Totally Impressed With My New MK3  

Re: Totally Impressed With My New MK3

By the way, I also want to commend the folks in the online product support group. Both Shane and Felip were extremely helpful as I tried to sort through the problems I was having with prints not sticking to the powder-coated steel print bed surface. I very much appreciate their knowledgeable support, despite the fact that we were not able to come up with a solution other than using the glue stick.

Re: Totally Impressed With My New MK3

Right there with you! It is an awesome printer and the support and documentation is first rate. There is a reason it is a highly recommended printer just about everywhere.

BTW,I am sure support recommended it, but did you try washing the sheet with warm water and dish soap? I had an issue with prints not sticking and used warm water and palmolive or dawn on both sides, dried it off and reprinted the same part and no issues since.

Re: Totally Impressed With My New MK3

I totaly agree with you, got my MK3 DIY Kit in january, first I was impressed by the quality of the packaging, by the well done assembly manual, and by the final result. Since I print with no particular issues. Realy an amazing printer. At a time I had bed adhesion problems, since I use Dimafix spray for all my prints.

Re: Totally Impressed With My New MK3

Glad you are happy. This is a great printer.

However, you really shouldn't have to use a glue stick with this printer unless you are using some exotic material. It's up to you, and if you are happy, you can leave it alone, but as was mentioned above, try washing the build plate thoroughly and make sure your Live Z height is well adjusted. I'm sure you're thinking "But its brand new why should I wash the plate" and the answer is "I'm sure you handled it during unboxing and building". If you touched the thing at all, you need to wash it. Use regular dish soap and water and a good scrub sponge. Nothing too abrasive is needed. Next, spray it down with just a little IPA (90+%). These tend to work magic.

If you've washed it well, make sure your Live Z is well adjusted. Use the calibration square from the thread "Life Adjust Z my way". The Prusa method is fine once you have experience, but it's really not great for someone new to the machine. I spent most of the first 4 hours I had the machine moving Live Z down. I was quite surprised how low I had to get it, but once I found the right setting it was much, much better.

Happy Printing.

Re: Totally Impressed With My New MK3

I've had a great experience with the MK3 also...it's a very impressive machine. I also built the kit...probably took way longer than I needed to. I did a lot of checking and re-checking parts fit, squareness, nut/bolt tension, etc as I was paranoid about having issues later. I thought for sure there would be some troubleshooting to get it working well...but when I fired it up it calibrated perfectly and has been absolutely fantastic to work with ever since.

So far I've mostly printed functional parts with mine...prototypes with PLA and then final parts with Taulman Tech-G and mine has run for hours a day since I completed it and I have yet to have a single failed print or any issue at all really. Many of the parts I struggled to get a decent print out of with the Creality CR-10 (sometimes several failed attempts) have come out perfect on the first try with the MK3. I had the Tech-G printing much better on the MK3 in the first day than I could ever do with the CR-10 after months of tinkering.

Regarding the bed adhesion I second the recommendation for making sure your live Z is dialed in and make sure the bed is clean. If a good wash and alcohol wipe down doesn't work try wiping the PEI surface down with a clean paper towel and some acetone. Just be cautious if you're going to print PETG after getting the bed really clean. Do the suggested wipe with Windex beforehand or the bond to the bed can be too strong (I've been doing this with the Tech-G and it works perfectly).

Re: Totally Impressed With My New MK3

Thank you everyone for your helpful input. Here's the timeline of what happened with the prints not sticking to the bed issue:

1) Completed the assembly of my MK3 and proceeded with the self-calibration steps. Prior to starting this process, I thoroughly cleaned both sides of the textured powder-coated bed plate with 91% isopropyl alcohol (IPA). All went well expect for the First Layer Calibration (FLC). The very first layer of filament from the nozzle simply rolled off the textured powder-coated bed plate as if the plate were coated with Teflon.

2) I removed the bed plate and thoroughly cleaned this time with pure Acetone.

3) I then fined-tuned the FLC with a -.0835 mm setting, which reproduced the patterns shown in Prusa's online guide for FLC. The amount of "squish" with this setting appeared to be near perfect. And the entire calibration pattern was sticking to the plate without glue. I thought I solved the problem with either the Acetone cleaning and/or the fine-tuned FLC.

4) I then proceeded to print the Prusa Logo sample gcode that's included on the SD Card. Again, the filament simply rolled off the bed plate like it was made out of Teflon. The thing I noticed is the shape of the line of filament that was being deposited on the bed plate was not the same shape as in the FLC in step 3) above. It was completely round, with no squish shape.

