blown esc - RC-Monster Forums

wyattroa · **blown esc -** 09.05.2010, 05:35 PM

2 blown esc in 3 weeks. This last time my motor is fried too. The first time I didn't even get to run the truck.. This is for a rc8t with 2200kv system running on 6s. The first time I plugged the battery in and the esc blew. This last time I got to run the truck through 2 packs and half way through the second pack I get smoke again. Upon inspection the esc is smoked, smells horrible..also the engine does not turn like it used to...

freeagent · 09.05.2010, 07:07 PM

I would like to know how these escs blow so easy for some and not for others?

My v3 is almost 3 winters old, it shipped with 1.19, and I feed it 6s mostly, 4s for my gf..

Im not knocking you or anything, I just want to know..

wyattroa · 09.05.2010, 07:11 PM

Quote:

Originally Posted by freeagent

I would like to know how these escs blow so easy for some and not for others?

My v3 is almost 3 winters old, it shipped with 1.19, and I feed it 6s mostly, 4s for my gf..

Im not knocking you or anything, I just want to know..

No, I understand you completely... I got my savage flux new the first day my hobby shop got it in...Two months ago the esc let go..It was running on 6s and the high speed pinion like HPI says to use with no issues. Runs like a champ now with the new esc in. I have read the same thing on the forums, some have not one issue and others have a shit time over and over again..I think the rc8t is starting to fall into that category.
Robert

freeagent · 09.05.2010, 07:15 PM

Its a bummer man, sorry for your loss :(

What are you running for jo0s?

scarletboa · 08:18 PM

Quote:

Originally Posted by wyattroa

2 blown esc in 3 weeks. This last time my motor is fried too. The first time I didn't even get to run the truck.. This is for a rc8t with 2200kv system running on 6s. The first time I plugged the battery in and the esc blew. This last time I got to run the truck through 2 packs and half way through the second pack I get smoke again. Upon inspection the esc is smoked, smells horrible..also the engine does not turn like it used to...

what is your gearing? by the sound of it, i'm guessing way too high.

it sounds like the 2nd time was your fault and the motor overheated, causing the esc to let go. the 1st time just sounds unlucky

wyattroa · 09.05.2010, 08:15 PM

Quote:

Originally Posted by scarletboa

what is your gearing?

it sounds like the 2nd time was your fault and the motor overheated, causing the esc to let go. the 1st time just sounds unlucky

The gearing was 46/20. It's a bummer for sure. The motor on the first battery pack. Was running fine though. Just half way through the second pack came the dreaded smoke and smell

Robert
Robert

scarletboa · 08:28 PM

Quote:

Originally Posted by wyattroa

The gearing was 46/20. It's a bummer for sure. The motor on the first battery pack. Was running fine though. Just half way through the second pack came the dreaded smoke and smell

Robert
Robert

Differential Ratio: 4.5
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 20
Total Voltage: 22.2
Motor KV: 2200
Tire Diameter (inches): 5.5
Tire Ballooning (inches): 1
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 2.3 : 1
Total Ratio: 10.35 : 1
Tire Circumference (inches): 23.56 inches (598.47 mm)
Rollout: 2.28:1
Total Motor Speed: 48840 RPM
Vehicle Speed: 105.29 mph (169.13 km/h)
Effective KV Value: 2200
KT constant: 0.61 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

there's your problem. the CC2200, or just about any motor for that matter, cannot handle that much gearing
usually, a good speed to gear for is 35-45mph. maybe 45-55mph with an oversized motor such as a castle/neu 1520 or a 1717

wyattroa · 09.05.2010, 08:50 PM

Quote:

Originally Posted by scarletboa

Differential Ratio: 4.5
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 20
Total Voltage: 22.2
Motor KV: 2200
Tire Diameter (inches): 5.5
Tire Ballooning (inches): 1
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 2.3 : 1
Total Ratio: 10.35 : 1
Tire Circumference (inches): 23.56 inches (598.47 mm)
Rollout: 2.28:1
Total Motor Speed: 48840 RPM
Vehicle Speed: 105.29 mph (169.13 km/h)
Effective KV Value: 2200
KT constant: 0.61 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

there's your problem. the CC2200, or just about any motor for that matter, cannot handle that much gearing
usually, a good speed to gear for is 35-45mph. maybe 45-55mph with an oversized motor such as a castle/neu 1520 or a 1717

Just double check the pinion is 15 in there..But, this still doesnt make sense to me. The spur that everyone is running in their rc8t is the plastic 46 spur from the electric kit. Castle says to run the 2200kv for a truggy. If the engine got hot all of a sudden on 15 pinion then gearing the pinion down would have made the engine even hotter, am I correct in my thinking?

scarletboa · 09.05.2010, 09:29 PM

Quote:

Originally Posted by wyattroa

Just double check the pinion is 15 in there..But, this still doesnt make sense to me. The spur that everyone is running in their rc8t is the plastic 46 spur from the electric kit. Castle says to run the 2200kv for a truggy. If the engine got hot all of a sudden on 15 pinion then gearing the pinion down would have made the engine even hotter, am I correct in my thinking?

no, gearing the pinion down to about a 11 or 12t will be best for temps on 6s. 15t is still too much for 6s. if you were running 4s, a 15t would be just fine.

hemiblas · 09.06.2010, 12:21 AM

So if my math is right a 15T pinion would land us in the 79mph range. Yeah thats a lot. What type of batteries are you running?

wyattroa · 09.06.2010, 01:20 AM

I am just trying to figure out why it ran cool the first pack. I am running 2 6s 5000mah 30c lip in parallel.
Robert

nuz69 · 09.06.2010, 05:23 AM

2 6S 5000mAh in parrallel !!! That's very heavy, especially for a truggy geared for 100 mph

With your crazy gearing, I am surprised that the ESC blown before the tires ^^
Seriously man, a truggy is not design to go over 45-50mph in normal ways, next time try with a 11T pinion, the castle 2200Kv run good geared for 35-40mph, if you want more speed you need to get a bigger motor, in order to reduce the amp draw.
You are right, if the gearing is to small, the motor can overheat if the throttle is continuously full, but it would be with a 4-5T pinion !
Good luck for the next time anyway.

hemiblas · 05:55 AM

A ten tooth pinion would get you half of scarlets speed at 55mph with a very heavy setup. I'm thinking 8 tooth pinion if thats even possible. Originally I was thinking you didnt have enough battery to produce those types of current draws. Apparently you do, but it looks like the weight of your setup with the overgearing is what did you in.

I think everyone should own a wattmeter that buys a brushless vehicle. Its really helped me keep my setups in line. Brian's RC speed calculator works just as well. If only we could get more people to use it ahead of time.

wyattroa · 11:45 AM

I never meant for the truck to be a speed truck, I have an onroad for that. I guess I just got confused because I know on my savage by going to 6s they have you put a larger pinion in with it. I was actually surprised at the trucks weight. You would think it would be crazy heavy but it's not. But like I said before I still can't get over why the temps were fine my first run, maybe because the body was off and I was double checking? Everything was fine to touch by hand on the first run, the second run was on a day that was only 10 degree hotter.
Robert

Arct1k · 09.06.2010, 01:21 PM

Quote:

Originally Posted by wyattroa

I guess I just got confused because I know on my savage by going to 6s they have you put a larger pinion in with it.
Robert

That I believe was a mistake in the manual....