Air Cooling my x5

[methods]

That is nothing

My last X5 did not fail until it hit ~215C (420F) 125C is only ~250F.... it can get up to 170F (77C) in your car on a hot day with the windows rolled up.
All that is in there is a bunch of wire and some magnets....

I dont know the class of wire used - maybe I will ask Kenny - I am thinking it was E.
Be nice if he gave us data sheets on the magnets and wire.

-methods

 

[methods]

What if we just attach fan blades to the Disk mount?
Cut up an old 6" disk and set it up to take different plastic RC plane blades
I have every shape and size from 3" to 18", no pitch to 10 pitch

Even though the motor is spinning at the same rate, the blades will still throw air at the motor - faster you go the more air you get.
Average maybe 500 RPM?
Probably not fast enough - would need some serious pitch.

I may just mount a ducted fan for a test.
Easy enough to run it off the throttle... higher the throttle, higher the fan RPM

Would make for one hell of an evil sounding bike

-methods

 

[John in CR]

The big question is did you admit to the wifey that you rode around with the brake on and that's why the motor was smoking when u got back.

LOL

...and you're worried about selling stuff to noobs...

Thanks, that's the funniest thing I heard all week, so I get to end my week with a big laugh.

John
(just hoping I don't pull something similar)

 

[methods]

Yes I told her - and it is more funny than you think.

To make a really long story short, when we first got together and started to "exercise" she always wanted to walk. I hate walking so I went out and bought the cheapest bike I could find - $10 on craigslist. I didnt know jack about bikes.....

We start riding this thing and I come to learn that I HATE BIKES!
It was so hard to pedal... So, so hard. Nothing like I remember as a kid.
It got so serious that she wanted me to go to the doctor because I would get tuckered out after only a 5 minute ride.

Turns out the springs on the rear V brakes and popped out and I was dragging the rear brake :?

So -> This is not the first time I have done this.

I am also famous for dragracing a FWD car with the ebrake on.

-methods

 

[steveo]

Hey everyone,

So happy to see almost everyone doing the air cooling!! ... The holes, and the risk of getting the windings dirty is nothing to lose sleep over compared to the faster cooling .

Yes I told her - and it is more funny than you think.

To make a really long story short, when we first got together and started to "exercise" she always wanted to walk. I hate walking so I went out and bought the cheapest bike I could find - $10 on craigslist. I didnt know jack about bikes.....

We start riding this thing and I come to learn that I HATE BIKES!
It was so hard to pedal... So, so hard. Nothing like I remember as a kid.
It got so serious that she wanted me to go to the doctor because I would get tuckered out after only a 5 minute ride.

Turns out the springs on the rear V brakes and popped out and I was dragging the rear brake :?

So -> This is not the first time I have done this.

I am also famous for dragracing a FWD car with the ebrake on.

-methods

lol, i don't know whats better this... or the video where you lose the front hub motor hahaha. ..

dude, where did you find the nice temp monitor ?

-steveo

 

[GGoodrum]

Dude, you left the frickin' brake on? What a dufus! :lol: :lol:

 

[voicecoils]

You owe yourself some Hookworm tyres Methy.

For high speed / high powered street riding they are the way to go.

http://www.jensonusa.com/store/product/TI707A12-Maxxis+Hookworm+Tire.aspx

You'll hate me when you try to mount them to the rim though. I'm not responsible for any loss of fingernails.

What kind of suspension squat are you getting under acceleration? Might want to wind out the rear spring and make sure rebound is not too slow.

 

[John in CR]

OK, so now we know who those ebrake switches were meant for. Time to hook them up Methods. Let me know if you need a pair.

If you'll promise to always have it on your bike, I'm sure we can pull a collection together for a little video recorder. Thanks to the cat we missed the wheel falling off, and I'm sure there's a lot more stuff we're missing.

Thanks for being such a good sport and sharing. Please keep the funny stuff flowing. Just don't get yourself hurt.

