Tim's 3D Printer Project

Neil, That was pretty quick. Did you order right from Prusa or did they have it here in the US?
 
Just for fun said:
Neil, That was pretty quick. Did you order right from Prusa or did they have it here in the US?
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I ordered it directly from Prusa. No one had these boards in stock except Prusa. It was last Sunday evening that I placed the order, so it took about eight days. Very happy about that. Hope to work on it this evening.
 
I finished my first print. I need an extension for my light switch timer in the green house. My wife wanted it in orange so that what it is. I'm pretty happy even though it didn't turn out perfect, it warped on two corners. I drew it up in fusion, now to see if it fits. The orange that I have is PETG, and I was using the smooth plate. I had the shop warmed up to 66° to start with and by the time it was finished the shop was at 70°, one problem is that the printer is next to the window, and it was in the high 40s to low 50s today.

All in all, I'm pretty happy with my first try.

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With my Prusa Mk3S+ I use the textured sheet for PETG and smooth sheet for PLA. I've found that increasing the bed temperature by ~10 degree C helps a lot with the corners lifting like that...

Have fun!

Ted
 
adding a brim instead of that skirt will help too. Just make it one layer deep and go out maybe 5mm or so. Still, temp is the main issue, and it can be the bed temp, or a combination of nozzle temp and speed that's doing it. PETG is a little temperamental that way. If too many layers get put down before they can cool, they all cool at nearly the same time and amplify the shrink.
 
I have a Prusa printer on way, how do you compensate for general shrinkage? I received a 3d part and it was slightly off on dimensions. I realize we are talking plastic but what's the process for getting parts on dimension? Is the shrinkage isotropic or different in the different axes? What kind of accuracy can one expect?
 
@Just for fun Tim, I would recommend slowing the print cooling fan down for the first five to ten layers. You can do this in PrusaSlicr. It is under "Filament Settings" and subset "Cooling." I believe you need to have "Expert Mode" selected to see all of the menu options. I do not have the print cooling fan running at 100% for the first layers for any of my prints but rather, have it ramp up as the print progresses.
 
WobblyHand said:
I have a Prusa printer on way, how do you compensate for general shrinkage? I received a 3d part and it was slightly off on dimensions. I realize we are talking plastic but what's the process for getting parts on dimension? Is the shrinkage isotropic or different in the different axes? What kind of accuracy can one expect?
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@WobblyHand There are some general shrinkage parameters based on different materials which will get you in the ballpark. Picking a filament type and brand and then doing some test prints, such as small cubes, and then measuring them would be a viable route. There are most likely are some test prints available on www.thingiverse.com that will be of great help to you.
As you well know, the tolerances of these printers are very different than machining a part. What level of precision are you looking for when you say "slightly off?"
 
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7milesup said:
@WobblyHand There are some general shrinkage parameters based on different materials which will get you in the ballpark. Picking a filament type and brand and then doing some test prints, such as small cubes, and then measuring them would be a viable route. There most likely are some test prints available on www.thingiverse.com that will be of great help to you.
As you well know, the tolerances of these printers are very different than machining a part. What level of precision are you looking for when you say "slightly off?"
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I suppose percentage wise it's not that much, but on the order of 1% error is what sticks in my mind right now. Need to go back and measure things carefully. Have to give things a fair shake and make sure I'm not measuring a brim or nubbin sticking out.
 
WobblyHand said:
I have a Prusa printer on way, how do you compensate for general shrinkage? I received a 3d part and it was slightly off on dimensions. I realize we are talking plastic but what's the process for getting parts on dimension? Is the shrinkage isotropic or different in the different axes? What kind of accuracy can one expect?
Click to expand...
I'm really into 3D printing. Customizing and Tuning are large part of the fun for me, so I have to restrain myself. Tuning is important, and you'll need to develop print profiles for the different filaments that you use if you really want great results. It's involved to write about, but this Teaching Tech has a good video on it:
 
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