Unique 200A ESC cooling system

[Jeepers]

I have a 9XL power MM on 4s and the packs are all the way back.. for me it's perfect!

Brushless,Questtek is making more power than you are, I will bet he has to run his cg that far forward just to keep it on the water. He is running 4s2p and pulling 170amps. Things change when you start putting more power in the water.

[tanasit]

Thanks for sharing. After I burnt my Etti 150A esc months ago and still have the smell left today, everytime I open the hatch I just can't stop thinking of the better way for cooling. I also have one of the cheapo 200A esc, which I added 2 water colloing plates as well as a fan with custom shroud and I even added the air scoop up front and the vent out back using the right angle 1/2" pvc plumber pipe. In winter I can plug them with the cap. So far no heat problem and the white pipe blended in for the not so ugly look.
At one point, I almost cut a square hole on the hull bottom and block it off with aluminum sheet that will attach to the cooling plate or directly to the FET board. If I don't care much about the look, I may have install the esc on the outside altogether.

[Jeff Wohlt]

Cool stuff! I am not sure when an ESC blows that it will not blow the top right off, since we know it can almost blow hatches off, that you will not end up with a big mess. Maybe no fire but you will have fluid everywhere...which is not bad since it can't really hurt anything.

Might be some neat ideas for boxes or bags for this system. Lipo bag filled and sealed. I would think some small boxes would work well and just seal them up good first with good RTV sealer then drill a small hole to fill it and then cover that hole.

Keep it going! Fun stuff. I knew questtek would hop on this challenge.

[Jeff Wohlt]

I can see a small oil cooler radiator mounted on top the hull to get a water spray and cool the oil. Questtek....did you seal around the fins on your shot up there? I guess you could and make it sealed. Nice job!

[JMSCARD]

Brushless,Questtek is making more power than you are, I will bet he has to run his cg that far forward just to keep it on the water. He is running 4s2p and pulling 170amps. Things change when you start putting more power in the water.

Yeah I have a NEU 1515 1.5y I run on 6s2p in my mean machine... I have to put the COG a little more forward to keep my boat from becoming a plane:)... NEU Torque causes serious front end lightness:)

[befu]

Some great stuff going on here. I advised some of the top racers back in 2005 to build a closed/ containerized system using FC-770 3M fluorinert and they could get some serious performance increase. It fell on deaf ears.

I still have a gallon laying around and played with doing just what you are now. It could be a real winner with a small circulation system. But what I have learned over time is stick with KISS. Size my components so they run at their best eff. Then I dont need to add unnecessary items or rely on complexity to allow them to operate beyond their limits. But it sure is fun playing around with this kind of stuff no matter what!

John

Back in the mid 90's I remember helping machine parts for a data acquisition for NASA on thier high altitude scram jet, a system that used a flurornert fluid for cooling the electronics. that was some "cool" stuff. That stuff could leak out of ANY small opening and boil off in the atmosphere. I am sure they have better stuff now, but the oil is definately easier to get and probably easier for the hobbyist.

Brian

[Steven Vaccaro]

For you electronics wizards, what causes a esc fire. I've seen full infernos and just some smoke. Is it just a chain reaction of one fet failure?

[befu]

heat sink

Not sure why to even use an aluminum heat sink. Just remove the wrapping and heat sink. Seal and submerge in the oil. If the oil gets too hot, add the cooling to that. make the case aluminum and as mentioned, mount it in the bottom of the hull or sponson so it stays cool, cools the oil. Or run cooling lines through the case.

Quick, someone with a CNC mill make a case. Finned on the inside to absorb heat from oil. Bolt on cover with O-ring seal.... hmmm, wish I had gotten that cnc mill at work....

Lots of potential here

Brian

[questtek]

One of the things that we tried in RC warship combat was filling the servo's with mineral oil. Keeps the water out and they work, but the rotated really slow. So instead, we used a 3m conformal coating on the circuit board. I forget which one, but it is a sticky brown goo. Coat the board well and it would run underwater just like a dry one. Motor and pot were the only thing left unprotected.