John

 

[dogman dan]

Re the brake locked up, good one. Made my day :lol: . I once had a truck stuck in a ditch, and three trucks made a train to pull me out. When the truck moved, the back wheels didn't. Sorry about the emergency brakes dudes.

Put some window screen on the holes in that ventilated motor. Off road at least, rocks get in the darnedest places on my trail bikes.

Hill efficiency, The key to getting a dd hub motor to make less heat up a really steep hill is to go slower. Or faster. Going slow, you can get closer to running the motor no load by getting in a low gear and just using the motor as assist. You'd only need this method if the hills are very steep and miles long. I rode my 5304 in 24" wheel all summer in 95F weather on a route that goes uphill for 5 miles nonstop with no heat problems. The same route was frying a hienzmann in the winter. Going fast on a shorter hill, just keeping the bike moving above 18 mph keeps the heat down two ways, the motor is less stalled, and the hill is over with quickly. Time is part of the motor heating equation after all.

Anytime you are stalling the motor, like full throttle under 15 mph you are making heat, and might still go 15 mph with less throttle.

 

[icecube57]

Speaking of tires. My Walmart Bell tires arent holding up so well. The rear one is fine and has plenty of life but the front one is shot. Its all the way down to the purple wear indicator I guess. You know you have serious torque when a big 290+ guy is having problems getting a wheel to stick under acceleration.

 

[methods]

dude, where did you find the nice temp monitor ?
-steveo

Fry's electronics.
There are two: One is the size of your pinky but it is only good up to around 250F. This one cost $10 more but it is quality.
NIST Traceable calibration.

If you hold the button you get real time reading
If you tap the button it holds the reading
It also does a bunch of other useless stuff.

Remember the 90's? Why did everything have to have a stopwatch built in? Who the hell needs a stopwatch anyway?

-methods

 

[Doctorbass]

That is nothing

My last X5 did not fail until it hit ~215C (420F) 125C is only ~250F.... it can get up to 170F (77C) in your car on a hot day with the windows rolled up.
All that is in there is a bunch of wire and some magnets....

I dont know the class of wire used - maybe I will ask Kenny - I am thinking it was E.
Be nice if he gave us data sheets on the magnets and wire.

-methods

Usually sealed motor have Class H that is 160-170 celsius.

But like we already said previously.. we should more consider the hall sensor max temp... typically 135 celsius... instead of the winding...

My motor in sealed condition avg 135 celsius and peak to 165 celsius without any problem.. it only smell the hot winding varnish coating...

Looking at the pics of youe C-A you had peak up to 17kW ( 198A and 86V) ! nice!

Doc

 

[317537]

Not saying you should do this but he mentions air pressure being higher on the outer radius of a hub.

http://www.youtube.com/watch?v=[youtube]J-xUP4t35L8[/youtube]

You could do this and for water resistance spray varnish onto the sensitve parts you would need to. Dirt is another foe to a bl motor.

Pot rivet and thermal paste some aerodynamic shortish fins to the hub. They could even be circular with a flange that steps out. Like a spiral vawt but shaped to take air from the centre and throw it out . Anything that increases the surface area would help.

To decrease resistance you could induct the air flowing past it rather than catch it.

@\<--<--<--<--Wind

Edit.

Create a second axel conduate on the opposite side of the phase cables and run a heat pipe through there and use water cooling. Because the coil array chasis doesnt move you could braze a coil of copper piping around the hub coils chasis. and use a water pump and an external radiator

 

[methods]

Usually sealed motor have Class H that is 160-170 celsius.
But like we already said previously.. we should more consider the hall sensor max temp... typically 135 celsius... instead of the winding...
My motor in sealed condition avg 135 celsius and peak to 165 celsius without any problem.. it only smell the hot winding varnish coating...
Looking at the pics of youe C-A you had peak up to 17kW ( 198A and 86V) ! nice!

