A whole new level of spun axles - what 10KW does to an X5

methods

1 GW
Joined
Aug 8, 2008
Messages
5,555
Location
Santa Cruz CA
So this is my second X5.
I have "blown it" and "resurrected it" 4 or 5 times now
I am running on 24S lipo with a 120A current limit (via my Gangster controller)

The last two failures were due to the axle cutting into the phase wires...
Know why?
Because I am running so much power that I have managed to rotate the stator on the axle :shock:

Damn stator rotated 90 degrees on the axle and that is why my cables keep getting cut....
.
.
003_Nov09_axlefubar.jpg
.
.
In case you were wondering, that cable guide slot is suppose to line up with the circuit board.

WTF?!? :?

Exactly what the hell am I supposed to do now...???
Yea - I know it can be rotated back and I can machine a key between the two but COME ON....

I suppose I should feel like some kind of bad-ass for wrecking shop on X5's but I had plans to run this hub on my new KMX trike
This sucks - I am going to sell it to someone who can fix it I think.

Cant we get a proper hub motor around here.........?

-methods
 
Yahoo :mrgreen: :twisted: :mrgreen: :twisted:

If the stator is steel, weld the axle to the stator, after lining it up of course.

I had a similar deal with a brushed motor I melted. Instead of a stator on the axle there was a similar looking hub with the magnets on it. The thing was in two pieces, and when it got hot, the outer band would expand and start slipping. So you'd hear the motor running inside, but the dang wheel would not turn? Huh? That one took awhile to figure out.
 
bikeraider said:
Hi Methods.

I think the axel never turn, the motor as turn as certain point and show you what I mean with this picture.
I hope, it helps, good day!
Bikeraider

I dont quite understand what you are trying to say. I think it is a translation issue.
I can tell you that the Stator has turned in relationship to the axle by about 90 degrees.
There is no doubt about this fact.

-methods
 

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Yeh I don't know if I would weld it I think I would try but the axle is hardened steal it might not be very easy to weld. But I am kinda seeing that the x5 may not be for us methods. I will try mine out again soon. But I am thinking I have two future options buy another x5 and weld it or machine it to hold and figure out the cooling! One thing I must say methods if you could keep you stator cooler it will hold tighter on the axle! I am sure we will see pics of mine on here soon as well!
 
methods said:
bikeraider said:
Hi Methods.

I think the axel never turn, the motor as turn as certain point and show you what I mean with this picture.
I hope, it helps, good day!
Bikeraider
I dont quite understand what you are trying to say.
-methods
I think bikeraider is suggesting that the material in the stator sheared along a "fault line" a short distance out from the axle...
 
There are actually 3 parts in there: The axle, the stator, and some sort of insert. The slip happened between the insert and the stator
I am sorry - I am a mechanical retard so I am not very good at expressing myself in mechanical terms. :|

-methods
 
methods said:
The slip happened between the insert and the stator...
So those two parts would need to be joined by something stronger than a press-fit, looks like.

I wonder if drag racers encountered these kinds of problems as they took passenger-car motors and hugely increased their power... it's conceivable that some of their solutions might be useful here, to hold things together which were never supposed to come apart :shock:
 
You mean like my Honda Prelude that had a 2.2L DOHC Supercharged VTEC or Lukes insane nitrous hatch or my turbo hatch-monster? :mrgreen:
Man... been there.... done that... that is why I am here! Too expensive :(

With the cars it is all about aftermarket parts.
Take up out - bolt um in.
Luke fabs his own parts but he is a rare bird.

Here we are on the cutting edge... No aftermarket to lean on. Only the guys with a fab in their garage can really get crazy.
Hacks like me have to do the lame-rod shuffle.

The way I would fix this would be to machine out a groove between the two parts. I would then press in a "key"
I could do it down at the local machine shop but I am not willing to put another $50 into this crapwagon.

-methods
 
Methods...if you can drill half a dozen holes around the insert (from the other side right through to this side possibly?)
Do the same with the stator and then cut a doughnut shaped plate (*2 of them) bolt them up in place to secure the two together, no welding required only a drill press some high tensile steel bolts and some steel or aluminium plate...

