[Sammus]

Originally Posted by sikeston34m

Yes, this is true. There isn't a specific comparison thread about it, ya gotta read between the threads. LOL

Or just ask.

Both setups use 5000mah 20C 4S Lipo

AXI 2826/8 geared 22/40 - Great little setup. I would have to say the MOST efficient setup I have ran. Usually about 10 extra minutes of runtime than an inrunner setup. This motor will run higher gearing, but temps get "uncomfortable".

Medusa 36-60-2000kv geared 52/18 - Another Great setup. Medusa makes the best inrunners I have ever owned.

It would have been easier to compare the two if I were using an older style feigao 2 pole motor. The gap on efficiency and operating temps would have been large.

When Medusa made this line of motors, they did alot of things right. The 4 pole design is truly superior to the old 2 pole motors. I love my Medusa. A little less runtime than the outrunner, but it makes good power. This setup continues to break driveshafts.

On the other hand, the AXI setup would dominate on short track.

Mike's speed calculator shows these two setup like this:

AXI geared for 30.15 mph
Medusa geared for 33.59mph

I GPSed the Medusa setup at 38mph, so these the calculators figures are a little low.

The AXI setup tops out ALOT faster than the Medusa setup. It's quicker "out of the hole". It will yank the front end right at startup, where as the medusa comes into it's real power a little farther off the starting line.

"when sik said "A super low kv inrunner would make ALOT more torque" I thought he mean than an equivalent size/kv outrunner. Now I think I may have misinterpreted his response."

Sorry, I should have said "A super low kv inrunner would make ALOT more torque than it did before." Not to be interpreted that it would make more than the outrunner.

That is a marked difference. Did you get to GPS it with the outrunner in it? The calc figures show the medusa is geared 10% taller, it would be interesting to know how much difference the runtimes etc would be if they were geared a little closer?

Nice results though.

Originally Posted by sikeston34m

Let's talk about why outrunners have more torque.

A Medusa 36-60's armature is 15mm in diameter and is 35mm long. It has 4 VERY strong magnets, thus making it a 4 pole motor.

An AXI 2826's stator size is 28mm in diameter and is 26mm long. The ID of the magnets inside the rotating endbell is 29mm.

The larger diameter is "easier" to turn because of leverage. This is why there's a knob on the door instead of just a shaft sticking out. LOL

Take a look at my avatar. For each phase shift, there are 4 teeth of the stator energized at any given time.

This means, at any given time, there are 4 magnets in use at any given time. More Magnets, greater force.

Understood. Before and after ;)

Originally Posted by Takedown

Sammus, go on youtube and search 'outrunner stampede'.My setup was MM modded, 4s 5000mah lipo, hextronik 36-48 size outrunner that directly fit into the stock tranny. Motor mount spacing was the same aswell. I could have geared up a ton but didnt have any higher tooth pinions at the time. The motor pulls 850w max. I dont know about you but that outrunner for how small it is puts out a sh!tload of power. Tbest thing was the MM and the lipos were ice cold. The outrunner ran hot , undergeared...

Are you sure it was undergeared? maybe the hobbycity outrunner was just pulling more current than it could handle. At any rate, unless you've directly compared to an inrunner geared to a similar speed, the test results don't mean a lot to me :p Sure looks like a lot of fun though, and is motivating me to experiment. Soon as I get this damn government payout haha. Our stimulus gives nearly everyone in the country about $900 we're encouraged to spend. Sweet, so the missus can't convince me to save this time lol.