Air Cooling my x5

[El_Steak]

Good for you guys, my bike will CAUSE me sure death or disability

I Second that

[LarsE]

Hi

Some cooling modifications to my rear hub motor that I am working on..


Uploaded with ImageShack.us]
The cooling is 48 of http://www.dealextreme.com/p/aluminum-cooler-heat-sink-chipset-for-ram-memory-square-type-8-piece-set-35817
They are grinded to the radius of the hubmotor 16cm with a homemade tool that fits a cordless drill and then glued on with arctic alumina.
My side panels is of course vented with big holes to let ear inn and out.
Its been a lot of work, (the grinding) so I am hoping it will take some kW without overheating.

[Doctorbass]

Hi

Some cooling modifications to my rear hub motor that I am working on..


Uploaded with ImageShack.us]
The cooling is 48 of http://www.dealextreme.com/p/aluminum-cooler-heat-sink-chipset-for-ram-memory-square-type-8-piece-set-35817
They are grinded to the radius of the hubmotor 16cm with a homemade tool that fits a cordless drill and then glued on with arctic alumina.
My side panels is of course vented with big holes to let ear inn and out.
Its been a lot of work, (the grinding) so I am hoping it will take some kW without overheating.

The problem is not to add surface dissipation INSIDE the motor.. but it's more evacuating the heat from the inside to the OUTSIDE of it

Doc

[John in CR]

The heat sinks sure can't hurt. The real key is the strategy you use to create an actual flow of air bringing fresh air into the motor. I'd hate to see all that heat sink work go to waste with ventilation holes that do little to flow some air like are typically done around here. You can always add fans like Arlo1 did with some sucking air from one side to the other that makes one side the intake and the other exhaust, along with fans blowing on the stator too for extra turbulent flow at the stator.

[Arlo1]

Hi

Some cooling modifications to my rear hub motor that I am working on..


Uploaded with ImageShack.us]
The cooling is 48 of http://www.dealextreme.com/p/aluminum-cooler-heat-sink-chipset-for-ram-memory-square-type-8-piece-set-35817
They are grinded to the radius of the hubmotor 16cm with a homemade tool that fits a cordless drill and then glued on with arctic alumina.
My side panels is of course vented with big holes to let ear inn and out.
Its been a lot of work, (the grinding) so I am hoping it will take some kW without overheating.

Yup get some active air flow from the out side into the motor and onto those sweet heat syncs and you are ready to push that motor to over 30x its rating like me lol.

P.S. The pic of the peak in my SIg is real and its acurate and on my x5 thats fan cooled

[LarsE]

Hi.
The heat sink needs vented side panels, and they are. How effective the heat sink will be is unknown, only time will tell. The side panels are maybe not the most extreme open design but close (afraid it will collapse if I overdo it.
Next up is gluing the heat sink to the other side of the stator (only 24 heat sink in picture) and treading the phase wires.
I have been looking for some fans too run inside of the motor but I have not yet found something with the ability to take the heat and vibration so the fan cooling is canceled for now. Maybe I will look more into it next winter
This year I am happy with heat sink + vented side panels + fatter phase wires.

P.S. Arlo1: almost unbelievable level of current with a hub motor, with those Amp's I expect you are taking phase wires under the bearing or more likely your hub motor got zapped with lighting in a storm or something.

Lars E

[El_Steak]

Major fail for me this morning...

Hit a nasty bump and one of my cute little aluminum fan blade broke off inside the motor at around 60km/h.



Predictable carnage occured inside the motor. After I managed to slow down safely, my rear wheel locked completely. Had to get someone to pick me and the bike up in a minivan. Humbling experience...

Those "blades" where just epoxied with JB-Weld to the side of the "ribs" inside the cover.

I particularly appreciate the fact that I had predicted this would happen and even built a metal disk to epoxy on the other side of the blades to secure them in place. But I procrastinated and never got around to installing said disk...

Tomorrow when the epoxy has set, I will glue this metal disk over the blades. It will serve 2 purposes:

1- Secure all the blades together and prevent a single blade from coming loose and trashing the windings
2- "Channel" the fresh air directly to the windings instead of the stator.

I'll post pics of the thrashed inside when I get back home tonight.

Now I need to get a new 2807 quickly to get back on the road, hopefully I can just do a stator swap and not have to rebuild the nice 24inch wheel that Holmes did for me.

[John in CR]

Ouch! Sorry to hear about that. That possibility made me nervous enough to use bolts and epoxy in mine with blades. Good thing too, because my son is really hammering the motor....1 bolt on each blade to secure it, and epoxy to both hold it in place and secure the nut.

[Doctorbass]

So you can say that this blades principle also offer amazing braking force advantage?

Sorry to hear you broke your motor

I know how frustrating it can be wneh you need the help of unknown person to cary you and your ebike to your home... not a good publicity for ebikes...

Doc

[El_Steak]

So you can say that this blades principle also offer amazing braking force advantage?

¸



I was lucky it didn't lock up at 60km/h, don't know If I would have been able to remain on the bike...

Do you guys know if I can insert the stator of a new-style 9c motor with ISO disk mounts covers inside the magnet ring of the old-style 9c motor?

