Neu motors

[glassdoctor]

Well... I met BrianG today at the track. It was kinda hectic so I didn't get to talk with him too much and I didn't get to see his Jato. Next time...

I just got home from from the trophy race. I got 2nd in truggy and broke my buggy and got 9th.

Bummer is that the weekend did not go as planned and I did not get the testing/feedback I was looking forward to from my setups. It was all I could do just to get the cars on the track etc....

Long story short(er)....

I had one run where the Mamba got very hot , when I geared the truggy higher and had no fan on the esc. Mamba hit about 230, and after the race it was acting funny and I think it thermalled... but only after I was done and stopped for a second... then it wouldn't go. I think the gear mesh may have been a little tight. I geared from a 12T pinion to a 14T. The truck was very fast with the gear change....

But I geared back to the 12T for the mains just in case the mamba didn't like it. Mains were shortened to 15 min due to weather... I got 2nd from last place start (missed quals) and motor was 175... mamba had a fan on it and was under 100 by the time I got to temp it. Probably was higher while racing.

[glassdoctor]

I have to charge up the battery and see how much juice it used in the 15 min race. I'm guessing not much :) these motors rock...

[BrianG]

I must admit it was neat to hear all those Nitro "mosquitos" buzzing around the track, and there came glassdoctor's blessedy quiet and pollution-free truck tearing up the track. :)

I was able to get a look at two of his trucks and the tiny Mamba Max looks funny in those large vehicles. Seemed to run very well though.

[glassdoctor]

Just charged the pack from the truggy.... guess how many mah the ICE put back into it after a 15 minute main... including a couple warm-up and "victory" laps?

Just over 3600mah. Cool. I never would have thought that's possible with a 11lb+ truck.

So I could easily run a 45 minute main at that rate with the 12000mah pack and a 30 min main on an 8000 pack.

I can't wait to try gearing up again and see what difference that makes to motor temp and runtime.

You got me excited about the Mamba Max/ Neu motor setup. I spent most of the day working on my Hyper 7 making a new top chassis plate to hold the MM and the other electronics. I hope this is the last top plate I have to make for a while. I've set it setup with a fan on the ESC and one on the motor just for good measure. I'm happy with the way it looks. Took it for a quick run on the back yard grass just to make sure it works. Can't wait to get it out in the dirt.

-Cartwheels/ aka Muck

[glassdoctor]

sweet... what motor is in it?

I've got some pretty aggresive tires on it so I went with the 1515 1.5Y It was hard to decide which one to get.

I misspoke, I have a 1515 1Y. Also, I'm running 4s, 6400mah UBEC and MM.

I ran the setup over the weekend. It works pretty darn good. Temps were good. I had a fan on the motor and the blades flew off. I had to stop to fix the bare wires. Then ran for another 12-15 min. Motor was at approx 150*F with no fan, MM was at about 125*F with a fan. Outside temps was about 91*

The Mamba Max is amazing. The Quark would have overheated. The MM does have more of a punchy feel. My gearing was 12/51. It may be geared a little low. Top speeds weren't bad, but it felt like I could go up a tooth on the pinion. I've run 4 other ESC in this buggy. All in all the MM is a very good way to go. I like how easy it is to progam and the fact that you can have custom cut off for the Lipos. If the Quark didn't thermal it might be up there too.

Glassdotor, I'm glad I took your advice!

Cartwheels/Muck

[glassdoctor]

Sweet.

But did you run the Neu with any other speedos? That's the part I don't know yet... can the MM handle the other motors or is it just that the Neus are that efficient???

I'm having a hard time making the effort to put the old motors in my buggy to try it.... guess I should just so I finally have the answer....

It's got to be a little of both. Now that it's working good it's hard to go back and try other stuff that didn't. I did do some work on my Quark and I will try it out with the Neu motor. It should be able to handle that but It might be a couple of weeks!

[Finnster]

I'm glad to hear others aer having good success w/ the MMaxs, I've been running mine now for ~month with great success. I was getting high temps w/o a fan, but with a 12v 40mm fan (on 16.8v) I wasn't breaking 120. I just switched to a 5v 25mm fan running off of the 6v from ubec. Obviously a lot less airflow. I was running through the grass about 10 min and it hit 130.

What fans are you guys running? I'm hoping to 25mm will work, but if I need to go back to the 40mm its ok.

The biggest prob is the motor heat. The 8xl (15/51) on 14 cells gets upto 150 routinely, and was ~160 in the grass run. Its still ok, as I don't race, but I'll have to keep an eye on it. The neus sound great. I may look at one next year and maybe they'll have enclosed ones by then.

[neweuser]

Actuall, regards tot he fan. a 30mm 5v will push more air than a 40mm 12v. The 12v fan is not getting the full juice it needs unless you run it off the batts. i would go 30mm. i run two on my quark and they really MOVE!

[Finnster]

Originally Posted by neweuser

Actuall, regards tot he fan. a 30mm 5v will push more air than a 40mm 12v. The 12v fan is not getting the full juice it needs unless you run it off the batts. i would go 30mm. i run two on my quark and they really MOVE!

The 40mm was running off the batts (16.8V.) It def moves a lot of air, sounds like a tornado, but i worry about the lifetime running it at that high a voltage. I want to stich to the 25mm 5v fan for 2 reasons: The 25mm fan mounts neatly on the esc' heatsink and the ubec provides a steady 6v power source (close enuf to 5V) rather than sending ~20V full charge to a 12V fan.

[BrianG]

If you're running 20v to a small fan, which probably pulls no more than 300mA (most likely ~200mA), you could use a 12v regulator. Power dissipation will only be 2.4W or less. It would need a heatsink though.

Using the 5v fan is fine on 6v though. If you were really concerned about overvolting it, just run a diode in series. The 0.6v-0.7v drop will bring the voltage even closer to 5v.

[Finnster]

Originally Posted by BrianG

If you're running 20v to a small fan, which probably pulls no more than 300mA (most likely ~200mA), you could use a 12v regulator. Power dissipation will only be 2.4W or less. It would need a heatsink though.

Using the 5v fan is fine on 6v though. If you were really concerned about overvolting it, just run a diode in series. The 0.6v-0.7v drop will bring the voltage even closer to 5v.

Yeah I thought about doing that if the 25mm doesn't do a good enuf job, but I wasn't excited about having to add more clutter, plus I wasn't sure at what point I'd need a HS.

The good news is I ran 3 pairs of packs yesterday and the temps on the esc stayed low. Max temp was less than 125 on the HS (generally in 1teens tho) and max of 135ish on the caps. The drawback to the 25mm is its not blowing on the caps so they are running hotter than before, but still well in spec. The bad news was the motor peaked at 165+ after ~45 mins of hard running on the dirt (jumps, high speed runs, powerslides, climbing and other bashing goodness.) The HS was only getting to ~125, so I'm worried poor contact may actually be insulating the motor some. Had a blast tho. :)

Strangely, the rear steel output shaft for the tranny got to ~165. :013: I was careful to have the drivetrain freespinning when I built it, and had to do a little chassis trimming for the shafts. I did notice the shaft moving a bit under high throttle, so I'm thinking a bearing is busted. I do not see any signs of wear between the chassis and the driveshaft. Hopefully addressing these two issues will bring down the heat some, else I may be looking at a Neu sooner than later..