need a little advice on ABS wall thickness for my first project.

[dmehling]

Do you have a picture of the device? If I'm looking at the orientation correctly and how the device might sits in it. I would at the very least Chamfer the rear inside corners. I think you might be able to reduce the "front" walls dims down to 2.5. BUT it would be helpful to see how the device would sit in the 'cradle' to give more help.

I have attached a picture of the device sitting in the holder.