Prints just a bit smaller than what they should be  

RE: Prints just a bit smaller than what they should be

It could be normal shrinkage depending on the filament used.  

RE: Prints just a bit smaller than what they should be

@cwbullet

Thanks, but I don't think that's the problem.  Been using the same Protopasta HTPLA for years, beautiful prints, no problems.  And no problem with the same filament on the 2nd printer.

RE: Prints just a bit smaller than what they should be

What is the filament?

Is this new filament or old stock?

Is the printer in a draught? or an especially cold workshop?

By how much is it too small?  Is it small in all dimensions? Is there an error in the degree of curvature (XY plane) of the part?

And roughly how many hours printing has the machine done?

Cheerio,

RE: Prints just a bit smaller than what they should be

Posted by: @steveszu

@cwbullet

Thanks, but I don't think that's the problem.  Been using the same Protopasta HTPLA for years, beautiful prints, no problems.  And no problem with the same filament on the 2nd printer.

Is that the same spool on both printers or two different spools of the same brand?

Cheerio,

RE: Prints just a bit smaller than what they should be

@diem

Same brand, different colors of Proto-pasta on two different printers running now.  

RE: Prints just a bit smaller than what they should be

What does a calibration cube show?

RE: Prints just a bit smaller than what they should be

@diem

Everything has been a constant for years.  Just now the older machine has started with these prints that are just a bit too small.  Can't really tell with the naked eye and measuring with calipers don't show much difference at all.  I have been doing this for years now, no problems.  Many, many hours on both machines.

RE: Prints just a bit smaller than what they should be

@steveszu

OK, two thoughts:

I have been doing this for years now, no problems. Many, many hours on both machines.

Presumably wear in the drive pulleys, bearings and rods will eventually have an effect, I don't know how long Prusa expect to retain accuracy.  Prusa support will know which parts are most susceptible.

Possible workaround.

Print a calibration piece, a square much bigger than your regular prints (X-Y  200mm at least, Z is probably OK) and measure it.  This should be enough to calculate a calibration value in each axis - then apply the calibration before printing.

Cheerio,

RE: Prints just a bit smaller than what they should be

@diem

Thanks.  Did a small cube, I think it's 20mm, looks pretty good. 

I was also thinking the same thing, possibly worn bearings, etc.

I attached photo of the cube.

RE: Prints just a bit smaller than what they should be

@steveszu

That cube says there's nothing much to worry about for run of the mill printing.

It would be a pity to retire a basically sound machine and replace it with something new you'd have to attune to.

I would try the calibration route first.

Cheerio,

RE: Prints just a bit smaller than what they should be

@steveszu

That cube is really nice.  Looks like you have it dialed in.  

RE: same problem

i have same problem now, whatever filament, over 100mm object is 1mm smaller (like something is 95%, not 100%). i think problem is prusaslicer (i use mac version) but i dont understand what i must change.