1515 2200kv heat issues in buggy
 

I have been running a mmm 2200 combo in my mp9e for about a month total now and have been in a constant battle with heat issues. Ever since I got it it has been a struggle to keep temps under 200. I geared it as high as possible and got some great runtimes but it actually seems to just make things worse.

I have checked gear mesh, drivetrain for binding, tried a bunch of different batteries, cut cooling holes in my body, set timing to 0 and even replaced the motor and esc. I'm stumped as are the guys at the track and castle phone support.

Right now I have a 14t pinion and 46 spur which puts my top speed just over 40mph and it comes off the track at around 180-190, after about 15 minutes with a 4500mah 30c 4s pack. I still can't get through my 5200mah packs without getting dangerously close to 200. I've tried as small as a 12t (geared for 32 mph) pinion and I still get temps of almost 200 after just 15 minutes.

Anyone have any ideas? I'm getting desperate, I bought this motor hoping to keep temps low...

I ordered an eagletree and a new temp gun, mine did seem to read about 10* hot compared to my friend's. Also replacing all of my bearings and rebuilding my diffs today just in case.

Ambient temps are about 75 now, but the really high temps were in 80-90* weather.

Hello
There is an issue indeed, my mp7.5 with 14/46 ratio and 1515 2200Kv on 4S barely breaks 100-105°F... If you have the same problem with different motors and ESC it comes from somewhere in the vehicle. Is your motor mount correctly installed ? There is black plastic under the motor, maybe it strains your motor ?? Give us some closed photos so we can see if the motor is well installed.
Or like you said maybe your temp gun, so measure the temp with your friends temp gun.

Last weekend I took the readings with my friend's temp gun and it was at 175 on the end-bell and 150-155 on the sides. Ambient temp was 75 and windy. Better, but the lower ambient temp I'm sure had something to do with it. The weekend before, track temps were like 120 degrees.

I was under the same assumption, that the vehicle was the issue, but I cannot find any binding at all, it is very smooth. When I let off the throttle it coasts as easily as can be expected from a notchy 4-pole motor. I am going through the drive-train and rebuilding though just as a precaution. My motor mount is installed properly, and I put a piece of foam rubber on the black plastic thing to cradle the motor better.

As I was typing this I was inspecting the mount and the black plastic brace thing. I pulled the motor and noticed quite a bit of wear on the underside of the end of the can, it looks like the brace was doing nothing for the motor and it was slapping the chassis. I wonder if you are on to something and the pinion is binding under flex causing added heat. I'll test the motor in another vehicle this weekend and see how it temps with the same gearing. It would have to be something that only happens under throttle or under flex causing binding if the car is the issue.

Anyway I don't like the kyosho 2 pieces mount, I replaced it with the RCMonster one, and the spur is far better close to the motor, meaning less strain on the front bearing. But with the kyosho mount I had'nt this kind of high temps. There is probably something with the motor mount :oops:

It's something to look into anyway. I'm trying to eliminate any possibility. I really like the two piece mount for convenience though, I haven't really looked at the rcmonster one.

So, I logged the issue with my eagletree today but now I'm even more confused.

I used 14/46 gearing with a 4500mah 30c turnigy 4s pack. The temp got up to 140 in a few minutes and stayed there until 16 minutes. Then suddenly the temp started to climb and actually peaked just over 200 at about the 23 minute mark. The esc temp stayed around 150-155 and didnt climb. My peak amps were just over 110 and, and voltage drops were pretty consistent all the way to lvc. The graph didn't show anything out of the ordinary aside from the temp at that point. My second graph was the same, but with a second identical battery. Unfortunately the guy who's laptop i was using left before i could copy it to my memory stick so I'll have to wait to post the graph.

What could possibly cause the temp to shoot up so high so fast like that? Is it possible for the battery to somehow cause that without effecting the esc?

