevephoon

Well, did I mention that the motor was crazy strong??? The second flight I was pushing it a bit. Then.... tail flutter .... No control .... Into a tree...

and it was the only tree in miles.
That's actually happened to me, more than once. Sorry to see this.
Proving that Murphy is really out there, the last two times I had this happen was when I actually had too little power, but tried to keep flying and should have just landed right away.

[Don Stackhouse]

Steve, looking at your pic of the radio compartment in post #221, it looks like you did not tin the pushrod cables at that end, and you also have a very long unsupported length there. Pushrod flexibility ANYWHERE, including the servo end, opens the door wide open for flutter. A lot of folks make this mistake, take all sorts of precautions at the aft end, but forget to cover their bases at the servo end. This is probably a significant culprit in your flutter episode.

[Stevephoon]

Don, You could be correct. I did tin part of the rear but not the front. I'm sure that contributed to the control problems either way. Trying to push on the flex cable while fluttering.... Not a good thing.


Now that I am over the shock and disappointment.... I have taken a good look at the wing and removed some of the covering. The main spar is cracked on the one outer wing with damage and it's shattered on the center wing on the one side with all of damage. At a minimum about 2 in of main spar would need to be replaced, and then spliced in. All of the ribs in that area are broken, the trailing rear spar is broken in multiple places and so is the trailing edge. If the main spar was not so screwed up I'd say it's fixable, but with the spar broken that bad in what I think is a relatively high stress area, at least that 1/4 of wing should be replaced. Of course that 1/4 of a wing is epoxied to the other side... And there is a outer wing with significant damage...

So I guess it's time to order a new wing.

Well it did fly for about 15 minutes. At least I didn't step on it or drop something on it before the maiden. The first flight was about 13 minutes and the 2200 mAh battery was only down to 68% charge according to my battery charger. Good long flights are definitely possible, even when there are no thermals around.

Crashingly yours,
Steve

[FishHawk]

Just wondering how much space do u need to fly the Chrysalis? Is soccer field big enough?
FishHawk

[Don Stackhouse]

Depending on your skill level, not much. Joe and I have flown ours in little league baseball diamonds, and in an elementary school schoolyard with tall trees and buildings all around (however, I wouldn't recommend doing that unless absolutely necessary, and unless you have enough power for near-vertical climbs). The area behind my house is large farm fields, gobs of room (as long as it isn't full of twelve-foot-tall corn), but the landing space in the back yard itself is only about 60' x 120'. Plenty of room, if you know what you're doing. A soccer field should be enough if you have adequate flying skills.

The plane is almost as maneuverable and can turn almost as tight as the 1.5 meter HLG version, if you know how. There are some articles in the "Ask Joe and Don" section of our website [url]www.djaerotech.com[/url} that discuss some of the special techniques for making really tight thermal turns.

However, a beginner should plan on a lot more space, and without a lot of obstructions around the edges.

[FishHawk]

What is the best way to get the proper angle when sanding the balsa block?

[Don Stackhouse]

Which balsa block?

[FishHawk]

The one next to the A rib on the inboard side of the wing . I don't have the plan in front of me so I hope you know what I mean. FishHawk.

[Don Stackhouse]

That provides a reinforced area for the forward attachment bolt if you build the bolt-on wing option.

Fitting blocks like that is a fundamental skill you will need in many future building projects. Just sand it with a sanding block till it matches the tilt in the A rib. It only requires removing about 0.022" of width at the top of the block. Get it as close as you can by sanding and trial-fitting, then glue it in place. Use a gap-filling adhesive like white glue or 5-minute epoxy, in case you don't get an absolutely perfect fit.

[FishHawk]

Thank you again Don. FishHawk

[Stevephoon]

I just received my new wing kit! Thank you to Joe and Don for getting this out so fast! I will not be able to start on it until after Christmas and the covering I used is still out of stock at HobbyPartz. The only other transparent purple/violet I see around that looks to be the same shade is Ultracote Lite, Trans Purple.

http://www.horizonhobby.com/products...purple-HANU968

I'm not sure if it's really the same shade or not, but it seems close in the pictures. I was hoping I didn't need to recover the tail that was not damaged. We shall see...

Steve

[Don Stackhouse]

Ultracoat Lite is OK for the fuselage and tail, marginally OK for the outer panels of the wing, but do NOT use it on the inboard wing panels, you could have flutter problems.

[Dimeflyer]

Fluter not god for planes , may cause wings or fusealoge to break under stress ?
George

[Don Stackhouse]

Flutter is good for flags. Not good for airplanes.

[Neko]

Don,

Can you comment on the Chrysalis compared to the Stevens Helium? The Chrysalis is half the price! May I ask what makes the difference? I've never worked with fiberglass before. Is this going to be difficult?

Thanks,

David

[Don Stackhouse]

The price is lower because we do our best to keep our products as accessible as possible, and because a long time ago (around 2007) our webmaster left to serve in Afghanistan, took all the passwords and update procedures with him, and we have not been able to update the website since then. We are presently working on fixing that problem.

We have NEVER raised the price on the Chrysalis series kits since we put them in production back in the mid 90's. We have managed to hold the price, although it's been tough. Obviously that can't go on forever, but we will do our best to keep the kits as affordable as possible.

I have not flown the Helium, but from what I hear it builds well and flies well. Just looking at the design, I would expect it to float well, but not range and penetrate as well as the Chrysalis.

The amount of fiberglass work on the Chrysalis is just a few reinforcing patches and tapes. It isn't difficult, and we can talk you through it if you have questions. There are also a number of forums (including this one) where we have covered the techniques and special tricks. It isn't difficult, and it's something that all model builders need to know how to do.

[Dimeflyer]

Neko
Don is good to his word guy !
I have seen the kits he sells they are well thought out and fly great if you are carefull in construction and fly safely !!
George

[Neko]

Ordered. Can't wait. Haven't built a plane in probably 15 years.

[Dimeflyer]

Why you wait so long guy ?
George

[FishHawk]

I'm back building the wings , which I started before the fuselage. This build is a good Winter project. FishHawk