ANOTHER Flux MMM goes up in flames!? - Page 3 - RC-Monster Forums

fastbaja5b · 08:51 PM

I'm yet to see a Flux esc go on 4s, but many on 6s because people read the manual, assume they need to "gear up" to a 25t pinion for 6s and then slap on some monster tyres.

I stopped running Nubz and Dirtbonez on my flux on 4s with stock gearing as it showed signs of being undergeared.

However the stockers and Terrapinz all fall within that safe 35-40mph range on stock gearing.

(Well the Terrapinz actually sit at 42mph and I don't see them balloon that often)

Unsullied_Spy · 05.19.2009, 09:07 PM

IIRC, adding voltage makes the amp draw go up unless you gear down. If you want to run those 40 series wheels with stock gearing on 4s try it but check those temps. If your ESC fan is coming on a lot, motor is getting too hot too fast, and your lipos are heating up beyond the safe limit (I consider 120 at the shrinkwrap to be the absolute hottest you want them to get) then you need to drop a few teeth.

Stock gearing, 6s lipo, 40 series, and WOT through grass you'll cook it in a matter of minutes. This may sound a bit complicated at first, but you've got to get your gearing dialed in a bit before you'll have the best reliability. On 4s lipo and 40 series I'd aim for about 35 MPH and keep temping it and go from there. Then you can step up to a 5s setup if you want more speed. Those wheels/tires weigh over a pound each so you're going to lose a lot of performance and I expect the lifespan of the differentials will be greatly reduced.

05.19.2009, 09:25 PM

idiot.....i want to slap him really badly...............

then again...i can just go to the LHS and listen to the same thing....then slap them...i guess someones getting slapped twice at the LHS tomorrow

10:31 PM

Quote:

Originally Posted by Unsullied_Spy

IIRC, adding voltage makes the amp draw go up unless you gear down. If you want to run those 40 series wheels with stock gearing on 4s try it but check those temps. If your ESC fan is coming on a lot, motor is getting too hot too fast, and your lipos are heating up beyond the safe limit (I consider 120 at the shrinkwrap to be the absolute hottest you want them to get) then you need to drop a few teeth.

Stock gearing, 6s lipo, 40 series, and WOT through grass you'll cook it in a matter of minutes. This may sound a bit complicated at first, but you've got to get your gearing dialed in a bit before you'll have the best reliability. On 4s lipo and 40 series I'd aim for about 35 MPH and keep temping it and go from there. Then you can step up to a 5s setup if you want more speed. Those wheels/tires weigh over a pound each so you're going to lose a lot of performance and I expect the lifespan of the differentials will be greatly reduced.

I"ll take that chance, monster trucks are meant to have big ass tires. I refuse to believe that 2200kv will have a hard time powering 40 series wheels with the torque that thing puts out...

Unsullied_Spy · 05.19.2009, 10:35 PM

Quote:

Originally Posted by Freezebyte

I"ll take that chance, monster trucks are meant to have big ass tires. I refuse to believe that 2200kv will have a hard time powering 40 series wheels with the torque that thing puts out...

I like big wheels as well, hence why I've still got them on my Muggy, but you have to gear down to keep your temps down and keep from over drawing.

JThiessen · 05.19.2009, 10:36 PM

Seems to me that when you ran the calculator, your balloon factor was a little low - I'd plan on .5 to .75 with those tires.
Someone else correct me if I'm wrong, but his numbers showed about 36K rpm. I try to hit the low to mid 40's for rpms.

Your right - trucks are meant to have big tires. Go have fun with it, quit worrying about everything you read. You'll find that 90% of internet posters are the one that are having a problem. The vast majority - those who dont have issues - dont bother to come on forums and read/post/learn. You've started to ask the right questions, and by using the caluculator, your now one more step further in understanding the parameters involved in making these things work, and, as we've all experienced, dont work. Everyone of us who have lambasted this guy have at one time burnt up a motor or esc or blew up a battery 'cause we did something stupid.

