Is 40k RPM too much for Neu?

[Thomas]

Hi there,

I've been reading about conversions and doing calculations for over a year, but now when it comes to ordering, I'd like to get some advice from experienced users.

I'm going to convert my TTR S3 to electric and have chosen 6s Kokam 2400 mAh 30C batteries. For the motor, I was set on the Tekin Neu 1509/2Y/f with 1820 kv. This will spin around 40k RPM on the straight, geared to go just a tad faster than the nitros (using truggy bevel gears).
But, Tekin is recommending this motor for 5s and the 1509/2.5Y with 1450 kv for 6s.

I'm now in doubt which motor is better for me. I thought the Neu motors could handle 40k RPM easily and since the 2Y needs less torque with the shorter gearing, should run cooler instead of hotter. I want sufficient power for racing and long run time (efficiency).

Which motor would you choose for 1/8 buggy on 6s, 1509/2Y or 1509/2.5Y, and why?

Thanks for your help.

Thomas

[scarletboa]

the genuine neus can handle 60k rpm easy. the cc/neus don't like to go too much over 50k rpm.

[Metallover]

A good effiecient rpm is around 40,000. With a neu, maybe 45,000-50,000. Anything else will probably work, but run hot.

[himalaya]

efficiency is a function to amperage, not velocity, as long as you gear it correctly to keep it working under right current region(40~70 amps most time), the efficiency would be just fine.

Neu, Castle and Medusa are all rated at 60k rpm.

[scarletboa]

i've seen a neu 1521 run at over 90k rpm. it could only run for about 2-3 minutes before it hit 170F.

[littlegiant]

Originally Posted by himalaya

efficiency is a function to amperage, not velocity, as long as you gear it correctly to keep it working under right current region(40~70 amps most time), the efficiency would be just fine.

Neu, Castle and Medusa are all rated at 60k rpm.

Every motor has a certain range of RPM at which it will run at its max efficiency.

Originally Posted by Thomas

Hi there,

I've been reading about conversions and doing calculations for over a year, but now when it comes to ordering, I'd like to get some advice from experienced users.

I'm going to convert my TTR S3 to electric and have chosen 6s Kokam 2400 mAh 30C batteries. For the motor, I was set on the Tekin Neu 1509/2Y/f with 1820 kv. This will spin around 40k RPM on the straight, geared to go just a tad faster than the nitros (using truggy bevel gears).
But, Tekin is recommending this motor for 5s and the 1509/2.5Y with 1450 kv for 6s.

I'm now in doubt which motor is better for me. I thought the Neu motors could handle 40k RPM easily and since the 2Y needs less torque with the shorter gearing, should run cooler instead of hotter. I want sufficient power for racing and long run time (efficiency).

Which motor would you choose for 1/8 buggy on 6s, 1509/2Y or 1509/2.5Y, and why?

Thanks for your help.

Thomas

First, skip the 1509 for a 1/8 buggy. Been there, done that, and got the t-shirt. It will run a little hot. not saying it won't work, but your gearing will need to be PERFECT. You are much better off with a 1512 sized can.

In my experience, I find the Neus to run most efficient at around 31,000 rpm, at least for racing. You can easily run a Neu up to 60,000 with no problems though. I have run a 1512 1.5d on 5s with no heat probelms. I have also raced that same motor on 4s (49k) with no heat issues too.

However, I have found I get the best run time when I keep the rpms right around 31,000 rpm.

1/8 scale i would run a 1515 series motor personally

Keep your RPM range close to 40k and youll be fine.

[BrianG]

I agree with the 1512 suggestion. IMO, the 1509 is really only good for the serious racer where you are running short heats (less time for heat build-up), have lots of throttle control, and want the lowest weight possible.

[Thomas]

Thanks for the replies.

Edumakated, what kind of running (track size, surface etc.) did your 1509 see and how much did your buggy weigh? Were you using a Tekno Neu or an original Neu?
My 6s compared to 4s should be an advantage, though.

Now if I wanted to get a 1512 size motor, with Tekno Neu 1512 out of stock, what would you recommend? What work is required to have an original Neu work well in a buggy?

*edit*
There is quite some information about 1509 from nmt on page 548 of THE conversion thread: http://www.rctech.net/forum/electric...ml#post4605075

I'm not sure how that compares to my situation. Our tracks might be small compared to yours, very different driving profile and low traction (except some temporary grass tracks). Plus, milder weather.

Why is 100°C (210°F) a problem? If it doesn't get over 120°C, it should be fine, I thought?

[TexasSP]

Get the CC 2650 motor if the tekno is out of stock. It basically a 1512 but made in China.

That motor on 4s will give you plenty of torque, rpm, and gearing options.

Originally Posted by Thomas

Why is 100°C (210°F) a problem? If it doesn't get over 120°C, it should be fine, I thought?

Increased wear, magnet degradation, etc.

Best to keep motors under 200F for longevity and better performance.

[Metallover]

I say about 160 is when it gets too hot. 130-140 is the hottest I would go on a run to run basis. That's how I personally think it should be,,,

[Thomas]

I got two Kokam 3s 2400 mAh 30C LiPos, a Tekno Neu 1509/2Y/F, a hardened 13T pinion, a plastic RC8E spur gear and made some CFRP battery boxes. Next, I'll machine a motor mount and rebuilt the buggy.

For the ESC, I would order an RX8 if it was available seperately, but the Mamba Max Pro is tempting. I will probably see what is available when my buggy approaches completion.

I will build this buggy on the standard chassis first, but already have some ideas for a custom-made chassis with optimized layout.