Help needed with electricity......

Need some help with motor selection please gentlemen......

Will be converting the Primo profile 3d/fun fly to electric. Model currently flies on Irvine 53 with west throttle pipe with an apc 12x6.

Planning to fly on 5 cells as that's what's available in the consortium (model is jointing owned!)

I'm looking at the following 3 motors as options but don't know which one would be best. Over powered would be ideal.

Model weighs 4-4.5lbs www.swanyshouse.com/primo/primo.aspx

www.hobbyking.co.uk/hobbyking/store/__14..._670kv_46_Glow_.html
www.hobbyking.co.uk/hobbyking/store/__19..._550kv_46_Glow_.html
www.hobbyking.co.uk/hobbyking/store/__19..._300kv_60_Glow_.html

Any help would be appreciated.

Thanks
Dave

Dave, I don't understand, why would you go from a power plant full of character to one with no charisma; anyway knowing SFA about leccy I'd go for the one that says 60_glow. Hope this helps.

The kV of the G60 is too low. You'd need to swing a very big prop on 5s to get the current high enough for any real power.

The kV of the G46/670 is possibly too high. You'd need to swing a smaller prop and might be disappointed with the 3d performance. This motor has very similar specs to the motor that I'm using in my Blue Angel and Chris has in his Wot4 - both on 6s and 11x8 prop. Kevin also uses this motor in his ATS Kite-like-thing, but on 5s. It will work in a 3d model but you'll have a fast revving setup.

The G46/550 might be the way to go. Reading the reviews, you'd be able to swing a big prop for loads of thrust without too much pitch speed.

YMMV, and if you get the G46/550 and it's not good...don't blame me!

Dave - One of these should be about right
(turn up the volume and put your tea to one side )
vimeo.com/52119932

Dave - What (Wot) revs does the Irvin run at with the 12x6? With 5cells (18.5volts) the kV can be calculated for similar revs with a similar prop.

With 5cells the 670kV will run at 12395rpm and the 550kV will run at 10175rpm (maximums).

From the details below the maximum power from the 550 will be 1017.5 watts and that from the 670 will be 740 watts.
The 550 gives approx 2.4 kg of thrust with a 12x6 which is just over your proposed model weight. Since this is running at 36.5 amps you could up the prop diameter and/or pitch to get nearer the maximum allowed current (55amps) and even more thrust.

Hope this helps.


PRODUCT ID: G46-550
Battery: 4~5 Cell /14.4~18.5V
RPM: 550kv
Max current: 55A
Test Data: 18.5v - 12x6 prop - 36.5A - 2450g Thrust

PRODUCT ID: G46-670
Battery: 4~5 Cell /14.4~18.5V
RPM: 670kv
Max current: 40A
Current capacity: 55A/15sec

Required;
60A ESC
4S~5S Li-Po / 12 ~ 16-cell Ni-MH/Ni-Cd
12x8 ~ 14x10 prop
Suitable for sport and scale airplanes weighing 4 to 7 pounds (1.8–3.2 kg).

Alan, Mike, Ron (and Kevin) Thank you all for your advice. I will continue to do a little more research into it but will most likely go for the 550kv.

Will update on how it goes.

Ta

Dave

Dave, always a pleasure to help.
Top tip: Velcro is often used to secure flight batteries

Another good tip for those dabbling into electrons. Don't run your Lipo packs down to zero. You do have to recharge them at some time, just like refuelling. :lol:

AlanF wrote: Dave, I don't understand, why would you go from a power plant full of character to one with no charisma?.

Actually, I suggested it