Motor Freezing
08-11-2007, 01:26 PM
#16
True, but there are ways to get it done safely(to a degree). I found that while we were running the Novak 13.5 here with the bonded rotor(they forced us to do that, so they'd be closer in performance to a brushed stock motor), if you geared it right for the track layout, it would DEFINITELY overheat, no one could find a gearing that'd allow it to stay cool enough to avoid a thermal shutdown. So after some experimenting, I ended up first adding Novak's own heatsink to the motor, & then using a freezing spray on the heatsink(& ONLY the heatsink) right before a run, & THAT finally allowed it to stay cool all the way through a race. You don't have to freeze the whole thing, just enough to prevent a thermal shutdown will work....
08-11-2007, 01:26 PM
#17
True, but there are ways to get it done safely(to a degree). I found that while we were running the Novak 13.5 here with the bonded rotor(they forced us to do that, so they'd be closer in performance to a brushed stock motor), if you geared it right for the track layout, it would DEFINITELY overheat, no one could find a gearing that'd allow it to stay cool enough to avoid a thermal shutdown. So after some experimenting, I ended up first adding Novak's own heatsink to the motor, & then using a freezing spray on the heatsink(& ONLY the heatsink) right before a run, & THAT finally allowed it to stay cool all the way through a race. You don't have to freeze the whole thing, just enough to prevent a thermal shutdown will work....
08-11-2007, 02:19 PM
#18
..when racing at Racer's Haven in Bakersfield ealier this summer..I would put my car up infront of the Big BLUE BLOWER when it came off the track (when I came back from Marshaling I stuck it on the P&C Racing Motor Cooler until the next round of qualifying...and the motor felt just a tick stronger...but more importantly it came off about 15 degrees cooler on that run than the uncooled run. (Outside temp was probably 102 degrees)
This was a 10.5 SINTERED Pro type Novak Motor
P and C Racing Motor Cooler
This was a 10.5 SINTERED Pro type Novak Motor
P and C Racing Motor Cooler
08-11-2007, 02:59 PM
#21
..years ago we would wedge a piece of DRY ICE onto the top of the motor during the race.
Then as motors got better we faded away from doing this...it's become really popular to cool motors again now (we were doing it 15+ years ago)
Back then - we also used BUMP BOXES on our batteries at the LINE to keep our batteries as HOT as possible up until the very last second before the TONE sounded...
Sometimes it's funny to watch things in this hobby come and go...and come back again.
Then as motors got better we faded away from doing this...it's become really popular to cool motors again now (we were doing it 15+ years ago)
Back then - we also used BUMP BOXES on our batteries at the LINE to keep our batteries as HOT as possible up until the very last second before the TONE sounded...
Sometimes it's funny to watch things in this hobby come and go...and come back again.
08-11-2007, 08:51 PM
#22
Tech Adept
Cooler
Spidar, It helps alot, we run a spec class with 8min races and the motor comes of the track at around 130-140*, without cooling the motor the temps well above 160*. I also find that on really hot humid days the MuchMore cooler is less effective, thats when I turn to the cooler method. I temped a motor just before I put it in the car about 2min before the race and it was at 29*, plus no condensation. As I always say, a cold silver can is a happy silver can
08-11-2007, 10:10 PM
#23
..years ago we would wedge a piece of DRY ICE onto the top of the motor during the race.
Then as motors got better we faded away from doing this...it's become really popular to cool motors again now (we were doing it 15+ years ago)
Back then - we also used BUMP BOXES on our batteries at the LINE to keep our batteries as HOT as possible up until the very last second before the TONE sounded...
Sometimes it's funny to watch things in this hobby come and go...and come back again.
Then as motors got better we faded away from doing this...it's become really popular to cool motors again now (we were doing it 15+ years ago)
Back then - we also used BUMP BOXES on our batteries at the LINE to keep our batteries as HOT as possible up until the very last second before the TONE sounded...
Sometimes it's funny to watch things in this hobby come and go...and come back again.