Oh forgot to mention my 1800kv 1512 had a much more linear temperature climb, maxing at about 180 with a 17/46 gearing and the same battery. No abnormal spike at all. runtime was quite a bit less though, only about 16 minutes vs 25 from the 1515 2200.

Ok, couldn't get the chart from yesterday, but... I logged some mopre runs today, 1st with a 14T and 2nd with a 16T pinion. I put a huge heatsink and fan on to save my motor and set the LVC to 3.4.

Now after looking at these charts it seems that the battery is complete junk! I think I got about 10 runs out of this pack. All of my turnigy packs are having the same symptoms, losing power and cogging, and hitting LVC after a short time. Is this what has been causing my heat issues all along?

IMO, the charts don't look horrible in terms of the packs performance, but...........

When is it cogging? on startup? It cogs more in the 16 tooth, than the 14 tooth, doesn't it?

What top speed are you geared for?

Cogging itself creates HUGE amounts of heat VERY quickly. Cogging also will suck the juice out of the pack very quickly.

What are your ESC settings?

I would look at addressing the cogging issue itself, then log some more runs. You have to get the cogging stopped.

The cogging isn't necessarily the Lipo.

Cogging is usually the result of improper gearing or improper ESC settings.

Start power low, 0 timing, no punch. Never cogs until about halfway through the pack, on startup, and gets much worse as the pack gets low. Did you see the voltage dips on the 2200 16t graph? I hit the 3.4v Lvc after just 1400 mah. Gearing is for about 39 on the 14t pinion or 45 on the 16.

Also keep in mind I had a huge heatsink and fan otherwise my temps will hit over 200 even on the 14t. The temp spike happens right around halfway through the pack when the power suddenly drops and cogging starts. It's the same for both of my turnigy 4500 30c packs and the pairs 5200 30c packs. In fact it is worse with the 5200s. It didn't cog at all when the packs were new, and didn't have the power loss or other symptoms but the heat. It didn't even cog with the 17t at first.

I rebuilt the diffs and changed the bearings, and checked and triple checked the drivetrain for any signs of binding.

Anyway I've got over $400 worth of thunderpower packs on the way. If they don't help the issue at least I'll save a bunch of weight and eliminate that possibility.

I notice on those graphs that the issue arises when the temp gets to 125-130. Your larger mah packs probably help to heat the motor just that little bit quicker.

I would imagine the esc would be getting fluctuations of temp at the same point but harder to notice if you are just using a gun and that's roughly when the fan kicks in.

Given it happens to any motor but the issue arises when the motor gets to a certain temp, one might assume mount is not integral at those temps. However, the car still rolls freely with no binding. Does it roll freely in reverse? I ask because that would be the direction of pressure on the drivetrain under acceleration.

Ah, missed this bit. So it is not happening to every motor. The first couple of times you ran the 1515 did it get excessively hot? Is it possible you demagged the rotor just a little, so the cogging happens at the higher temp range? Particularly in the middle or at the end of a run when there is less voltage to feed the system.

The 1515 would be more efficient as it is a longer motor which would explain some of the runtime difference, but I don't know if that is the complete story. Do you drive differently with the two motors? eg- light on the finger for the 1515 because of more torque.

Just read your thread over at rctech. Someone mention high reving motors get hot.

Have you thought about running 3s just as an experiment?

I'm a little lighter on the throttle on the 1515. These graphs were with the LVC set to 3.4. Set to 3.2 I was getting 24-26 minutes on the 2200.

If the 1515 was damaged by heat, it wouldn't make sense. What would have caused the initial heat problem, which was consistent with the heat problem on my last 2200?

I have a conversion on the way for my mbx5r so i can compare graphs between the different vehicles, and isolate it as an electronics issue for sure.

no i haven't tried 3s yet.

Firmware, what firmware are you using ? Try to back the firmware to 1.24 or 1.24beta, the most recent firmware give some problems to certain people, especially cogging at start-up...

I'm on 1.24.

