View Full Version : G.P. spectra motor
01-14-2006, 05:13 AM
I have a Spectra and a 30 amp brushless esc.What motor and batterys should I use? I,d like to use lipos and or nimis. Thanks!
01-14-2006, 11:38 AM
To Stroland, my recommendation for a 2 meter powered glider would be an AXI 2800 series outrunner, I'm using a 2808/16 with a 9 x 6 Cam folder on a similar 2 meter. For batteries, 8 cell NiCad or NiMh, between 1100 and 1800 mAh. You can also check the Hobby Lobby catalog, their recommendations for power systems sre pretty good. After you've picked out a motor (or several) try running the specs through
http://adamone.rchomepage.com/calc_motor.htm to help optomize battery and props. Good Luck!
01-18-2006, 08:38 PM
The Axi outrunners are great for 2M sailplanes, except that they can be a problem mounting in many 2M gliders. I had a G.P. spectra ARF that was spectacular with a Multiplex brushless with 4.4:1 gearbox and 15-10 aeronuat on 7 cells, 30 seconds to thermal territory.
P.S. if you have the ARF version the wing is not as strong as the BIY version:mad: Wing folded while spinning down from "way" too high, as I said "I had a G.P. spectra ARF"
Good luck, the Spectra is a lotta fun for the money!
01-21-2006, 01:57 PM
I have a new motor in package, see my post in "Falcon 550E", it is a Leisure Electronics setup, that was put in many two meter electric sailplanes, mine is in a kit that will be started very soon - an Airtronics Eclipse 2 meter. This is one of the later production kits and includes the improved Leisure Electronics 3:1 gearbox, fully mounted with switch installed (most will put in an ESC) and is factory test run, it also includes a K&B 13x8 folding prop. Let me know, price for all will be $25 shipped.
Only selling because I have an Astro 05 FAI, with 50 amp Electrify ESC that will be used with Lipo's. If you have any other construction or setup questions, I would be glad to answer them.
02-25-2006, 05:58 PM
You might find some useful tips in this thread.
Spectra with 7 cell subC 2800+ MAh NiMh pack weighs about 56 ounces, or about 3.5 pounds. Put in a 2 cell Lip and you cut about 8 ounces to 48 ounces or 3 pounds.
Be sure your speed control has a break or your folding prop won't fold.
When looking at motors, assuming a brushless motor:
40 watts/pound input = Adequate power
60 watts/pound input = solid climb
80 watts/pound input= very strong climb - easy on that throttle
100+ = Too much for a Spectra
Volts X Amps = Watts
So a 7 cell 8.4 V pack X 17 amps into the motor = 142 watts or about 41 watts/pound for a 56 ounce Spectra.
Do the same set-up with a 2 cell 7.4v lipo pushing 16 amps = 118 watts or 39.5 watts per pound. Lower wattage, but lowered weigh so you get similar performance. :D This set-up will likely thermal better due to lighter wing loading. It will also land a little slower.
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