HiModel 4s-8s 200 amp esc

[domwilson]

The purpose of sanding is to get all the FET's flat so that the cooling surface will contact each FET uniformly.

[ED66677]

Ok, how does one get more timming out of these escs?
my MM 9XL motor sounds slow..

more timming? 2 pole motor require low timming!!!

[Jesse J]

The purpose of sanding is to get all the FET's flat so that the cooling surface will contact each FET uniformly.

I think masking would be ok, if you use thermal paste/epoxy, shouldn't need to actually touch fet to cooling plate, the sub millimeter space should be no prob with good thermal paste. Correct me if I'm wrong, I'd like to know.

[Jesse J]

more timming? 2 pole motor require low timming!!!

Could be, but I know that the one I use allows my 8XL to wind up, while my Dad's (same set up) doesn't. We reprogrammed it with higher timing, but didn't get a chance to test it yet. I hope it doesn't blow!

[domwilson]

I think masking would be ok, if you use thermal paste/epoxy, shouldn't need to actually touch fet to cooling plate, the sub millimeter space should be no prob with good thermal paste. Correct me if I'm wrong, I'd like to know.

Initially You are correct, it won't be a problem. Just over time, it can be as the paste will eventually dry up leaving the space filled with a chalk like substance.

[Jesse J]

I would suspect that could be the case with the cream, but how about the thermal epoxy? it cures up solid in a matter of hours and stays tight, right?

[Brushless55]

Could be, but I know that the one I use allows my 8XL to wind up, while my Dad's (same set up) doesn't. We reprogrammed it with higher timing, but didn't get a chance to test it yet. I hope it doesn't blow!

Hey Jesse, let me know how that turns out.. I think I'm having the same issue, better yet give me a call, I would like to see that boat run!

[domwilson]

I would suspect that could be the case with the cream, but how about the thermal epoxy? it cures up solid in a matter of hours and stays tight, right?

You mean like Artic Silver? I don't think it would be a problem as long as you keep it away from circuit traces, FET connections, etc. http://www.arcticsilver.com/arctic_s...l_adhesive.htm

[ksm2001]

I use Arctic Silver Alumina Thermal Adhesive http://www.arcticsilver.com/arctic_a...l_adhesive.htm on both my Himodel 200 esc's and didn't sand the fets this is different than what you mentioned Dominic since it's a non conductive thermal epoxy so if you get some on the circuit board it won't cause a problem, it dries in about 5 minutes and is solid to the cooling plate.

I have my timing set to 1 degree running the 8xl in my DF29 knock off on 4s running at 57 mph.

Ken

[domwilson]

Where did you pick it up from?

[questtek]

I found the two-part thermal expxy to work great. Here are some pictures of mods that I did on 100 and 200 Amp inexpensive Mystery ESc's. I think the controller circuit board is the same for many of the ESC's that fall in this same class. (compare the close up pic with your controller) They up the amp ratings by just adding more FET boards.

My mods include:
adding more caps, generally to 4000 uf
ALWAYS using a BEC
re-routing all the wires so they come out the same end.
adding a thermistor to measure DIRECT FET temps, not just the surface of the heat sink
adding a 100ohm 1 watt resistor to prevent arching when connecting
Increasing the power wire size to 10 guarge with large bullet connectors.
On some units I also put a copper heat sink on the caps and a thermistor under it to measure actul cap temps (all feed into my Eagle Tree)

Pics attached. Suggestions?

[ksm2001]

Where did you pick it up from?

I bought the Arctic Silver Alumina Thermal Adhesive form a computer store here where I live called Memory Express but any bigger computer products store should carry it.

[NativePaul]

I also use arctic alumina epoxy to fix the heatsink to the fets, and the tubes to the heatsink, while it would be best to sand and lap the FETs then apply thermal paste then clamp the heatsink in place to stop it moving around with this ESC I don't see clamping as practical so choes just to mix a little AAE , put a dob on each fet, push the heatsink on then pull off and check that the AAE has spread out over each FET, then put the heatsink back on and weight down with a book or something heavy for 20 mins (its like 5 min epoxy), while this isnt perfect it is a lot better and easier than lapping the fets and then using a thermal transfer pad which are crap unless your willing to spend over £100 for a sheet a few inches square and then there still not very good.

Note, I do not conformal coat my ESCs prefering to enclose them in heat shrink and seal the ends with electrical grade silicone, but if I did I would sand the regular epoxy (or silicone or whatever the conformal coating is) off the tops of the fets before applying the AAE.

When doing the tubes simply squish the aluminium tube flatish with a vice or small hammer so it will fit between the fins (there are 2 fins with a wider gap than normal use these) leaving the tube round on either side of the Heatsink, look and blow down the tubes to make sure you didnt flatten them too much and restrict them, then glue in place with AAE as you would normal 5 min epoxy.

[wolf IV]

I just use a flux paste light brush and paint on the epoxy everywhere but the tops of the fetts... I then lightly block sand the top of the fets as lapping doesnt do any good with un even hand laid fetts like the hi-models... Arctic silver is the way to go!!

[Brushless55]

I found the two-part thermal expxy to work great. Here are some pictures of mods that I did on 100 and 200 Amp inexpensive Mystery ESc's. I think the controller circuit board is the same for many of the ESC's that fall in this same class. (compare the close up pic with your controller) They up the amp ratings by just adding more FET boards.

My mods include:
adding more caps, generally to 4000 uf
ALWAYS using a BEC
re-routing all the wires so they come out the same end.
adding a thermistor to measure DIRECT FET temps, not just the surface of the heat sink
adding a 100ohm 1 watt resistor to prevent arching when connecting
Increasing the power wire size to 10 guarge with large bullet connectors.
On some units I also put a copper heat sink on the caps and a thermistor under it to measure actul cap temps (all feed into my Eagle Tree)


Pics attached. Suggestions?

Good stuff man!