HV Brushed Matrix? - Page 2 - RC-Monster Forums

BL_RV0 · 09.20.2008, 10:33 AM

Where are you going to get a 13t spur?

Takedown · 09.20.2008, 12:45 PM

#25 chain driven sprokets aka "pinions"- http://www.electricscooterparts.com/sprockets.html

BL_RV0 · 09.20.2008, 12:47 PM

How are you going to mount it to the centre diff?

Takedown · 09.20.2008, 12:49 PM

Should be pretty damn easy. Im most likely going to purchase an 8mm shaft of the proper length along with some 8mm beaings and grind some flat spots on it. Should be quite easy.

BL_RV0 · 09.20.2008, 12:51 PM

So its going to be a spool?

Takedown · 09.20.2008, 12:57 PM

Ill be running a 90' angled mount directly mounting to the chassis nitro engine mounts. This way it wont stress the center diff.

BL_RV0 · 09.20.2008, 01:09 PM

I mean how are you going to retain the centre diff function and have basically a pinion rather than a spur mounted onto it?

Takedown · 09.20.2008, 06:01 PM

Spur/center diff will be gone. It will be a pinion on an 8mm shaft for the center driveline. Basic easy and strong.

BL_RV0 · 09.21.2008, 01:12 PM

Quote:

Originally Posted by Takedown

Spur/center diff will be gone. It will be a pinion on an 8mm shaft for the center driveline. Basic easy and strong.

Ooooooohhhhhhh.......

Mister-T · 09.20.2008, 07:48 PM

Litlle off topic maybe
A well built brushed motor can have decent efficiency, at my job the largest brushed motor does have only 246 KW output, enjoy your torque monster :P. and the whole motor is just warm after few hour of running, however there is a permanent cooling over brush.

SpEEdyBL · 09.20.2008, 09:45 PM

Make sure your pinions gears are wide enough so the can of the motor doesn't hit the driveline. For mod 1.0 to be used and if there is 5 cm of space between the motor shaft center and the driveline you, need more than 100 teeth total (pinion + spur). For 13 and 14 tooth pinion gears to be used, your pinion gear must be at least Mod 4.0 pitch. I still don't see how you get 2440 watts out of that motor or how it will pull 81 amps. I've never heard of scooter motor making anywhere near that amount of power as the human body can easily out run and out accelerate anyone on any electric scooter ive seen and were talking less than 500 watts. I can output about 550 watts on a rowing erg which uses all the major muscles in your body and an olympic rower does about 750 watts during a race.

Takedown · 09.20.2008, 09:50 PM

Like I said before its not an amp hawg. Amps x Volts= Watts and if the motor doesnt pull any amps then its not making sufficient watts over the spool up period. The motor is all torque and if geared enough the watts will go up bigtime because of the fact that it will be trying to gain its full potential with a higher ratio which in return equals more amp draw meaning more watts. All depends on what your setup is....

SpEEdyBL · 09.23.2008, 02:07 PM

[QUOTE=Takedown;214664]Like I said before its not an amp hawg. Amps x Volts= Watts and if the motor doesnt pull any amps then its not making sufficient watts over the spool up period. The motor is all torque and if geared enough the watts will go up bigtime because of the fact that it will be trying to gain its full potential with a higher ratio which in return equals more amp draw meaning more watts. All depends on what your setup is....[/QUOTE

Higher amp draw does not mean more watts. In fact, the motor draws the most amps when its not moving or stalled, which means its making 0 power and has 0% efficiency. And as you may notice, motors have a limit to the current they can pull.

brushlessboy16 · 09.23.2008, 03:05 PM

[QUOTE=SpEEdyBL;215515]

Quote:

Originally Posted by Takedown

Like I said before its not an amp hawg. Amps x Volts= Watts and if the motor doesnt pull any amps then its not making sufficient watts over the spool up period. The motor is all torque and if geared enough the watts will go up bigtime because of the fact that it will be trying to gain its full potential with a higher ratio which in return equals more amp draw meaning more watts. All depends on what your setup is....[/QUOTE

Higher amp draw does not mean more watts. In fact, the motor draws the most amps when its not moving or stalled, which means its making 0 power and has 0% efficiency. And as you may notice, motors have a limit to the current they can pull.

That is incorrect, motor draws the most amps at startup, and because its pulling high amps and the batterys can deal with the load (no voltage drop) your making the most watts possible getting everything spinning... and for the split second where it is drawing the most amps-dont quote me on this one- but the whole motor wouldnt heat up that fast-making it more efficient.

just my dueces

SpEEdyBL · 04:35 PM

Actually what i said is 100% correct. You said it yourself. The motor is not moving and is drawing the most amps at startup. Very good. So at that very point when the motor is not moving, that defines it as doing no work, thus not making any power. And Power = Work per second, Work = Force x Distance.

It takes torque to get something moving, it takes power to get it to move at a high velocity.

I don't mean any discouragement. I want to be aware that it takes more than just a typical electric scooter motor to meet the performance needs of a large scale r/c vehicle. Don't be surprised if acceleration is sluggish, and it will be no matter what motor you use if you are not using lipos.