I have taken the heatsink off. It was basically where the large spaces are now. It would only cool the block (albeit poorly) by the heatsink. But the contact area was very small and no thermal paste either so is questionable if it really did anything at all.
So the heatsink is gone, the fan can now cool the block itself, the filament assembly, and the motor itself. All is running considerably cooler now.
I also back the motor away from the assembly with small washes as the heat from the motor and the bar all be transferred the cogs and ultimately to the filament.

- IMG_6766.JPG (211.6 KiB) Viewed 2022 times

- IMG_6767.JPG (250.81 KiB) Viewed 2022 times
Initial tests with a bit of tension by hand on the filament thing to limit me to about 250mm / min even at 250c temp (PLA) .
But I have never tried anything that slow before, the defaults were around 5500 mm / min in software. The filament that slow would take like a 5min parts more like a hour
But I will go down to this slow speed and I suspect the problem will not be there, but this is not really a realist use a printer at
