Electrified Northstar
12-31-2015, 06:29 AM
#52
Yes, two blade APC "E" prop. 11x8
You can subscribe to Markus' propeller ecalc for about 5 bucks a year.
http://www.ecalc.ch/
He has sub menus of motors, batteries, props, and escs. Real simple.
You can subscribe to Markus' propeller ecalc for about 5 bucks a year.
http://www.ecalc.ch/
He has sub menus of motors, batteries, props, and escs. Real simple.
Last edited by Mustang Fever; 12-31-2015 at 06:31 AM.
01-20-2016, 11:06 AM
#53
Weight and balance of e-Northstar
I am to the point where I can put all of the major components and hardware of my Northstar together to get a weight (uncovered) and an estimated balance. It looks like it comes in at 5.5 lbs (with 1.1 lb battery) + the weight of covering. Does anyone have an estimate of the weight of a monocote covering + using balsa stick on the key joints? I was trying to stay below 6 lbs but it doesn't look like I will make that goal. Where should I be using fiberglass reinforcement on an electrified Northstar?
It looks like it will balance at/near the suggested CG with the battery in the forward section of the radio/ servo compartment.
It looks like it will balance at/near the suggested CG with the battery in the forward section of the radio/ servo compartment.
01-20-2016, 12:41 PM
#54
The Arrow had stress concentrations in the rear corners of the battery/electronics hatch. I reinforced that area by running the hatch rails aft about 4 inches, and making them of spruce rather than balsa as called for. You should probably get in there with some glass, too, or the weight of that pack on a hard landing will try to crack the nose off, like mine did.
01-20-2016, 01:55 PM
#55
Good suggestion. I think I have the problem partially covered since I installed a pair of carbon fiber tubes running through the radio compartment that serve to hold the battery, servos, and esc. The forward ends of these tubes are terminated in the plywood bulkhead that holds the front landing gear, which I am not using. The rear ends are terminated in the balsa bulkhead; I will need to add some carbon fiber strips above and below the tubes to spread the stress.
Any ideas on how much weight the film finish will add?
Any ideas on how much weight the film finish will add?
01-20-2016, 02:37 PM
#56
Monokote is so light, I quit worrying about the weight of it. The thing about it on a box like the Northstar or the Arrow, is it's impossible to keep tight, as the sides bow in on you with age and use. Also, it doesn't last a long time with exposure to water.
07-10-2017, 10:49 PM
#57
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I am planing to build the North Star and I liked what you did installing the front wing, can you let me know how does it work and how did you adjusted to make sure that there is not too much up or down. It looks like that you have full up when coming for landing or take off. how the airplane behaves ?
Thanks for the information.
Eldio
Thanks for the information.
Eldio
07-10-2017, 10:59 PM
#58
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My Lochstar model is (obviously) Northstar based, but with many changes (aerodynamic structural and cosmetic).
My motor is Chinese, Tower Pro 3520, 44.7 mm dia, 58 mm long, 237 g weight, Kv 1000, rated 600 watts
Turns APCE 10x5 at 13500 rpm on a freshly charged Kokam 3200 mAh 5S taking 55 amps (static) and that's just under 900 watts. It will unload in the air and as the battery loses its charge peak.
All the radio gear/servos are up front, the 60 Amp ESC is beside the battery aft of the cockpit and forward of the step, to achieve balance. The ESC has a little ex-computer cooling fan that takes a few mA from the separate radio battery, and I extended the 3 motor wires up through the fin leading edge.
Performance is like that of a good 40, rather than a howling 53. Adequate but not startling.
I expected to save weight but it has tuned out at 3250 g (7.15 lb), about the same as the IC version.
I built mine such that I could convert to an Irvine 53 with mini pipe later, but I will leave it electric for now, until something burns out.
P.S. I have just moved the Rx battery to the aft end of the nacelle/tank bay to help with balance. Now I can fit a 5000 mAh battery.
My motor is Chinese, Tower Pro 3520, 44.7 mm dia, 58 mm long, 237 g weight, Kv 1000, rated 600 watts
Turns APCE 10x5 at 13500 rpm on a freshly charged Kokam 3200 mAh 5S taking 55 amps (static) and that's just under 900 watts. It will unload in the air and as the battery loses its charge peak.
All the radio gear/servos are up front, the 60 Amp ESC is beside the battery aft of the cockpit and forward of the step, to achieve balance. The ESC has a little ex-computer cooling fan that takes a few mA from the separate radio battery, and I extended the 3 motor wires up through the fin leading edge.
Performance is like that of a good 40, rather than a howling 53. Adequate but not startling.
I expected to save weight but it has tuned out at 3250 g (7.15 lb), about the same as the IC version.
I built mine such that I could convert to an Irvine 53 with mini pipe later, but I will leave it electric for now, until something burns out.
P.S. I have just moved the Rx battery to the aft end of the nacelle/tank bay to help with balance. Now I can fit a 5000 mAh battery.
Thanks for the information.
[email protected]
Eldio