Doc

Good to hear about the windings. I have since lowered my current limit to 70A, then 50A -> Bike has less power but I am trying to map out the effect on temperature. Surprisingly, the motor does not cool down much until the current limit is down to around 50A. At 70A I was seeing the same 125C temps. I think I am going to put it back up to 100A and just try my luck.

Good news - all this testing was on a 90F day.

I think the hall sensor max temp is driven by the manufacture... The hall sensors on my last X5 got up to 215C and they still work fine.
I put over 1000 hard miles on them - half that time with the Kelly at 220A current limit. Many times I could smell the varnish.
Everyone has seen how black my windings were...
3 times I melted the hall wires together. Once I de-soldered a lead!
Out of all the times my motor failed from heat, it was never the hall sensors themselves.
I suspect that hubs have been coming in with counterfeit low quality hall sensors.'

If a hall fails I will replace all 3 with high quality sensors.

-methods

 

[methods]

Just for the record . . .

My rear brake was not locked up because I was retarded.
The rear hub is shifting left and right on the axle
When it shifts too far in one direction it jams the rotor against the caliper.

It could still be argued that I am retarded - but that is beside the point - I say the locked rear brake incident was caused by the hub, not retardedness.

I have fought it all day long and if I cant find a way to stop the hub from shifting left/right I am going to have to run a different brake.
I was hoping they had fixed this issue on the latest X5. . .

Anyway -> back to air cooling.

-methods

 

[John in CR]

Wait, an X5 is not press fit securely on its axle?

John

 

[methods]

The stator is fixed on the axle but the magnets/case are only tied to the axle via bearings.

The bearings have a little slop
the vertical bearing to axle interface has a tiny bit of slop
the major slop is left to right on the entire case where it mates to the stator - when you tighten down the fastners there must be a few thousands between the bearing and the flat on the stator or else you would end up binding the bearings with a side load. So the assembly of the two side covers + magnet ring can shift left to right on the axle. Picture what I am saying?

Add all those up and it wiggles around - gets worse after you get it real hot
They all have slop, I just thought the new ones might be better.

I guess the answer is to try to shim it up a little.

-methods

 

[ZapPat]

I guess the answer is to try to shim it up a little.

... or dump your rear disk brake and use a regen brake on the rear instead. Just keep a front disk brake, it's more than enough in case of emergency and to complement the rear electric brake.

And of course I'm writing this because I know it'll just get you on your soap box talking about how you don't/use like electric motor brakes! :wink:

 

[John in CR]

The stator is fixed on the axle but the magnets/case are only tied to the axle via bearings.

The bearings have a little slop
the vertical bearing to axle interface has a tiny bit of slop
the major slop is left to right on the entire case where it mates to the stator - when you tighten down the fastners there must be a few thousands between the bearing and the flat on the stator or else you would end up binding the bearings with a side load. So the assembly of the two side covers + magnet ring can shift left to right on the axle. Picture what I am saying?

Add all those up and it wiggles around - gets worse after you get it real hot
They all have slop, I just thought the new ones might be better.

I guess the answer is to try to shim it up a little.

-methods

I got it. I hadn't even thought about that play, since I haven't tried a disk brake on a hubbie. To me that mean disks are out, because as you turn, hit bumps, whatever, some movement is going to occur. I have enough trouble getting perfect alignment on a regular wheel. It sounds like we need a new kind of caliper with an extra long stroke.

John

 

[methods]

Ok - I will start a different thread for my soapbox rant Pat :wink:

Who has some Air Cooling pictures?

Steveo - you got any new data for us? Doc? data?

Anybody want to try to mount a ducted fan on the frame pointed at the wheel? Leaf blower?

I put my current limit back up to 120A and rode 20 miles today in 104F heat. Never got over 130C on the windings.

-methods

 

[steveo]

Hey methods

I'm working on a 2wd star/delta 88.8v setup ..

I've hit 94km/h on one motor ... and that was on 79v ... its now higher ...

easily expecting over 60mph+

i'm convinced i can take docs x5 drag bike

-steveo

 

[Doctorbass]

Hey methods

I'm working on a 2wd star/delta 88.8v setup ..

