Temp problem help please - RC-Monster Forums

JerryC · 06:42 PM

Hello all,
I have a problem that maybe someone can help with. I have an RC8 that was converted with the AE conversion kit. After I ran the RC8 for the first time (about 15 to 20 min of hard running in a big field) I came up with the following temps, motor 160F esc 105F but the fan was on? and the battery packs were 91F. This was with 15/46 gearing. The second time I changed the gearing to 16/46 and the motor temp went up to 190 degrees. So I pulled out the 16 tooth and replaced it with a 13 tooth pinion. I ran it today and the motor temp was over 200 degrees. This time I was on a tight local track so there was not to much in the way of WOT. I was running in a big feild for the first 2 runs.
On the ESC, drag brake is turned off, timing is at lowest, I also beleive punch control is set to 40. as for the other info the RC8 has a V2 mamba monster esc, medusa 60 2200kv v2 afterburner w/rc monster heat sink, 2 2S 20C 5000 Orion pack, diffs 5,7,3 silicon fluid, 1ST(46/15), 2nd(46/16), 3rd(46/13) for gearing. Between the 2nd and 3rd run I took the entire car apart and cleaned, oiled, and greased every thing, so all moving parts on the drive train move freely and smooth. So what else can I do? What would you do. I have just about ran out of ideas. Please help if you can.

Jabe · 03.10.2009, 07:06 PM

I think you should change your timing back to "normal 10".
Havent tried any lower timing, on my 80mm 2200kv, but 10 seems to be most powerful, compared to 12 and 15.
Medusa says that timing should be betwene 8-15.

lincpimp · 03.10.2009, 07:12 PM

Do you have hardcase lipos? If so your temps on the lipos are not entirely accurate.

I would say that a 15t pinion looks to be the "sweet" spot... I am guessing that the lipos cannot keep up, and the fan on the esc is keeping it ok...

JerryC · 03.10.2009, 07:13 PM

Do you think the timing could make it run so hot, they say (castle) it is suppose to run cooler.

JerryC · 03.10.2009, 07:16 PM

Yes the lipos are hard case. How does the lipo make the motor temp go up? It has tuns of power

Jabe · 03.10.2009, 07:26 PM

Well, i have noticed that, when timing is too low, motor runs hotter than whit higher timing.
My MM temp cutted often, when running on lowest timing, when i changed it back to normal, it didnt temp cut anymore.

Its something worth of trying, small test and see how temps go.

JerryC · 03.10.2009, 07:30 PM

will try, heck I guess it can't hurt

lincpimp · 03.10.2009, 08:04 PM

Try the normal timing. It should not make much difference but worth a short.

Hardcase lipos do not transfer the heat to the case, so the actual cell may be much hotter inside. Check your motor to esc connections, and make sure they are good... A picture may help us figure it out too...

slash_48 · 03.11.2009, 11:18 AM

My opinion is you need to run a heatsink and fan because the motor is a little small for a 1/8 scale buggy. I would have done a 70 0r 80 mm.

js058515 · 03.11.2009, 02:41 PM

If you have already gone over 200 degrees I would be careful. From reading your original post, it looks like your motor might have had problems from the start. Possible short in the wires, motor screws too longs, or something during the manufacturing process. Now that you have gone over 200 you should call Medusa (if you haven't already) and explain to them what has happened. They are ok with customer service.

JerryC · 03.11.2009, 05:35 PM

I know this is going to sound kind of crazy, but I took the RC8 to the track again today and after about 15 min. of running (just like yesterday) the temp only got to 145* the only thing I changed was the timing to normal (10*) in the MMM. I did not get to run it as long as I wanted because I blew out one of the front bearings. So I will try it again tomorrow and see if the same thing happens again (not the bearing). The motor seems to still be running very good even though it made it past 200* yesterday. I know the temp was right because I temped it with 2 different guns, but I did slowly drive the car around yesterday after it hit 200 to help it cool down.
Jerry

js058515 · 03.11.2009, 08:36 PM

Sounds like your ok then JerryC. You would definitely be able to tell if the motor burned out. Hopefully the change in the timing helped.

JerryC · 03.12.2009, 11:35 PM

Took it out again today, I ran it as hard as I could at the track and temp made it to 147* I guess I need to keep my timing at normal. Thanks for the help all.
Jerry

js058515 · 03.13.2009, 07:18 PM

This was a good post.....I might have run into similar problems and would have had a hard time figuring out what was going on. I had been running a Neu 1512 on low timing with no problems and just replaced it with a Medusa. Now I know what to set the timing on. Thanks everyone.