ok, just wanted to mention is all just in case. how far in does it peel off? mine is setup downstairs in the basement, temps are in the mid 60s usually & I don’t see it too often. long prints in PETG have pulled up on the corners.
Hi.
I also printed the core recently in a very cold room <5°C.
I had the bed all the time at 60°C, not just the first layer. It keeps the object warm in the first layers, where it would warp the most.
I put the printer in a cardboard box and put some insulation around (old blankets). Take care, that is not fire-prove!
The exhaust heat from the nozzle and the bed is heating up the air inside, that reduced my warping a lot.
Also I used a brim (dont know how much this helps on a big part) and cleaned the bed with acetone. It sticked so bad, I ruined my magnetic/flexible buildplate. So maybe acetone is too much…
Nozzle temp. maybe as low as possible to reduce temp.differences.
I turned of the fan completely to keep the object as warm as possible, and bridging / tops of the holes were good anyhow.
good luck
I wanted to drop a thank you for this thread. I have had a number of failed prints in a row. I now understand that leaving the window open near my printer was almost certainly the problem. As I write this, its 37F 2.7C outside!
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oh temps dropped below that, like low 50’s. the warping was happening in the left corner so i moved the part in prusa slicer over a bit to see if maybe the bed had heating issues but same thing.
60c! thats hot!! highest ive gone was 85f, i just received the core i purchased from V1 so all good now, just trying to source some polished SS tube now
i did the same thing when i started 3D printing even had a fan blowing on it, lol. hey we learn something new everyday huh?
bummer you had to buy the core but congrats on moving forward on the build! all my prints finished last night, so looking forward to ordering the hardware / electronics kit from V1.
After reading various posts on the MPCNC forum (and having already printed all the other MPCNC parts with 0.1mm layers) I have now just completed my first core print. My core print went so well I printed a second one, but this time with 0.2mm layers (print time was just under 25 hours for the second print). Well, it was the weekend so why not!!
I spent a great deal of time finalizing my parameters and having read comments of some makers who were having difficulty or having print errors I count myself lucky that my first core print appears to be spot on and the print time was just over 23 hours.
Following Ryan’s advice, I printed the first core with 0.3mm layers for strength.
I split the infill 70/30/70 at 24mm and 116mm, as also suggested by Ryan, to save on print time.
I did not use any brim as I thought the core’s print base area to be large enough to keep it stuck down and from my print result this seems to be fine.
I also had a target of having a print time (if possible) of no more than 24hours.
Printed on a Prusa Mk3.
I am in SE Queensland, Australia, where the ambient temperature is currently between 20˚ - 30˚C but my printer/build room is air-conditioned at a constant 24˚C. Probably to the dismay of 3D print purists my printer sits directly below the ceiling air duct and is not in an enclosure. Printing in PLA in this case, so maybe that is not an issue, but I have not had issues when printing PETG.
My filament spools are kept in an air-tight container with two desiccant containers (each 50 x 50mm vented cylinders) and the humidity inside the box varies between 16 – 19%. My room/house humidity can vary from 30-60% so the spool container gives me great consistency at a much lower level. Because my printer room is at a constant 24˚C the spool container correspondingly stays at that temperature.
I only use eSun filament simply because I believe it better to stick with one brand and get to know it thoroughly. Why eSun? It was one of the first brands I used when I started out, it seems to me to be of good consistent quality, an economical price and supply is easy to obtain. There are plenty of other quality filaments out there (and maybe some of better quality) but for my purposes eSun fits the bill.
I had initially prepared my g-code using a 0.5mm nozzle but when I went to print, my Prusa Mk3 only had 0.2, 0.4 and 0.6 nozzle sizes fixed into its settings. So, I quickly rejigged the g-code to a 0.6mm nozzle and just as quickly changed the nozzle on my printer. This also reduced the print time by about 1 hour. If I can find a way to introduce a 0.5mm nozzle into the Prusa parameters I may have another go resetting the g-code to match.
I prepared my g-code using PrusaSlicer 2.3 for the core (and all the other MPCNC parts) and I’m happy to pass the core g-code on to anyone wants to try it out. I am absolutely no expert at this so cannot guarantee it will work for you, but it worked for me (twice) and I am happy to share it with others to try. Previously I kept looking for someone else to ‘drop’ a g-code to save me the trouble but after having to fiddle and adjust it myself I am pleased that in developing my own g-code I have learnt much more about slicing.
Of course, any comments on my g-code, positive or adverse, will be appreciated and any improvements or suggestions on my g-code will also be greatly appreciated.
I do have a question is regarding variation in the strength of 0.3mm v’s .02mm layers. From what I have read the thicker the layer the ‘stronger’ the final print. Can someone explain in detail why this is so? Is the variation in strength due to an engineering cause or is it due to some material/composition/adhesion cause? Or both?
From what I have read the thicker the layer the ‘stronger’ the final print. Can someone explain in detail why this is so?
Stefan at CNC Kitchen explains:
Also one of the things that has become apparent to me from reading the forum topics, is that strength and stiffness are not the same thing. Stiffness is the important factor with the MPCNC’s 3D printed parts, and typically the MPCNC does not stress the parts in such a way that strength plays a major role. Most of the data I see on printing techniques focuses on strength, so there is very little practical data on what settings are best for stiffness.