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Apr 14, 2020, 10:00 AM
Lee
Lee
PERFECT LANDING !!!
Lee's Avatar
Thread OP
Great video!!!

When we designed the Snowball we found that it was as fun on the ground as it is in the air.
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Apr 17, 2020, 06:54 AM
Light flies right!
Just finished a 20" Snowball yesterday evening. This is actually my second one; the first was a 10-incher that had Parkzone gear, and it was a blast. Like many others have done before, this new one is made of minwaxed Dollar Tree foamboard. Power is provided by a C20 2050kV motor and 2S 800mAh lipo. AUW is 230 g or 8.1 oz, so not a super lightweight but I'm happy with that since I fly in the (sometimes windy) outdoors.

Maiden went great, once I toned the throws down and added some expo. Handling is pretty smooth now, and there's no sign of it wanting to tuck at speed. At one point I think I had it doing some type of knife edge.

Thanks Lee and everyone else for contributing to such a fun design!
Apr 17, 2020, 08:35 AM
Registered User
dbacon's Avatar
Oh, Oh, Oh, teach me how to knife edge my 14" Snowball, I will be the envy of the Church Gymnasium!

The 1mm CF hoop in the front is more than a prop saver, it is a spectator saver!
Last edited by dbacon; Apr 17, 2020 at 08:44 AM.
Apr 17, 2020, 09:16 AM
Light flies right!
Quote:
Originally Posted by dbacon
Oh, Oh, Oh, teach me how to knife edge my 14" Snowball, I will be the envy of the Church Gymnasium!

The 1mm CF hoop in the front is more than a prop saver, it is a spectator saver!
I wish I could tell you exactly how I did it, but I'm definitely not a seasoned aerobatic pilot. I think I was able to do it for a split second after coming out of a hover/high alpha. I think the motor torque caused it to flop over to the left, and I was somewhat able to hold the nose up with right rudder. It did not want to stay there though. I'll have to see if I can replicate the maneuver again, and a rearward CG may help. I currently am using the standard 25% of diameter and have yet to try moving it back.

That micro 'Ball is really cute! The prop guard is a great idea too.
Apr 17, 2020, 09:22 AM
Registered User
Aereonaught, please say some more about Minwax and foamboard. Assume it's the water based polyurethane? Do you remove the paper first? Does it make it stiffer? Does it add a lot of weight?

Thanks!
Apr 17, 2020, 10:13 AM
Registered User
dbacon's Avatar
Aer0naught

Neat name... thanks for the knife edge report, I will try it next time I fly the little snowball, which might not be until this Fall. I try to get all my planes to do knife edge, most do, but my Capricorn won't and I never thought it would be possible with the snowball.
Apr 17, 2020, 10:18 AM
Light flies right!
Quote:
Originally Posted by Flyboy Steve
Aereonaught, please say some more about Minwax and foamboard. Assume it's the water based polyurethane? Do you remove the paper first? Does it make it stiffer? Does it add a lot of weight?

Thanks!
Hi Steve, I used Minwax oil-based polyurethane as described in this video from Flite Test:
Flite Test - Painting Foam Board - TIP (9 min 17 sec)


Basically, all you need to do is brush on a coat to saturate the paper, then wipe it off. The point is to waterproof the paper, so there won't be much benefit in doing it to bare foam, other than weight. Speaking of weight, I found that the Minwax coating added 4 grams to the weight of the 20" diameter disk, maybe 5 grams total to the AUW if the rudder is included. I think stiffness is about the same as before, but the paper might be a little bit tougher due to being plasticized. Definitely worth the treatment IMHO.
Apr 17, 2020, 11:12 AM
Registered User
Thanks! Gonna be doing some building this weekend! (Can't go anywhere...)
Apr 17, 2020, 12:32 PM
Registered User
dbacon's Avatar
Snowballs are great, but prop it for slow, they go wild at any kind of speed
Apr 17, 2020, 12:50 PM
Registered User
I'm kind of amazed at the stuff on OIL BASED polyurethane.

I tried the water based, and as others have found, it de-bonded the paper from the foam. (Hey, it's WATER based, and WATER lifts off the paper. Duuuuuh!)

I've always thought that the oil-based product would soak through the paper and eat the foam. BUT, if you brush it on and WIPE IT OFF like the video says, maybe ok....

Worth a try!

Steve
Apr 18, 2020, 06:34 AM
Learning to make
Quote:
Originally Posted by fossil1999
Snipped
Success! AUW is now 320g instead of 370g using the exact same electronics.
And it's even stiffer and more agile in flight than before.
Apr 18, 2020, 07:06 AM
Registered User
dbacon's Avatar
Quote:
Originally Posted by fossil1999
Success! AUW is now 320g instead of 370g using the exact same electronics.
And it's even stiffer and more agile in flight than before.

I am trying to discover what you did, the lower one looks newer because the floats have been lightened with an internal cutout.
The upper one looks newer as it has red rectangles on top that were not on the lower one.
The lower one looks lighter, no T-tail.
The upper one looks more current, as it has the motor.
So what is the answer to this riddle?
Apr 18, 2020, 07:11 AM
Learning to make
Quote:
Originally Posted by dbacon
I am trying to discover what you did, the lower one looks newer because the floats have been lightened with an internal cutout.
The upper one looks newer as it has red rectangles on top that were not on the lower one.
The lower one looks lighter, no T-tail.
The upper one looks more current, as it has the motor.
So what is the answer to this riddle?
The red rectangles were on a doubler sheet of epp that acted as the 75% step of the attempted KFm3 airfoil. I took off that doubler, and that is why the lower one has no red rectangles.

The lower one looks like it still has the doubler because the foam underneath is pristine white!
Apr 18, 2020, 07:21 AM
Learning to make
Better comparison pic.
I say that 90% of the weight reduction was from eliminating the T-tail and the magnets holding the floats on.
But I think the cut-outs in the floats make them more flexible in a nose down crash and less likely to rip the main 'circle'
Apr 18, 2020, 07:37 AM
Registered User
dbacon's Avatar
I love a good puzzle, but often can't solve them without help, thanks for the help!


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