Cooling brain fart

[domwilson]

Are you sure you dont have to make the hot side hotter to make the cool side colder?

Yep. That is why you normally put a heat sink on the hot side. Like in drink coolers, small refrigerators, CPU coolers, etc.

[norbique]

you're right mr. wilson i didn't think of that...

[Jeff Wohlt]

Well here is a cheap and easy pump.

58mm x 33 1.3 amp at 6v

http://www.cornwallmodelboats.co.uk/acatalog/graupner_1951.html

Might have to try one of these to see how well it does for flow.

[norbique]

that's a very nice gear pump.

[Jeepers]

wow this thread died!Did the ideas work?

[Jeff Wohlt]

Yes and very well, I might add. The cold water was the best. Questech did the hard work on this and shows many results in another thread you should e able to search. Cooling temps were way down.

When we need it the most is in the summer when it is 85-90 degreee water.

I think the biggest key is making sure all fets are in contact with the plate and the copper is much better than alum plate. But Alum is okay.

I have another cooler for the motor I am planning and will show it soon. Both of these can use the same pack to run the pump and the part I am trying to develop now.

[questtek]

Yes and very well, I might add. The cold water was the best. Questech did the hard work on this and shows many results in another thread you should e able to search. Cooling temps were way down.

When we need it the most is in the summer when it is 85-90 degreee water.

I think the biggest key is making sure all fets are in contact with the plate and the copper is much better than alum plate. But Alum is okay.

I have another cooler for the motor I am planning and will show it soon. Both of these can use the same pack to run the pump and the part I am trying to develop now.

Thnaks Jeff but you were a big contributor with lots of great suggestions. Here is the link:
http://forums.offshoreelectrics.com/...ad.php?t=10810

Here is a quick summary:
1. ESC's are an expensive but weak link in FE boats
2. The failure mode of the ESC is often due to overheating so more effective cooling techniques may greatly improve their performance and life.
3. The use of water cooling is one of the best and most pratical ways to achieve good ESC cooling. Although many other techniques have been carefully examined and experimented with, including thermo-electrics, fans, and even heat pipes, water cooling appears the clear choice.
4. Proper water cooling to an ESC is done to keep the FET temps in a reasonable range and to determine this thermistors were placed on the FETS as well as caps and cooling water system. Logging was done by an Eagle tree system both in the desk test set-up and actual lake testing
5. Origionally I was interested in passive cooling however through extensive testing it appears that a closed ice and water cooling system has the absolute best performance. The key is to keep cost, complexity and weight down.
6. There are two BIG advantages to the closed-loop ice/water cooling system:
a. It cools more than just the ESC but greatly assists in motor cooling.
b. Drops the temps down to an incredibly low value..from the 150's to the 80's-90's.

I have inlcuded a pic of the set up I am currently using in several FE's The tank is a light weight (0.9 oz) nitro fuel tank and note that I have a thermistor installed in it so I can keep track of the closed loop cooling temps, and the small 6 to 12 VDC pump (2.5) oz. To use this system, the nitro tank is half filled with water and frozen. Before putting in a FE the tank is tapped off with cold water. You can put the pump on a switch but for simplicity I just connect it to the same small LiPo pac I use in my BEC circuit. It runs all the time with minimal draw.

I continue to use the Eagle Tree system for logging and the 3 temps I measure are FET temp, coolling water temp and motor temp. I am very happy with the overall results!

[Jeff Wohlt]

Love it. Mine will be set up for this next year in most of my boats. Everything will run cooler. Tanks are cheap and you can take your cooler along with some ice and just make a ice water mix since the block will not stay solid for too long but in a cooler it should and with ice around it. It would be neat to have a nitro lid on it and extend it up thru the hull where you can just fill and drop some cubes in.

I also like pre-cooling and even letting her run after for a few minutes after a hard run.

The next is a motor cooler that should do very well.

[ozzie-crawl]

i think still having cold water running threw the system after a run is probably the biggest benefit that a closed system has, if you data log a run then watch the heat when you stop and every thing heat soaks
it jumps up a fair bit very fast, boat mite be running at a good temperature but by the time you get the lid of and temp the esc/motor it looks like its running a lot hotter than it really is
just my thought

[greeneyed684]

why not just use or make small pump to push water through existing cooling system . just an idea?

[Jeff Wohlt]

That is what this is. Closed loop so you maintain cold water.

[greeneyed684]

what i meant was instead of water being pushed into pick up [ open loop] why not circulate water through speed control, motor faster with small pump just thinkin ways to keep weights down but still be more eficiant in cooling just an idea

[questtek]

what i meant was instead of water being pushed into pick up [ open loop] why not circulate water through speed control, motor faster with small pump just thinkin ways to keep weights down but still be more eficiant in cooling just an idea

If you read the threads in this forum you can see this is exactly what we are doing. Closed loop means you only circulate the onboard water (ice and water actualy) and do not discharge or intake any additional water. The pump is very lightweight and operates from 6 to 12 VDC.

[Xcesive8]

Hey Questtek,

Where did you find that pump?
Wouldnt mind buying and playing around with this idea.

Cheers

[questtek]

Hey Questtek,

Where did you find that pump?
Wouldnt mind buying and playing around with this idea.

Cheers

I bought several of these pumps on E-Bay from a HK company. I lost the link but just do an E-Bay search and you will find several different small 12 vdc pumps for sale. Hope this helps.