Oh, & I'm also glad we now have sintered rotors that can take the heat & then some(so much so that I've heard of guys simply unplugging the temp sensor wire from their ESC's so it won't go into thermal shutdown, I think either Charlie or Bob Novak himself told me the sintered rotor can withstand temps as much as 100 degrees F above that point)...
08-11-2007, 11:19 PM
#24
And this is why I switch to brushless you don't have to do all this crap to be competitive With brushless motor, The motor stays cool, Power never fades, motor is consistent throughout the whole race.
Save yourself the hassle and just get a brushless system.
Save yourself the hassle and just get a brushless system.
08-11-2007, 11:36 PM
#25
08-12-2007, 11:07 AM
#26
08-12-2007, 12:17 PM
#27
No, I mean 100 degrees ABOVE the tolerance of the bonded rotor(which is around 160-170 degrees F), so if I understood it right, the sintered rotor could handles temps as high as 260 degrees without difficulty(though I'd never wanna push one that hard).
Oh, & Jochim_18, you're right if you're using thesintered rotor in a brushless, but with the older bonded rotors, you DO still have to watch temps closely(in truth even moreso than we did with brushed motors, because if it thermals even a half dozen times, that can be enough to permanently damage the magnets in it, & then it'll run hot all the time & hesitate kinda like when a brushed motor has a hung brush). So when using it(as I had to do for some time before we finally got everyone to let us use the sintered rotors), doing what I did to keep it cool was absolutely vital....
Oh, & Jochim_18, you're right if you're using thesintered rotor in a brushless, but with the older bonded rotors, you DO still have to watch temps closely(in truth even moreso than we did with brushed motors, because if it thermals even a half dozen times, that can be enough to permanently damage the magnets in it, & then it'll run hot all the time & hesitate kinda like when a brushed motor has a hung brush). So when using it(as I had to do for some time before we finally got everyone to let us use the sintered rotors), doing what I did to keep it cool was absolutely vital....
08-12-2007, 12:41 PM
#28
08-12-2007, 01:27 PM
#29
When they said that though, it was when they were mostly just using bonded rotors, there's no doubt the bonded rotor is the weak link, & when Charlie or Bob told me about the temp tolerance of the sintered, as far as I know they were only referring to the rotor itself, I agree that I'm not sure if the windings in the stator could handle that much(which is why I said I wouldn't ever wanna try pushing the motor THAT hard)....
And yeah, I wont push my luck that far, 76 for a sintered novak, and 100 for a LRP and sintered rotor, I know I dont have the money to test that out lol
08-12-2007, 05:23 PM
#30
They say that a picture worth a thousand word... 
And I could add that when I run a stock 27t on a Turbo Dyno on 5V, the cold motor as an increase of about 3 to 5 watt compare with the same motor at room temp. The RPM seem to stay about the same but the torque increase. Some racer like to put one more teeth on the pinion and the motor finish the race at the same temp as with no freezer and a teeth less.
Ronald
CrazyRonny
www.crazyrcracing.com
[email protected]
Originally Posted by Originally Posted by EAMotorsports
There are no adverse affects of freezing a motor that I have found. Keeping it cold allows the motor to stay cooler longer which reduces resistance (as the motor gets hot the resistance goes up...one of the reasons a motor slows down during a race) and it keeps the magnets cool as well as their strenght goes down with heat.
Cant go wrong with a motor cooler that actualy works (like this one does) in my opinion.
EA
Cant go wrong with a motor cooler that actualy works (like this one does) in my opinion.
EA
And I could add that when I run a stock 27t on a Turbo Dyno on 5V, the cold motor as an increase of about 3 to 5 watt compare with the same motor at room temp. The RPM seem to stay about the same but the torque increase. Some racer like to put one more teeth on the pinion and the motor finish the race at the same temp as with no freezer and a teeth less.
Ronald
CrazyRonny
www.crazyrcracing.com
[email protected]