What am I doing wrong - RC-Monster Forums

brushlessboy16 · **What am I doing wrong -** 08.30.2009, 09:07 PM

I just got done racing my 8ight (3rd in the a-main by the way) and im having a really bad heating problem

Started off the day running the 2200kv setup, 16t pinion geared for 45mph.. after a 5 minute heat the motor was about 150 F.. I didn't have another pinion I could put on so I ended up throwing a 1515 2d in the car (2050kv) and ran the car, ran the second heat fine, didnt bother to check temps, then i ran the main, starting off with my rc-monster 2s packs that bit the dust... had to do a battery swap to my Smc 4100mah packs about 7 minutes into the 10 minute main, then continued to run the race.

Car ran flawless- great power, acted like all was well.

Then come to find out as a I drove up pit lane to pull the car off I happed to check temps. The motor was at 180 degrees, batteries were at 105 or so and speed controller was 100 even.

Am I geared too high? I know people are running 1512's in buggies that run cooler.

emaxxnitro · 08.30.2009, 09:12 PM

Quote:

Originally Posted by brushlessboy16

I just got done racing my 8ight (3rd in the a-main by the way) and im having a really bad heating problem

Started off the day running the 2200kv setup, 16t pinion geared for 45mph.. after a 5 minute heat the motor was about 150 F.. I didn't have another pinion I could put on so I ended up throwing a 1515 2d in the car (2050kv) and ran the car, ran the second heat fine, didnt bother to check temps, then i ran the main, starting off with my rc-monster 2s packs that bit the dust... had to do a battery swap to my Smc 4100mah packs about 7 minutes into the 10 minute main, then continued to run the race.

Car ran flawless- great power, acted like all was well.

Then come to find out as a I drove up pit lane to pull the car off I happed to check temps. The motor was at 180 degrees, batteries were at 105 or so and speed controller was 100 even.

Am I geared too high? I know people are running 1512's in buggies that run cooler.

yes you are geared to high. try a 13 or a 14 tooth pinion. i run 9/46 on my 1512 2650 and it runs 150* max.

08.31.2009, 12:57 AM

how was the track surface? sounds like you had alot of wheelspin, causing the motor to get hot and not anything else, i have a 1550 tekin on 5s geared 15/46 and the motor was 180 after the 20 min main, speedo was 102, i put a 16 on there and they dropped to 150

starscream · 01:51 AM

Quote:

Originally Posted by brushlessboy16

I just got done racing my 8ight (3rd in the a-main by the way) and im having a really bad heating problem

Started off the day running the 2200kv setup, 16t pinion geared for 45mph.. after a 5 minute heat the motor was about 150 F.. I didn't have another pinion I could put on so I ended up throwing a 1515 2d in the car (2050kv) and ran the car, ran the second heat fine, didnt bother to check temps, then i ran the main, starting off with my rc-monster 2s packs that bit the dust... had to do a battery swap to my Smc 4100mah packs about 7 minutes into the 10 minute main, then continued to run the race.

Car ran flawless- great power, acted like all was well.

Then come to find out as a I drove up pit lane to pull the car off I happed to check temps. The motor was at 180 degrees, batteries were at 105 or so and speed controller was 100 even.

Am I geared too high? I know people are running 1512's in buggies that run cooler.

Unfortunately, emaxxnitro is incorrect on this one.
The faster a motor spins the more heat is generated.
So, a smaller pinion will only heat the motor up even more as the motor will spin even faster causing more heat.

My recommendation to reduce motor heat is to set the ESC timming to 0 and the ESC punch control to 50% or more

02:35 AM

Not necesarily starscream. In both my revo and slash, reducing pinion size reduces temp. It is easier for the motor to push a car around if the gearing is lower (lower temps), unfortunatley that comes at a cost; speed. The motor will ALWAYS spin at the same speed with it's correlating throttle position, no matter what the gearing. If you increase pinion size, it is harder for the motor to move a car (more heat) but you get higher speeds.

MetalMan · 08.31.2009, 02:35 AM

starscream is referring to the undergeared condition, which, IMO, seems to be the case. Typically in these setups the ESC should heat up pretty comparably to the motor, so low ESC temp/high motor temp is often indicative of too little load.

Too little load means that efficiency won't be in the "sweet spot", so more energy will be wasted as heat.

starscream · 08.31.2009, 04:29 AM

Thanks for clarifying metalman, sorry my description was not very helpful

Brushless configurations can be a bit of juggling act. In order to configure an efficient BL system there are several factors to consider such as proper voltage/motor kv/gear ratio etc.

