3D Modeling (Software or Method) Using Boolean Operations

Question

I am looking for a 3D modeling software that will allow me to build a model using shapes. Now, yes, I could use Blender (and have been for some time), but I find it absolutely frustrating to use based on the way I like to 3D model. My 'method' is to start with a simple shape and subtract and add to it using other simple shapes until the final design. Using Blender, only the Boolean modifier seems to work for this purpose, but even then it usually fails me, and in the end the object isn't solid. The piece that I just cut from will have a gaping hole in it (since models in Blender are hollow). I have to go into edit mode and join the points together to make faces so the object appears solid, which can be very time consuming. I do not want to do this process manually.

So, in summary...

Problem: Need other (hopefully free) software to suit my modeling method or a better method (A different modifier? Different modeling techniques?) for creating the desired object using Blender.

Here is an example of my current problem I am working on, before and after the Boolean modifier was applied in Blender, as a series of images. The final design would have this process completed on all four sides of the 'cube'.

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Before and After Boolean Modifier

Before on the left, after on the right. Not so good in the photo below, I will have to fill in that gap manually (or see below for the way I cheated...)

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Desired and Actual Result

The following top photo looks good, right, so why am I complaining? I cheated using the solidify modifier (adding thickness until the 'hole' was filled). As you see below in the X-ray view (bottom photo), all sorts of crazy geometry is generated as a result of the solidify modifier...maybe not desired, but maybe there is a way to fix this? There also seem to be some glitchy parts in the 'desired' photo near the bottom of the cut.

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Answer 1

You could take a look at 3dc.io, it supports subtracting primitives and exports to .obj and .stl, also works on mobile/tablets.
Full disclosure, developer of 3dc.io here.

Answer 2

You are looking for something based on CSG (Constructive Solid Geometry). One of the examples is Unreal Engine: a powerful tool; you could export a model from UE to pretty much any format you like. It does allow you to subtract as well add 3D shapes. And it is free.