MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
What's holding the spring in place? The taper on the top of the CNC probe cover? I'm not from the states, so I can't use McMaster-Carr easily to get exactly the same parts you used.
Also, what is the washer for? I don't see it anywhere.
For those trying to find a spring, it has to be at least 18.58mm tall, have a small diameter be less than 9.5mm and a large diameter less than 22.18mm. The distance from the end of the collet/chuck to the bottom of the printed part is 43mm.