Parts not fitting together

[mdavisgtm 1]

I downloaded a screw and nut from thingiverse and they do not fit together. Is this a problem with my printer settings or is it Cura? Its a UM2 using PLA at recomended settings and .04 layer height. Printer firmware version 14.03 and Cura version 14.03 any help would be appreciated.

 

[dkaygee 0]

PLA parts tend to be stickier and they don't shrink as much as ABS. When people design items they can do so with this in mind or not. It just depends on the designer. With PLA screws and nuts you might have to do some post finish work such as light sanding to get your parts to fit.

 

[anon4321 16]

Alternatively, you can use Cura to scale either part a little to account from shrinkage or lack thereof.

 

[mdavisgtm 1]

OK I'll try it with ABS and see if it works any better. I did think about scaling one of the parts but I don't want to have to do that everytime, especially if I am printing a big assembly.

[gr5 2,168]

In general the screw should be mostly to spec but the nut hole will be a bit small. Probably around .5mm too small. Aside: .04mm might be too low -- I recommend .1mm layers as you will probably get better quality.

There are 3 reasons why vertical holes are .5mm too small if you really want to know. And it varies by your own settings so it's best to just adjust the holes (or nuts in this case). So scale up that nut so that it is .5mm larger in the hole diameter.

Even better get some calipers and measure the error exactly and scale up the nuts accordingly.

 

[markstruct 0]

"There are 3 reasons why vertical holes are .5mm too small if you really want to know."

 

Yes, please enlighten me on why it's always 0.5mm too small?