HV Brushed Matrix?
 

Have any one of you guys ran lets say 36-48v on a 1/8 with a powerful brushed setup? Ive been thinking about doing something like this with my matrix so it will have absolute gobs of power and some good speed. I was thinking I could run a motor such as the "24v 100w black can"...
http://www.electricscooterparts.com/motors.html

on lets say 36v "2x of those"...
http://www.hobbycity.com/hobbycity/s...00mAh_5S1P_15C

and a brushed HV ESC...

http://www.astroflight.com/index.php...products_id=91


I know its RCM "The best place to be for brushless activity but I want to see how this will run. I will ofcourse be running chain drive to the center diff and a custom mount for the motor.

oh here we go again :lol:

Yeppers, I just want to see what kind of torque this thing will have because the driveline is pretty damn solid. BTW: respond on aim.

Heres what I figured...

ESC- $60
Motor- $30
Batts- $160
Custom mount- ?
Trays for batts- ?

Really not that bad if you ask me.

batts don tpush that many amps... why not just get bl

Motor wont pull any amps. Its a small Razor E100 motor. These motors dont pull many amps. Their all torque.

The only good thing about brushed is the absolute lack of any chance of cogging. But, for a given motor output, there will be more losses in a brushed setup which obviously results in lower efficiency. Not to mention brush and contact wear.

That said, those two 18v motors would have to be put in series to operate on 36v.

Other than that, it should be fine.

These motors are heard to have run up to 48v with a light load meaning 40-60lbs kids riding them. It will run 36v-48v without issues.

Im not worried about efficiency because I'd take power of runtime. I'd be happy with 5mins runtime.

hey ryan... might have found you a SIM motor..


Needs some endbell bolts but the comm is clean and brushes have lots of life in them,

74% efficiency
440kv
5280rpm on 12v. should be able to do 36 :D

Why do you think I quoted this in the first post...:no:

I think Im going to have to pass on the motor ben. It will be a amp hawg if it has 4x the kv ratings of all the other motors of the same size and I want this to be a very low amp draw setup.

Do you plan to put diff locker oil in the shocks? You're gonna need it. Its basically going to be a 35mph cinderblock.

I don't think this is going to be any faster than a stock tamiya rtr. Tell me how a 100 watt brushed motor = "a poweful brushed setup." Plain and simple 100 watts is 100 hundred watts, so even if it has 10 times the torque of a 1000 watt brushless motor, it will have 1/100 the rpm.

The 100w is rated differently than any brushless motor you guys have on the forum thats used in an r/c. Its all torque like lutach and a few others have stated before and no big amp draw so it spools up very fast and then conserves energy. So it will have gutwrenching power, and the rpm rating doesnt bother me because I have that all figured out. It will be around 4100rpm total with a 14t pinion and a 13t spur "chain driven". I already calculated all this out...

http://i301.photobucket.com/albums/n...nRCU/power.jpg

I still have to figure out what I'll be using for a mount. It needs to be somewhat light but very rigid to hold up the 4.5lb motor.

Where are you going to get a 13t spur?

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

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

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.

So its going to be a spool?

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

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

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

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.

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.

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....

Ooooooohhhhhhh.......

[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.

[QUOTE=SpEEdyBL;215515]
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

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.

Just because its a scooter motor doesnt mean it has no potential... I own a 24v Currie Phantom with a 450w brushed motor and I can wheelie from a standstill somewhat and I weigh 183lbs. A 31lb 1/5 r/c running on 36v with even a lower ratio should preform even better. It will have more torque and will have good top speed.

too bad u arent keeping the car

Oh well. Ill leave this idea up to you.

well im throwing the idea otu the window.. 1515 here i come :lol:

Lol...