R/C Tech Forums

Sponsored by:
Go Back   R/C Tech Forums > General Forums > Monster Trucks

Reply
 
Thread Tools Search this Thread
Old 07-02-2015, 07:58 PM   #1
Tech Rookie
 
Join Date: Jul 2015
Posts: 2
Default HPI Savage Flux help!!!!!!!! Esc burns up!!!

I need help. I bought a stock Hpi Savage Flux almost a year ago, Love the thing so much fun. The trans went out, so I decided to go the alza center diff route.
I bought the kit, and waiting for it to come. I also bought Hpi vorza center diff with 48t spur, currently running a 16t pinion, also bought bigger tires 3.8" proline trenchers with Alza wheel spacers. I install all the new parts and run it. About 20 mins into it the Hpi Blur esc shuts off and wont turn back on. I figured I got about a year on the esc so it was just worn out. I bought a brand New Hpi ELC-6s waterproof from dollar hobbyz, so I installed that. After about 10 mins that esc started to smoke, melted my lipo battery case and stopped working, so I sent it in for warranty. 2 weeks later I get a new warranty esc from Hpi. I put it in and ran it on a local baseball diamond, 10 mins into the session and it burns up again, so this time Hpi want me to send the motor with the burnt up esc so they can test it. After waiting 3 wks I finally get it back, Hpi sent me a new torq 2200 motor and a new Elc-6s esc. I took it out for it first run today, at the same baseball diamond, and 10 mins into the run the esc starts to smoke and stops working. Im running the same batteries ive always ran since I got the truck about year ago. I have one set of matching Reedy 2s lipo 7.4v 5500mah 60c (one has a melted case now), and another set of matching Protek 2s lipo 7.4v 7400mah 100c. Both set of batteries hold a charge and are still fine. PLEASE HELP!!!!!!!!! I'm at my witts end at this point. I havent got to run my truck for almost 2 months now.
savagedude is offline   Reply With Quote
Old 07-02-2015, 09:18 PM   #2
Super Moderator
R/C Tech Elite Subscriber
 
Join Date: Oct 2007
Location: Rochester Hills Michigan
Posts: 7,232
Default

A couple thoughts. I don't have any experience with gearing a Savage, but in general taller tires need lower gearing (smaller pinion) to compensate and prevent overloading the motor and/or ESC and/or battery pack.

Also suggest picking up a simple and small infrared temp gauge like this one, or one of the many similar deals. When making significant changes like larger tires, or changing battery voltage, motor, even running surfaces, it's wise and easy to check temps after a couple minutes and then again a little later to get an idea where they are on both motor and ESC. Recommendations and opinions vary, different items have varying practical limits, but generally somewhere in the 160F range or lower is safe for most for reliable operation. Cooler if it can be achieved is better, but I suspect a big powerful truck is challenging to keep much cooler.

Welcome to the forum.
Dave H is offline   Reply With Quote
Old 07-03-2015, 07:51 PM   #3
Tech Apprentice
 
hobbez84's Avatar
R/C Tech Elite Subscriber
 
Join Date: Jun 2014
Location: Northern VA
Posts: 94
Trader Rating: 12 (100%+)
Default

I haven't had a chance to run my savage with the Alza center diff mod, but it sounds like you're gearing is blowing your esc. Get a temp gun, and try dropping 2, maybe even 3 teeth on your pinion.

