New i3 MK3s build finished, question  

RE: New i3 MK3s build finished, question

Also, on the lcd screen it says "layer hight" "0.15 ?"

Do I need to concern myself with the question mark behind "0.15"

Thanks in advance.

RE: New i3 MK3s build finished, question

Here are a couple of pictures from the kit build and a few pictures and short video of my first print :

https://flic.kr/s/aHsmPv8P24

RE: New i3 MK3s build finished, question

The Prusa Mini printer has a display that will show the model being printed. The Mk3/Mk3s is limited to the 4 line character display. 

The question mark behind the current nozzle height just means the printer hasn't been homed yet, so it can't establish exactly where it is located. Next time you print, it will home the nozzle and the question mark will disappear as the actual Z height is determined.

Get used to those "long" print times. I though it would be a much faster process starting out. I've learned a good print can take a LONG time. Have fun with it!

RE: New i3 MK3s build finished, question

As Bob says before you start 3d printing you don't quite realise how long the process takes.  2 hours is a short print 🙂 

I think my longest was around 64 hours and that was with a 0.6mm nozzle and 0.3mm layer height.  It was supposed to be around a week with 0.4/0.2.

RE: New i3 MK3s build finished, question

Thanks for the info.

I'll have plenty more questions going forward 🙂

here is one now :

The video says to use Isopropyl alcohol 90%, but the majority of brands are either 70% or between 99%-100%, and very few are 91%,

so for me the easiest to get hold of are 70% or 99-100%,

so 70% is probably too low and 99-100% is too high.

Can I use between 99%-100% ?

I've seen many wiping cloths that are 70%, those are easy to work with as well.

Which is best ?

RE: New i3 MK3s build finished, question

Get used to those "long" print times. I though it would be a much faster process starting out. I've learned a good print can take a LONG time. Have fun with it!

Posted by: @neophyl

As Bob says before you start 3d printing you don't quite realise how long the process takes.  2 hours is a short print 🙂 

I think my longest was around 64 hours and that was with a 0.6mm nozzle and 0.3mm layer height.  It was supposed to be around a week with 0.4/0.2.

Exactly what I was thinking when I saw a file on the sd card with +13h beside it, LOL

RE: New i3 MK3s build finished, question

To answer you Ipa questions yes 99.9% can be used.  When I do use ipa I have 99.9% (well it was when it was new).  IPA absorbs moisture over time so the concentration will lower over time, especially if left open to the air. 
What many experienced users do though is not use ipa for day to day cleaning. Ipa like other alcohol based cleaners dilute greases and oils. They then effectively spread that round in a thin layer. Unless you use LOADS of ipa. Which is expensive and nowadays it can be harder to get in gallon quantities. 
Using a basic dish soap like dawn/fairy, with no additives actually removes much more grease and oils, when combined with rinsing in copious amounts of HOT water it’s far more effective.  Prusa say not to as there is a slight risk of rust on the steel sheet but if you dry the sheet off with clean paper towel and either use straight away or put it on the bed and heat it to bake the remaining moisture off the actual risk is negligible. 
Once clean only touch the sheet edges with your fingers to avoid transferring skin oils back on to it.

I have been using my original smooth sheet for years cleaning it the sink and it’s still just as effective today and only has normal wear and tear marks on it. Long time users will tell you the same.  Besides Prusa class the sheets as consumable items. 
Once you get a clean bed and have the first layer height set correctly you can get some awesome bed adhesion. I love posting this picture that shows what you can get away with -

RE: New i3 MK3s build finished, question

Posted by: @ilja-coveliers

[...] The video says to use Isopropyl alcohol 90%, but the majority of brands are either 70% or between 99%-100%, and very few are 91%, so for me the easiest to get hold of are 70% or 99-100%, so 70% is probably too low and 99-100% is too high.

You want 90%+ ideally. 70% works, but simply is not as effective as higher concentrations. A bit of trivia: The reason 70% is so common is that a bit of purified water slows the evaporation, making the alcohol more effective against bacterial. That's why most pharmacies don't stock the higher concentrations. The higher the concentration, the more effective a given volume will be against grease.

Can I use between 99%-100% ?

Absolutely. It can be tough on the skin though, so protect yourself accordingly.

I've seen many wiping cloths that are 70%, those are easy to work with as well.

Those work and the 2 samples included with the printer do work... against very small amounts of grease. However, as @neophyl notes, alcohol is ultimately only breaking down grease. You can wipe away some, but that tiny cloth isn't too useful for that. IME, the wipes are a waste once you start using your printer heavily. The "dunk with Dawn" wash is the most effective means of cleaning your sheet. Just avoid touching the print area as much as possible, including when peeling parts up. Consider a plastic (not metal) scraper or razor to help reduce touching.

Which is best ?

Everyone has their favorites. I like a dunk under the sink with dish soap when possible. I'll use a squirt of 99% isopropyl alcohol when in a hurry now and then. For my other printer with a fixed bed, I'm stuck with alcohol, so use 99% there.

RE: New i3 MK3s build finished, question

@neophyl, @bobstro

Thanks very much for the info !!

RE: New i3 MK3s build finished, question

Here is my first 3D benchy :

3D Benchy

Tell me what you guys think of the finish.

Maybe there is something that can be improved with altering settings ?

Thanks in advance.

RE: New i3 MK3s build finished, question

The one thing I noticed immediately is that it does not show that tell-tale line on the outside hull right at the point where the deck joins to the hull.  This is a 'good thing', as that anomaly is known to be present in some Benchy prints.  A while back there was a discussion of it when one user had it with black Hatchbox ABS.  As a sanity check I printed one just like it, as I had plenty of black Hatchbox ABS, and it did show up on mine as well.

I see some minor stringing and a few zits in there, but nothing significantly bad.  The drooping under the bridged sections can be expected.

To answer your question about isopropyl alcohol, 91% used to be commonly available here in the States, but since the pandemic it's been irregular in supply.  Here in the Omaha, Nebraska, USA area, 70% is common but lately 91% has been nonexistent on the store shelves.  I can get technical grade (translated: not intended for clinical use) 99% and that's what I'm now using.  I've also had good luck using what they call 'denatured' ethyl alcohol here in the states.  This is grain alcohol which has been rendered undrinkable by adding various nasty adulterants.

Isopropyl is my first go-to solvent for routine build plate cleaning.  If I've been using glue stick, denatured alcohol seems to dissolve it better, and every once in a while I use acetone on the smooth sheets.  The party line is to never ever use acetone on the textured sheets, but some have reported doing it.

RE: New i3 MK3s build finished, question

@jsw

Thank god the benchy printed fine then.

I did manage to find a bottle of 1L isopropyl alcohol 91% and ordered it.