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Old 10-05-2010, 04:04 PM
UBCECC UBCECC is offline
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Default Watercooled Curtis 1238 for your AC50

Hi everyone,

I am a member of University of British Columbia's Electric Car Club. We recently drove our electric beetle 6400km from Vancouver to Halifax across Canada in 14 days.

After we climbed over the rockies and drove hours and hours at highway speed without over heating. A few local EV enthusiast here in Vancouver asked us to sell them the same water-cooling system we had in our vehicle for the Curtis 1238 motor controller.

The reliability of semi-conductor is exponentially correlated with it's operating temperature. Which means the cooler you can run your controller, the more reliable it will be.

This water-block was designed by a master student in mechanical engineering with the goal of maximizing efficiency and minimizing pressure drop.

The Waterblock is cut from a solid block of aluminum on a CNC, so economics of scale is a big factor when it comes to manufacturing a small amount of these. The more we can make this, the less it will cost per unit. If anyone is interested in joining in on a group buy, please e-mail me at rickygu@ubcecc.com

I've attached a couple images of the waterblock we installed in our vehicle, one is bare aluminum, one is finished in anodized black.




for more info on our trip across Canada, see link:
http://www.wired.com/autopia/2010/09...ast-in-canada/
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  #2  
Old 10-05-2010, 05:09 PM
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Coulomb Coulomb is offline
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Default Re: Watercooled Curtis 1238 for your AC50

So is this one piece that is sealed to the base of the Curtis 1238?

It looks something like one half of the one that Jack Rickard made for one of his vehicles, perhaps the electric Mini. They glued the two halves together (I hope I am remembering this right), and bolted the resultant block to the controller.

As long as the Curtis controller's base is flat enough, and doesn't warp much with the heat, a single piece glued to the controller would seem about as reliable. You seem to have plenty of bolt holes there to keep the heatsink and controller connected well.

Any time you have to take out the controller, you'd take the heatsink with it, disconnecting the two coolant connections instead of undoing a dozen or more bolts.

Do I have the right idea?
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Old 10-06-2010, 12:15 AM
UBCECC UBCECC is offline
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Default Re: Watercooled Curtis 1238 for your AC50

this water-block is a 2 piece design. In the first picture you can see a plate in the back which will be bolted to the thicker piece and rubber is sandwiched to seal the fluid.
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Old 10-06-2010, 08:31 AM
tomofreno tomofreno is offline
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Default Re: Watercooled Curtis 1238 for your AC50

What are the x-y dimensions of the plates? Are the two sealed by an o-ring seal, or just a flat rubber gasket? What did you use for a liquid-air heat exchanger for cooling the liquid? What fluid flow rate did you use? Could you give some typical controller/ambient temperatures you saw on your trip? For example, I am using a simple finned (5 cm fins) heat sink with small (260 cfm) fan on my 1238-7501 controller. This summer during a climb at about 67 km/hr up about 488 meter change in elevation at average 4.8% grade in 33 C ambient, max controller temperature was 56 C. During a climb at about 70 km/hr up about 1372 meter change in elevation at average 4.5% grade in about 33 C ambient, max controller temperature was 58 C. It would be nice to keep the controller cooler, but it is not close to its spec'ed max of 85 C on these runs which are the most demanding I typically do, so I'm not sure it is worth dealing with the plumbing.
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Old 10-12-2010, 04:55 PM
UBCECC UBCECC is offline
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Default Re: Watercooled Curtis 1238 for your AC50

Quote:
Originally Posted by tomofreno View Post
What are the x-y dimensions of the plates? Are the two sealed by an o-ring seal, or just a flat rubber gasket? What did you use for a liquid-air heat exchanger for cooling the liquid? What fluid flow rate did you use? Could you give some typical controller/ambient temperatures you saw on your trip? For example, I am using a simple finned (5 cm fins) heat sink with small (260 cfm) fan on my 1238-7501 controller. This summer during a climb at about 67 km/hr up about 488 meter change in elevation at average 4.8% grade in 33 C ambient, max controller temperature was 56 C. During a climb at about 70 km/hr up about 1372 meter change in elevation at average 4.5% grade in about 33 C ambient, max controller temperature was 58 C. It would be nice to keep the controller cooler, but it is not close to its spec'ed max of 85 C on these runs which are the most demanding I typically do, so I'm not sure it is worth dealing with the plumbing.
We had two of these radiators:
http://www.koolance.com/water-coolin...product_id=636

and 1 of this pump:
http://www.koolance.com/water-coolin...product_id=858

We sealed the plate with flat piece of rubber. dimension is the same footprint as the 1238 controller. Threading is g1/4" for o-ring fittings.

Running at 110km/hr for 2 hours on the highway, hottest temp was around 50degrees.
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Old 10-16-2010, 07:29 AM
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Default Re: Watercooled Curtis 1238 for your AC50

That's a very nice looking cooler, but comparing your results to Tom's I'd say it's probably not worth it, considering the cost of the cooler, pump, fans and radiators.
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Old 10-16-2010, 11:20 PM
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david85 david85 is offline
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Default Re: Watercooled Curtis 1238 for your AC50

UBCECC,

Saw your team's car on the news a while back (showed up on the forum newsbot too), just wanted to pass along a congrats on that.

I didn't realize you were a member here, welcome.
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