Originally Posted by Chairwolf

I guess the hollow fuse would be easier to put stuff in. However, I'm wondering if this might be a cost-cutting area. Also thinking of crash resistance. I don't have a SkyS, so I can't really criticize it... I'm just making an observation here.

Bob

Perhaps if you don't pile drive it into a mountain it wont matter.
Just a thought...

Originally Posted by 2500GENE

Perhaps if you don't pile drive it into a mountain it wont matter.
Just a thought...

Yes, Eugene, perhaps...

Originally Posted by Chairwolf

Yes, Eugene, perhaps...

That's 'Mr." Eugene to you, Bobby Boy.

Originally Posted by 2500GENE

That's 'Mr." Eugene to you, Bobby Boy.

How about "Eugenius!!"

Originally Posted by Ron RC

Ok, so it is reported that the CG is @ 72mm from LE. So I take the washers out. I could not get a decent balance (looking for slight nose down) with the stock battery all the way forward in the fuse. If I add 2 washers (taped to the battery top) I am looking pretty good @ 72mm CG. With my spare 1800mah 20c batt (which is about 1/3 longer than the stock batt) and I have it all the way forward, I am looking good. Am I on the right track? How did you get yours to balance @ 72mm with the stock battery and no washers? Something doesn't make sense. Help me out here.

Ron

Currently, I fly mine at a CG 78mm. But, I prefer a plane to be a little tail heavy for my flying style. Ok. With that out of the way, though a lot of math and then flying experience, I recommend a CG of 68-72mm (a tiny bit nose heavy) for the initial maiden (or forever if you like it). As for your situation, your calculations are where I would expect them to be and your logic is flawless. Both adding two washers or using an 1800mah 3S1P Lipo are both correct. When I maidened mine, I had the CG at 75mm (I measured it wrong-I wanted 72mm). So, again, what you are experiencing makes perfect sense to me. After moving it all around from 65-85mm, I discovered that the bench math was ultimately correct and 72mm was the optimal for everyday flying in light winds (0-6mph). I hope all this helps. It sure would have saved me a devil of a lot of time to just post the CG in the assembly instructions. Oh, currently I use a pitch gyro and it seems to fly best (for me) at 78mm (from above). However, if you want to have some safe, reasonable fun to find out what CG you like the best, put in a pitch gyro ($10-13 from EBay). Then, you can safely move the cg between 50-90mm (WOW!!) and find out what your own preferences are. Initially, I flew mine at 88mm with the gyro. Inside loops are about 16-18" in diameter. Actually, the big deal about gyros is that they take care of any gusts on landing, thereby preventing those unfortunate stalls 1-2' above the ground.
AJ

Originally Posted by Chairwolf

I didn't realize that the entire fuse is hollow! Hmmm, looks weak to me, no?

Bob

That was the first thing I noticed too. And, I completely agree. antennahead put in one more CF rod than I did and I agree with him. I put a 4mm cf rod in the antenna slot like he did (he uses a 3mm which is what I should have used). So, IMO, he did what I did a little better.
As for crash resistance, I had my first crash today - nose in. I must not have added any glue to the rear of the vertical stab and it came completed off - Read CRASH. It spun in from about 100-150' and hit some lawn (dry). To my utter amazement, the nose was only slightly crunched and the fuselage sustained no damage (just some grass stain on the nose. I hot glued the assembly back on and was flying in about 5 minutes. After I got home, I made some soup and the compression came right out and it looks literally like new. If would have hit the asphalt (about 3' away), I am sure it would have been much, much worse. I was lucky, very lucky for such a bonehead mistake.

AJ

Originally Posted by ajbaker

After I got home, I made some soup and the compression came right out and it looks literally like new.

How do you make foam "soup"? How do you apply it? How do you get the compression right?

Currently, I fly mine at a CG 78mm. But, I prefer a plane to be a little tail heavy for my flying style. Ok. With that out of the way, though a lot of math and then flying experience, I recommend a CG of 68-72mm (a tiny bit nose heavy) for the initial maiden (or forever if you like it). As for your situation, your calculations are where I would expect them to be and your logic is flawless. Both adding two washers or using an 1800mah 3S1P Lipo are both correct. When I maidened mine, I had the CG at 75mm (I measured it wrong-I wanted 72mm). So, again, what you are experiencing makes perfect sense to me. After moving it all around from 65-85mm, I discovered that the bench math was ultimately correct and 72mm was the optimal for everyday flying in light winds (0-6mph). I hope all this helps. It sure would have saved me a devil of a lot of time to just post the CG in the assembly instructions. Oh, currently I use a pitch gyro and it seems to fly best (for me) at 78mm (from above). However, if you want to have some safe, reasonable fun to find out what CG you like the best, put in a pitch gyro ($10-13 from EBay). Then, you can safely move the cg between 50-90mm (WOW!!) and find out what your own preferences are. Initially, I flew mine at 88mm with the gyro. Inside loops are about 16-18" in diameter. Actually, the big deal about gyros is that they take care of any gusts on landing, thereby preventing those unfortunate stalls 1-2' above the ground.

