Notifications
Clear all

MK3 to MK3S Upgrade  

  RSS
Krispee
(@krispee)
Active Member
MK3 to MK3S Upgrade

Hi all.

Right, first off  I was sent an upgrade after buying my Prusa MK3 a few years ago. I think the upgrade came a year or so after I bought the original printer and then it sat around for at least a couple of years, maybe three, before I decided to take the plunge and actually do the upgrade. It was free, I'm not sure why, I never did work out that part as I never actually ordered it. Also, it came with already printed parts with one or two duplicates, like more magnets than I wanted, that sort of thing. The whole thing did assemble just fine, the odd problem but nothing serious.

I also upgraded the firmware to the latest version, as I hadn't done that for a while either. That also went through without a hitch.

When assembling the gears and filament loader I did notice that the filament was pretty tight (tighter than the original). In fact the filament bent a bit more than usual. When loading to print for the first time it loaded fine, although I did have to release the screws a bit, so the gear wasn't too tight on the filament.

Anyway, printed a couple of prints and started noticing problems with the printer finishing its prints, filament getting jammed in the head etc. It would start fine but then stop extruding filament but continue to print as if nothing had happened.

I've included some photos of the printer parts and prints.

 

 

 

 

I mean, fair enough the upgrade allow you to partially dis-assemble the head so the extruder releases more easily, something that I put to good use over the next few prints after the filament got jammed in the head. After a few times of this I stopped and decided to try and find out if this had happened to anyone else and there were solutions there.

You know, before I upgraded my printer was working just fine. I'm wondering whether to revert back to the original parts and re-assemble.

Anyway, if anyone has an advice then I'm happy to hear it, although my printer is currently at work as I had some larger prints and wanted to keep my eye on it.

Thanks for reading.

Kris.

Engineer - Writer - Artist

Posted : 05/02/2022 11:04 am
Milos V.
(@milos-v)
Prominent Member
RE:

It does not necessarly have to be because of upgrade. Have you tried to replace the nozzle? 

When you are assembling the hotend back again, do it precisely, flollow the guide. Small mistake and jaming is the result.

The only problem in the extruder assembly could be, that the hole where filament enters the extruder, the gear and the hole filament goes to the hotend is not in one line. If this is fine, problem will be most probably in the hotend, not in the extruder body touched by upgrade.

My first guess would be semi clogged nozzle. Second would be wrongly assembled hotend (space between nozzle and PTFE tube or other mistake in assembly).

Posted : 05/02/2022 10:47 pm
Krispee
(@krispee)
Active Member
Topic starter answered:
RE:

I haven't tried a new nozzle yet, I will look into that.

I promise you that I followed the guide precisely. The printer does work to start with, even through the setup, the first layer etc - it's only part way through a print that it stops extruding the filament.

I definitely thought the way the filament entered the head was a little too offset in my opinion, more than the original. There was nothing I could do about that as the parts wouldn't allow for any other way of assembly.

I did dis-assemble the hot-end at one point and the PTFE tube is a little tricky to set right, I did have a problem or two with that, but it seemed to be fine in the end. I will purchase a new nozzle and look at the hot-end assembly again.

Thanks for your reply.

This post was modified 8 months ago 2 times by Krispee

Engineer - Writer - Artist

Posted : 06/02/2022 9:08 am
Krispee
(@krispee)
Active Member
Topic starter answered:
RE:

I have purchased a new nozzle and am trying it out now, also slightly shortened the PTFE tube as it seemed to me to be interfering with the bond gears. So far, having problems with the first layer sticking to the sheet.

Must mention that I purchased a new sheet before upgrading the extruder assembly. I am having problems with the first layer sticking now, although the First Layer Calibration tends to work very well the first layer of a print does not. I'll post some photos later, but I do have a question that has bothered me for a bit; where is the print strip that First Layer Calibration still has and the prints do not? Right at the front of the sheet the printer prints a 2 inch strip that, in my experience, clears the nozzle prior to printing and now, since updating the firmware and software, is missing. The printer goes straight into printing and doesn't print the prelim strip at the front.

Is there something in the slicer software that I haven't done?

This post was modified 7 months ago by Krispee

Engineer - Writer - Artist

Posted : 01/03/2022 8:53 am
Milos V.
(@milos-v)
Prominent Member
RE: MK3 to MK3S Upgrade

The strip is not a matter of printer, but gcode. So if during print printer is not even trying to print this, you might have wrongly setup the slicer. But check if printer is really not trying to print this. Maybe it tryes, but there is no filament in the hotend. Could be because of the filament leak during warmup. 

How filament sticks to the bed is given by first layer Z height (how much it pushes the line to the bed) and much more by the cleanness of the print sheet. So clean it better (under warm water + liquid soap).

Posted : 02/03/2022 7:20 pm
Krispee
(@krispee)
Active Member
Topic starter answered:
RE: MK3 to MK3S Upgrade

 

Posted by: @milos-v

The strip is not a matter of printer, but gcode. So if during print printer is not even trying to print this, you might have wrongly setup the slicer. But check if printer is really not trying to print this. Maybe it tryes, but there is no filament in the hotend. Could be because of the filament leak during warmup. 

How filament sticks to the bed is given by first layer Z height (how much it pushes the line to the bed) and much more by the cleanness of the print sheet. So clean it better (under warm water + liquid soap).

 

Soap and water? Really? I was always told to use Isopropyl Alcohol, which is what I've always used, every time I start a print. I have printed a couple of small objects successfully but also a couple that stopped extruding filament about 3/4 the way through and carried on printing air. I can clear the blockage using the needle and heating the end up but it doesn't seem to finish a larger print. It does seem to be sticking a little better.

I can't see anything in the slicer software that enables the strip print, perhaps I'm missing something.

Engineer - Writer - Artist

Posted : 02/03/2022 9:05 pm
Milos V.
(@milos-v)
Prominent Member
RE:

IPA is good to clean before each print. Once the bed is too dirty (grease on it), you will not make it with IPA. Soap and water helps. But dry it fast with paper towels to avoid some corrossion or such.

Lead strip (intro line) is part of the Start G-Code defined in slicer for the specific printer. If you use PrusaSlicer, you can find it in the Printer Settings - Customer G-code - Start G-code. It is there by default.

If the print fails in the middle because of blockage, there might be many different reasons. Clogged nozzle, inconsistend filament, but in your case I would bet on wrong hotend assembly (you wrote you disassembled before). Use the hotend assembly manual, follow each detail very carefully. There are many guidelines how to solve this, but also many reasons.

Posted : 02/03/2022 9:40 pm
Share: