12S power systems ideas and options

[skibum44]

How much run time are you getting out if the 6s 2600 in your extra? Also do you know what your AUW is on the extra?

I don't have a 78" Extra yet... been holding off for it to go EXP status, but I am a little impatient. Probably will get a 91" powered by the 50CC subsonic motor before I get my hands on a 78" EXP, if ever. With the 6s 2600s and my 71" Slick I get between 6:00 and 7:30 depending on how I fly... telemetry tells me when to land.

 

[wedoitall]

oh Ok I thought you were using the 2600's in your 60" Extra also.

 

[skibum44]

oh Ok I thought you were using the 2600's in your 60" Extra also.

Sorry I thought you were talking about a 78"extra with 2x 2600s. With the 6s 2600 I tend to use it as a floaty setup for the 60" extra and it is as floaty as the 57" Extra is with the 6s 2600s. I fly it around different then I do with the 6s3300s (more low and slow), flying yesterday I got 5:45 on the two flights I did with the 2600s. I usually get between 5:15 and 6:30 depending on how much throttle I use. I could probably burn the packs in about 4 mins if I fly super hard.

EDIT: Pop tops and such sure do sacrifice with the lighter batteries.

 

[Ken Man]

Motrolfly 5335 update:
Found out that these are not in the shipment coming to me today or tomorrow. I made a few small changes and that has held thing up. One of which is the prop washer, as you can see in the picture it is rather thin though it does not do much but make a template for drilling holes through the prop if one wants to and protect the prop from getting damaged by the nut. I was told it looked bad being this thin and agreed so had that changed.

I'm hoping they get sent out mid January still.

 

[3DeltaFly]

Thanks for the update Ken.

Another motor I believe there's a good market for would be one that will spool a 22x10 prop to 3000 ~ 3200 watts on 12S. I.e. for the 78" wingspan planes in the 12~13 lb AUW range. You know, for us slow-N-low 3D nuts

ByronC

 

[CanCanCase]

If only there was a 50cc airframe that was truly built for electric...

Ummm… There is!


WrongWayRC 50cc Laminar Sukhoi.
Mine sits just under 17# AUW, and is a monster with:
Scorpion 5545-150kV
Castle HV Edge 120A
Value Hobby Elite Series 6S/5000 - 40C or 60C (2 in series to make 12S)
Xoar 25x12 PJN-series

I like the setup so much, I'm seriously considering selling off my JC-60 that I was going to put in the EE50cc when I get around to building it… I fly quite a bit of 6S/550kV Motrolfly stuff, and would be VERY interested to see what a 12S/150-200-ish kV Motrolfly setup could do.

I will also say, I'm coming to realize there's a lot to be said for…. I don't know enough about this stuff to be too technical, but I'll use "EFFICIENCY" for lack of a better term… I started this setup off with 6-minute flights. After settling in on the 25x12 prop and getting comfortable with the plane, I've got my flight timer up to 8 minutes, and I've still not put more than 5500 mAh back into the packs. Granted, I'm not throwing the thing around as violently as, say [MENTION=335]SupaTim[/MENTION] would, but I think a moderately skilled 3D pilot could easily see 10-minute flights with this setup.

-Case

 

[skibum44]

Thanks for the update Ken... Now I just need to get the funds in line for a 50CC. Sooner then later I hope.

 

[Enterprise]

Cool. I really don't like profiles for some reason. I have been searching for airframes for my 20cc gassers and most of the good flying ones are profiles.

What I would like to see is a full fuse airframe that is setup to hold 2x 6S 5000s, motorbox advanced for the electric motor, and a canopy that is latches instead of bolts.

I think the 78 MXS will fit the bill for me as I have 6S 3300 and 4000s for the Laser. Still looking at the Hacker A60-8S. Ken's motor looks wonderful, but is probably more appropriate to a 12S 5000 setup.

 

[Aeroplayin]

The 150Kv is fine for the 25" prop but we've already had a 23" on the 78 Extra at the field and I still think I'd feel more comfortable on a turf runway with the 22. Not disrespecting the Scorpion, but I'd also feel more comfortable with Ken's motor swinging big props through 3D maneuvers.

As far as the EF 78 Extra 300, the 22x10E Mejzlik and PJN are really great props for the 78 Extra to 6500-6800 RPMs, which is about 3320W and 76A. I'll need an all-up weight of the 5335 motor with hardware, but if it comes in at or under 1010g, the 78 will easily stay in the 13.5 pound range. I've already had a 1007g (all-up) motor in one, so there will be no balance or CG issues. My calculations suggest 4115W and 93A at 7275 RPMs with a 200Kv version on 12S with the 22x10 PJN. Considering what this motor is really built for, it should deliver this 300 Watts per pound power on the 78 without even reaching lukewarm temps here in FL... in August. For those of us waiting for the 78 MXS, this may be the perfect available e-setup. I'm looking at 6 mins easy with only 4000mAh capcity. 2x 4000mAh should be about 1200-1250g.

 

[Ken Man]

I've done some 4330 12s motors that will run 3000 to 3200 watts.
The 216Kv with a 20x8 was hitting 72amps and 3200 watts using 2 2600 glacier 30C packs.
The 195Kv and a 21x10 would probably be the same watts. Maybe a lower Kv of around 180 would work well with a 22x10