Bummer.

Not suprized about the KD motors, they do only seem to last about half a dozen runs before the temps go a bit ka-ka. So, back to waiting for the 70mm medusas again....

hey neil sorry for bringing up this thread but i wanted to know what gearing would you reccomend for this motor? i just ordered the 1845 version and will be using 14 cells for now. waht gearing should i use? i have a 68 tooth spur gear. waht pinion would you reccomend? im a basher and own a 3905 (stock tires pretty much stock besides bulks and rpm stuff) and i am looking for a balance and speed and power with cool temps. i also have the MMM. thanks again if you can help.
also would you reccoemnd changing the stock connectors to the high amp 6.5 castle ones?

I'd definately say change the connectors- 5.5mm ones are more than fine, and easier to solder/ find heatshrink tubing for too.

I have the 1845kv motor (9XL), and currently run 24/70 on 5s lipo, so I think for your 3905 truck and 14 cells, something like 24/68 comes out at 35mph, which I believe is about the best you could hope for really using nimhs and a large BL motor. Depends though, the lighter the truck, the higher you can gear slightly, so 65/24 is possible, just watch the battery temps closely more than the esc and motor. Good luck.

thanks a lot neil. ill be ordering my pinion soon...i have to get more solder those connnectors reallt do use up a lot.

Final update on testing:

Killed it :cry:

Its weird, 3 trips back the motor was fine, just needed a cooling down break after 10 minutes or so to keep things under 180*F.

2 trips back I decided to gear up seeing as the batts and MMM were fairly cool, so maybe I was too conservative on the gearing and actually under geared it. Answer was no, I was just pushing to hard and got the motor upto 180-190*F in 5 minutes, so lots of coolling down breaks that session (until I killed the tranny again).

Final trip out on Saturday and I was hopeful- geared it down a fair bit and ambient temps were stupidly cold, so... Anyways, started out fine and after 5 minutes I was only at 110*F on the motor, brilliant, then a large crowd gathered round of families and kids who were in the park (who takes their kids to the park on a freezing winter's day, weirdos...), asking lots of questions like how fast/much £££/where from/ power source etc etc. I put on a little show for them; basically stupid amounts of WOT and crazy suicidal high speed passes that were rather dangerous as the crowd were stood infront and to either side of me, so I couldnt really see where I was going all that well from my parkbench/shelter location. No injuries though, just lots of 'woos' and 'wows' :mdr: (massage that ego baby), until the truck suddenly ground to a halt and refused to move again, just rocked back and forth when I appied throttle. I was hoping it was a loose pinion as I now have an all metal tranny gear setup, but nay, I saw the small stream of white smoke coming from the front of the motor when I picked the truck up, and knew it was toast; temped at 242*F which is much less than the 358*F the hobbyshitty motor died at.

Upon opening up the motor I noticed the magnet was incredibley weak even though it hadnt been cooked that baddly- free spinning with zero resistance, and the windings smelt like an old ashtray again, so no saving this motor saddly. Still, I have another cool fridge magnet, and a really cool pencil holder...

Anyone know if Mike will be selling the 80mm Medusas? I emailed him about it on saturday so hopefully will hear something next week (only the 50/60/70mm motors in the store at present).

Man, i wish i had a cool magnet...... Sorry to hear about the motor.

Neil man time to give up on your great Chinese hope. You are 3/4 of the way owning a Neu 1515 2d with that waste of experiment. Not too fast (sometimes) not to slow (ever) for 5s lipo or your 6s a123 perfect motor !!

Hobbycity 9Xl = $30
BidProduct 9XL = $46
Total = $76

Not quite the ~$250 needed for a neu 1515, heck, actually about the same cost as a feigao, and that would've burnt on me too probably. :mdr:

Now Im just waiting to hear back from the Monster with regards to the 80mm medusas- how dare he take a christmas break like the rest of us! :whistle:

Add the shipping costs lol.

mine died too this christmas eve! i split the rotor right in half right after i bought my 4s pack. it was really fun on 4s but now im just going to wait for some money to accumulate and get the 70mm medusa! it was a good little motor but once i got a good battery it new its days were numbered.

Bummer, must be some kinda suicide cult...

Shipping costs werent too bad really, I think about $10 for each motor, so nothing too steep. Still, if you dont take a gamble every now and then, you'll never find out if these things are any good or not. :smile:

yeah that is true.

i think it would be better powered with nimhs. likw some good 7 cell packs not old and probally shorted packs like mine.

Sounds like the rotor was de-magnetized by overheat, and then a deadly pull on your throttle sent the coils to heaven.

These motors are also known for their weak magnets, can easily fail by hi rpm, just split into pieces.

You mean the bidproduct ones specifically?

The magnet is a nice one piece item, but it seemed to de-maggetize a bit too much/easily compared to the hobbycity one I had back along.

Interesting question though for the masses: is a single piece magnet better or worse than a segmented one, all other things being equal?...

Segmented is better. Splits up the magnetic eddy currents. Also, if there is a weak spot in the material, using a segmented setup increases the strength by splitting them up - kinda like how plywood is better than solid wood for the same reason.