Robert Bauer

My Feedback: (1)

I know there was a wealth of information on the Excelleron 90 about a year ago, but would like some first hand info on the 50. I plan on using a Magnum 80 four stroke up front. I am sure the landing gear mount plate will be a weak point and I plan on a proper mod for it. Haven't looked at the fuel tank height for inverted engine mount, but I sure will, and realize the tank C/L must not be higher than needle valve especially with inverted engine. Any other Heads Up's or flying tips would be appreciated

rwlewis

My Feedback: (4)

It's a beautiful, extremely well built airplane...My Dad has hundreds of flights on his with a Saitio 72. I've flown throught the advanced sequence with it plenty, and it flies like a "big plane" in the way it handles, very comfortable on the inverted exits and outside stuff. It could however use a little extra power, so the 80 might be just the ticket.

He scrapped the stock linkages, and cut th e bottom of the fuse bottom open and installed a carbon fiber DEPS and CF rudder pushrod, a worhtwhile exercise IMO.

The gear has been forcibly removed from his a couple of times, but not really because it is weak, just some rough landings.

Another siginificant modification was a change in wing incidence to improve the pitch coupling with rudder. He flies with an experienced pattern guy and they incrementally lowered the TE before it really tracked well. A little extra work, but again worthehile to get it to perform like the big boys (I'll get him to comment on how much when I see him). Not really a mod that a sport flier woudl ever see the need to do, but it really made a difference for sequence flying.

Any specific questions, just ask...

Richard

Yogi-Bear

I'm building one right now also powering it with a ys .63 its a beautifully made kit, I cant wait to get this baby in the air.

snap_roll

beware of the stabiliser, reinforce well as a mate @ the field broke his elevator in the air

rwlewis

My Feedback: (4)

Hmmm...Haven't seen any stab weakness in my Dad's plane, but with mass produced items, it is always possible for there to be a bad apple in the bunch (or whole bunch of bad apples). I don't remember, but if you have to cut away the covering on the stab to glue it in, be careful not score the underlying wood in doing so. I use a soldering iron with a very fine tip to melt the covering instead of cutting it.

As for the incidence changes, they lowered the TE on my Dad's about 1/2". Flew it one day adding poscicle sticks under the TE until it flew straight with rudder. Then he modified the belly piece on the wing and the wing saddle to fit the new wing position. Not as difficult as it sounds, worth the time.

BTW - I asked him, his has easily got 500+ flights on it...[X(]

Richard

woxman

I too had a failure of the horizontal stabiliser. It fluttered in front of me. I posted elsewhere on this forum. Interetsting to see someone else has had a similar problem.

Woxman

Robert Bauer

My Feedback: (1)

Thanks for the info from all. SNAP ROLL and WOXMAN, where did the stab fail? Was is at the fuselage where some 1/4" triangle would help, or did flutter rip off the elevator?

woxman

Rob,

This is some info taken from an earlier post as indicated.



"Has anyone out there experienced horizontal stabiliser flutter on the Exelleron 50 airplane?

Yesterday I experienced horizontal stabiliser flutter, and I still have the aircraft to tell the tale. This occurred on flight number six.

I experienced flutter of the tail whilst at about 30 ft and about 100km/hr (occurred right in front of me). I managed to recover the aircraft intact (by miracle) to do an inspection. The forward and aft spars had broken symmetrically (both LH and RH side where indicated) and snapped the elevator pushrod out of the servo arm. I have attached some photos of the horizontal stab with the covering cut away showing this spar damage.

The elevator gaps were sealed and the control linkages had very little or no backlash or slop."

Regards

Wox

PS The horizontal tail structure is quite flimsy on the 50. I'd be interested to know whether this is the same design as the 90. It seems that no one has experienced tail problems in the Excelleron 90?

PS. I have rebuilt the tail, and after a dozen flights I have yet to experience flutter

Robert Bauer

My Feedback: (1)

Thanks again WOXMAN I sure will modify the stab before I fly it. Right now I think I will sheet the bottom of both sides and recover. Will add a bit of weight aft but I am sure I can balance it out with battery or whatever. Now is the time to do it.

Yogi-Bear

Did you take photos of the repair?

woxman

Here is the repair. It consisted of applying reinforcing to the forward and aft spar as shown, and then sheeting upper and lower surfaces with 1mm balsa. Note that the break was at the first rib recess into the LE and that the aft spar broke outboard. The spar reinforcing restores strength in bending and the sheeting provides torsional strength.

Does anyone know what the internal geometry of the Excelleron 90 horizontal stab? The 90 doesn't seem to have this problem?

Cheers

Woxman

Robert Bauer

My Feedback: (1)

WOXMAN: If I remember the Excelleron 90 had an entirely different vert stab. I think it had a symmetrical airfoil. MAYBE??