Having difficulty importing a DXF file

Dantech

I am trying to modify some STL files for my 3D printer I just bought. What I'm doing is converting an STL file to DXF in Blender, then trying to import that DXF file into OnShape so that I can edit it. Unfortunately OnShape wont open it. 
I was hoping to upload the dxf file here, but it seems like I cant do that either.
I'm no expert at OnShape, but have been doing drawing on it for years. This however has me stumped.
I wish OnShape had the ability to convert STL to DXF.
Thanks for any help, Dan.

Edit; I just tried again using a different editor to convert STL to DXF, and now when I try to import that DXF, OnShape gives me an error that there's too many entities. Very frustrated as I've been trying to do this for hours now.

john_mcclary

Can't you just upload the stl into Onshape? Why convert to dxf? 

Dantech

 This only works if I don't have to modify the part.
I now have a few STL files that I want to print, but I need to add a hole and a tab to the part first before I print.
Basically, I need to be able to modify an STL file and want to find out the easiest way to do this with my limited CAD knowledge. 

Dantech

I just downloaded "Meshlab" and tried converting to DXF. The conversion worked fine, but as soon as I upload it to OnShape, it give me an"- Could not import unrecognized entity" error! All day I've tried to figure this damn thing out and I'm syill no further ahead. Ready to give up I'm so frustrated. This happens everytime I need to deal with DXF files !!!! Why is it so difficult????????

john_mcclary

Because dxf is only supported in 2D in Onshape. 

You should be able to modify meshes now. Something like adding a hole should be possible 

S1mon

You can add a hole to the STL import. 

https://www.youtube.com/watch?v=qOQqbb9KHj8

Dantech

Thanks for the help, but I give up on this. Way beyond my CAD knowledge. I watched that video and was more confused afterwards. Too bad Fusion 360 is not free anymore for us hobbiests.

dirk_van_der_vaart

Try this one
https://all3dp.com/2/stl-to-step-how-to-convert-stl-files-to-step/
The second one you need to have, freecad