RE: Spark F3A, from Krill Models - SPAIN TEAM
 

I am rekitting a used Spark Dynamic so I also came along this design fault. I would think in normal flight this should not be an issue; however if you snap it's a different story I think.

What kind of snap settings (deflection in degrees of each surface) does one typically use for rudder and elevator?

Volkert

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

This is a modification that I've made to my Spark Dynamic. I've seen in done by a few fliers and my hope is it will add some yaw stability.
Also I'm using a new prop designed by Hatta from Japan. Hatta is using the Hacker Q80 as am I. The prop size is 19x12.5. I replaced a Rasa 20.5 x 14 and I really think this prop is a huge improvement. With this prop I get better braking on downlines and its a tad slower on the flats which I needed to have happen. The pull and climbing strength are equal to the Rasa.
Best improvement is my routine is using about 5 to 10% less mils from the pack on avarage. Before a routine would use 3900 to 4000 mils now I'm avaraging 3600.
I've yet to try the new stab fences but hopefully I'll get to test it today. Mike Mueller

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

today I lost my Spark Dynamic! [:@] This is really a bummer since the plane flew so well!!!

I just wondered if anybody had a similar failure. The wingtube broke out of the right wing completely during the P011 figure 1 (M). Please let me know.

PS: I don't blame Krill or anything, I am just curious since I haven't heard about such failure.

Volkert

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Hi Volkert,

That really sucks mate!

I've not heard of such a failure before. On my 2008 Spark I did a small cart wheel on landing in extremely strong wind. It happened as a strong gust got the model airborne again and there was little I could do. This particular field is like landing on an aircraft carrier. There is a 20' drop at the end of the runway! Needless to say, after my flight the comp was called.... Anyway, I thought the worst (and so did others) but when we got to the model there was only minor damage. One wheel pant was damaged and the wing TE had punctured the fuse a little. Upon further inspection, I found the glue joints on one wing tube socket had fractured. It was easily fixed and the model is still carving up the sky.

Can you post some pictures of the failure? Pictures tell a thousand words....

I'm currently building (assembling) a Spark Dynamic. Progress is slow but I will finish it soon....

Cheers,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Don't know if this picture tells it; the only thing you can clearly see is that the outer tube is just completely gone, ripped out of the wing.

Volkert

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Hi Volkert,

I'm amazed at how the root rib has shattered like that as it's glassed both sides. [X(] As I stated, I did a slow speed cart wheel with my Spark and it didn't damage the root rib at all....

I note that your aileron linkage is broken. Did this happen when the model hit the ground? Might be a clue....

Regards,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

I think that happened at impact. However, you never know.....

Volkert

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Seems the side of the fuse gave in as the wing retaining nut is still on the wing.

Sorry this happened.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

The wing tube mounting would have had to have failed in the wing for that to happen.

Volkert, what happened to the front wing mounting screw?

Did the wing tube break?

Cheers,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

A piece of the fuse is still with the rear wing mount screw, if you look that area carefully. To save weight, the wing mounts are just two thin pieces of plywood glued to the side in a E-power plane. The area has to be strong enough to withstand the pull from the two wing halves.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

There shouldn't be any forces on the two wing retaining bolts. The ply rings are quite adequate and don't forget the wing adjuster aft of the rear bolt. The tube and socket should take all the stresses and loads. Having said that, the tube and socket on the Spark is very short. It must be adequate though....

If I had to put my family jewels on it, I'd say the wing tube socket mounting has failed on the outboard end. It actually looks like the wing has split apart on the LE join and then the skin peeled back.

I'm curious to know where the front wing bolt and root rib is...

Cheers,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Actually, the more I look at the picture, the more it looks like the LE glue joint has failed. It almost looks like the glue has not adhered to the top skin.... If that joint had failed, the whole wing integrity would be compromised..

Cheers,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

well, I had one more (and final look) into the garbage can.

To answer some questions:
- the other wing retaining bolt was found broken off in the fuse
- the wing tube is still in one piece
- the outer tube of the broken wing I found with the fuse but it was broken in two (split down the length). The actual outer tube is very thin but still not easy to break so that is interesting
- the aileron was seperate of the wing when I found it

Jason, you triggered some thought with me. Maybe the aileron linkage broke, the aileron started fluttering which caused the wing to go???

Volkert

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Hi Volkert,

Flutter is what I was thinking with the linkage breaking. The fact that most of the wing looks intact is a clue. It's hard to tell from the picture but it looks like you're using the glued carbon/titanium linkage set-up. If this is the case, did it break on the glue joint or at the end of the titanium insert? It also looks like the kevlar hinge has separated. hard to tell from the picture but the outside end looks unusual.

Splitting the wing tube socket sounds strange. Can you post some pictures?

I'd be contacting IVO about this if I were you. He may be able to offer some insight and in all honesty, if there's a problem, he needs to know...

Regards,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

all that was left is now in the garbage and I don't really want to look at it anymore!!

The Spark Dynamic is a great airplane so once I have collected my thoughts again I really want to have another one! This year I have lost two planes (after 5 years without anything...), really sucks.

Volkert

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Hi Volkert,

Not only does it suck, it really hurts the hip pocket.

On the positive side, perhaps upgrade to the new Spark EVO?

Best thing to do is jump right back onto the horse.

Cheers,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

I will definitely go for a new Evo but I will first now finish this season with my good old ZNLine Twister!

I did sent a short mail to Ivo Krill, let's see if something comes out.

Volkert

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Has anyone flown the Spark Dynamic and Evo 1 to see which one flies and presents better, it looks like the dynamic has a taller canopy and is a little more forward, any thoughts?

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Hi Guys,

Well, today is the day of reckoning. My Spark Dynamic is finished ready for maiden flight. I don't expect any dramas as I have set it up the same as my 2008 Spark.

I'll post some pictures and a brief report on how it flies compared to the older Spark tonight.

Cheers,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

It should be very close! Enjoy!!!

Volkert

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Hi Guys,

The Spark Dynamic has been maidened. It was uneventful really which is good. Out of the box it needed one click of up trim, one click of left aileron and three clicks of left rudder. I have since made some initial adjustments to get all back to neutral. Only small adjustments were needed to do that. Now the real trimming starts.... On LH top knife edge there's a slight pull to the belly so the CG probably needs moving forward. Downlines have a slight pull to the canopy. Wing incidence will be tweaked to reduce that. On the old Spark I actually had 3% down elevator mixed in with low throttle. This model will probably be the same. Early days..

As promised, attached are some pictures.

Cheers,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Has anyone actually worked out what the MAC is on the Spark? With the wing's unusual shape it's not an easy calculation.


Regards,
Jason.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Seems the diagrams don't take into account the step and the extra sweep at the tip!

Where is your CG relative to the wing tube? Mine is now at the back edge of the wing tube.

BTW, I replaced the stock UC (163 grams) with that of PT model (103g). The stock gear look great but were too flexible, at least on mine. So the PT version is stiffer and cuts 60 grams.

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Anyone seal the aileron or elevator hinge on there Spark?

RE: Spark F3A, from Krill Models - SPAIN TEAM
 

Do you mean the gaps on the bottom?

Woodie