Printer down, replacement parts and upgrades (and question on MK3S->MK3S+ x-axis)!  

Printer down, replacement parts and upgrades (and question on MK3S->MK3S+ x-axis)!

Hi,

I bought an MK3S kit last July, but I didn't get around to building it until about May of this year I think, for Christmas, my wife got me the MK3S to MK3S+ kit, but I never got around to fit most of it on the basis of "if it ain't broke".

I did do a couple of mods over the intervening time, super pinder and a y axis belt mods, but I strayed from going anything else that would have resulted in me having to go through calibrating everything again.

So everything has been going fine, until last week when I had a blockage and the filament snapped, I tried a few things but ended up having to dismantle the extruder.  Even with the hotend out, I was unable to remove the stuck filament and in the end I had to remove the PTFE tube with a reasonable amount of force, once I'd freed the PTFE, the blocking filament just fell out, I believe I had suffered heat creep which resulted in this who chain of events.

I replaced the PTFE with a spare, reassembled the hotend, and tried printing again.  Now I was getting blobs of filament, I couldn't work out what was going on and I thought it was the filament I was printing with (that had caused the initial jam), so I switched to black PLA, and at first glance, it seemed better, but then I started getting "bogeys" of the previous filament, often hours into the print and it clearly wasn't happy, so I knew it was time to strip down.

I realized now that filament was leaking from the top of the block and would make its way down eventually to the print and resulted in the issues I was seeing, I knew it needed a much deeper delve to fix the problem.

It seemed logical, that while the printer was in this state that I may as well perform the rest of the upgrades in the box, so I did everything barring the x-axis, this seems like it's going to be a reasonable amount of work to bring the machine fully up to MK3S+ spec and it's not covered in the manual, in fact, 7 or so months ago prusa themselves commented in the manual saying "it's coming soon" and it's still not there, so the answer is to look at the MK3S+ assembly guide an work back, it's fairly obvious that the Z top mounts need to be removed and the 2 Y motors unscrewed end then unscrew the rods to get the x carriage + x ends off the rods.

I'd then be left with the whole X assembly intact there I would need to remove the rods from the ends so I could replace them with the new ends, before pushing the rods back in.

Can anybody explain exactly what steps need to happen to make the job easy, I'm by no means sure if I'm going to bother, this change out of all the others seems to be the most intensive for a no/small gain.  Does the carriage need to come off the ends, or is it possible to perform this upgrade with the extruder still mounted to the rods?

My other question stems from the hotend issues I had, I have had to order a replacement heater block, the one I had when the leak occurred ended up with filament in the threads both for the nozzle and the heatbreak, I couldn't find an easy way of removing this hardened filament, I tried various methods but in the end, decided that I'd get a replacement block because I'd be starting from a much better place, I dismantled the block and cleaned up the heater cartridge ready for inserting into the replacement block.

So, the question on that is, is there something you use to clean up when you get problems as I did, obviously the block needs heating to clean out the threads, but space is limited on getting in there and cleaning them up, and at the same time I want to avoid damaging the thread and ending up creating a situation where it's going to leak no matter what.  I did see mention of a thread die being used, but clearly, you'd need to be very careful with that and even then, I'm wondering if that would leave everything pristine, my thoughts here are that if any filament gets left behind then I might be creating problems further down the line.