It's actually not so much shrinkage as you would get it over the whole model and not just the holes. someone explained it here before but basically you will get it more if your circle has less points.
It is very common and it's usually closer to a fixed amount than a percentage. For example a 30mm diameter hole may come out at 28.6mm, that is 1.4mm less than expected and a 3mm hole comes out at 1.6mm.
Some slicers may cater for it like slic3r I hear but most others don't seem to.
You just have to design your model with a bigger hole than you want or get your drill out.
It only happens with horizontal holes (vertical ones can get it but much less)
Other things you can do in your designs are make "C" shapes which won't close up as much and have a bit of spring to accommodate whatever shaft etc. that is going in to it.
One other thing you can do is print a template that has many holes in it from 1mm to 50mm etc. going up in size 1,1.5,2 ... 10,11,12 ... 20,22,24 ... 30,35,40,45,50. Some people have put them on thingiverse.
Then you measure your holes and record them in a spreadsheet or whatever for future reference when you are designing something.
I've found when I slice with KISSlicer mine all end up about 1.4mm less diameter so I just go that much bigger plus or minus depending if I want a tight fit.
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billdempsey 0
Actually, that's not strange at all. It's typical. Plastic shrinks as it cools, which makes the holes in particular shrink. For example, any time I want an 8 mm hole, I have to create it as 8.4 mm. A 3 mm hole has to be 3.1 or 3.2 depending on the filament I'm using. Sadly, the shrinkage isn't linear, or we could just calculate it. The larger the hole, the shrink percentage increases. It has been a trial and error process to figure out what dimensions to use for various holes I regularly put in objects. The good news is, you get better at instinctively accommodating the shrinkage the longer you use the printer.
EDIT: Actually, if your shrinkage is remaining constant for every size hole, that IS strange. The holes look round, so it is probably not belts or motors as those usually create distortion in one direction or another. My money is on software. I'd download Cura and try it. I purchased NetFABB, but it never worked right for me, so I abandoned it in favor of Cura. Unfortunately, it's not perfect either. I've created a model which just won't slice correctly in Cura no matter what I do.
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