pbmax

It seems I've FINALLY found a motor that can get me to 50+mph on 3s lipo in my mini inferno without overheating the poor quark. And that motor is (you guessed it) the permax 400/4d with a 3.2mm shaft so I can run bigger pinions

I'm running the permax in a 3racing fan/heatsink engine mount wired directly to 11.1v (poor fan is rated at 7.2v). The fan keeps it at a pleasant 120F while the ESC tops out at just under 160F. I'm very happy with the fan so far - lowers motor temps about 30F (no joke!).

It's running an 18T pinion and a 30T 3racing delrin spur / slipper replacement gear with 1/10 touring car foams for a theoretical top speed (assuming droop to 10.5v, 5200kv, and 61mm tire diameter) of 49.25mph. In previous GPS testing, the permax tended to run a bit faster, so I'm probably hitting 50+.

From the temps, I can probably bump it up even more. I might try a 20T this weekend...we'll see. [8D]

I wrecked my brand new (body isn't even painted yet) brushless / lipo xxx-4 today so the poor KMI is going to have to hold me over until replacement parts show up. The neighbor had the nerve to put cinder blocks in his yard.... [] I came darn near thermaling the mamba max I just got today too...who'd have thought 26T and 65mph would be over-geared for a 7700kv motor!?

jaejw1

I knew it would work,,, but no one would take the time to find the right gearing,,, im glad you did,,,, I will post this link in halfeight.com and also one18th.com if you dont mind,,, I even think mr. mugen had his doubts aout the motor....

glad to see this motor is well rounded for any vehicle,,,,, now it is time to race it among other KMI

pbmax

I figure if I mount a small fan to the ESC heatsink like I have on the motor mount I can push it even further. We'll see...

Go ahead and cross-post; everyone should enjoy permax happiness! [8D]

jaejw1

how fast do you think it woul be just with a 2s lipo.. and maybe a larrger pinion

Frozen72

Yea I'm going to for my birthday and the end of the summer. Yea a fan would help a lot it did on my ESC.

jaejw1

i posted the links here. http://halfeight.com/forums/showthre...7167#post27167
and here.. http://www.one18th.com/forums/showth...279#post400279

jaejw1

i have no issues with my esc.. none.. it stays cooler than my motor..

big terp 77

anybody run it in the 18t? how would it compare to the mamba series.

jaejw1

it wont work,,,, the pinion gear you would have to use wont fit the chassis,,,, it would need to be something as rediculous as 26/55 ,,,, but why would you subject yourself and limit yourself to something like that when the mamba motor is a perfect match,,, for the cars gearing and weight

big terp 77

i hear you guys always raving about the motor. i was just curious.

jaejw1

well put it this way.. my ammo 3900 motor in my detta st geared at 19/41 was about as fast as my rc18t with mamba 8000 motor geared at 12/60.. about the same torque and same speed.. this is with a 2s lipo..

pbmax

Unfortunately, to get decent speed out of it you'd have to gear it pretty high. With a stock 32T spur and a 20T pinion, it hits 50 with 3s. The same gearing at 2s would put it about 33mph, which is okay...but not great. 19/45 2s gearing in the vendetta puts it about 43mph with the permax (according to calc and gps), so comparatively the KMI on 2s + permax would be running significantly slower. I think there's room for maybe 4 more teeth (effectively - smaller spur, bigger pinion), which puts the speed at around 40mph (with a 24T or 22T / 30T), but I'm not sure how well the motor would handle the high gearing. I guess I could try rigging up a 2s parallel setup with my 2 vendetta 1500mah lipos (and lots of tape / zipties...) and see how it does.

The above calculations assume the cells are at 3.5v under load and tire diameter (1/10 foams) is about 2.4".

MikeMayberry

My Feedback: (1)

The motor is also available in a 2.3mm shaft version that can use the stock pinion. http://hobby-lobby.com/brushless-multiplex.htm

This combo on 3S Lipo is perfect for all around use.

Mike.

erichiu

Well, that what I am using, permax 2.3mm with quark. I have hard time to looks for pinion gears for it. Anyone know what 2.3mm shaft size gear that fit KMI? I am running GPM 16T/ Atomic 32T with 8-cell 1500 elite battery pack. I don't have a rader but it looks like around 30+ mph. Pretty happy about it.
The ESC is kind of at the warm side. Would like to connect a fan but don't know how...

jaejw1

why is everyone getting the 2.3mm shaft version..... you are limited on pinions

next time get the 3.2mm ,,, there is a wider range of pinions to use