5) Next I did some additional searching on the Prusa Forum and saw several suggestions for washing the plate with water and dishwashing liquid (DL). So I tried that, with Ajax DL. I then reran the Prusa Logo print and the same thing happened as in step 4). The filament was not sticking to the bed plate.

6)) Next I tried the Kores glue stick (GS) that's included with the MK3 kit. Again, I reran the Prusa Logo print and perfection...the filament stuck to the bed plate beautifully, and the print came out perfect.

7) I then sliced some of my own STL files in the Slic3r Prusa Edition 1.41.0 slicer that comes with the kit. I thoroughly cleaned the glue I used in step 6) from the plate using warm water and multiple paper towels. That was followed with a good cleaning using IPA. I then proceeded to print one of my own models, and again, the filament would not stick the to plate. There was just no way it was going to stick under the current conditions. So as in step 6), and spread some glue down at 50 deg C bed temp, and reran my print. Perfection...the print stuck to the bed just as I would expect to.

8) I've printed multiple models in the past week or so, the tallest one at 200 mm (Z). They've all come out beautiful, but I've had to use glue with all of them. If I happen to mis-judge where to apply the glue and the first layer partially prints on a small section of the plate where there is no glue, it simply will not stick. So at this stage, my question is, could it be that there's some setting in Slic3r Prusa Edition that is changing the Z setting and/or Speed for the first layer to something different than what's being used when the First Layer Calibration is successfully being run? The first layer sticks to an untreated plate in FLC, but then won't stick (without applying glue) when printing a model sliced in Slic3r Prusa Edition. It doesn't make sense.

Re: Totally Impressed With My New MK3

4) I then proceeded to print the Prusa Logo sample gcode that's included on the SD Card. Again, the filament simply rolled off the bed plate like it was made out of Teflon. The thing I noticed is the shape of the line of filament that was being deposited on the bed plate was not the same shape as in the FLC in step 3) above. It was completely round, with no squish shape.

It sounds to me like you need to lower your love-Z a little more. I've found the built in calibration only gets you in the right neighborhood, and additional adjustment is usually still needed.

Re: Totally Impressed With My New MK3

As Phil mentioned above...maybe try adjusting your live Z with this method:
https://shop.prusa3d.com/forum/assembly-and-first-prints-troubleshooting-f62/life-adjust-z-my-way-t2981.html#p106130

I found this much easier to dial in the live Z with. I used the factory included routine first and then tried this routine and found my live Z was not low enough yet. If I hadn't tried Jeff's routine I might have had a few failed prints before I figured it out...

Re: Totally Impressed With My New MK3

Well, I finally solved my issue with prints not sticking to the textured powder-coated bed plate. Per the suggestion of Christopher.d16 and several others above, I needed to fine-tune the Z distance using Live Z. When I first calibrated my new printer over a week ago, the setting I ended up with using Prusa's First Layer Calibration (FLC) method was -0.835 mm. In fact, I zeroed in on that setting with the help of one of Prusa's online support staff. I had originally settled on a setting of -0.855, but after looking at my uploaded images of the FLC pattern, the Prusa rep's observation was "Hmmm...looks a little squished to me. Try -0.835. I did so, and we both agreed the resulting pattern appeared optimal. But my prints still wouldn't stick to the textured bed plate without glue...up until today. I decided to use a wide brim pattern that's part of one of my own models as a proxy for the "Life adjusted Z - My Way" pattern that several folks suggested. Starting from -0.835, I slowly decreased the distance between the nozzle and the bed plate as I observed how the brim pattern was being printed on a plate surface that was thoroughly cleaned...first with 91% IPA, and then with pure Acetone. The filament material didn't start sticking until I reached -0.875. I continued to decrease the Z distance until I reached what I now believe is the optimal setting...-0.950 mm. So it ended up requiring 0.115 mm less Z distance in order for my prints to finally stick properly to the powder-coated bed plate without applying any glue. I agree with Christopher's comment above...the FLC method merely gets you in the ballpark. It requires a careful fine-tuning with Live Z to actually calibrate the First Layer Z distance. Thanks again to you all for your helpful comments. It's become obvious to me that another huge advantage in opting for the Original Prusa i3 MK3 printer is the awesome global support network represented by like-minded (in terms of having a passion for 3D printing) individuals in this forum!! 🙂