Mooshu Beef

iTrader: (7)

Hi guys, I posted this in the on road forum, but I think more people on this forum will have had experience with this:

"Hi guys, some of you may remember the Pro 2 turned into a rally car by the means of a polycarbonate tray on the top and bottom to give the driver more confidence when driving through gravel pits with a belt drive car...

However, after a run to test how the drivetrain was holding up to my Mamba Max 6900kV motor, it was the mamba that was closer to breaking point.

After picking it up and opening the cover, I touched the heatsink and burned my finger. It had that post-burn-feeling last night, but now it is fine. I don't know if that will better gauge the temp.

My question is that I believe I am going to have lots of temp problems. I had been using a TT-01 which was a 20:61 ratio and the 31T (I think):81 spur gear was a bit much. I do also have a 91T and a larger spur gear that is purple from HPI--I dunno how many teeth that has.

However, I think the main problem is lack of circulation. Is there point to putting a fan in a chassis that basically traps the heat? Should I open a hole just in front of the ESC so air can flow through it, and another larger hole in the back so the air has somewhere to go?

Also, there is no room for a heatsink for the motor. Is there any low profile heatsink that is effective?

If this all fails, I will take off the cover. However, one of the reasons I got this was to use the cover (but mainly for the higher clearance. My area is very bumpy/hole-y).



Also...I really can't fit my ESC that well in this chassis. There is basically no room next to the belt.

Thanks in advance for any responses!"

Questions: how do you keep your stuff cool even if it is under a cover? I know the 501X and other chassis are closed to keep out debris and such.

-How would you secure the ESC? My mamba keeps coming off the tape because it gets so hot and the adhesive doesn't hold that well.

Mooshu Beef

iTrader: (7)

no ideas...?

Paul_Sinclair

I really have no experience running with a closed chassis, but just some thoughts...

A fan would help circulate air around the chassis, even if you left it closed up.

Better idea: I would put a few holes in the body in front of and behind the motor to allow air flow through the chassis and across the motor. Then, go get some fine mesh screen and shoo-goo it across the openings, inside the body. Belt drives aren't too susceptible to fine dust in the short term; the real fear is small rocks, clumps of dirt, pebbles, etc. So the fine mesh will keep those out while allowing airflow. Its kind of a compromise, as you'll have to clean the belts and pulleys kind of frequently (because of the dust allowed in), but you won't risk insto-death for the belts and will have a cooler-running car.

I don't think there are really any competition off-road cars that are sealed up by the body, for the reason you're pointing out. Even cars such as the 501X and the Yokomo BX, which have open belt drives, have large cooling holes for the motor and electronics:
http://www.oople.com/rc/photos/super.../OOP_0795.html

Hope that helps some.

STEALTH

iTrader: (21)

Paul hit the nail on the head! Strategically placed vents on the body (to allow proper air flow) plus a fan should drastically help keep your ESC temps down. The motor may be another story... you may have to bite the bullet and just gear down. The mesh and shoo-goo idea is key as well... its what I do with all my kits that are sealed up...

Mooshu Beef

iTrader: (7)

Thanks guys, I think I'll end up doing that. I need to find a fan for this though...