I have had fairly good success by tweaking the "hole expansion" setting in Cura. I do use this in combination with the "horizontal expansion" settings as well as the outside of my parts were coming out oversized slightly. If redesigning the part isn't an option on something, this is a good place to start.
I work in a design engineering office where the other designers are used to dimensioning for machining tolerances, and sometimes I do have to print parts that will later be machined (out of metals), so we cannot specifically dimension the models for the effects of 3D printing. This is where the settings mentioned earlier come in. I still have to drill out holes for press fit items, but they are very close to start, and often can be drilled with a pin vise instead of a full powered drill.
Recommended Posts
gr5 2,224
Please show a photo of what you mean.
If you are talking about vertical holes (not horizontal holes) through your part then yes, it's normal and common for vertical holes to be about 0.5mm too small. This has to do with the fact that the plastic, while liquid, shrinks in the first few milliseconds and acts like snot or mucus and is pulled inwards while printing inside corners and holes.
I add around 0.4 or 0.5mm to most vertical holes (regardless if it's a 2mm hole or a 30mm hole). I do this in CAD. Sometimes I need very tight tolerances. For those cases I add 0.3mm and then drill the whole out with a drill later (even if 20 holes it goes quick if they are all the same diameter). For holes that can be a little loose I usually add 0.5mm. For the rest I usually add 0.4mm to the diameter.
Link to post
Share on other sites
haldemir55 0
Thanx gr5. I understand. It is not related any software and hardware. It is simply the natural behaviour of the melted plastic.
Link to post
Share on other sites