Zipper configuration

[donkboy]

I am flying a 54" Goldberg Zipper with an E-flite 25, and a 1250 mah li-po. The plane weighs 2 lbs., 3 oz. ready to fly. The prop is 11-7. Does this sound like a good set-up for nostalgia timed events? Have not entered or seen any contests, but would like to give it a try. I fly in Denver, high alitiude flying.

Thanks,
Don

[pd1]

Don, how about some pictures?

I'm using an E-Flite 25 on a 3 pound Trainermaster, I'm using a 12x8 prop.

I think you might be able to get more out of the motor with a bigger prop.
Or are you propped that way because of high altitude?

Inquiring minds want to know.

[donkboy]

Here is a pic of the Zipper I fly with an E-flite 25 and 1250 mah li-po.. I think I will try a 12" prop next time I fly to see if performance is enhanced. It flys great like it is, but maybe I can get more altitude with the bigger prop.

don in Denver

[boberos]

Nice work on your Zipper.
I have an old Comet 54" "Zipper" kit. From the 40's, I believe.
Doubt I'll ever get at it.
Bob

[Sky Sharkster]

Hello Don, Welcome to Wattflyer!
The 25 sounded like a lot of motor for that plane, so I checked the specs here;
http://www.nesail.com/detail.php?productID=4927
The motor is rated for 12 to 16.8 volts, and they recommend a range of props from 11 x 8 to 14 x 7. I would imagine the smallest props are for the higher voltages, so a 3 cell LiPo (11.1V) wouldn't get into the best voltage range. Even a 10 cell NiMh would be marginal. I'm guessing a 4 cell LiPo (14.8V) would work well, and that would fall into the middle of the prop recommendation range, maybe a 12 x 8 or 13 x 6 or 7.
This is a LOT of power and torque, it should climb very well.
Where do you fly in Denver? I've flown at the "Vintage + Old Timers" Fun Fly the last two years, they have an electric "Climb + glide" contest, great fun. It's held at the Arvada Associated Field, off Hwy 93 West of Arvada. I'm a member there, they have a separate "Electric" and Glider field.
http://www.wattflyer.com/forums/showthread.php?t=22771
Good Luck with the Zipper, it's a beauty!
Ron