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Tilman Baumann

Staufenbiel Challenger 2.4m

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Tilman Baumann

I got a new toy.
 
Staufenbiel CHALLENGER 2.4m
 

With powerful Himax motor with propeller and alu-spinner

The CHALLENGER is an allrounder with flaps.

The model is ready built and has the high degree of prefabrication which is known by EPSILON and SPIRIT. The fuselage is made of fiberglass and has already been painted. The wing is a balsa sheeted styrofoam construction that is covered with ORACOVER. The model is made for allround flight with a mixture of light aerobatics and thermal floating. With its flaps the CHALLENGER can be adapted perfectly to different flight conditions and because of the possible butterfly mix, landing is very easy.

 
http://www.modellhobby.de/Models/Modelplanes/Electric-glider/CHALLENGER-2-4m-with-HIMAX-motor-alu-spinner-prop.htm?shop=k_staufenb_e&SessionId=&a=article&ProdNr=0314067M&t=3&c=31&p=31

 

 

The build is quite straight forward. But I will make a effort to point out the few quirks I discovered. Especially since the manual is German only.

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Tilman Baumann

Servo frames

 

Staufenbiel supplies nice plywood servo frames. Of course they are unlikely to fit the servos you where planning to fit.

 

I did not have the budget to buy their brand of servos. But if you would you would of course get a nice convenient option like that.

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Tilman Baumann

Multiplex Uni-Lock

 

Staufenbiel says in the instructions the wings are to be secured with the Multiplex Uni-Lock system.

But there are no pre-cut holes and no Uni-Lock parts are supplied.

 

Uni-Lock is neat, but it is really not necessary. My wing would probably stay on by friction alone. And electrical tape is just fine too.

 

So forget what the instructions say. But it's a nice suggestion. I will put Uni-Lock in.

 

9676038094_2be950f2dd_z.jpg

 

11mm hole in the fuselage. Seal Uni-Lock lug back side with tape and hold in with more tape at front.

 

9672821785_88a6f64b71_z.jpg

Smother with Epoxy thickened with micro ballons from the inside.

 

I have not done the wing side yet. It's basically a 4mm plastic pin that needs gluing in.

I will coat the lug and everything around it with release agent, press the pin in and slot the wing on.

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Tilman Baumann

Quality

 

I'm torn about the quality.

The seams of the fibre glass fuselage look terrible. There is no two ways about it.

There is a horrible brown line where the gel coat was sanded off.

 

But that is purely optical. Everything else is just top. And what should I expect for £200 plus tax?

It's all right.

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Tilman Baumann

Flaps

 

Staufenbiel must have changed the design on the Flaps but have not changed the instructions.

The instructions show control horns on the bottom for ailerons and flaps.

 

The flaps are now done differently. And I'm not sure it's really better.

There is a hole on the bottom side of the wing and the pushrod is fed through diagonally.

But they have not really thought that through. To make it work I had to bed the pushrod a lot and cut some wood around the holes in the top sheeting.

 

If you now think, "Bugger that I will just do that the old way". Well, you can't the blister servo covers for the Flaps would not fit.

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stewartg

The multiplex uni-lock seems a good idea but a google search suggests they are no longer available.

Anyone know if this is true or can you still get them, if not is there an alternative? Looks a bit like the fasteners for some loudspeaker grills

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Dave Miller

I think Stewart is right about the loudspeaker grill fixings. Could magnets be used instead although tape does have the advantage of sealing any gap.

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Tilman Baumann

The multiplex uni-lock seems a good idea but a google search suggests they are no longer available.

Anyone know if this is true or can you still get them, if not is there an alternative? Looks a bit like the fasteners for some loudspeaker grills

I heard that too. But I had no problem buying mine. (At Staufenbiel)

I also found alternatives. A US site I believe.

It's a neat system. But you really can do without.

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John T

I have the multiplex uni-lock system on a 3.6m DG600 i recently purchased and at first glance they don't appear to be up to the job....it was only when i tried to remove the wings for the first time that i found a great deal of force was necessary.

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primitivebow

The multiplex uni-lock seems a good idea but a google search suggests they are no longer available.

Anyone know if this is true or can you still get them, if not is there an alternative? Looks a bit like the fasteners for some loudspeaker grills

Hello,

 

Multilock system is still available, for example from Lindinger.at:

http://shop.lindinger.at/product_info.php?cPath=1809&products_id=45886

 

I have used it on several gliders and if used in conjunction with the plastic wedge that is supplied, taking off the wings is gradual and easy.

 

I bought the Challenger over a year ago, it was my second glider changing over from foamies.

 

I highly recommend changing the incidence of the stabiliser to neutral, as it comes with about -2º declare (equivalent to +2º on the elevator.)

 

After changing the incidence to near 0, I was able to reduce the total weight in the nose by about 40 - 50 grams.  This drastically improved the flying characteristics of the plane, allowing for a slower flight, more responsive on all controls and with out the danger of suddenly dropping a wing.

See the following videos:

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Tilman Baumann

I highly recommend changing the incidence of the stabiliser to neutral, as it comes with about -2º declare (equivalent to +2º on the elevator.)

 

After changing the incidence to near 0, I was able to reduce the total weight in the nose by about 40 - 50 grams.  This drastically improved the flying characteristics of the plane, allowing for a slower flight, more responsive on all controls and with out the danger of suddenly dropping a wing.

Will see how mine works out.

You mean if I end up trimming in too much up elevator I might have the same issue?

Will see how it goes. I don't have a pitch gauge or whatever you would use to determine that.

See the following videos:

Are those yours?

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Tilman Baumann

I bought the Challenger over a year ago, it was my second glider changing over from foamies.

PS: How do you like yours? Mine is still not fully built. I hope to get in a test flight on Saturday...

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primitivebow

With the elevator neutral, the whole stabiliser has built in up elevator to compensate the extra weight in the front.  So I just built a wedge of balsa under the elevator.  See photos of the Cougar I modified from the same company.

 

bve.JPG

 

This allows bringing the CG further back to make it fly sweeter.  Incidence meter is a good tool to have for gliders.  It makes the difference if you are a good flyer.

 

Yes videos are mine, I sold my glider a few months ago.  Only flying mouldies now.

 

I found it flew well after the modification.  Out of the box, it likes to fly fast and no sharp turns at slow speed or it will drop the wing.  Also, needs down elevator when applying motor.

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Tilman Baumann

Had the first test flight yesterday.

I'm quite happy with it.

It was a bit weak on the Ailerons. I probably gave it too much Differential. But I suppose it will always be a plane that appreciates a bit of rudder to get it around.

It pushes through manoeuvres very nice. Very nice inertia. Not a moldie, but as I hoped a good intermediate level I think.

The engine is incredibly powerfull and has no strong tendency to pitch up. Very nice.

Flaps and Crow are very effective.

But it stalls quite violently. I did not have quite enough down trim in the land flight phase which mad for some very frightening moments. It stalls hard!

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Tilman Baumann

Oh, and another thing to notice.

The servo wells are only one layer of weak wood. I would advise to strengthen the whole cavity with some glass cloth or use servo frames to spread the load.

I ripped one of my flaps servos out at the first flight.

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Tilman Baumann

Loving this model more and more. It lands so easy with the big flaps. And flies very straight and determined. (after I got the trim right.)

I removed all div on the ailerons. I get much more bite out of them now, totally worth it.

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