feiago 9xl
 

Is anyone more than 15 minuets of run time without overheating?

yup. you probably want to post your setup. It's going to be pretty hard to troubleshoot your issue by only knowing the motor you run. At a first guess, I'd say you're overgeared. As a second guess, your batteries aren't up to snuff.

J.

youll be able to test that theory soon 83gt :D

lol. If I could run the revo for 25 minutes on the 8xl without overheating, I imagine the 9xl should have no troubles at all.


J.

The Feigaos are gonna heat up eventually no matter what. Running a HV setup with a higher turn (lower kv) motor and gearing just right will be the best way of improving heat.

My set-up is a jammin crt x1 with feigao 9xl,heat sink,mm esc, thunder power 4s1p 5000mah lipo 12/46 gearing and stock diffs.

Hrm. That seems like a pretty solid setup to me. Is it the ESC that is overheating or the motor ?

J.

Hi,

I'm running the 9XL with 5S 4000mah Maxamps packs. Gearing is 13/46 in a heavy buggy (around 4.7 kg). My esc is a BK 12020 under a 60mm fan sharing the same battery as the motor. This setup allows me to run around 20 minutes with manageable temps. I live in the tropics where ambient temperature can reach up to 35 deg C. So far, the 9XL has survived. I'm usually more concerned with the esc blowing up though.

Regaards,
Joe Ling

The motor was way hotter than the esc, couldn't touch it. I could hold my finger on the esc for about two seconds and the battery was warm but not hot. It would shut down for a couple seconds let off the throttle for a few and it would run and then repeat, but no esc warning or anything.

maybe under geared.... I'm assuming the connections are all good and the car/truck rolls easily..

i think undergeared - i would guess that the motor is running flat out most of the time...

Do you find yourself at 100% throttle for long periods? Have you used briang's script - gear for 35mph ish

do you have an rcm heatsink - works well and you can add a couple of 25mm fans iy you want

The crt has buggy ratio diffs, 43/13. So he is way overgeared, with the 46/12. I have a crt and will upgrade it to the HB truggy diffs, 43/10, and run 46/13 primary gearing.. Stock spur on the crt is 62t. So changing back to that spur and running a 12t hardened pinion would do the same as the truggy diffs. Give that a try if you can, and see how it does!

It's a crt x1, not the buggy. Mike at rc monster told me that I was undergeard and needed a 16t pinion. Does that make sense. Oh and to answer the other questions, I do have a heat sink and the connections are perfect. Also the truck rolls fine. thanks guys

According to OFNA website online manual for the crt x1 it has buggy ratio diffs, 43/13.

They list 40516 for the pinion: http://www3.towerhobbies.com/cgi-bin...FVSEARCH=40516

And 40517 for the ring gear: http://www3.towerhobbies.com/cgi-bin...?&I=LXLMX2&P=7

The truck also comes stock with a 62t spur gear and a 13t clutchbell to make up for the tall tires, 5.75", considering it has the buggy ratio diffs.

So you are only turning the 9xl 27k rpm max right now.

Here is the speed calc of your setup:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 12
Total Voltage: 14.8
Motor KV: 1853
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0092
Spur/Pinion Ratio: 3.83 : 1
Total Ratio: 12.67949 : 1
Tire Circumference (inches): 18.06 inches (458.83 mm)
Total Motor Speed: 27424.4 RPM
Vehicle Speed: 37 mph (59.43 km/h)
Effective Speed Rate: 2.5 mph/V (4.02 kmh/V)
Estimated Adjusted Speed: 35 mph (57 km/h) - 5% loss
Effective KV Value: 1853


I am not sure why this is getting hot, but I do not think it is undergeared, just undervolted. Getting the motor speed up to 35k or so will provide better results, but then you will have to gear down. That is why i suggested to either go with a larger spur or the hb truggy ratio diffs.

I thought you had a buggy for some reason, which is why I suggested a 16t pinion - 12/46 on a buggy would be undergeared, but on a truggy it may be the opposite, considereing the buggy ratio diffs. Using the stock spur, a 16t pinion is about the sweet spot for a 4s 9xl motor (buggy or truggy usually).
I would agree with the pimp on this one. The gearing isn't too far off at all for a truggy with buggy diffs - perhaps slightly overgeared if anything, but it sounds just about right. 5s and truggy diffs would likely reduce motor heat for this. The 9xl ran pretty hot in my Losi 8t - after dumping a 5000mah 4s pack, it was typically around 180F or so. This is kind of the nature of the lower end motors - for cool temps under hard abuse, a Neu motor is the answer. Fans would also help the cause - cheap insurance IMO. :)

Mike- nice to see you online, can't wait for my new parts! -Harold

I am here every day - I just don't log in, so you don't see me (but I am watching you, so don't get out of line). LOL :)

uh oh, big brother is watching! :wink:

Mike, when are you going to fix your avatar?

So if I go with the neu motor I can leave everything else the same diffs,battery and gearing?

Thanks Mike, that is what I figured, the motor rpms are a bit low on 4s, and the taller gearing will load the motor more causing higher temps. I have a crt, but have not got around to doing the conversion. I figured that I will put the truggy diffs in it, as I have them. I want to use the kyosho spur as the pinions I have to fit the KB45 are not hardened.

On a side note Mike, do you think that you could have the hardened pinions made with 6mm bore? Or would it be better to have my local machinist turn the shaft down to 5mm? Also, any chance the motor mounts could be modded during machining to fit the larger bolt pattern on the kb45 series? I do not mind making my own mounts, but yours are much nicer looking, and stronger too.