i dunno how well the heatsink would work in practice but this extruder / hotend defiantly looks cool.
https://www.billsprototypestudio.com.au/products/bps-3d-printer-extruder-kit-v3
I think it would be: heatcreap that shit out of the filament xD
I think Angus has one of them on Test…
it sure is compact. put a ventilator to cool between the stepper and the extruder 
Oh, at first I thought those were channels for water cooling.
I’m on the 4th iteration of a similar design, needed to practice small detail CNC machining, and brush up my pinfin calcs so an extruder was a natural choice.
Q comes from both the stepper and the heater block. Iteration 1 dead. Only accounted for convection and conduction of heater block.
Wanted self contained QR assembly, iteration 2 dead.
Created internal plunger assembly, but still not dissipating enough Q to run over 190 degrees (heat creep noted above) iteration 3 dead. Tried anodizing, results worse than calculated.
Iteration 4 looking pretty promising but does contain a fan. It looks really cool but won’t release till we can extrude nylons.
I would be more concerned about that long transition zone
Cool concept, but really sub-optimal heatsink design. With no fan, it needs all vertical fin channels for convection cooling. With a fan, it needs cross-cut fin channels. Either way, the circular fins in the center are a bad approach because they will act as stagnant zones for airflow.
@Ryan_Carlyle couldn’t agree more. The fan I had to add hits a horizontal set of fins that curve to the vertical and the lower section of these fins push air towards the heater block. The hope is when physical testing takes place the convection from the heater block is removed due to this air flow only leaving the conduction to be removed.
But, this guy may have something going on I don’t know about. Did we determine it was absolutely not water cooled? That would remove huge amounts of heat energy and may make this design work really well. I barely have room for the wires going to the extruder/hotend, much less a couple of water hoses.
Water cooling would certainly solve all the possible heating issues, but then I don’t think it it would have external fins at all.
It looks like it was designed more to be “cool” than to perform well. What is the purpose of a heater block of that shape? And the heat break is too thick, it will need a PTFE liner.
@Shai_Schechter Apparently there is a PTFE-lined version for low-temp filaments and an all-metal version for high temp filaments.
I think the hot block shape is for visibility and airflow near the small nozzle, but it would be useful for non-planar slicing stuff where hot block collisions are an issue.
The proportion of that heater block to the nozzle seems inconsistent in my opinion. There will be a lot of heat transfer from the heater block to the print because it’s so close to the tip.
@Shai_Schechter I agree. It seems like aesthetics trumped functionality in this case.
Pretty funny, if this guy watches his web traffic he’s going to see a huge uptick today! Ha.
If you extrude like hell you could mount a fan directly to the stepper motor shaft. 