This bike is my main mode of transportation to work so I want to get back on the road as quickly as possible and if I can avoid rebuilding my 24inch wheel, all the better...

Until then, I'm stock back in traffic with the rest of the cage drivers

[Doctorbass]

You are lucky that you had not a FRONt hub motor

I dont know about the size and standard of 9C..

[El_Steak]

Here are the autopsy pictures...







And here's the coroner report:

1- A single blade broke off when I hit the bump
2- As I slowed down, it somehow got sideways through a hole in the stator
3- Properly braced in the stator, it then ripped off ALL the blades on BOTH sides of the motor
4- Hilarity ensued

What bothers me the most is all the crap that is now stock on the magnet ring, I don't think i'll be able to pop another stator in there, looks like I'll probably have to rebuild that nice wheel Johnrobholmes built for me

[Arlo1]

El_steak I will buy the whole motor with out the wheel for 25 pluss shipping.

[El_Steak]

El_steak I will buy the whole motor with out the wheel for 25 pluss shipping.

Will you rewind it like LFP did with his HS35 ?

I'm not sure yet if I'm going to re-use the cover or flange but if I don't, I'll send it to you free of charge (just shipping).

Blackarrow has already reserved the disk adapter though... you guys are like vultures ripping out parts of a corpse

I'll know more in a few days...

[Arlo1]

El_steak I will buy the whole motor with out the wheel for 25 pluss shipping.

Will you rewind it like LFP did with his HS35 ?

I'm not sure yet if I'm going to re-use the cover or flange but if I don't, I'll send it to you free of charge (just shipping).

Blackarrow has already reserved the disk adapter though... you guys are like vultures ripping out parts of a corpse

I'll know more in a few days...

That works. I will experiment with it for sure! And I promis it will lead to kick ass videos!

[spinningmagnets]

I plan to make a fin-and-disc similar to your design, but attached to the outside of the left side of the hub. I only plan to have side-plate inlet holes near the axle.

I would suggest that if you repeat the same style inside the hub, perhaps only have holes on the hub sideplate near the rim, and completely seal off the sides and tops of the fin/disc assembly. Centrifugal force will fling air trapped in the finned voids out the rim holes, and the lowered interior pressure will draw in fresh air. Maybe add a few inlet holes on the other side of the hub?

Best of luck with whatever you try!

[El_Steak]

Share the results of your design with us, the more info the better.

For my new 9c motor I simply did a lot of big-ass holes similar to icecube / metallover. In my daily commute, it keeps the motor under 120C which is good enough for me.

[Farfle]

Here's my side covers I did with the schools CAD mill:

[El_Steak]

Looks very nice Farfle.

[deVries]

I bet that the fan energy consumption vs the energy gain in the motor to wheel with cooler system is lower and that it really help!

So we must cool down the motor with forced air fans to get better power at the wheel without sacrifying our precious Wh energy.

Probably that a 20W fan motor is lower as the output power at the wheel lost due to higher resistance winding due to temp increase!

I must test that!.. guys you are pushing me to test that idea!

Hi Doc, ok, push!

I haven't found a post from you that documents your cooling technique for your X5 motors. Have you modded any of your motors for cooling & posted your ideas/mods with pics?

What do you think is the best way to cool an X5?

Thanks!

[hillzofvalp]

I wonder if it would be very effective to get a heat pipe with heatsinks on the outside perimeter of the motor between the flanges or a heat pipe alone..... and then have the wheel do the work of circulating the coolant to, say, the rim. If you ran low profile tubing in the rim, maybe you could use it as a heat sink. I don't know the physics of it... but I think the shape and orientation of the tubing would slosh the coolant around. Maybe there is an ideal double walled rim that can be sealed up so that you could use the rim itself as a thermal conduit..

It's far out there, and maybe just something to balk about.

[auraslip]

I'm confused by El Steak's testing. Mostly why plugging the middle holes decreases cooling instead of increasing it as was assumed.

I wonder, could the cassette or disc brake be interfering with the air flow to the intake holes closest to the axle?

[John in CR]

I used to think El Steaks mid radius holes may have a negative effect, but El Steak's results proved that incorrect. Think about a squirrel cage fan and how they intake air over a broad range.

Another thing I had to think on for a while was his lack of improvement with blades, and I came to the conclusion that the air gets spinning full rpm by the time it reaches the perimeter regardless of his blades. I still do blades in mine (epoxy plus one bolt to avoid a motor killing loose blade like happened to El Steak a while back), but I shape mine so the flow of air off of their tip is directed at the stator iron and coils. The seems far better than much of the flow moving unfettered along the sides of the cover to the exit and bypassing the stator.

John

[ambroseliao]

Hi John,

Can you post pix of your blades setup?

Ambrose

[El_Steak]

I'm the first one to be disappointed by the numbers I got in my testing, but hey numbers don't have feeling and hopefully they helped some members refine their designs.

After my motor destruction, I went for a simple design with just a bunch of large holes close to the perimeter. I can't do my test run with it because the road I was using was destroyed this summer when we had a major river flood. It hasn't reopened yet.

In my daily commute however, the cooling is suffient to allow me to ride at full throttle 100V/100A.