Unsullied_Spy · 05.19.2009, 10:41 PM

Quote:

Originally Posted by JThiessen

Seems to me that when you ran the calculator, your balloon factor was a little low - I'd plan on .5 to .75 with those tires.
Someone else correct me if I'm wrong, but his numbers showed about 36K rpm. I try to hit the low to mid 40's for rpms.

Your right - trucks are meant to have big tires. Go have fun with it, quit worrying about everything you read. You'll find that 90% of internet posters are the one that are having a problem. The vast majority - those who dont have issues - dont bother to come on forums and read/post/learn. You've started to ask the right questions, and by using the caluculator, your now one more step further in understanding the parameters involved in making these things work, and, as we've all experienced, dont work. Everyone of us who have lambasted this guy have at one time burnt up a motor or esc or blew up a battery 'cause we did something stupid.

+1. As for the last part I've cooked 2 motors, 3 speed controllers, and a lipo. Live and learn. They've all been expensive mistakes, but they help to realize what you're doing wrong and keep from doing it again. I just hope my screw ups can help someone else from making the same mistake. The most important thing is to watch those temps, if they're OK then you're not overgeared. That Neu has plenty of torque just don't be reckless with it or think it's invincible because they do have their limits.

fastbaja5b · 05.19.2009, 10:18 PM

Just as an example Nubz tyres are 146mm and Dirtbonez are 150mm in Diameter, now I found these two to be undergeared in the Flux (high motor temp, low esc and battery temp) on stock gearing, and the Dirtbonez on stock gearing calculates at 35.45mph

Stock GT-2 tyres are 160mm (6.3 inches) to calculate at 37.856mph
HPI Terrapinz are 170mm (6.69 inches) to calculate at 40.199mph

All 3 fall within the safe 35-40mph range on 4s for the Flux on stock gearing, however my experience has shown that the Dirtbonez are a bit on the undergeared side and should go up to say a 22t pinion for 38.99mph

The set up you have shown that "blew up" may be fine on 4s Lipo (38.46mph) but on 6s Lipo it's out at 57.68mph stock gearing and a crazy 72.1mph on a 25t pinion if you take the manual as gospel (which it aint)

And that's not considering the extra weight your alloy bling rims throw in the mix.

Add in a sock over the esc which resticts air flow as the fan doesn't draw air in, merely circulates what is available, I'm not at all surprised it blew up!

05.19.2009, 10:28 PM

Quote:

Originally Posted by fastbaja5b

Just as an example Nubz tyres are 146mm and Dirtbonez are 150mm in Diameter, now I found these two to be undergeared in the Flux (high motor temp, low esc and battery temp) on stock gearing, and the Dirtbonez on stock gearing calculates at 35.45mph

Stock GT-2 tyres are 160mm (6.3 inches) to calculate at 37.856mph
HPI Terrapinz are 170mm (6.69 inches) to calculate at 40.199mph

All 3 fall within the safe 35-40mph range on 4s for the Flux on stock gearing, however my experience has shown that the Dirtbonez are a bit on the undergeared side and should go up to say a 22t pinion for 38.99mph

The set up you have shown that "blew up" may be fine on 4s Lipo (38.46mph) but on 6s Lipo it's out at 57.68mph stock gearing and a crazy 72.1mph on a 25t pinion if you take the manual as gospel (which it aint)

And that's not considering the extra weight your alloy bling rims throw in the mix.

Add in a sock over the esc which resticts air flow as the fan doesn't draw air in, merely circulates what is available, I'm not at all surprised it blew up!

I'll be using Axials plastic 40mm beadlock spoke rims, not Prolines. And I'll definently cancel my plans to use a blue overwears on my ESC as well...

fastbaja5b · 05.19.2009, 10:44 PM

Agreed, however I find I don't get a lot of ballooning at all on the stock tyres or the Terrapins (unless I lift the truck up and hammer the throttle)