Check your solderings and connectors, a connector that is old and worn will work like a resistor. Maybe you are undergeared? My Erbe were running hot when it was geared for 40, geared up to 45 and problem solved... These 4pole motors don´t like to rev high they like to work with the torque. I hope you will solve the problem.

I do not agree with this statement :whistle:. To really sense the effect of an undergeared motor, you need to gear it very very low (15-20mph), and be constantly on full throttle, like a motor pushed full throlle with no load. All the vehicle I see are running cooler with a lower top speed.

I agree with Nuz69.

Higher gearing means more load, and usually means more heat.

i was wondering about my connectors too, especially the esc battery connector. Its possible I had a bad joint somewhere and it got worse with usage causing the low voltage issues and the cogging. I really don't think my gearing could cause cogging on this motor in a buggy.

I don't see how that could be the source of the heat issues though, but certainly should be investigated. It would be more probable than having 2 bad 4s packs and 4 bad 2s packs.

Still going to order some high quality packs, any recommendations between hyperion 5000 30c, polyquest 4500 42C or polyquest 5050 35C?

+1 on hyperion, 5000mAh 25C G3 is well enough for a 4S buggy ;) You said earlier that you have done the test with 2 different ESC + motor combos with same problem ? You should definitly check the batteries or the motor mount.

Could you be more specific about checking the motor mount? I don't see anything out of the ordinary.

If it was a bad connector then you would have more than one. It is the same problem with 2 different esc's and a number of batteries.

A motor mount can flex under load. If it heats up enough it might flex more than usual. What is it made of?

Ummm metal... Lol I am not sure it looks like cast aluminum. I put a brace under the motor and set the mesh a little loose and it didn't change anything. I doubt it's the mount but I'll find out for sure next weekend when I try it in my converted mbx buggy.

I was thinking, don't those temps on my 1800 seem a bit high too? I am pushing that motor a little on 17t but 16t is only about 36 mph.

Still doesn't make sense, I'm often getting higher maximum amps from the 1800 and less heat... But my friend who geared for the same speed in his xray with his 1800 had his spur smashed against the pinion and binding in his front diff and had about the same temps.

I changed my connectors today and noticed on my esc terminal there was a nasty gouge on both prongs, one side looked like it was barely making contact with only about a mm of the tab. That may be the source of the battery issues, but I won't know for sure until track testing. I changed over to the 4mm bullets instead of the traxxas I was using.

Well now I'm about ready to give up... Today My heat problems seem to have migrated to my ESC. I was running a 14T pinion and was only able to get about 2000mah out of my 4500 packs before I got severe cogging and the esc would shut down. I thought it was lvc but I wonder if it was thermalling. I touched the esc and burned my finger pretty bad on the motor connectors. The heat gun read 200 on the esc and 150 on the motor. The motor wires were really hot. The battery wires were warm but not hot.

Same setup as before but I never saw over 165 on my esc. Even when my fan died it only hit 170. The same batteries run fine in my mbx5r conversion with my 1512 1800 and mmpro.

Another odd thing, my 1800 only hits 160 and esc 140 in the mbx with 10* timing, but the same motor and same gearing but 0 timing in the mp9 with the MMM the motor hit 190 and esc 160. Also no cogging issues at all in the mbx.

I'm going to try the mmpro in my mp9 next weekend and see what happens. I'm beginning to suspect my MMM is the culprit in all this.

Could be the ESC struggling. That would explain the sudden heat increase with pack depletion. Could be some dodgy (or previously overheated) caps that aren't up to the job and are causing the cogging which is driving the heat up...

I run the 1512 1800kv and MMP w/Polyquest 4500mah 45c 2s in series for 4s in a Losi 8 2.0 buggy.
I have no issues with my setup and would highly recommend the batts. Motor temps are around 150*-160* after 20 min mains. I do like using nothing but 6.5mm bullets from Castle for ESC, Motor, Batts. I like knowing there is a much less chance of resistance when using the larger bullets as they keep their shape way better than smaller bullets and offer way more of a contact patch. Couldn't hurt to try.
I also use the Thunder Power's 3200mah/40c 4s batts in parallel and highly recommend these as well.