KiM

EDIT: quicke photochop to explain better the idea-->

ES Methods.JPG
Alternatively, DONT drill the insert WELD the disk to the axle and bolt to the holes in stator
 
HAL9000v2.0 said:
YOU ARE MY IDOL !!! :twisted: 8)
...

Nice Job!

The spoked part is aluminum, so welding is out.

Drilling and pinning would seem the easiest approach. It may be difficult to spin the stator back to its original position. I'd suggest drilling a cross hole, but since the stator is in the way, you can't come in at 90 deg. to the axle. You could come in at an angle as close to 90 deg. as you can get with your drill. I'd suggest doing a pilot hole of smaller diameter first, then follow with the full sized bit. After that a bigass roll pin should slow it down. Maybe two roll pins, one on each side. It would be ugly, but nobody will see it.
 
I know something that you just all can't imagine about strengh of EPOXY !!!


The 3M DP-460 IS WHAT YOU NEED Toughened to provide high peel and shear strength.

I used it and personally tested it on many conditions.. and this epoxy is incredible!!

That structural scotchweld epoxy is like steel!! and the adherance is awsome on any metal.. aluminum, steel, cooper, etc...

It's like that epoxy have been made for broken axel/stator on X5 !!

the PSI is incredible

when it is completly dried, it is as hard as steel !!

The surface preparation is the key with glue.. I suggest to clean everything and to sand with 120 sand sheet

http://www.3m.com/intl/kr/img/adh/adhesives/dpseries/DP460.pdf

some spec:

Aluminum, Overlap Shear, at Temperature (PSI)
-67°F (-55°C) 4500
73°F (23°C) 4500
180°F (82°C) (15 min.)1 700
(30 min.) 1000
(60 min.) 1400
(4 hr.) 2500
250°F (121°C) (15 min.)1 220


15.99$ on ebay
http://cgi.ebay.com/3M-Scotch-Weld-...emQQptZLH_DefaultDomain_0?hash=item19b4f676d0


Doc
 
I suppose I could have the machine ship press the axle out and re-seat it.
I could then grind groves all around the seam and epoxy.

Either way - If I do waste any more time with this I will definitely pin it afterward...
I really dont think it will take much to stop the rotation from happening again.

Hrmph!

Now the only thing I have to use on my KMX Typhoon (Matt Hunter) is this drilled 9C that I just made :twisted:

001_Nov09_9Cmod.jpg
002_Nov09_9Cmod.jpg
005_Nov09_9Cmod.jpg

Dont need Delta-Wye because this bad boy does 50 in high torque mode.

-methods
 
Hmmm.. now you got me wondering if i'm going to have similar problems with my chopper.. ( almost done PSI battery pack, 80 amp controller..

The X5's smooth instant start is what i like the most, and no buzzzzz of the 9C but rather a nice quiet howl.

But.. fear not method man.. where there is a will there is a way ! put on the aluminum foil hat and get'r done !
 
methods said:
So this is my second X5.
I have "blown it" and "resurrected it" 4 or 5 times now
I am running on 24S lipo with a 120A current limit (via my Gangster controller)

The last two failures were due to the axle cutting into the phase wires...
Know why?
Because I am running so much power that I have managed to rotate the stator on the axle :shock:

Damn stator rotated 90 degrees on the axle and that is why my cables keep getting cut....
.
.
.
.
In case you were wondering, that cable guide slot is suppose to line up with the circuit board.

WTF?!? :?

Exactly what the hell am I supposed to do now...???
Yea - I know it can be rotated back and I can machine a key between the two but COME ON....

I suppose I should feel like some kind of bad-ass for wrecking shop on X5's but I had plans to run this hub on my new KMX trike
This sucks - I am going to sell it to someone who can fix it I think.

Cant we get a proper hub motor around here.........?