Brushless motors require a certain amount of load to run efficiently. If your setup does not provide adaquate load you may experience an increase in motor heat.
In turn, if you are over geared (demanding more power from the system) you will experience higher ESC and battery temps.

In general
If your ESC/Batts are hot but the motor temps are OK then gear down or descrease the ESC motor timing to reduce the motor load
If the Motor is hot but the ESC/Batt temps are OK then gear up or increase the ESC timing to increase the motor load.
If the ESC/Batts & Motor temps are hot then you got major problems

You can always try gearing down but watch the temps. (as a burned up motor is no fun)
Let us know how it goes

Ryu James · 08.31.2009, 05:30 AM

since there is already a thread on it i figured i should ask. i have been having some issues in the heat dept. also. well, not completely but i want to get my temps a little lower if possible. i was running a Neu 1515 1y on 5s in my 8b. gearing is 16/46. when racing temps were always around 130 on motor, 130-140 on esc and 100 on batts. which is where i like everything. now i have switched to a hacker c50 7xl 1973 kv. i ran the same gearing and have just been running on the street so far. today temps got to 135 on the motor. so i am concerned on race night its gonna get closer to like 150 or more. which i really like to see my motor temps around 130 and not much hotter than that. is there anything i can do to get my temps down a bit with this new hacker motor? i am using the Neu for a truggy so i only have the hacker to run in my buggy.

also, if anyone can help with this. i like to use a clutch but when i do temps shoot up 20-30 degrees making me uncomfortable. i can drive with clutch or pinion but if i had a way to use a clutch and get temps around 130 i would. anyone out there using a clutch and seeing these temps on a buggy/truggy? what is your setup? i have only 5s packs too so my setup has to be configured for 5s.

emaxxnitro · 08.31.2009, 11:45 AM

whats your spur count. i just wondered since most buggys use a 44-50t spur.

brushlessboy16 · 08.31.2009, 11:58 AM

its a 48.

the track was really dry and bumpy- had quite a bit of wheelspin- there just wasnt any grip out there, Might try punch control and gearing down a bit.

emaxxnitro · 12:23 PM

punch control WILL make power delivery much different when racing. i dont like it for racing. set timing to lowest and start there. 45mph is a bit high for racing. 38 is the sweet spot for me at least

brushlessboy16 · 08.31.2009, 12:18 PM

Quote:

Originally Posted by emaxxnitro

yah then 16 may be under geared. idk. punch control WILL make power delivery much different when racing. i dont like it for racing. set timing to lowest and start there. 45mph is a bit high for racing. 38 is the sweet spot for me at least

you say im under geared, but telling me to go to a smaller pinoin

I cant stand punch control when racing, i need throttle control.

wouldnt going to a smaller pinion envoke more wheelspin?

emaxxnitro · 08.31.2009, 12:22 PM

Quote:

Originally Posted by brushlessboy16

you say im under geared, but telling me to go to a smaller pinoin

I cant stand punch control when racing, i need throttle control.

wouldnt going to a smaller pinion envoke more wheelspin?

yes but at lower speeds.

i missed the edit

fixed now

brushlessboy16 · 08.31.2009, 12:28 PM

Quote:

Originally Posted by emaxxnitro

yes but at lower speeds.

i missed the edit

fixed now

ah

definately not doing punch control. makes my car feel really slow.

ill try gearing down and hope that helps

starscream · 08.31.2009, 01:55 PM

Quote:

Originally Posted by Ryu James

since there is already a thread on it i figured i should ask. i have been having some issues in the heat dept. also. well, not completely but i want to get my temps a little lower if possible. i was running a Neu 1515 1y on 5s in my 8b. gearing is 16/46. when racing temps were always around 130 on motor, 130-140 on esc and 100 on batts. which is where i like everything. now i have switched to a hacker c50 7xl 1973 kv. i ran the same gearing and have just been running on the street so far. today temps got to 135 on the motor. so i am concerned on race night its gonna get closer to like 150 or more. which i really like to see my motor temps around 130 and not much hotter than that. is there anything i can do to get my temps down a bit with this new hacker motor? i am using the Neu for a truggy so i only have the hacker to run in my buggy.

also, if anyone can help with this. i like to use a clutch but when i do temps shoot up 20-30 degrees making me uncomfortable. i can drive with clutch or pinion but if i had a way to use a clutch and get temps around 130 i would. anyone out there using a clutch and seeing these temps on a buggy/truggy? what is your setup? i have only 5s packs too so my setup has to be configured for 5s.

What ESC are you running?
Did the temps of the ESC and batts change after you switched to the Hacker?
I would presume the ESC temps went down so I would recommend trying a 17T pinion