Yeah that setup works awesome in my mbx. Ill be trying it in my MP9 to try and isolate the source of the problem. If it works well, I'll have to send in my 2200 combo again I guess.

I just read the whole thread, and it sounds like your motor was bad from the start. A shorted winding in a motor WILL cause short runtimes/hot components/cogging no matter what your gearing/voltage/ESC settings. A bad ESC could have the same effect, but I think if it were the ESC you would've seen smoke by now.

Edit- Hmm actually you did say you tried another motor/ESC right? Is it possible they might be bad, too?

This is my second MMM 2200 combo. The first was replaced under warranty, the esc came apart and tore the wires from the board and the motor was testing out to 2700kv and running hot all the time.

My current symptoms were a bit different. The motor was fine and leveled off at about 140* until about halfway through the pack it would suddenly heat up and keep climbing to over 200 by lvc. Then I started getting cogging and power loss at about that same point but i had a heatsink and fan on the motor to prevent damage but esc temps were still under 160. Now the motor doesn't heat up because the esc is thermalling at about that same halfway point all of a sudden.

Weird... Well, if you've checked all the connections and they look sound, then I think you got a bad ESC and/or motor...(again?) Are the settings on the new ESC the same as before? High timing/start power would cause this with in-runner motors. Maybe try re-updating the firmware incase there was a glitch somehow.

Sorry to sound like a broken record. If the car coasts smoothly while off power then I don't think it's a drivetrain issue, unless, like you suggested, there is some strange on-power flexing going on.

Could you post a couple pics of the setup? It might help us help you. :smile:

I actually changed all of my connectors. I switched the traxxas battery jack to ec3, and went through and rebuilt the entire drivetrain for the 5th time. Settings are the same on the esc. Low start power, 0 timing, etc. I actually tried some punch but it made the cogging worse. I'll post an eagletree graph of what happens in a minute.

By "tried some punch" do you mean you increased the punch control %? Increasing the PC% would actually be less punchy, since you're adjusting the amount of control, not the amount of punch. In other words, 0% would be maximum punch.

I normally run no punch control but I tried 25%

Here are the graphs. Keep in mind that last huge voltage dip was in a chicane not on a straight. My LVC was set to 3.1 V/cell for this test. I also tried firmware 1.29 for this test and aside from maxing out at 138A instead of my usual 110-120 the results were the same as 1.24.

Volts
http://i48.photobucket.com/albums/f2.../10172200V.jpg

Amps
http://i48.photobucket.com/albums/f2.../10172200A.jpg

And the moment of shutdown including that huge drop in voltage:
http://i48.photobucket.com/albums/f2...f/1017zoom.jpg

I just thought of something. Those huge voltage drops coincide with glitches in my eagletree brushless rpm sensor which reads esc pulses. I'll post a graph with the rpm when I get home from work. I wonder if that could indicate an esc problem.

Here they are:

When the ESC died, same as the other zoomed graph.
http://i48.photobucket.com/albums/f2...f/1017rpm1.jpg

RPM and V during a couple of the other glitches:
http://i48.photobucket.com/albums/f2...f/1017rpm2.jpg

RPM and A:
http://i48.photobucket.com/albums/f2...f/1017RPMA.jpg

Something is not right there. Looks to me like you are using a 4s pack and getting over 50k revs from the motor.

16.8V * 2200kv = 36960rpm

Actually, something is causing the sensor to glitch. It reads the pulses from the esc to the motor, and since it is happening most often when I see huge voltage drops which sometimes don't even have an amp spike, I'm wondering if it could be a problem with the esc. Also I forgot to mention it reads 7k rpm at 0 but that is apparently normal for certain esc's and everywhere else is accurate. I think it might be when it's cogging that it glitches but I can't say for sure.