need help converting a file to stl.

You can google and download netfabb basic, a free app from autodesk. It will let you convert from and to many popular formats and also it can fix various problems with a model and make it print ready.

Also consider Meshmixer from autodesk (http://www.meshmixer.com/) powerful tool jet easy to use, and its free. Also has lots of feature to correct mesh error’s, etc. and export different formats including STL. Its also a nice scilpting app with some interesting mesh painting features.

@LemonadeCG and @iterateCGI, thank you both so much for your help. I'll try that!

Oh, what's wrong, I have several models of 3d skullcaps here, the printables are very useful, here's the link in case you want to take a look my place

Write my

You can make use of several free online converting tools available online such as:

1. http://www.greentoken.de/onlineconv/
2. https://www.makexyz.com/convert/obj-to-stl
3. https://www.meshconvert.com/

Besides, you can find several other ones on the internet.

You can use Blander, to convert the files