I've hit 94km/h on one motor ... and that was on 79v ... its now higher ...

easily expecting over 60mph+

i'm convinced i can take docs x5 drag bike

-steveo

Nice speed!! :wink: .. pretty close to mine i should say!

Steveo.. dont forget this math equation:

24kmh front wind + 75% throttle limited + 100V = 94.4kmh

Now just imagine that:

NO wind + 100% throttle + 130V and 220A (KELLY) = ? kmh

Doc

 

[steveo]

Hey methods

I'm working on a 2wd star/delta 88.8v setup ..

I've hit 94km/h on one motor ... and that was on 79v ... its now higher ...

easily expecting over 60mph+

i'm convinced i can take docs x5 drag bike

-steveo

Nice speed!! :wink: .. pretty close to mine i should say!

Steveo.. dont forget this math equation:

24kmh front wind + 75% throttle limited + 100V = 94.4kmh

Now just imagine that:

NO wind + 100% throttle + 130V and 220A (KELLY) = ? kmh

Doc

Hey doc,

will you be able to run the bike before winter .. or will we have to wait till next year?

I hope you could brake thie 60mph barrier for us!! ...

fyi...

my freewheel speed at 95v-/+ on 16" wheel is 155km/h ..

-steveo

 

[Doctorbass]

Hey methods

I'm working on a 2wd star/delta 88.8v setup ..

I've hit 94km/h on one motor ... and that was on 79v ... its now higher ...

easily expecting over 60mph+

i'm convinced i can take docs x5 drag bike

-steveo

Nice speed!! :wink: .. pretty close to mine i should say!

Steveo.. dont forget this math equation:

24kmh front wind + 75% throttle limited + 100V = 94.4kmh

Now just imagine that:

NO wind + 100% throttle + 130V and 220A (KELLY) = ? kmh

Doc

Hey doc,

will you be able to run the bike before winter .. or will we have to wait till next year?

I hope you could brake thie 60mph barrier for us!! ...

fyi...

my freewheel speed at 95v-/+ on 16" wheel is 155km/h ..

-steveo

I hope doing that this weekend!.. but it will depend on the weather.. if we have rain i'll need to delay that for the next summer

I still have not installed the kelly controller and it is not programed ... I still wasen't able to program the Kelly controller with USB to RS232.. it is still not detected..

Just imagine.. a 5302 with 135V


Doc

 

[methods]

Update on the big 1" holes with no screen covering


So I rode the bike hard on the trails. Maybe a hundred miles or so on dirt. Lots of jumps, lots of long swinging skids, begged to get rocks and dirt in there.
The new X5's use a low temperature glue on the hall sensors so I already had a temperature dependent hall failure.
The hall sensor did not fail electrically it self but glue melted away and one hall was nearly out of the track and the wires were popped off of another.

This gave me an opportunity to inspect the stator

The only place on the stator where you can see evidence of the mod is around the hall sensors where the glue melted, then captured little weeds and dust particles, then hardened back up. Nowhere else on the stator can you see any sort of wear that indicated damage from rocks etc.

I recorded a peak temperature above 160C but stopped monitoring the temps after the first few days.

My conclusion is that the risk associated with drilling big holes is minimal. If you are riding on the street it is a non-issue. If you are riding below melt-down temperatures it is also a non-issue. I can say that I have pushed the drilled 5305 as far as it can go in very nasty environments and it came out fine.

Screen? Well... that adds a lot of restriction to the flow and I wont be dont that on my motor.
I wish I could run fans (though that would just be one more failure point)
Maybe scoops later

-methods

P.S. For the record... The V2 X5 side covers slip side to side on the axle and this can cause your disk brakes to bind up so dont tune them too tight. Ideally you should use hydraulic brakes with an adjustable pad distance and leave about 1mm of play on either side. I guess a pro would shim up the bearings... but I am a hack, not a pro. :wink: