Starting a MPCNC build today. I printed the parts on a tevo tarantula about 6 months ago. the tubing is 3/4 in conduit, this size is the one that worked, 1 inch dia was to large for the mpcnc print option. They offer 3 sizes to print the parts and if you decide to just grab a set of files and start printing for 50 hours then realize the designer is a metric dude. Not his error, the website for mpcnc has warnings about this but I dont read instructions until i am finished with a job.