Running temps

[dont slow down]

I took my EKOS out for a run today and I've always been cautious as far as my temps go. I have only once run a full set of packs through this, I'm always worried about burning something up. I live in Clearwater FL and it gets hot down here. Today the temp was 90 at 11:00. With the FL heat my electronics get hot and I'm looking for some info as far as what is ok and what is too hot. I ran the boat with stock electronics and motors and 2 Turnigy 3S 5000mah 35-45c Lipos. After a few WOT passes I would slow it down for a lap or two then do a few more WOT passes. I ran it total for about 8-10 minutes. I opened the hatch, disconnected the batts, put the hatch on and brought it back upstairs. Once I got it up here I opened it up and checked temps.

Port motor: 115*
Port ESC: 90*
Port LiPo: 89*

Starboard motor: 98*
Starboard ESC: 91*
Starboard LiPo: 90*

For some reason the port motor is hotter. Everything rotates freely and is greased. Are outrunner motors able to withstand higher temps than inrunners? I'm going to reprogram the ESC's and check all my couplers to make sure everything is straight. How much timing should I run? I'm using the 36mm plastic props.

[EricSchlaifer]

I live in California and deal with the same type of temps here. I have found I get cooler temps with higher timing on the outrunners. I run 15 degrees in my ekos and with my larger outrunners I run 30. I'm going to gradually bump the timing up on these smaller outrunners and check temps. But my temps went down about 10 degrees when I bumped the timing up from stock. It is my understanding that outrunners like higher timing. And the other thing I have found is check the spacing between the teflon spacer, your drive dog, and the end of the stinger. You need to have a gap there since the shafts contract when running. I usually leave about 1/8th of an inch. That solved one side running hotter (and using more power) for me! And your temps are still low, you can run longer safely :)

[dont slow down]

Ok cool. I don't run a gap in my drive dog and stinger since I have wire drives, so that can't be it. I'll reprogram the ESC's to make sure the timing is equal.

[EricSchlaifer]

how do you like the wire drives? I'm thinking I need to go that route when the flex shafts finally go (so far they've been good to me knock on wood)

[dont slow down]

Well I'm still working on them. They are nice not having to worry about direction, seem to run good but they leak a lot. Since they are so much smaller than the cables there is a space in the stuffing tube and I get quite a bit of water in the hull. I tried yesterday to fix this by pulling out the plastic liner and took a short section of brass that was the next size down and put that in the plastic tube. Then I took the wire drive, slid it back in the plastic tube and took a piece of heat shrink and put it over the plastic tube, brass tube and wire and shrunk it. I was hoping to sort of step down the tube to the drive size to keep water out. It helped but I still got some water in the hull. Not a lot but probably a good 2 table spoons worth. I keep dry sponge in the back of the hull to soak it up but I gotta find a better way to keep it out.

[G-UNIT]

I don't see anything wrong with those temps, sounds like it running good,
I am in sanford fl and run a impulse 30, bj26 and a u-l1,
and at times my temps are alittle higher, I don't worry untill they get into the high 120 to low 130s on motor
esc temps at around 110-115.
batts about 98-115 max.
JMO.

[EricSchlaifer]

I don't see anything wrong with those temps, sounds like it running good,
I am in sanford fl and run a impulse 30, bj26 and a u-l1,
and at times my temps are alittle higher, I don't worry untill they get into the high 120 to low 130s on motor
esc temps at around 110-115.
batts about 98-115 max.
JMO.

I agree... outrunners are good for higher temps. I know quality motors like scorpions cant take as much as 250 degrees!

[dont slow down]

Ok good to know. Thanks for the info guys. I'm going to reset everything today, maybe get it back out this afternoon.

[Fluid]

Yesterday we were out running in 100*F heat, our motors, ESCs and packs were coming in from 120* to 140* after one mile. It matters where you take the temps, search for the hottest part of each component. I don't like anything to be over 140*, but that limit works without damaging anything. Realize that these temps were recorded less than one minute after pulling the boat from the water. The ESC especially can cool off very rapidly.

I've burnt up Scorpions at less than a measured 200*F. The wiring shorted internally; they are very good motors but are designed for airflow in planes and and are not bullet-proof. Here is what their copy says:

"The stators are epoxy coated to prevent shorts, and are wound with wire that is rated at 180 degrees C (356 F). The magnets used in Scorpion Motors are rated for operation at 200 degrees C (392 F), making a motor that is virtually impossible to burn up in normal use."

It is not uncommon for one motor in a twin setup to be a bit hotter than the other. One works harder in turns, so which is the hot motor depends on which direction you turn....

.

[stadiumyamaha]

+1 fluid. Outrunner can take more heat but run all the same wire coatings as Inrunners which is the weak point.
I over cooked a castle outrunner, the motor was fine but all the coating on the wires were melted.
I also don't worry about anything over 140 here in Texas in the summer.
Fluid is also right about checking temps as soon as you pull the boat from the water. Things cool down quick.

[fleckster48]

Hello,

The port motor on my KOS runs hotter and is in the same range as yours. One thing I noticed is that the two motors are different. The port motor has three screws that secure the end cap and the starboard has one in the center. I may be wrong but one must be set up for reverse rotation. Since one channel feeds both, that is my thought. I don't see any wires reversed so?? Does anyone know.

Thanks,
fleckster48