Keep up the ideas, we like them! I remember people saying outrunners were only for planes and spinning larger diameter air props. Hah!

Brian

I thought I would do a bit of submerged component testing. The set up is shown in the attached picture. I have a small aquarium filled with tap water plus an older Futaba servo, Mystery 200A ESC and brushless motor that is ready for in water testing. All these components have been soaked in corrosion X.

The video can be seen at:

http://www.youtube.com/watch?v=NdibfAqFCzI&feature=youtube_gdata

They say you learn from stupid mistakes and bad assumptions, thus making me the smartest dumb guy in the forum! I failed to take into account that my 40 year old home in SoCa. was built with aluminum wiring and iron pipe plumbing!

Enjoy the video as you shake your head and roll your eyes!

[questtek]

Cool stuff! I am not sure when an ESC blows that it will not blow the top right off, since we know it can almost blow hatches off, that you will not end up with a big mess. Maybe no fire but you will have fluid everywhere...which is not bad since it can't really hurt anything.

Might be some neat ideas for boxes or bags for this system. Lipo bag filled and sealed. I would think some small boxes would work well and just seal them up good first with good RTV sealer then drill a small hole to fill it and then cover that hole.

Keep it going! Fun stuff. I knew questtek would hop on this challenge.

Jeff, I know both you and I have put a lot of thought into this. Maybe we just have the record for the most burnt ESC's!

In my testing I first put the 200A Mystery into a tupperware container with heatsink and non-conductive oil. I Eagle Tree'd the running of the system and found that the oil became too hot. Even with the boat movement to circulate the oil the temp just keept going higher. This is when I realized that using a fan would be a great help and it turned out to be true.

You can try just putting the ESC in a bag, etc however I am concerned of the continued oil temp build up since there is no way to remote the heat it continues to conduct from the FET's and ESC.

You and I both have a good system using a small pump to circulate cool water over the ESC but I just wanted something a bit simplier. This is a "works in progress" and I certainly welcome your input and suggestions.

[questtek]

Not sure why to even use an aluminum heat sink. Just remove the wrapping and heat sink. Seal and submerge in the oil. If the oil gets too hot, add the cooling to that. make the case aluminum and as mentioned, mount it in the bottom of the hull or sponson so it stays cool, cools the oil. Or run cooling lines through the case.

Quick, someone with a CNC mill make a case. Finned on the inside to absorb heat from oil. Bolt on cover with O-ring seal.... hmmm, wish I had gotten that cnc mill at work....

Lots of potential here

Brian

Please see my comments to Jeff. Your idea is good with the plate on the bottom of the hull however on a cat is the flat inner bottom of the hull in contact with the water? Go get that cnc mill!

[daveives]

There is a difference between old servos and the newer servos. The feedback pot in the old servos had a much lower resistance than in the newer servos. Thus what works for an older servo will usually not work for a modern servo. The newer servos (using a lower pot current) can fail when wet by running to one end and burning out, while the older servos work fine. Also, salt water on a newer servo plug will stop operation after a minute or so as rapid battery-driven corrosion happens (much faster than normal water driven corrosion.) Of course, one logically uses an older (expendable) servo to test with. I am up to about a dozen burnt ESC's, so I like what you are trying to do.
Also, does the fan air get into the Tupperware (ie: could water get in?) or is there an undiscussed seal between the inside and outside. Thanks

[ray schrauwen]

Hammond makes some nice Aluminum cases to make a sealed unit.

Nice thread Dave!

[tanasit]

RE: Enjoy the video as you shake your head and roll your eyes!

Well, I didn't do either of those but smiled and admired your test and learn something new. Thanks...

[Doug Smock]

With all due respect to the OSE scientists, I think I'll continue to run my equipment at or just below their specifications.

Last week I had to replace a 208v 3 phase 1 hp evaporator fan motor in a -20'F warehouse freezer. The stator was cooked.
I wonder how that happened at that temperature??

Doug