kraddon

Hi all I have a 3905 e-maxx with ali roll cage RPM E-Maxx True-Track Rear A-arm Conversion and 4 heavy duty shocks on the back, running maxamps 8000 mah lipos with a novak hv pro 4.5 esc and motor i get about 10min hard run time and it OVERHEATS ? I am not running in long grass only on the road and a well mowed park almost forgot standard gearing with a 12 turn pinion !
ANY ADVISE WOULD BE APPRECIATED .

happywing

The 4.5 is a very high KV motor for this application. The 6.5 or 7.5 with some aggressive gearing would run cooler. Are you using any fans?

sloppyG

the added weight of the roll cage doesn't help things either

guver

My Feedback: (325)

You have over twice the battery capacity as I do on my 4.5 hv and I get 12 minutes of hard running. I think you are geared too high and have possible battery/charger problem.

dirtpile

I also suspect that you may be overgeared. Your pinoin should be between 12 and 17 teeth. With the added weight of the roll cage you may want to stay between 12-15 teeth. If you meant to say you have a 12 tooth pinion instead of 12 turn, which would indicated that your gearing wasn't reduced from stock, then I would check to make sure your esc fan is functioning and install a heatsink on the motor. You may also want to cut a hole in the windshield of your body to let some air in.

Novak has a heatsink for that motor: [link]http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNAB1&P=SM[/link]

kraddon

Hi Dirtpile I did mean to say I have a 12 tooth pinion instead of 12 turn ,Opps, the esc fan works great and I have a heat sink on the motor, cutting out the windshield
is a great idea and have done that, still hot though have ordered some fans for motor from tower wondering if something could be faulty?

dirtpile

It's possible.

Are there any other mods, like oversize wheels, that you may have forgot to list? Also have you put really thick oil in the diffs?
If not check the wiring. Make sure the motor power wires are all going to the correct phase tab. And check the sensor wire.
If that all checks out ok then start checking the driveline for anything that doesn't spin easily. One bad bearing can be a real drag.

kraddon

Thanks for all the advise gents had another hv 4.5 system I was going to sell, looks like its going in the truck instead.
Will give it a try tomorrow ,No oversize wheels but am waiting for 17mm hex adapters to put on a set of proline rims with
crime fighter 5.65x2.68 rubber! very thin compared to standard!! Thanks again Dirtpile

kraddon

Thanks Happywing I have these coming Integy Twin Motor Cooling Fan + Heatsink Blue 540/550 from tower
Sure hope these beggars help!

kraddon

The rollcage weighs 300 grams the hex adapters weigh 5.8 grams each but the tamiya part no 9404461 weigh 2 grams each! I have taken off the rollcage and trying to loose weight, I have changed my gearing to 15/68 and is now running 147.2 F better than before cooling fan and hexes should be here next week I will post results then.

dirtpile

Good to hear it's doing better. Is this with your original system or your second one?

kraddon

Its the second one unfortunatlly Hey anyone know if those of us who have the novak hv pro system 4.5 can run these MaxAmps Lipo 5000HV 11.1V E-Maxx Pair More Information

The ultimate upgrade for your Brushless E-Maxx. This is for 1 pair of our 5000HV 11.1V lipo packs. One left side and one right side custom wired to fit the E-Maxx battery compartment. These packs are NOT for a stock E-Maxx and will only work with brushless upgraded vehicles. Will these work with our system or will it blowup?

guver

My Feedback: (325)

I use 5S in mine and according to Novak is over voltage spec. I believe that 6S would be over spec for esc and motor. Try it, let us know. Gear down some more from your current set-up.

scamblermaxx

if you are already having heat issues why would you want to increase the voltage? that will ony heat things up some more-

unless you had a different setup altogether where you could run higher voltage combined with a lower kv motor- this seems to give lower overall temps in general, but your HV system won't work in this manner.

guver

My Feedback: (325)

That's right, going to Novaks slower motor 6.5 or slower would be ideal with the higher voltage.

kraddon

Scramblermaxx I was just curious that's all and my temps are way down now, I did have a 6.5 motor but it ran for 2 days started squealing and then I could stop it spinning with my fingers so got the 4.5 mistake? I am trying to get the 6.5 fixed under warranty from a main hobbies but apparently because i am in Australia warranty is void ? I am getting the runaround from these people an getting po ed. Ill keep trying till warranty time runs out .