ABS vs PETG - Same STL, different part size
Good day to all
I am trying to reprint some components as a spare for my printer, but, i don't want to use ABS, so, the obvious choice is PETG.
The issue I encounter is that the final dimensions of the printed parts are not the same as the ones supplied with the kit, even though the official stl files are used, the bearings in the Z carriage are somewhat loose.
I presume this to be due to the shrinkage of the ABS and the PRUSA files compensating for this shrinkage.
Has anybody found a scaling ratio to compensate the dimensional deviation between the two different materials?
All help is most appreciated and welcome.
Best regards to all.
Re: ABS vs PETG - Same STL, different part size
💡 there are three things to mention about your experience:
1st: ➡ yes, abs and petg have different shrinkage. but the exact amount is related to the brand and even depends on how you've printed it (bed temperature, cooling fan etc.). if you look into other 3d printing related boards, people use scaling factors between 1.01 and 1.03 (between 1% and 3% upscaling to target the shrinkage) for abs.
shrinkage of petg is nearly negligible.
2nd: ➡ shrinkage practically only affects x and y direction. z is determined during the printing process by the layer hight, which is "forced" by the mechanism with the spindles, the z-steppers and the number of microsteps required to move it 1mm up/downwards.
3rd: ➡ if you mean with the z-carriage (there is none!) the x-end motor and x-end idler parts, where the bearings that run on the z-rods are located: there are differences between the parts for the i3 mk2 and the i3 mk2s. at the mk2s the diameter for the bearings is a little bit larger than at the old mk2 part.
not severely, but some users experienced that their bearings will not be hold tight anymore. so you can either print a new part with an altered *.stl, or simply use a layer of 3M, scotch or tesa tape at the outside of the bearing.
dem inscheniör is' nix zu schwör...
Re: ABS vs PETG - Same STL, different part size
💡 there are three things to mention about your experience:
1st: ➡ yes, abs and petg have different shrinkage. but the exact amount is related to the brand and even depends on how you've printed it (bed temperature, cooling fan etc.). if you look into other 3d printing related boards, people use scaling factors between 1.01 and 1.03 (between 1% and 3% upscaling to target the shrinkage) for abs.
shrinkage of petg is nearly negligible.
2nd: ➡ shrinkage practically only affects x and y direction. z is determined during the printing process by the layer hight, which is "forced" by the mechanism with the spindles, the z-steppers and the number of microsteps required to move it 1mm up/downwards.
3rd: ➡ if you mean with the z-carriage (there is none!) the x-end motor and x-end idler parts, where the bearings that run on the z-rods are located: there are differences between the parts for the i3 mk2 and the i3 mk2s. at the mk2s the diameter for the bearings is a little bit larger than at the old mk2 part.
not severely, but some users experienced that their bearings will not be hold tight anymore. so you can either print a new part with an altered *.stl, or simply use a layer of 3M, scotch or tesa tape at the outside of the bearing.
JeffJordan to the rescue as always...... thanks you so much.
I did in fact mean the x-end motor and x-end idler, and yes, I did print from the MK2s STL.
I suppose the 3M tape is a solution, at least more appealing than the hours of machine running to re-print.
Once again, thank you so much, your feedback is most appreciated.
Best regards