Yes, depending on the film, you can improve thermal properties with anodizing.
This is what I was referring to, though. Might be a little tough to see in the pictures, but the one on the right has been treated. Hoping to get some data to share, but there’s up to 4x as much surface area with this surface finish. @Whosa_whatsis
Yeah, this method may also make it easier to not affect the threads, which could reduce thermal conductivity.
It’s typically done before threads are cut, so yes. It’s also cheaper than anodizing. Doesn’t look as cool, but function over form, right?
But you could also screw something into the threads if they are already cut (for instance, if you bought it already-made from E3D) to protect them during the process.
This is why? More surface-area?
Not sure I follow you… the rate of heat transfer is directly proportional to the surface area through which the heat is being conducted. If there is a significant increase in surface area - there would definitely be an increase in the rate of heat transfer - at least theoretically.
Perhaps that isn’t realized because the fan CFM fan is too low to achieve more cooling. Is that what you were getting at?
Yes, but it’s also proportional to the difference in temperature between the surface and the air moving over it. If you can’t conduct heat to the surface, you’re only cooling the surface and not the core. Likewise, if you transfer heat to one bit of air, them that same bit of air goes over another part of the surface, there will be less difference in temperature and less heat will transfer away from that part. Adding turbulence will ensure that the air is thoroughly mixed, and you won’t have areas of cold air next to areas of warmer air coming off the heatsink.
Air could get trapped in the rough anodised surface and act as an insulator.
I didn’t mean to suggest that it would increase 400%, simply that the surface area is increased by up to 4x. I’ve yet to get in front of a FLIR camera, but hope to soon. I don’t expect a big difference at temperatures below 260C (as it relates to printing performance - a few degrees C cooler may be statistically significant, but may not have any noticeable effect on the printing process), but I have a feeling there could be a not-insignificant one at higher temps.
I did thermal vision on my E3D and was disappointed. The whole heatsink was the same temperature, roughly 10deg above room temperature. Booring. But good 
I would not trust a thermal camera. Shiny vs rough surfaces shoe up differently on thermal cameras, right?
@NathanielStenzel it would be able to tell you the relative heat distribution (on the surface), even if it doesn’t give you an accurate absolute measurement.
@Whosa_whatsis so you would compare near the heat block to the rest of it and then compare those contrasts for both treated and non-treated cooling fins?
Wouldn’t a more definitive measure be the duty cycle of the PID algorithm? If the coating is improving heat dissipation, that should result in a higher duty cycle to maintain the same temperature, right?
@Alex_Wiebe If your thermal break is doing it’s job, you shouldn’t see a huge difference in the power needed to keep the hot end hot. With a good thermal break, the other end of it will heat pretty gradually, and the heatsink and fan are just there to keep it from eventually getting warm enough to cause issues.
This makes me wonder something. Has anyone put a thermistor somewhere past the heat break in an area you intend to keep cool?
My undergrad focus was on thermal sciences. Things are not always as initiative as you might suspect. However, a controlled test would eliminate the guessing.
@NathanielStenzel Well, it in the case of a heatsink, it’s pretty hard to insert any type of measurement device. The better you couple it to the material of the heatsink, the more you are going to alter the local properties of the heatsink. Making a hole to insert a thermistor into increases surface area and decreases thermal conduction. This type of thing is easier to use non-contact sensors for, they just have to be properly calibrated for the emissivity of the surface.
At this point, I should probably point out that this post was meant as an aside to this post/thread
https://plus.google.com/+shaischechter/posts/A9xSNPhxpvQ
I was not positing anything definitive, but rather offering a possible way to increase cooling in the event it was necessary on the new hot end that @Shai_Schechter is releasing…
I started a new thread to A) post a picture, and B) not totally hijack…
