Outrunners supported/held by the shaft?
 

I am working on a unique project that includes an outrunner motor (not just a direct drive)... my question is this: is the stator and rotor held together by the shaft that is removable? I know you can take the shaft out, but then does the stator and rotor separate at this point?

I know not many people have experience with outrunners, but maybe Sike or Linc can chime in?

At the front of the motor on the mounting side, there is usually a locking collar or a snap ring. After removing that, just pull off the endbell.

Be careful. The magnets are very strong and if you slip, it will pinch your finger tips.

I hope this helps.

When you get it apart, check out the winding on that bad boy. :yes:

Yeah the shaft is moveable to allow you to drive from either the static end or the rotor end. Another tip I learned, when putting the rotor back over the stator, don't allow the field to 'snap' the rotor back on. The impact can take out the front bearing, which really sucks if you just changed it.

Okay, so when the shaft has been taken out, can the stator and rotor still spin, and/or is it supported by something else as well? The project I'm doing does not require the shaft, instead will use something else (a shaft of sorts.... shut up Linc :wink: ), I will just have to do it a little differently than I was originally, no big deal. I can't believe no one has tried this yet! (it's a little complicated, but still) Sorry, can't tell you what I'm doing! :rules:

Nope, not the way your thinking I'm afraid. An outrunner is just an inrunner turned inside-out. One piece shaft, full length. Excess shaft can be cut off, but the shaft needs the collar on the stator end, that's the main thrust bearing. The front bearing is only for alignment, it sees no lateral load.

Between myself and other members like sike and linc (there are still more, just can't remember who) we've had plenty of experience with outrunners. And why is it you can't tell us?

Cuz then I'd have to kill you.



J/K, but it really is that unique, and it very well deserves developing, whether I do or not remains to be seen though... I just need to make prototype first and see if it will work.

Can we guess? :mdr:

Go for it man, I encourage it!

BTW, welcome to the forum! :smile:

This is the model I am going purchased to design it around. Quite powerful, but only one of a couple that will work.



http://www.innov8tivedesigns.com/pro...roducts_id=539

Awh, no HK series? Those things, judging by the numbers, seem like they should be real powerhouses. Too bad the kv is so high...

My guess would be that you are planning on using the motor to replace a diff, and are planning on using some sort of planetary reduction. At least say if I am close?

Time machine............

You're close. :smile:

Thanks!
My guess would also be on replacement of a diff. Other things that come to mind are mating a ring gear on the shaft, and attaching the motor to the bulkhead. Or replacing the standard shaft with a nitro engine crankshaft turned down, for attaching a clutch.
Keep us updated!

Here's a simple question I hope you can answer: what voltage will you run?

6s lipo

Hmmm... 10 slots, 12 poles- is it me or does that make 60 "ticks" per revolution.... :mdr:

So a top RPM of ~10,000. And if using truggy/MT tires it would require a reduction of about 4:1 to achieve ~45mph.

Will there be only one for the entire vehicle (assuming 4 wheels)?

It would make 30 commutations per revolution. I am just wondering what the torque is on this thing, and what the max rpm is, then I can get a relative measure to how powerful it will be. I wish they had a peak power rating for it as well, as it would be more useful than continuous power rating.

Metalman, about your question about why not "HK" series, the Kv. for the non-HK model was the ideal number (460 kv.) for 6s lipo.

Yes, this will be for a truggy platform, as it would be too fast for a Revo drivetrain (2.8:1 diffs)

You can get the Scorpion Calc here:
http://www.scorpionsystem.com/downloads/
(2nd item on the list)

So it will use truggy diffs. Will the outrunner's output shaft be a part of the diff input shaft?

Thanks for the link Metalman, I DL'ed it, but it doesn't really do us surface guys any good as it is based on max rpm loads, and not full rpm range. It states a peak 90% efficiency which is nice.

About your question, I can't tell. :smile: You may as well stop asking, no one will ever guess it. :wink:

Here is a spec sheet, doesn't tell much useful, but cool to look at non the less.

