Brushless power... How much?
 

Brushless setups are obviously very powerful, but how powerful? How much torque per-feet does a brushless motor like a CC 1515/1y produce, compared to an LRP .28 for example?

Brushless motors get full power pretty much instantly, while nitro motors take awhile to get up to full power. But I was wondering, is a brushless motor still more powerful even if you compare their power at each of their peaks? Not just from the get go..

I've seen some drag videos done here with a brushless motor. I don't remember his name, but he had a 1527 in an E-maxx, and beat out pretty much all nitro motors, including a Baja.

Also, I was wondering, if you push down (Prevent it from going forward.) on a brushless car with a powerful motor, like the CC 1515, and hit the trigger, will it just stand there and hum, or will it shatter the gears/spin?

They make alot, current equipment cannot measure what they put out. Until better equipment is made we will all be in the dark. Kinda like magic.

And bad batteries will limit the power as well.

Torque (in oz-in) at the motor shaft is derived from 1352/kv*amperage. There are a couple pages at the R/C Calc site that estimates torque.

However, under load, kv does drop due to copper losses. And amperage is dependent on load (gearing/weight/etc). So any calculated value will be approximate. I don't know of anyone who has "dynoed" their BL setups.

By the way, DO NOT EVER purposely stall a motor. When you do that, the rotor isn't turning (obviously), therefore no back-EMF (resistance). The only thing limiting current when you do that is the copper resistance of the wire, ESC, other wiring, and batteries. Theoretically, a 2200kv Castle motor will draw 3700A on 6s under stall. Of course, that won't happen because something will fry.

what you will get is something breaking or smoke from the electronics.

I realise that something would break yes, but in theory, if the electrics held up, would the motor stall/hum and not go anywhere, or would it be so powerful that it breaks part of the drivetrain. Just to get an idea of the power, you know.

And Brian, I couldn't find any info on torque estimation on the RC calc site. Do you have a direct link?

IF the electronics could hold it together, then yeah, you would probably shear everything in the drivetrain at once. :mdr:

BL can have way more power than any nitro for limited amounts of runtime, that's why the straight line speed records for all R/C disciplines (cars boars planes and helicopters) are held by electrically powered models, all the fastest drag model cars, boats and choppers (don't know of any plane drag racing going on)) that I know of are electric too.

As for what happens if you push down on a car to stop the tyres spinning and give it some welly, I have to say I've not tried it, but I guess you would likely burn out your ESC or break a drive shaft, with a MGM 12s 400A esc in a low geared scale crawler you will rip a driveshaft/dogbone to pieces but with an MM in an 1/8 buggy geared for 100MPH you will smoke the ESC. either way its not going to be pretty.

The top speed estimator has it (don't forget to enter a current draw value), as well as the speed vs amp calc. Both show the torque in the results section.

With an Eagle tree measuring current, multiplied by the voltage at that current or just using the eagle tree software to do so you can get Watts. I forget the exact number but I know it's about 750 watts equals 1 HP. Using that theory my RC8T truggy with a Neu 1515 2.5D/f on 5s lipo has pushed over 3.3 HP

Show me a nitro RC that makes that much power

7HP is the peak I recorded on the Castle Baja system so far...

What average are you getting Chris? Just wondering what that heavy beast takes to move it around!