7xl super hot!
 

Ok so current setup is a 7xl, MMMv2 and a 4s lipo. Running a revo, locked into 2nd, standard ratio, 18/40 gearing. Motor is hitting 212 :surprised: , MMM fan comes on every once and a while, and batts never see above 100, currently have mech. brakes. Im not totaly concerned about blowing it up, as id like to get either a CC 2650 or a Medusa of some sort. Anyone experenced these temps and had a motor last. I guess im just wondering if i should expect it to die sometime soon. I've ran it 2 or 3 times and no mojor issues except heat.

Sounds like you're geared pretty high- those temps are not abnormal IMO.

That rotor is going to demag at that temperature...only a matter of time.. i dont give it long.

Lol thats what i thought, the motor was even hotter with a 16t on and i dont have anything else but a 20, and dont want to even attempt that. Im pretty sure im going to go after either a 2300, 70mm medusa, or a 2200 60mm one. Any input on those is much appreciated.

Stick dat 20 toother on 'er for a little 'fun'

If the motor starts to demag, it will pull more and more current for the same output until the ESC and/por batteries start to complain. I would take it easy until you get a different motor...

I'd say it ran over temp once, and now as it's damaged, it'll do it every time no matter what you do.

Maybe hunt for a replacement rotor, see if someone has damaged the windings etc make a good motor out of two dead ones.

7XL is toasty motor regardless- stick a 70mm 2000-2200kv item in the truck and you'll be much happier.

Hmm, ebay time for the 7xl. Get your 50-60 bucks and buy a 70mm medusa, something like a 2200kv model. Or the cc neu 2200. Either will perform leaps and bounds better than the "spinning toaster of death" (gotta love Neil's phrases!)

Yea im going to try to run this thing until it dies, do they blow up or just get really hot?

I wouldnt recommend doing that- the magnet will get weaker and weaker, causing the motor to pull more and more current- you will kill the esc and batts before the motor in all likely hood. When you run it next time, if its getting that hot in a very short space of time, just stop using it; you now have a really cool fridge magnet.

used to run the 7xl and it would run in the 180 on a cold night....Nothings gonna change though....its just a hot motor.


Are you running a motor clamp? if not the endbell will pop off probably...but otherwise it will jsut continue to get crappier and eventually the magnets will seperate and become a $70 paper weight:yes:

I am running the RCM Heatsink, and i even put a slew of cooling paste on the motor can and heatsink. Im going to pull it out tonight, and most likely wait on the funds to buy a better motor. Anyone running the 60mm medusa in a revo? Im debating between that and a 70mm, any suggestions?

Why go with the 60mm when the difference is only $9?
The debate is only for Medusa and Neu/Castle.:lol:

^ +1. The extra torque and surface area (heat dissipation) from the 70mm version will be even more forgiving with gearing...

Quite right too.

70mm for an erevo, depends on your voltage more- castle neu is 2200kv, good for 4s or 5s lipo (6s might prove too much), where as the medusas come in a slew of kvs- 2000-2300kv would be great for 4s lipo.

Went through a 7XL myself awhile back.
I believe I was running 20/68 gearing in my e-maxx on 4S using a mamba max and external BEC with a fan on the ESC and a fan on the motor.
I had the finned can, so no clamp for me and ended up popping the can one day.
Used epoxy to stick it back together, but efficiency got pretty bad not long after that. Most likely, what happened was I damaged the front bearing when the can popped due to the angle of the shaft changing while rotating.
The brakes were first to go. Upped braking to like 80-100% power and they were still weak. Acceleration started to be obviously hampered as well which is when I yanked the motor and put the stock titans back in.
The motor always got hotter than I would have liked, sooner than I would have liked and I am certain I hit over 200 degrees more than once.

I'd say they are worth the money anyways.
I put my motor through some serious abuse, so I am glad I didn't ruin a more expensive motor. Decent for a "first brushless motor", I guess.
Then again, I'm the kind of guy who needs that initial failure to really feel success. ;)

I think most of us start out with an Feigao level motor to get us hooked before moving on to the more hardcore motors... :smile:

I think the sweet spot is 20/68 for my emaxx with that motor. I have plenty of runs and with the novak heatsink the temps stay ok for on road use. During the summer I add a couple 40mm fans. I always keep the temps under 170 and havent had a problem with it. Letting it get up to over 200 is not a good thing as everyone mentioned. The 7XL is still enough to wow everyone including the nitro guys.

i think i have a "lucky" 7xl. i run a 24/68 gearing on my emaxx that hits 42-44 mph with the rcm heatsink and thermal paste underneath it. i only get temps of 150 or so after 15 mins of running in a 70 degree day. so i take breaks every 15 mins to cool it off.
THEN i installed a huge 40mm fan and now it runs 150 degrees max entire run.
so i said what the heck, imma gear it 24/58 and try and hit 47mph. i just installed the spur today and will try it out tomorrow if it doesnt rain. fan works wonders..prolly still stay pretty cool with this super high gearing.

oh hey just curious, what can i expect to gain with a 70mm medusa or a neu anyways.
i know speed comes with gearing and voltage, but say i keep it at 4s with the same gearing...woudlnt it just be the same performance.
i know you guys are gonna tell me....HECK NO. but seriously, what can i expect to see??? the 7xl already gives me sooo much torque, i needa turn it down with the punch control via the MMM. so if the expensive motors just offer more punch/torque....which i will just tame/turn it down anyways...
im not trying to start a arguement, but im also very curious to see if i want to spend the extra money on a 70mm medusa as well....is it only becuase of the heat issues that the 7xl has??

