My new E-REVO
 

First of all this is all very new to me. I have been into RC for 3 yrs & have 14 veh's most elec. anyway.
My REVO consist of: NUE 1515/1y, MM, 2- 7.4 8000mah Lipos, 2000mah Lipo to handle servo & to large fans for motor & ESC. also applied a 2700uf-25v that a friend gave me. I race this veh. it runs great and my main concern is keeping it COOL and avoid Thermal shut down. Any input would be appreciated. I just hope that my head don't explode.

Body vents, fans, caps, and heat sinks with appropriate gearing should work well.

Thanks, someone told me to get rid of RX battery & run off the main batteries. I was thinking about run time. I need 25min of run time for mains. Also thinking of adding some Caps. I whish i knew how to send pictures.

Sign upto photobucket.com.

You wont loose much runtime using the main batts for servo/Rx power, but you will need a seperate BEC to power the servos via the lipos, since 7.4v is too much, ~6v maximum really. Try BrianG's wesbite for wiring diagrams:

http://www.scriptasylum.com/rc_speed/_wiring.html

The capacitor should be wired to the esc's power wires, close to the esc as possible, + to +, - to - (in parallel).

You will also have to disable the built-in BEC by removing the redwire from the rx lead plug, and taping it back onto the lead.

Thanks for the info. Do you think that i will be alright with the set-up that i am running now. I have heard of a BEC but truely do not understand it and its function. Not to mention the wireing process. Seeing Brian G logo NO FANS makes me wonder. I just want to keep everything as COOL as possible and whats best for the truck.
I will check into Photobucket to learn how to send pics.

Don't worry about Brian- I have no idea why he hates fans so much, but they're fine. I use them on most all cars I have.

Thanks, I just read that the fans just cool off the caseings and the inturnal stays hot. The fans have to make some differance. I also thought that caps cool down the ESC. I installed a 2700-25 to my mm. I am getting ready to order a mmm to switch out the mm. Would that help in the cooling department.

FYI:

BEC = Battery Eliminator Circuit.

Basically, it does the same job as an Rx pack. Only difference being, it takes power from the main running battery or batteries, and switches it down to a useable voltage. For example, a 4s lipo pack (14.8v) down to ~6v. An Rx pack is simpler to use, but is another item to charge, and weighs more than a BEC. On the upside, an Rx pack wont crap-out and send the full pack voltage to the Rx and servos, which kills them instantly, as a few people have experienced lately...

with using the 2s lipo for you Rx I would be concerned about running the pack too low and having a potential for a puffed pack so you wont have a LVC

Lol, I simply feel fans are a bandaid approach to keeping a system run cool. Properly selected components for the application should require no fans IMO. I never run fans in ANY setup and things run perfectly. To each his/her own. :smile:

About the runtime issue: A UBEC is a switching voltage regulator. So, even if you are pulling 1A average at 6v to your servos, that is less than 0.5A from the actual batteries. Considering most MTs pull an average of around 13-15A from the batteries, an extra 0.5A will not noticeably affect runtime. If you get 20 minutes runtime with 5Ah batteries (15A average draw), running a UBEC with the same setup will reduce runtime to 19.35 minutes (assuming a 1A average servo current draw). For the mathematically challenged, that's a loss of 25 seconds of runtime. :smile:

Thanks Guys. as far as rx lipo pk. i have the H O lipo regulator. i thought it has a cutoff on it. Not to mention that i check & charge my bats way to often. i would really like to stick with the rx pk. As far as my extra 2700uf-25v cap. leave it or replace it with 3 small ones as Brian sug. BrianG great to hear from you. i app. your input and the way you make things look easy. As far as run time which is also a main con due to racing. I went to a page that had run times and saw a set up close to mine. can u var my time using 2x7.4 - 8000 max amps & 1515/1Y give or take 25sec or so.

What happens to the internal bec when you you plug in an rx pack. Does this automaticly disable the bec in the esc or do you have to cut a wire some where?

You have to remove the red wire from the rx lead, otherwise you end up with 2 power sources feeding into the radio and servos. Just pull the red wire form the plug, and tape it back onto the lead for future use.

Thanks Neil. I wish I knew what I was doing. I'm sending this E-revo to my son whom is stationed in England, for bashing and racing and I trying to make it as reliable as possible. He is searching for a track near Lakenheath. My Neu came today and I forgot to order bullet connectors. I guess I will test my crappy soldering iron to heat these monster size wires or I will be heading to the hobby shop tomorrow to purchase a Hakko soldering station so I can hard wire it.

Friend of mine said the same thing so he removed red wire for me. Crazysavage as far as durabilty & reliably. I have had my E for 1 month and run it and race it VERY HARD!!!!! Problems Sway Bars keep popping off (which are opp.) eyes are to tight, and striped Srur gear due to motor mount screw being to short and striping out. I purchessed a steel robinson racing TMaX 68t Spur & used a screw the lenghth to reach the end of the new motor mount / blue lock tight. Hoping my problem will be solved.