I have been sanding and sanding, took scrubs out, but the heat sink stil l do not fit in. I can push them if I gently hammed them in, but this will not work with a fully mounted hot end. Any advice? Thanks.
I used the sanding cylinder with a dremel on slow. Wasn't encouraging, but worked perfectly (very slow, very short, keep checking, obviously don't oversand).
A thick rolled up piece of fine wet and dry, roll up a thick piece just smaller in diameter than the hole and say three inches or so long so that you have plenty to hold, rotate gently so the imperfections get smoothed down. Keep trying the heat sink until it fits. Worked a treat. Took firm pressure but no more, certainly not needing a hammer. Dremel is dangerous, far too easy to destroy the part...... by hand with wet and dry used dry, far less danger of taking too much off or ending up with an oval hole.
The dremel for me was set at really, really slow and with a fine sanding drum. Barely took off anything actually. Took a surprising amount of time to sand it down...
Not having a Dremel around the house, I used a short piece of dowelling that was to hand and made a sandpaper lollipop (strip of paper, sticky tape one end to dowel and roll it around into a cylinder), popped it into the hole and rotated the printed piece with one hand (much easier than trying to turn the dowel), turning so that the paper was trying to unwrap. This was surprisingly efficient (in fact, I'm concerned that the fit is now a bit too loose, which I will discover in due course I guess).
I was also struggling with sandpaper, but a very very very short run with a Dremel solved my problems.
Are you at the step where you're inserting the hotend with the internal piece of PTFE tubing installed? That piece hung me up for a bit, so I ran an appropriately sized drill bit through the channel where it fits, and that helped.
When I got to that point, it was a real struggle - and I thought I'd done the prep on that. I ended up disassembling the whole lot and, as you say, running a drill bit through - this time taking extra care to test-fit the PTFE in all the appropriate places before re-assembling it. The parts-preparation instructions could do with a section on drilling-out and test-fitting the PTFE etc, as well as which printed surfaces are going to move against each other and possibly need smoothing out, so this can all be done before the parts end up within an assembly. One could have worked it all out by dry reading the wiki but... I took a few photos but want to wait to see that I actually have a working printer before posting the photo that shows me accidentally filing away the vital part!
I had the smaller dremel drum sander (perfect size) in a standard drill, took 30 seconds and worked a treat.
Glad I found this thread... Strip of 150 grit sandpaper (~100x30) wrapped around a standard AA battery did the trick for me.
mine fit perfectly out of the printer, maybe try calibrating your extrusion multiplier and print it again?