12S power systems ideas and options

[Tim H.]

I just ordered one for my 3DHS 91" Yak 55. Ken has a new 175kv wind that he suggested on a ZTW esc, 24x12, and 12s. I'm going with what Ken suggests... I'll post more when I get the motor and have a chance to run up the motor.

 

[Manta]

Cant go wrong on that wind.

 

[Tim H.]

That's exactly what I wanted to hear! Can't wait to get it in my grubby mitts...

 

[skibum44]

I have the 189kV due in Monday... Will be running it with a Ice 160hv. Also, will be testing with a few props. Have a Mejzlik 24x10TH and a 25x10PJN on the way. Will also be testing with a Xoar 24x10 beach and PJN, 24x12PJN, and a Mejzlik 22x10E. Hoping to see my 91" Extra Wednesday and hope to have some preliminary data by the following weekend, maybe.

 

[Tim H.]

Keep us updated on the props! My motor should be here today but I don't have any props to test with.

 

[gyro]

I have the 189kV due in Monday... Will be running it with a Ice 160hv. Also, will be testing with a few props. Have a Mejzlik 24x10TH and a 25x10PJN on the way. Will also be testing with a Xoar 24x10 beach and PJN, 24x12PJN, and a Mejzlik 22x10E. Hoping to see my 91" Extra Wednesday and hope to have some preliminary data by the following weekend, maybe.

Bryan, I had 6000w on my mine with 24x9 Xion CF prop, and I have a 192kv wind.

Recommend you start with the PJN 24x10 before the 24x12.

 

[Aeroplayin]

That must be a round-up peak reading, right? Averaging a 20 second block of readings off the Castle logger after the first 5 seconds of WOT were burned off in static testing, we're seeing between 5112W and 5137W to between 6847 and 6877 RPMs with the 24x10 PJN, and between 5236W and 5351W to between 6657 and 6669 RPMs with the 24x10TH Mejzlik. That's with the 189Kv, and even if the 192Kv lost nothing as far as efficiency and spun these props up to 7000 RPMs, we'd still be looking at 5250W with the 24x10 PJN and 5615W with the 24x10TH.

The Q80-8M is spinning the TH a bit better than the 5335-189, but the 5335-192Kv should do the 24x10 PJN to about the same production if it can do 6900 RPMs. I think the 189 and the 192 will have a little trouble with the 24x12 PJN, and maybe the 175Kv is right for that prop. Don't know yet, but looks good on paper with the load and efficiency relative to the 189Kv on the 24x10 PJN. So I'm guessing the 175Kv with the 24x12 PJN, the 192Kv with the 24x10 PJN, and the Q80 with the Mejzlik 24x10TH should all do something around the 37 pound of thrust mark after the peak values had a few seconds to burn off.

 

[gyro]

My reading was through an amp meter on batteries charged up to at 4.15v each.
Current was measured at 135a, watts measured at 3000w and doubled since watt meter was only on one battery in the series connection.

Readings taken on full power run after 15 seconds at full power.

One reason I'm seeing higher numbers than you is I'm not using castle.

I'm running a ZTW Gecko 150a HV ESC.

 

[Aeroplayin]

You'll have to give me RPMs because I've not seen any data where batteries help 4.15v per cell under load after a little while at WOT in any of the testing we've done over the last three years. The key is RPMs and prop specs because regardless of what the different meters and logging software says, the true comparison is how fast each motor can spin the the same prop over a decent block of time. With the prop specs and RPMs, we can calculate Watts-out and make a clean comparison. Especially since you're using a meter setup different than Watts-Up, Eagle Tree, and Castle log data.

 

[gyro]

You'll have to give me RPMs because I've not seen any data where batteries help 4.15v per cell under load after a little while at WOT in any of the testing we've done over the last three years. The key is RPMs and prop specs because regardless of what the different meters and logging software says, the true comparison is how fast each motor can spin the the same prop over a decent block of time. With the prop specs and RPMs, we can calculate Watts-out and make a clean comparison. Especially since you're using a meter setup different than Watts-Up, Eagle Tree, and Castle log data.

I didn't say they held that, I said they were at that voltage prior to the run. I forgot to note the drop under load.

Voltage was taken with a standard RC watt meter that is universally used... Numbers should be identical to those taken by other watt meters.

I'll get better watt meter numbers and RPMs this weekend.