New Neu HV Revo setup nearly complete, w/ data, pix and vids - RC-Monster Forums

othello · 10.30.2007, 08:15 PM

Great to hear that your setup even handles 12s A123. Your 1515 (1100kv) should hit around 40000rpm at this voltage (36-37V under load at full speed on concrete). Did you check your motor temperature after this run? Do you have some eagletree data of this run? I do not wonder that there is more speed potential in your HV setup. Besides ballooning of your tires and handling i think the next limiting factor would be the 1p configuration of your A123, then your ESC and only then your motor. But who needs 45mph anyway. It's a good feeling though that your setup can manage it without any issues. Others probably would have dealt with heat issues when trying to do this on 4 or 5s.

I would have loved to get a motor with a KV of around 1100. But the lowest Neu 1512 has a KV of 1400. This is why i saw rpm spikes between 42000-44000rpm in my buggy. Even if the Neu 1512 seems to do well at those rpm levels i think it would even run cooler when staying below 40000 rpm (but i don't want to run it on 8 or 9s A123 cells). I also had the impression that the motor feels torquier between 0 to 3/4 of its rpm range and then it becomes less and less (which would correspond to the typical torque curve of an electric motor). But i guess this is quite normal as air drag becomes more and more an issue at higher speeds, thus slowing down your acceleration more and more.

As soon as i have sorted out my pinion problem i will post some data and a new video with ET Data of my new truggy.

lutach · 10.30.2007, 08:50 PM

Quote:

Originally Posted by othello

Great to hear that your setup even handles 12s A123. Your 1515 (1100kv) should hit around 40000rpm at this voltage (36-37V under load at full speed on concrete). Did you check your motor temperature after this run? Do you have some eagletree data of this run? I do not wonder that there is more speed potential in your HV setup. Besides ballooning of your tires and handling i think the next limiting factor would be the 1p configuration of your A123, then your ESC and only then your motor. But who needs 45mph anyway. It's a good feeling though that your setup can manage it without any issues. Others probably would have dealt with heat issues when trying to do this on 4 or 5s.

I would have loved to get a motor with a KV of around 1100. But the lowest Neu 1512 has a KV of 1400. This is why i saw rpm spikes between 42000-44000rpm in my buggy. Even if the Neu 1512 seems to do well at those rpm levels i think it would even run cooler when staying below 40000 rpm (but i don't want to run it on 8 or 9s A123 cells). I also had the impression that the motor feels torquier between 0 to 3/4 of its rpm range and then it becomes less and less (which would correspond to the typical torque curve of an electric motor). But i guess this is quite normal as air drag becomes more and more an issue at higher speeds, thus slowing down your acceleration more and more.

As soon as i have sorted out my pinion problem i will post some data and a new video with ET Data of my new truggy.

I ran my BPP truck with 10S lipo today and it hauls. I was going to bolt my 1521/1.5Y, but the 1521/1Y is already in the truck. I will stick with a 6S lipo for now.

othello · 10.30.2007, 09:20 PM

Neu 1521/1Y (1577KV) @35-40V equals 55000-63000rpm

That is absolutely on the edge of its 60000 RPM limit. And i did worry about 40000-45000rpm ... feeling stupid right now.

So now you know how your motor operates at its limit.

lutach · 10.30.2007, 10:41 PM

Quote:

Originally Posted by othello

Neu 1521/1Y (1577KV) @35-40V equals 55000-63000rpm

That is absolutely on the edge of its 60000 RPM limit. And i did worry about 40000-45000rpm ... feeling stupid right now.

So now you know how your motor operates at its limit.

It is definitely a good feeling to know it can take it. I'm going to get some special batteries that will make my 1521/1.5Y and 1527/1.5Y do amazing things. All I can say is I'll be able to use 14S of this cells in the BPP truck, but I can go as high as 18S.

jhautz · 10.31.2007, 01:59 PM

how did you get those tapped holes like that in the edge of the heat sinks lon the MGM? Looks like a really clean way to be able to mount that thing. Id like to do that to mine to get rid of the zip ties I'm using now.

Did you drill those yourself?

Finnster · 04:27 PM

Mine came with them predrilled, I assumed for attaching the fan option they have. They are 2mm holes, so mounting it was pretty easy. I used a little piece of plastic as a slab to put the 2mm bolts thru, then I have that attached to the chassis w/ a couple 3mm bolts. Then its secure, but easy to pop out for any reason. Plus a bit of fuel tube in between for some dampening (see, it's good for something :) .)

I didn't get any ET data, I had it w/ me, but couldn't fit it in there lol. With those extra cells and the Y to connect them, it got a bit messy. Def not for everyday driving, but just to screw around with. I don't think tho I was ever able to even draw 60A as the power was just too much. I estimate it was capable of 2100W peak, but I could never put that down w/o doing a backflip.

There were few times I could bury the trigger, but that was only once it was already going quite fast, so you just wouldn't see that big power spike like on takeoff. Didn't last long either as the front came up or the truck got unstable due to the tires and had to let off.

The tires didn't balloon too bad as they are taped, but at such high speeds they don't balloon evenly and handling gets squirrely.