Wired Cruiser - monster truck of ebikes.

[Gionnirocket]

Wow... the more you look into these bikes, the better they get!

 

[PCeBiker]

There was a white pasty substance that looked like permatex teflon paste used to seal water pipe threads between the controller and mount,.. Another fella said it was used to transfer heat to the frame from controller.

It's most likely heatsink plaster,..

It's specifically designed to conduct heat but Not electricity.

Most things that transfer heat also conduct electricity.
The plaster is safe to use to remove heat without shorting out any wires or conductors.

They also have heat transfer tape and different colored heat transfer "grease".

I also ordered some silicone heatsink glue to glue things in place, but I was sent the same type of paste. It doesn't cure and harden up like I was expecting.

 

[Marcela]

It's most likely heatsink plaster,..

View attachment 199736

It's specifically designed to conduct heat but Not electricity.

Most things that transfer heat also conduct electricity.
The plaster is safe to use to remove heat without shorting out any wires or conductors.

They also have heat transfer tape and different colored heat transfer "grease".

I also ordered some silicone heatsink glue to glue things in place, but I was sent the same type of paste. It doesn't cure and harden up like I was expecting.

Ah. That is what it was then. Thanks for the info! I wasn't aware there was such a thing. Looking at the thermal conductivity of that stuff is like .671-4.8 w/m-k. Copper is 385-397 w/m-k and aluminum is 205!

 

[PCeBiker]

Ah. That is what it was then. Thanks for the info! I wasn't aware there was such a thing. Looking at the thermal conductivity of that stuff is like .671-4.8 w/m-k. Copper is 385-397 w/m-k and aluminum is 205!

So it looks like copper and aluminum conduct heat better, but you would still want heat sink paste between the mating surfaces so the heat can transfer between the surfaces.
You don't want any air gaps between the two surfaces.

They use it on CPU chips in computers and on aluminum heat sink fins for power transistors.


The original controller on my first ebike was fully potted, and they used the heat sink paste between the 9 Mosfets and the aluminum heat sink.

The replacement KT controller only used a high heat plastic strip between the Mosfets and the aluminum heat sink.
The plastic isolates each Mosfet electrically, but doesn't conduct heat to the heat sink nearly as well.

 

[Marcela]

The aluminum and copper antiseize comes in a paste, it would fill any voids between the two surfaces. The heatsink paste in comparison would act as an isolator. The only reason they use the heatsink paste is it doesn't conduct electricity, on the bike where the controller mounts, the screws from the frame into the controller kind of negate isolating the box with heatsink paste. Removing any paint between the two surfaces might be a consideration also. They want the controller to dissipate heat and it has fins, yet they either powder coat it or paint it, which is an insulator, doesn't make sense if it is that important.

 

[PCeBiker]

I did some searching,..

So yeah,..
If you're sure that you aren't going to short anything out electrically, Copper Anti-seize would conduct heat Way Better than thermal conducting paste.


Here's what the AI Robot has to say about it.

You don't want to be doing this,..

Or this, with copper Anti-seize,..