What you gain: Being able to run much longer since the motor doesn't heat up as much. No need for fans or taking breaks as often, if at all. Higher efficiency means either more runtime for a given battery, or more power for a given runtime.

i run an 8xl in one of my Maxx bashers, on 6S and i gear it 65/24. my temps are about 150-160 after 8-10 minutes or so of speed runs up and down my street.

I also have a handmade neu 1515 1Y that i have geared 56/25 on 6S in my other Maxx that runs about 150-160 after about 20-25 minutes or so.

when they're geared equally, there's only about 3- 4mph difference in top speed, but the neu seems to be able to run twice as long without any cool down time.

I love the feigao motors for speed runs...you can throw alot of voltage at them for short bursts and be fine. however, if i was looking to actually run a whole pack or race, the neu would be the obvious choice for me.

Yep, over all the feigaos are shitbags. Or in this case, shitcans. :lol:

I guess thats why its worked for me. Just dont go over 10-15 minutes of run time, keep it geared conservative and mostly on road use. The torque is just crazy. I'm with blue on the torque. Any more and my emaxx would probably fall apart and my stock tires would explode, but it keeps on running. I can see where they would not be good for a race and thats probably why everyone is against them. I'd still throw the 7XL against any nitro and come out ahead any day of the week.

I know Brian G is against the fans, but I just realized your in Iowa. Even a feigao wont heat up out there in the cold. Out here in Vegas when you start your run at 110 degrees the fan will keep temps under 170. Between May and August I just dont have a choice.

Yeah, when I had my converted Revo, a Feigao worked well for me too since I was using 14XGP3300 cells and got around 14-15 minutes of runtime. Just enough to have fun before the cells dumped and gave it enough of a break for proper cool down.

LOL, ya know, it does get hot and humid here in the summer too. 90-100*F days are not uncommon in the summer. Even then I never used a fan. Truthfully, if you need a fan, just get a bigger motor with a similar kv. Power drain will be the same but the added surface area helps a lot.

I'm agreed on the surface area, but the 7XL is as big as they make them. I spent some time experimenting trying to keep the motor cool, and even that small heatsink with an 80MM fan didnt do enough. Just blowing air over the motor didnt help much. Best thing that has worked for me is the Novak heatsink. It gives the motor a lot more surface area for cooling and with the body off it stays a lot cooler.
100, thats nice and cool. I'm sure the humidity gets ya though. I remember a couple years ago I couldnt go outside for a whole week and the temps were in the 115 range the entire time. It was painful to even just walk outside and you almost couldnt breathe.

Feigao does make a 580L can


http://www.offshoreelectrics.com/pro...prod=fei-580-L

WOW, thats a big motor.
"1400 - 1800 Watts Maximum with proper cooling."
Ummmm I dont think there is a fan big enough for that one.

I know it's probably a dead horse and all, but while adding a fan may stave off overheating, it can also provide a false sense of security, so watch out for that.

If you guys think running a feigao with a fan is dangerous you should try running one without and see how long it lasts. Without the novak heatsink I added, the motor heats up pretty quick and the can does nothing to dissapate the heat. Even blowing air over the can didnt do much to help. I think we are all agreed, its a good beginner motor to get into the hobby to see what these things can do, but its not a long term solution.

one thing to remember about a motor is that the heat is generated in the interior and works its way outward (thermal dynamics) and when you blow cooler air onto the motor the cooler temp will not go beyond the edge of the hotter temp, so when you use a fan all you are doing is cooling the case and doing nothing for the rotor and magnets (the important parts of an electric motor)

Ok so im looking for some suggestions on what motor to go with here, My revo is currently got a RCM Mount with mechanical brakes, 4s power and a MMM, is a 60mm medusa enough or should i bump to a 70mm? Any one running a Losi motor? any help os appreciated!

go with a 70mm

ok now that the weather had cleared up, i went to run the maxx with the new 58tooth spur from the 24/68 to a 24/58. and indeed, i did hit my 47 mph mark. well...46.9, but close enough. i gained about 2-4 mph.
and better yet, my motor stayed cool still. the entire run and motor only 152 degrees!
mmmv1 120 degrees and lipos 101 degrees.