-methods

Bicycle parts are just not going to work like motorcycle parts. You want motorcycle acceleration and speed from a bicycle hub motor, Take it apart before you ever power it a do major rework to it so it can withstand the stresses, if possible. That motor just isn't design for the stress your are putting to it. Fix the axle and you'll overheat it, break the magnet free or the aluminum spokes will crack its a scooter motor

It took me a year to go from bicycle/scooter hub motor to motorcycle hub motor and have a product. Along the way I think i encountered everything possible that could go wrong with a hub motor.

I started out with a X5 on a small motorcycle and pushed the bike home or limped home so many times.

Now with the 602 I just jump on the highway and go you got to use a product within its design limits or else!! :shock:

Mark

Mark
 
wow

spun the axle from the stator LOL


I never even thought that would happen with an x5 lol ... only you methods hahah

-steveo
 
^^^ exactly what i suggested previous page (along with the bolting method)
CAD drawing is better than my 30sec photochop effort though hahahaha
Seems like a simple fix too me methods, you have a welder
a drill and an angle grinder...

KiM
 
power junkies. love it

could you get away with drilling holes centered on the seam then just insert some steel rod the same diameter and call it ?

drill would want to wander to the softer material but a short drill bit may help.
 
methods said:
Damn stator rotated 90 degrees on the axle and that is why my cables keep getting cut....
Axle steel.
Stator wheel aluminum
With heat aluminum expands 4x more than steel.

So every time you heat up the stator it will loosen its clamping force on the axle.
Same reason head gaskets fail on motors with alu head and steel motor block.

It might be difficult to turn it back w/o pressing out the shaft. If the shaft is out anyway, why not install a key?

If you manage to turn it anyway, (Maybe clamp axle in vise, heat up stator with a torch, then try to turn),
then you could try Fechters idea of drilling radially though stator and axle. Not as strong as an axial key, but easier to drill. If you want to drill axially to put round keys where the steel meets the alu I would suggest using an end mill rather than a drill bit and ideally a milling machine or at least a very stable drill press. Otherwise you will likely gouge the aluminum, while barely denting the steel.
 
Methy I'm impressed! I'll bet you are the first guy that has done that. Also I like the almost krispy winding color.

As much as you might be tempted to drill a round hole and put in a roll pin. Please don't do it. At the torque you are making the rounded edges will "roll" and act like a wedge to split the aluminum hub. No good will come of that.

Take the motor to a machine shop, or send it to Luke, he knows what to do with big motors... :twisted: . Press out the axle hub insert. Have it knurled. There are knurling dies that will leave axial striations, just like small splines. That is really what you want is a press fit splined interface. Knurl on pseudo splines, then press it in with mucho pressure. I would go for a 0.005 to 0.007 or 0.010 interference on the id and the spline OD if it is steel on aluminum. Thats a pretty big range, but I don't know if that insert surface is hardened. The shaft might be hardened, but I bet the insert is soft. You said you spun the insert in the cast aluminum right?
 
bigmoose said:
Methy I'm impressed! I'll bet you are the first guy that has done that. Also I like the almost krispy winding color.

that is nothing. Have a look at my last X5 :p

file.php


bigmoose said:
As much as you might be tempted to drill a round hole and put in a roll pin. Please don't do it. At the torque you are making the rounded edges will "roll" and act like a wedge to split the aluminum hub. No good will come of that.

Ok.

bigmoose said:
Take the motor to a machine shop, or send it to Luke, he knows what to do with big motors... :twisted: . Press out the axle hub insert. Have it knurled. There are knurling dies that will leave axial striations, just like small splines. That is really what you want is a press fit splined interface. Knurl on pseudo splines, then press it in with mucho pressure. I would go for a 0.005 to 0.007 or 0.010 interference on the id and the spline OD if it is steel on aluminum. Thats a pretty big range, but I don't know if that insert surface is hardened. The shaft might be hardened, but I bet the insert is soft. You said you spun the insert in the cast aluminum right?

Thanks for the tips.
I am not sure if this motor is worth the investment.....
I may pay to have it pressed out, rotated, then pressed back in but anything over that would eclipse what I paid for it. I picked up several so I got a real good deal.

Hmmmm....

-methods
 
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