brushed revo questions - RC-Monster Forums

t-maxxracer32 · 05:57 PM

hey i will be getting an e-revo with dual 700 motors and an emaxx tranny. you can see the revo here http://cgi.ebay.com/ws/eBayISAPI.dll...3063&rd=1&rd=1 i have a mm esc that i COULD use with it. i like using it withmy rusty but if i have to i guess i will use it for the revo for the time being. i will be running this setup with either 12cell or 4s a123. not sure what the dual 700s can handle.

1. any pics or anything of how to do this?
2. how do i make the mm esc cappable to use dual motors?
3. how would this setup work?
4. is there alot of maintannce with the 700 motors?
5. how will the heating issues be?
6. what can i expect for my speeds?
7. will this be crazy accelleration or good top speed?

thanks for any help!!

jhautz · 03.01.2007, 11:23 AM

I havent tried a MM with a brushed motor, but dual 700's might be a little much for the MM. Just my feeling. It would make me worry. Dual 700's will probably draw some juice!

t-maxxracer32 · 03.01.2007, 05:03 PM

metal man said you could so i really didnt know how it would work.

lets see what others say!

MetalMan · 03.01.2007, 05:53 PM

In forward/brake mode, the Mamba Max is rated at 1000amps. For comparison, the Novak Super Duty is rated at something like 400amps.

jhautz · 03.01.2007, 11:11 PM

Quote:

Originally Posted by MetalMan

In forward/brake mode, the Mamba Max is rated at 1000amps. For comparison, the Novak Super Duty is rated at something like 400amps.

1000 amps!!! Holy #@&# !!!!!!!!!! Where did you find that spec? Is there any other esc that can handle that kind of current?

If thats the case... Wire up 4 of those motors!! :018:

t-maxxracer32 · 03.01.2007, 07:05 PM

so it would work fine then im guessing?... dont know about all that amps and what not... also how would i configure the wiring? im going to be getting it soon and wanna run it!!

thanks

t-maxxracer32 · 03.01.2007, 07:06 PM

i have this parrallel series battery connector. could i throw on deans to each of the motors and use this parrallel thingto connect it all?

thx

BrianG · 03.01.2007, 07:16 PM

Just wire the + motor leads together into a Y adaptor, and the - motor leads together to another Y adaptor. How you hook up the MM depends on how you want to run it. There is a normal power for/rev/brake mode, and then hi power mode with only forward and brake.

To have F/R/brake, use the red MM motor wire and the black MM motor wire. The white is not used.

For hi power mode, you're gonna have to wire all three MM motor wires to the - motor terminals, and then the battery + will have to go to the motor + terminals.

It sounds confusing, but the MM manual has pictures which is much easier to understand.

BrianG · 03.01.2007, 11:16 PM

Correct me if I'm wrong MM, but that figure is probably the combined current handling of the FET devices, and it's probably like a "burst" figure. Of course, you have to derate that value for heat...

MetalMan · 03.02.2007, 12:13 AM

I can't remember where I that number was posted, but I'm pretty sure that is the number that was posted. Brian, I'd be willing to be this is a peak value, but comes from the "combined current handling of the FET devices." After all, the three wires that would go to a brushless motor are paralleled when in brushed forward mode :).

Tower shows the Super Duty rated at 400amps maximum.
http://www2.towerhobbies.com/cgi-bin...?&I=LXJAC0&P=7

BP-Revo · 03.02.2007, 01:40 AM

Novak GTB on Brushed mode. 1620 amps.

http://www.teamnovak.com/products/es...spec_chart.htm

But I get the feeling Novak's ratings are super inflated because my HV4.5 motor fried the ESC...and there's no way the 4.5 draws 400amps with the runtime I'm getting...

Eitherway, I'd give it a try. Just keep a close eye on ESC temps and you are fine (skyrocketing temps are a sign that the motors are too much).

BrianG · 03.02.2007, 02:24 AM

That 1620A rating has a little footnote on it: "Transisotr's rating at 25 C˚ junction temp" (quoted with misspelling and all :)). I hate it when manufacturers rate things like that. What ESC have you ever felt runs at 25˚C? And that's the junction temp, not the case temp. The junction is probably at least 10-20˚C hotter than the case and there is quite a temp derating curve on some FETs. All it does is mislead the customer with inflated specs, as you said.

BP-Revo · 03.02.2007, 03:08 AM

25*C is what, 87 degrees F. My HV-Maxx ESC ran about 100, so lets say thats 125, even 135 at the junction. Is that really going to reduce current capability much?

I assume it can hold at least 60% of its rated capability...which would still be plenty in the case of 1600amps.

skellyo · 03.02.2007, 08:12 AM

Quote:

Originally Posted by BP-Revo

25*C is what, 87 degrees F. My HV-Maxx ESC ran about 100, so lets say thats 125, even 135 at the junction. Is that really going to reduce current capability much?

I assume it can hold at least 60% of its rated capability...which would still be plenty in the case of 1600amps.

25*C is 77*F

t-maxxracer32 · 03.02.2007, 10:18 AM

sheesh confusinggggg stuff!! ill look in the manual to see if i can find the wiring stuff.

thANKS guys!