Depending on how well the outrunner is built, they can go as high as the ESC can run it. I've heard of outrunner going over 30K RPMs. Some have been rewound to make sick amounts of power and used even to set a 400MPH+ plane record.

:surprised: Linky???

Enjoy the wonderful work of Powercroco:

http://www.powercroco.de/scorpion.html
http://www.powercroco.de/crocospeed.html
http://www.powercroco.de/extremmotoren.html

A modified Scorpion motor was used to set the speed record I mentioned, but I can't seem to find the exact link in the site. It was mentioned in RCGroups.

Edit: It's actually over 400Km/h+. I'm going through the links now and man, it's always awesome.

Wow, that guy has some serious motor winding skills. It would be nice if he had some vids... it seems like he just builds them and takes pics and no action, lol. :neutral:

I really like the slotless outrunner he made, very cool.

He has amazing skills. It would be nice to see some of the outrunner brushless gurus of RCGroups to come here and give some input.

So, what are you cooking up? Did you get abducted by some form of super intelligent creature and got some technology from them? So far I've only seen 2 UFOs, not little gray or gree guys, but just 2 UFOs.

I second that. :yes:

http://www.powercroco.de/slotless_outrunner.html

I think I might have to just spill the beans, because I am still trying to work out a few design issues in my head before I can even CAD it. The issues are mainly due to not knowing exactly how the outrunner in question is put together and a couple of 'assembly' unknowns.

I'll be on later to post a a simple drawing of it, and explain how it work... we may as well do this together! :mdr:

I'll be glad to help!

Alright, here it is. I hope you guys understand the drawing... the red shaft is a custom made shaft to replace one of the diff output shafts. It will travel through the outrunner (replacing the stock unit), and somehow be seperate and free from the outrunner stator AND rotor.

There would be a bearing support for the shaft where it comes out of the motor obviously, and that would be integrated into the whole support. The attaching of the motor should seem simple, but I would need to have both a CD and the motor in front of me to be able to design it, but I would like to get some opinions on whether it can even work. Some sort of adapter plate, but how is yet unknown.

Also, I was thinking Mike's slipperential design could be implemented into it as well, somehow making the attachment onto the slipper coupler on his unit and replacing the gear with a coupler of some sort.

I would just like to hear some comments on whether anyone would even want something like this, or if it's just not worth it plain and simple. I just think it's a cool idea none the less, and would allow allow almost perfect left-right balance in the chassis if twin packs were used and esc was centered, then the steering servo on one side, and the receiver/BEC (or Rx pack) on the other side.

This is just a little guy, but should give you an idea. This one is 38mm diameter X 25 long, 5mm shaft.

So you're trying to attach the motor to the diff casing, right? Seems like a simple adapter plate would work, or maybe run screws straight through the diff casing into the motor. You'll probably want a bearing around the outside of the diff casing to add support in the area where the two join. Looks like a cool project. :great:

Thanks guys, and thanks redshift for posting that... so are ALL outrunners assemble that way? If so, then that is perfect for the design, of course we just have to be sure...

BTW, I call it the "diff-runner"

That question is better left to the OR experts.

Sikeston..... I see you :whistle:

This is do-able for sure as long as you consider gear ratios and roll out in your setup.

By connecting the endbell to the diff, you're adding a flex point.

You can get by with this, as long as you use a motor with the endbell bearing. It's a press fit, but will prevent the magnets from contacting the stator during hard acceleration or braking.

Does your motor have the larger press fit endbell bearing?

LOL

I was processing.

Take a look at the 3032 Scorpion Motors on the website.

Here's talk about the bearing. Without something like this, you will have problems with flexing.

"The new version 3032 motors now have an extra ring bearing to support the back end of the rotor can for rock-solid stability. This prevents the shaft from flexing under load, and maintains the airgap between the stator and the magnets under all operating conditions."

If the Shaft will flex on longer endbells, your diff cup WILL flex for sure.

Are they all about the same construction Sikes? I know the larger ones use the rotor face instead of the shaft for drive connection, but the guts are the same-ish yes?

Yes, most are the same. Also, most outrunners can drive a prop from either end. By either using a collet on the mount side, or by mounting directly to the rotating endbell.