[trumpy81]

GDay All,

I have BobCAD v23 and when I import an .stl file that was created by Inventor 2012 it comes in at about 1 tenth of the size it should be.

For example, in Inventor the part measures roughly 43 x 57mm but in BobCAD it measures 5 x 6mm.

Anyone encountered this before?

Any ideas on how to correct this other than scaling the part in BobCAD?

Any help would be appreciated.

[ScottC]

Yep, when you click "save copy as" in inventor, before you save the file, click options and you can choose stl export settings. Change the export unit to cm instead of mm. Let us know how you go...

Dcott

[trumpy81]

GDay All,

Scott, thanks for that. That answers two questions I had about BobCAD and this model.

When I translated the model I had to move it .16 instead of 1.6 which it should have been.

It also explains why I couldn't do much of anything with it, it was tool small ... lol

Obviously, Inventor or BobCAD scales the model down by a factor of 10.

[ScottC]

Andy, I've never used BOBcad and dont know what file types you can import, just out of interest, why are you exporting out an STL for machining? I have found the best format out of Inventor is either a parasolid or acis sat. Circles remain as circles in my cam program and the model isnt faceted like a stl.

[trumpy81]

GDay All,

Scott, I have no particular reason for using .stl. I had exported this model for use in another CAD program which only accepted .stl.

I haven't had any issues with .stl before and they certainly are not facetted in appearance at least.

BobCAD can accept several different 3D formats, but I wanted to know why this particular model didn't work. I had made a few mistakes in the way I had drawn it so when the model is brought in it is upside down and sits below the XY plane a small amount.

It was more of a learning exercise for me since I have just acquired a copy of BobCAD v23 with Mill Pro & Lathe and I wanted to know if BobCAD had the tools necessary to correct the problem.

Thankfully it has got the right tools for dealing with something like this, but I missed the obvious problem of the model being too small.

At least now I know what to look out for when dealing with .stl files.

For most of my work I will use .dxf and .sat or .step which are no real problem in BobCAD even though it doesn't always import small arcs from .dxf's.

I'm sure I will encounter other problems with BobCAD, so I'll be back!

Thanks for the help Scott, it certainly is appreciated.

[Sowen]

STL is a non-editable format within BobCAD. While you can import , move and scale the model , that is all you can do with it. If at all possible use Iges, Stp.

[trumpy81]

GDay All,

Sowen, it is pretty much a given that most CAM programs are unable to directly edit the model formats presented to them. That is not their purpose. But, as in the case of this particular model, I needed to know if the geometry could be manipulated to give the correct toolpath results I needed.

Some CAM programs I have tried are not always able to do so, or at least with my limited experience, I am unable to achieve the goal with them.

I missed the most obvious problem with this model, and that was it's imported size. If the model had imported at the size I expected, then I probably would not have had any problems creating the necessary toolpaths.

Thankfully, this wasn't a critical part and I was simply exploring the capabilities of the software while learning how to command it.

The important thing is, that with Scott's invaluable help, I have learnt something about .stl files and Inventor that I was previously unaware of.