topic Re: STL export is about 5% too small in Fusion Support Forum

STL export is about 5% too small

Anonymous — Tue, 23 Mar 2021 05:59:30 GMT

I have exported designs to cura before and they printed fine.
But recently, prints have been about 5% smaller than the design.

Re: STL export is about 5% too small

taylorhsbennett — Tue, 23 Mar 2021 06:10:49 GMT

Sometimes the easiest thing to do is the math based on a ratio , for example take the same two distances between two points one from the stl file (the small one) and then the fusion the right one you should come up with a ratio of difference . Punch that ratio back into the stl in some other program to scale and enlarge it and then perhaps this will solve your problem.

Re: STL export is about 5% too small

Anonymous — Tue, 23 Mar 2021 06:15:28 GMT

Uum, no. That's pretty unacceptable.
A design should transfer and print at the proper size.
Especially sine it had been working fine until recently.

Re: STL export is about 5% too small

taylorhsbennett — Tue, 23 Mar 2021 06:22:33 GMT

Yea well I am having issues since last update also. Just saying that you could scale it if you had to as a temp fix , I know major headache but better than nothing.

Re: STL export is about 5% too small

Anonymous — Tue, 23 Mar 2021 06:23:22 GMT

I have been scaling. but it's indeed a PITA.

Re: STL export is about 5% too small

dsouzasujay — Tue, 23 Mar 2021 07:31:50 GMT

Hi @Anonymous ,

How are you exporting the .stl file to Cura?

Are you using file>export> Export with .Stl format? or
Right click on the top fusion 360 browser node and 'Save As STL'?

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

Re: STL export is about 5% too small

jj.space — Sun, 11 Apr 2021 20:24:20 GMT

Same Here!! Hope there will come a solution to this...

Re: STL export is about 5% too small

dsouzasujay — Mon, 12 Apr 2021 03:16:58 GMT

Hi @jj.space @Anonymous

Can you attach the design that you have created in Fusion 360? You can export by File>Export *.f3d/*.f3d file to your local drive and then Attach it here to a Reply.

How are you sure that the exported mesh file is 5% smaller, how did you confirm?

Re: STL export is about 5% too small

jj.space — Mon, 12 Apr 2021 06:25:46 GMT

hi,

It was my very first design for my very first 3d printer

I have no longer the files, I have deleted them. Maybe you can recover them from my autodesk recovery bin (if that exists??)

I made a simple tube with 2 x sketch center diameter circle command, inner circle 5.0mm, and then extruded to a tube.
Stl of that object.
into Cura with had no problems fit-printing other pre-designed objects.
and this tube did not fit the 5mm steel axis what is was intended for.
I measured it with a caliper - i am used of this
it turned out to be 4.5 mm inner diameter…

so in cura i rescaled the model to 111.11 %

et voilà: I ended up with perfect 5mm inner diameter tube that fitted snuggly on the 5 mm axis…

Re: STL export is about 5% too small

dsouzasujay — Mon, 12 Apr 2021 07:40:35 GMT

Hi @jj.space ,

You can recover your deleted files from A360.

Go to your project and you should be able to see Trash.

If you can share me the *.f3d file i can help you out.

Re: STL export is about 5% too small

jj.space — Mon, 12 Apr 2021 10:45:40 GMT

I re-did it and same result :
inner diameter should be 5.0 mm, it printed as 4.6 mm
outer diameter should be 8.0 mm, it printed as 7.9 mm

Re: STL export is about 5% too small

HughesTooling — Mon, 12 Apr 2021 12:05:27 GMT

Your STL measure correct.

This is quite likely down to the small size of the part and printer moving too fast and dragging the extruded material. Or heat build up in the part and shrinking. With FDM printers holes quite often end up under size, try printing something 50mm square and measure.

Mark

Re: STL export is about 5% too small

TheCADWhisperer — Mon, 12 Apr 2021 12:52:36 GMT

@jj.space wrote:
It was my very first design for my very first 3d printer

What is the tolerance of your printer?

Is it a $1000 printer or is it a $50,000 printer?

What material does the printer use?

Re: STL export is about 5% too small

jj.space — Mon, 12 Apr 2021 14:13:48 GMT

The strange thing is that I printed a ready made tube stl found on thingverse for that 5mm axis, and it printed perfectly snug, same printer, same filament...

Re: STL export is about 5% too small

TheCADWhisperer — Mon, 12 Apr 2021 14:18:33 GMT

@jj.space wrote:
The strange thing is that I printed a ready made tube stl found on

Attach file here.

Re: STL export is about 5% too small

jj.space — Mon, 12 Apr 2021 14:32:28 GMT

That little part: it has o hole in it that printed exactly snug fit on the 5mm steel axis.

Re: STL export is about 5% too small

HughesTooling — Mon, 12 Apr 2021 14:40:59 GMT

Are you sure the second STL you uploaded here is the one from thingverse because it's exactly the same as the first file you uploaded! Exactly the same mesh, which is surprising if it was made with different software.

This is the origin one in blue and the second one would show black if there were any differences.

Not a single mesh triangle is different.

Re: STL export is about 5% too small

jj.space — Mon, 12 Apr 2021 14:48:08 GMT

????

The tube-stl with "problems" is 3mm high, the tube-stl without problems here is about 10 mm high and has also a gyro-spinner in the stl... That is the only thing that I can say on this. (I am very novice!)

Re: STL export is about 5% too small

HughesTooling — Mon, 12 Apr 2021 15:02:21 GMT

Sorry might have saved to the wrong file when I downloaded the second one. With the last set of files there where several rings in one, I guess the one dimensioned below is the one you used and it has a 5.5mm hole.

Re: STL export is about 5% too small

jj.space — Mon, 12 Apr 2021 15:12:46 GMT

Thanks for checking this all out! Niw I know that for small diameter I have to be careful in my design for this my first Monoprice select mini v2 $200 printer 👍🏻😁👍🏻