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Differences between Mini and MK3S  

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Altruego
(@altruego)
Trusted Member
Differences between Mini and MK3S

Hi all,

Besides the smaller build envelope are there significant differences between the MINI and the MK3S?  I'm looking to add a couple printers to my print farm and found some MINIs at a good price.  The build envelope being smaller isn't a big deal.  I'm more interested in the difference in print quality and speed.

I know there is marketing material out there about this.  Looking for real world experiences.

Posted : 19/01/2024 1:35 pm
fuchsr
(@fuchsr)
Famed Member
RE:

I have Minis, Mk4s, Mk3s and one XL in my small farm. I'd be hard pressed to say there's a discernible difference in print quality between Mk3 and Mini. With the new firmware speed has gone up significantly. And IS on the Mini actually delivers really great results unlike IS on the Mk4 (I found IS on the Mk4 to be hit or miss). 

It's a Bowden drive system but the only limitation I have found is that I wouldn't want to print TPU on it. I know people have done it, though. The only modification I would say is essential is the Bondtech extruder or the Trianglelab clone. The printer works without it of course but I print with a lot of different filaments and material types, and I found I had to constantly adjust the idler screw. In about three years of running the Bondtech extruder, not once. Some people have reported issues with the PTFE tube and the heatbreak. I never had any issue with it myself (a Bondtech stainless steeel hotend "upgrade" is still residing in my drawer) but I also added Dragon hotends to my Minis and Mk3s a long time ago so I'm not really qualified to say much about it. 

This post was modified 4 months ago by fuchsr
Posted : 19/01/2024 5:16 pm
Altruego liked
mark
 mark
(@mark-3)
Reputable Member
RE:
Posted by: @fuchsr

I have Minis, Mk4s, Mk3s and one XL in my small farm. I'd be hard pressed to say there's a discernible difference in print quality between Mk3 and Mini. With the new firmware speed has gone up significantly. And IS on the Mini actually delivers really great results unlike IS on the Mk4 (I found IS on the Mk4 to be hit or miss). 

It's a Bowden drive system but the only limitation I have found is that I wouldn't want to print TPU on it. I know people have done it, though. The only modification I would say is essential is the Bondtech extruder or the Trianglelab clone. The printer works without it of course but I print with a lot of different filaments and material types, and I found I had to constantly adjust the idler screw. In about three years of running the Bondtech extruder, not once. Some people have reported issues with the PTFE tube and the heatbreak. I never had any issue with it myself (a Bondtech stainless steeel hotend "upgrade" is still residing in my drawer) but I also added Dragon hotends to my Minis and Mk3s a long time ago so I'm not really qualified to say much about it. 

Very interesting. What have you tuned on the MK4?  On my 3 year old Mini with the new IS firmware, I got significant improvement after adjusting the extruder tension (stock extruder), IS k factor, and flow rate multiplier. It is all quite good except of course at the seams, which are still not quite right on the Mini with IS. Now I am getting really good results, maybe the best it has been in 4 years. I thought the MK4 had an accelerometer so it could self tune IS.

Regards,

Mark

This post was modified 4 months ago by mark
Posted : 20/01/2024 11:17 am
Altruego
(@altruego)
Trusted Member
Topic starter answered:
RE: Differences between Mini and MK3S

 

Posted by: @mark-3
Posted by: @fuchsr

I have Minis, Mk4s, Mk3s and one XL in my small farm. I'd be hard pressed to say there's a discernible difference in print quality between Mk3 and Mini. With the new firmware speed has gone up significantly. And IS on the Mini actually delivers really great results unlike IS on the Mk4 (I found IS on the Mk4 to be hit or miss). 

It's a Bowden drive system but the only limitation I have found is that I wouldn't want to print TPU on it. I know people have done it, though. The only modification I would say is essential is the Bondtech extruder or the Trianglelab clone. The printer works without it of course but I print with a lot of different filaments and material types, and I found I had to constantly adjust the idler screw. In about three years of running the Bondtech extruder, not once. Some people have reported issues with the PTFE tube and the heatbreak. I never had any issue with it myself (a Bondtech stainless steeel hotend "upgrade" is still residing in my drawer) but I also added Dragon hotends to my Minis and Mk3s a long time ago so I'm not really qualified to say much about it. 

Very interesting. What have you tuned on the MK4?  On my 3 year old Mini with the new IS firmware, I got significant improvement after adjusting the extruder tension (stock extruder), IS k factor, and flow rate multiplier. It is all quite good except of course at the seams, which are still not quite right on the Mini with IS. Now I am getting really good results, maybe the best it has been in 4 years. I thought the MK4 had an accelerometer so it could self tune IS.

Regards,

Mark

The MK4s don't have an accelerometer but rather uses a static setting for the IS frequencies.  It's quite controversial.  However,  the IS frequencies can be tuned.  The link below has all the details on how to do it.

https://marlinfw.org/docs/gcode/M593.html

I've tuned mine and didn't see much improvement in the results so I think Prusa has the frequencies right.

It would be nice to be able to tune the frequencies from the MK4 interface as opposed to using g-code.  Currently, the frequencies can be viewed but not changed from the interface.

Also, regarding seams... a very clever person has created a post processing script for seams.  I haven't tried it yet but the script is supposed to make smoother seams using by using a technique similar to a woodworking scarf joint. Here's the GitHub page for that. It looks promising but I haven't had a chance to try it yet.

https://github.com/vgdh/seam-slope-postprocessor/blob/main/README.md

Posted : 20/01/2024 2:03 pm
mark
 mark
(@mark-3)
Reputable Member
RE:
Posted by: @altruego

The MK4s don't have an accelerometer but rather uses a static setting for the IS frequencies.  It's quite controversial.  However,  the IS frequencies can be tuned.  The link below has all the details on how to do it.

https://marlinfw.org/docs/gcode/M593.html

I've tuned mine and didn't see much improvement in the results so I think Prusa has the frequencies right.

It would be nice to be able to tune the frequencies from the MK4 interface as opposed to using g-code.  Currently, the frequencies can be viewed but not changed from the interface.

Also, regarding seams... a very clever person has created a post processing script for seams.  I haven't tried it yet but the script is supposed to make smoother seams using by using a technique similar to a woodworking scarf joint. Here's the GitHub page for that. It looks promising but I haven't had a chance to try it yet.

https://github.com/vgdh/seam-slope-postprocessor/blob/main/README.md

Thanks. I have seen the info about tuning and the seam post processsing. In the github for Prusa Slicer, there are maybe a half dozen or more issues raised about the seams, including one or more asking for them to add that scarf seam as a feature. In my testing, just changing the extra de-retraction at the seams only would improve them a lot. But, changing that for the rest of the print results in a fuzzy mess. So, I think there are things that they can do, but would be best done in the slicer itself. Prusa has not been the fastest at adding features, but IS for the Mini has been a pleasant surprise, so I am hopeful.

Regards,

Mark

This post was modified 4 months ago by mark
Posted : 20/01/2024 8:15 pm
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