Motor Cooling Coil

[EVADER09]

I'm gunna make a homemade cooling coil. I'v seen guys with alunimun ones and brass ones heck maybe some guys use copper. I was wonder what is the best to make my cooling coil out of. Aluminum or brass? I doubt anyone would say copper but what is the advantages or disadvantages using certain metals. The motor I'm making it for is a Speed 700.

[AndyKunz]

Aluminum.

Step 1:

Wrap it (pulling it tightly) around something a little smaller than the motor. It will loosen a little when you are done winding, and should fit snugly over the motor.

To hold it on the motor, first apply liberally some Heat Sink Compound, available from your local Radio Shack, to the inside of the coil.

Put the coil on the motor. Now use heat shrink tubing to lock it on tightly.

Step 2 (more important):

Solder short lengths of brass tubing (5/32" OD, about 1" long) to each of the tabs for wiring. Use fuel tubing (from the model airplane dept) to attach them to the coil you wound so that you have one inlet and one outlet for the water.

I suggest you do the plumbing so that the brushes get cooled first (colder water), then the can.

If you are using a water cooled ESC, it should be cooled before the motor.

Most boats only need one water pickup. Sometimes it's easier to run two of them, but it might increase the drag and probably the weight a little.

Andy

[EVADER09]

Hey andy thanks man, that information will help a lot. Not sure exactly about the brush part but I'll figure out a way. You said aluminum may I ask why? Why aluminum over brass?

[Zippifried]

Aluminum is lighter, and easier to wrap. Brass has to be annealed before you wrap it (heated to high temp), and it's heavier. Copper could work, but tends to get nasty after some exposure, and it's also heavier than aluminum.

[EVADER09]

Yeah thats what I basically figured, copper wouldn't be that bad to use I wouldn't get very yucky afterall thats what the water lines in your house is.

[Eric B]

HELLO ALL,

I was wondering if I would need to put two water pickups on my SH to coil the motor and tabs and a esc. I was also wondering if it would be fine if I used the one on the SH already (the one on the outdrive) and then a secondary one as well

Thanks,

Eric

[jtnrumrunner]

Thanks for the description Andy...

I'm wondering, can you T-off the original water input w/in the hull to flow the water to the ESC and motor/brushes separately... then have two outlets?

John

[twmaster]

Originally posted by Eric B
HELLO ALL,

I was wondering if I would need to put two water pickups on my SH to coil the motor and tabs and a esc. I was also wondering if it would be fine if I used the one on the SH already (the one on the outdrive) and then a secondary one as well

Thanks,

Eric

You can use separate pickups if you like. But like Andy said you may be adding drag if you are not careful. The pickup on the outdrive of the SH is way too small as-is to be useful. I have not yet done this but I am planning to drill out the hole in the drive to about 5/32. If the holder on the drive does not break I will glue a tube inside of it to pick up water, if it does break then I will make a simple mount for the tube on the outdrive.

I hope that was simple enough to understand.

[AndyKunz]

Originally posted by twmaster
The pickup on the outdrive of the SH is way too small as-is to be useful.

This year in Michigan Naomi ran my SH with an air-cooled ESC (an SC5-LP), so we didn't use water cooling.

I drilled out the pickup on the outdrive to accept a piece of 5/32" brass tubing, which I curved ever so slightly to improve the pickup face. This tube extends down into the propwash, and is cut at an angle to maximize intake. (I'll try to get a picture but my digicam is dead).

With this setup and no fuel tubing to bring the water indoors, the boat pumps a constant streat about 6' in the air. At low speed the water lands in front of the boat. It provides PLENTY of water for cooling.

Andy

[twmaster]

I have not drilled my outdrive out yet for tubing. I am glad to see your's drilled sucessfully. I will of course bo doing the same to mine.

Cheers,

[EVADER09]

Why don't you just heat up the tubing with a torch and press it down through the plastic pick-up spot to melt the hole through it. There would be a less chance of breaking it because you wouldn't have to do it with so much force. As far as I know Eric already knows how to do it all, he just wanted to know if it picked up enough water or if he would need to make additional pick-up. We talked about it the other day when I was there.

[Eric B]

Hello all,

What angle should I cut the end of the water pickup? I'm not sure, 45 degrees?

Thanks

Eric

[eddieh]

eric, 45 degrees will work, but if you go a little shallower say 30 degrees you actually get a bigger (longer)opening, Andy is dead on with the bend the very tip slightly forward to create a type of scoop, and I like to angle the pickup directly at the tip of the prop, if you lave the tubing a little long on top, it will allow you to cut a few different angles and see how they work, my 2 cents cheers ed