FWIW, I plan on running 11/46 for general bashing. Using a speed calc. I would get ~40 MPH with that setup.
hobbez84 is offline   Reply With Quote
Old 07-03-2015, 10:29 PM   #4
Tech Adept
R/C Tech Elite Subscriber
 
Join Date: Apr 2015
Posts: 122
Trader Rating: 4 (100%+)
Default

first mistake, to tall of gearing... number 2, use a temp gun to determine your gearing (wouldn't have blown escs if you did...number 3 trash the castle cremations junk and use hobbywing, ive burnt up numerous castles running high gearing in many vehicles, hobbywings seem to be able to handle more current without frying. I like to bash with about a 60mph top end(I always break shit and fixing is half my fun).
wilsonj1018 is offline   Reply With Quote
Old 07-03-2015, 11:06 PM   #5
Tech Master
 
chadj1980's Avatar
 
Join Date: Dec 2009
Posts: 1,451
Trader Rating: 32 (100%+)
Default

You are way way way off on your gearing...10/48...
chadj1980 is offline   Reply With Quote
Old 07-03-2015, 11:07 PM   #6
Tech Master
 
chadj1980's Avatar
 
Join Date: Dec 2009
Posts: 1,451
Trader Rating: 32 (100%+)
Default

I can't believe you didn't have a lot of cogging on take-off...
chadj1980 is offline   Reply With Quote
Old 07-04-2015, 01:12 AM   #7
Tech Master
 
Join Date: Apr 2009
Location: Long Island, NY
Posts: 1,909
Trader Rating: 18 (100%+)
Default

16/48 with 6.5" tall Trencher X's is 65mph before factoring in any tire ballooning. If you didn't tape the inside of your tires they're ballooning which effectively raises top speed even more increasing the load on the esc and motor even more. The top speed your geared for determines the load place on the esc and motor, the higher the load the higher the amp draw.

Now if you were geared for 65mph on 6s and only doing speed runs (speed runs entail cool down time between passes) you'd be ok. But 4s doesn't have the oomph to push that gearing even for speed runs on pavement let alone continuous off road running.

Chadj1980 has it right, drop back down to 10/48, maybe 11/48 if motor and esc temps check out. That 10/48 is 40-45mph depending on the exact amount of tire ballooning and temps should be fine. I say should because you never know and because you may have cooked the motor. In my experience the 2200kv will stay in safe temps on 4s when geared to about 50mph depending on vehicle weight and terrain. For a monster truck 45mph is more likely the limit. But I'm almost positive that with your current gearing your motor went above 180F and once you go over 180F you run the risk of demagnetizing the motor magnets. Once that happens the motor loses power, draws more amps than it should and just runs way hotter than it should. Drop down to 10t pinion, get a temp gun and cross your fingers.
__________________
LST XXL Castle MMM 1717 custom E-Conversion / TLR 8ight-T 2.0 Tekin powered / Redcat Ground Pounder / Traxxas Rally 1/10 / Tamiya Hornet shelf queen
Punch Control? I don't need no stinking Punch Control!!
Overdriven is offline   Reply With Quote
Old 07-04-2015, 01:25 AM   #8
Tech Master
 
Join Date: Apr 2009
Location: Long Island, NY
Posts: 1,909
Trader Rating: 18 (100%+)
Default

I'd also take a good hard look at the lipo with the burnt case. That tells me the esc shorted the battery when it fried. Batteries don't like being shorted and just because they hold a charge doesn't mean they're ok. And we already know that high of a gearing drew too many amps for the esc (and likely the motor too), it's entirely possible the lipos have been pushed too hard as well. I hate hardcase lipos because you can't accurately measure temps and it can be hard to see if they've puffed at all. But if any side of the hardcase is no longer flat it means at least one of the cells inside has puffed and you should discontinue its use. Just saying.
__________________
LST XXL Castle MMM 1717 custom E-Conversion / TLR 8ight-T 2.0 Tekin powered / Redcat Ground Pounder / Traxxas Rally 1/10 / Tamiya Hornet shelf queen
Punch Control? I don't need no stinking Punch Control!!
Overdriven is offline   Reply With Quote
Old 07-05-2015, 11:49 AM   #9
Tech Rookie
 
Join Date: Jul 2015
Posts: 2
Default Thanks for the Help

Thanks for all the help, Ill drop the pinion and get a temp gun.
savagedude is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 10:19 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net