Speed Calculator

[whitrzac]

Originally Posted by BrianG

Thanks, I'll put that in my next update...



No problem! And thanks!



For the price, a 60mm or 70mm Medusa is better IMO.

not when you picked up a working motor/esc combo for $25...

[SnoopMaxx]

I love your site and use it almost every

[BrianG]

Latest update:

- Added Traxxas Revo and Jato shock values.

- Added Novak HV motor data.

- Added the motor style/size to the brushed motors.

- Added Castle Creations Mamba Max 9000kv motor.

- Added Castle Creations Mamba Monster 2650kv and 2200kv motors.

- Added new feature to the Power Calculator page. Once the user enters the data into the form and calculates the power figures, it will also provide a table listing estimated runtime figures when using the same pack capacity at different voltages.

[mikey09120]

anyone have the mini e-revo and e-slayer tranny and diff ratios?

[Metallover]

brian- that runtime feature will be awesome!!

And is it just me or do I not see 2.2 truck gladiators?

[trev3813]

Originally Posted by Metallover

brian- that runtime feature will be awesome!!

And is it just me or do I not see 2.2 truck gladiators?

You don't. I looked for them the other day for my friends pede. i just used dirt hawgs.

[Metallover]

Originally Posted by trev3813

You don't. I looked for them the other day for my friends pede. i just used dirt hawgs.

Seems like most of the offroad 2.2 truck tires are 4", which is what the gladiators are. Some people don't know that though.. Maybe Gladiators can be put on the list for the next update?

[blueb8llz]

what motor should i pick if i had a traxxas velineon motor. its the one that comes stock with the vxl slash.

[BrianG]

Another update:

- Added Ofna Jammin CRT.5 shock values.

- Added 1/16 Revo and Slash (VXL) tranny and diff ratios, and the spurs. Not positive if these ratios are 100% correct, but I believe they are. I looked at the exploded diagrams at the TRX site and counted teeth. Also, I do not know the pitch value for the spurs.

- Re-added code to the "Lithium Battery Chargers" page to auto-fill the various values (max amps, max cell count, power limit, and efficiency). But, no other data was re-tained (such as other features).

[Semi Pro]

keep up the good work BrianG

[SnoopMaxx]

Your the greatest Brian

[Metallover]

I'm trying to figure out the amp draw I'll have in my crt .5. I'll have the medusa 3300 (.007ohms) and I want to know the amp draw for 3s and 4s lipo.

I went to the ohms law calculator and plugged in the numbers. I got like 2,000 amps and 30,000 watts. What am I doing wrong? Is ohms supposed to be in micro-ohms or something?

[brushlessboy16]

to find amps use this...

http://scriptasylum.com/rc_speed/_power.html


On the speed calculator the output power is dependant on the amperage you put in...

[Patrick]

Originally Posted by Metallover

I'm trying to figure out the amp draw I'll have in my crt .5. I'll have the medusa 3300 (.007ohms) and I want to know the amp draw for 3s and 4s lipo.

I went to the ohms law calculator and plugged in the numbers. I got like 2,000 amps and 30,000 watts. What am I doing wrong? Is ohms supposed to be in micro-ohms or something?

Motors don't have a constant resistance while running.

[BrianG]

Sounds like you are using the motor's DC resistance value, which is very low.

For simplicity, let's assume the PWM switched DC output of an ESC is AC, because it is.

A coil, being just a relatively short piece of wire, will have very low resistance. But, as soon as you use AC voltage to drive it, the alternating current causes a fluctuating magnetic field to form which counters the current. This looks like resistance to the supply because it is opposing. The amount of this resistance, called impedance, will vary with frequency, specific coil, and mechanical load placed on the motor. This is why getting a current value is near impossible.

The best you could do is get a runtime measurement based on your current setup, and calculate the average current draw using runtime and pack capacity used. The peak or burst current will be around 6-10X that value depending on drivestyle, esc settings, etc, but it gets you in the ballpark.

Or, use the following page once you have that data: http://scriptasylum.com/rc_speed/_power.html