AJ .... Ok thanks for your analogy. I will make my maiden with the stock battery and 2 washers all extreme forward. See how I do and make adjustments from there. I did notice that before I took the washers out and using 72mm CG, the stock battery had to be way back in the hatch, actually between the ESC and rx to get any balance at all. I said WOW, I'll never be able to run my longer extra battery in this thing unless I reversed the lead end and put it in pushing towards the tail. Maiden looks a long way off as the weather here in Ohio has been really windy and stormy lately and it may be awhile before things settle down. I'll keep you posted if I ever get to the field.

Ron

Originally Posted by caboflyer

How do you make foam "soup"? How do you apply it? How do you get the compression right?

There is a somewhat long history that goes with "soup". So, I will give you the Reader's Digest version. It actually started with the Multiplex Easy Star (I have 2 of them) which is made from Elapor (a Multiplex trade name) - I think EPO is the same thing. What happens during a nose in is that the nose gets severely compressed from the inertia of the plane hitting the ground. The nose looked a lot like an accordion. Well, someone a long time ago took a pot of boiling water and put the nose into it for 10-15 seconds (or whatever) and the nose decompressed to nearly the exact same shape as before the crash. Hence, the name "Elapor Soup" was born. Currently, it is referred to as simply "soup". If the foam is left in the "soup" too long, it will bubble the foam outward. But, a common kitchen spoon is all that is needed to smooth it out again. The first time you try it, you will totally amazed at how neat it works. For me, I have found that if I heat the water to only 190 degrees (using meat thermometer), I can leave the foam in the "soup" much longer and not get the aforementioned distorting bubbles in the foam. Make sense now?
The short answer - Take your crashed SkyS and break it into medium size bits. Add it to boiling water with chunks of Mississippi mud snakes in it and enjoy yourself a pot of homemade (tastes just like grandma's) chicken and dumplings.
AJ

Originally Posted by ajbaker

There is a somewhat long history that goes with "soup". So, I will give you the Reader's Digest version. It actually started with the Multiplex Easy Star (I have 2 of them) which is made from Elapor (a Multiplex trade name) - I think EPO is the same thing. What happens during a nose in is that the nose gets severely compressed from the inertia of the plane hitting the ground. The nose looked a lot like an accordion. Well, someone a long time ago took a pot of boiling water and put the nose into it for 10-15 seconds (or whatever) and the nose decompressed to nearly the exact same shape as before the crash. Hence, the name "Elapor Soup" was born. Currently, it is referred to as simply "soup". If the foam is left in the "soup" too long, it will bubble the foam outward. But, a common kitchen spoon is all that is needed to smooth it out again. The first time you try it, you will totally amazed at how neat it works. For me, I have found that if I heat the water to only 190 degrees (using meat thermometer), I can leave the foam in the "soup" much longer and not get the aforementioned distorting bubbles in the foam. Make sense now?
The short answer - Take your crashed SkyS and break it into medium size bits. Add it to boiling water with chunks of Mississippi mud snakes in it and enjoy yourself a pot of homemade (tastes just like grandma's) chicken and dumplings.
AJ

If you do use the 'soup" method be advised that wives don't consider it a great idea. If they catch you using their favorite stew pot with your plane sticking out of it in the kitchen they will voice their opinions and you may spend time on the couch.
Along with the soup plain old steam from a kettle or even careful use of a hair dryer works well. I use a cheap hair drier I got at a yard sale for 2 bucks. Under no circumstances should you use your wife's hairdryer unless you are a glutton for punishment.

Q

Originally Posted by ajbaker

There is a somewhat long history that goes with "soup".

Thanks, now I get it, one bullion cube, a shallot, 3 cups of water........

Next question. How can I repair a 1" chunk of foam missing from a wing? I tried to catch the plane, but the palm tree did instead! Reached right out and grabbed it, honest.

Originally Posted by 2500GENE

If you do use the 'soup" method be advised that wives don't consider it a great idea. If they catch you using their favorite stew pot with your plane sticking out of it in the kitchen they will voice their opinions and you may spend time on the couch.
...
Under no circumstances should you use your wife's hairdryer unless you are a glutton for punishment.

Q

So true! It's all in the timing. Wise pilot make soup while wife go shopping. Wiser pilot washes pot and put back where he found it before wife get home! Remember, remove all evidence from the crime scene.

So I stayed up late friday night to finish up the mods to my sky surfer, for a maiden today, but the weather isn't playing nice. tomorrow is looking nice , but it's mothers day, so no flying. I guess I'll just run around the house holding my sky surfer while making airplane noises...........

Anyway, here's some pics of the final mods.

GYROS??? !!!!!

Now you gonna say to the plane.. "FETCH" and it will get you birds parrots and whatever it can get from the air...

It was supposed to be an easy plane to fly.. why install gyros anw?

Originally Posted by antennahead

so i stayed up late friday night to finish up the mods to my sky surfer, for a maiden today, but the weather isn't playing nice. Tomorrow is looking nice , but it's mothers day, so no flying. i guess i'll just run around the house holding my sky surfer while making airplane noises...........
anyway, here's some pics of the final mods. :d

lol