Dimensional Accuracy
So I have my MK2 build and Printing and I love this machine. First Calibration went well with no issues.
Other than some issues with either models Sticking to the bed and being almost impossilbe to move or occasionally one not sticking and turning into a nice PLA Hair ball its going well.
My question is model accuracy. I have a model of a cube, 1" with a .5 hole, .375 hole, and a .25 hole. The holes on average are .1 smaller than the model. My Z diminsion is slightly bigger than 1.0 and my x/y is close but slightly smaller. Is this normal to expect from the MK2?
Is there an adjustment in the printer to adjust the prints so that I don't have to change the models? I have several models that I have machined into various parts on our Mill and would like to print some of the smaller ones rather than machine them.
Using Sli3r Prusa edition, PLA 1.75mm, .15 Optimal, changed to 70% fill (Not sure if this effects the model much). Also using OctoPrint as an interface as I like the network ability it gives so I'm not always moving memory cards around.
A point in the right direction would be much appreciated.
Chris
Re: Dimensional Accuracy
Check out this item on Thingiverse.
and an 8 inch (200mm) or greater caliper is recommended.
Re: Dimensional Accuracy
Thank you Ayourk. I am going to give that a try.
Re: Dimensional Accuracy
So any advice on holes in parts? My cube is correct within .001 or so but the holes printed in it are all undersized by .015. And since the holes are on three different sides it would be a product of x/y and Z and not just one Axis.
Re: Dimensional Accuracy
Holes come out a bit smaller almost every time (with FDM process). As time went on I learned to design all holes a bit larger to fit required exact dimensions.
Re: Dimensional Accuracy
Getting holes and dimensions in FDM correct is like making a technical drawing with a 2 inch brush. The extrusion withs are always a bit off. I have not found a better solution as mentioned to know your printer and contruct around its limitations...
Also shrinking after printing needs to be accounted.
For parts with holes that need to be correct I contruct holes in a way that I can ream them to the exact size and fit.
Carsten
My Prints: https://www.prusaprinters.org/social/15695-carsten/prints
My Employer: https://make-magazin.de
Re: Dimensional Accuracy
Thank you all for the input. I will proceed on with more knowledge and just design my holes .01 bigger.
Re: Dimensional Accuracy
I print the object and kill it after it has done 4 layers. Then you can take the outline it has made and place it in the real world. You can make 3 templates by slicing the object on the bed laying on each of the axis. It is fast and you see things you would not have seen while rendering the object in a CAD program.