One of the parts that have been significantly changed on the Mill One V3 compared to the V1 and V2 is the design of the Y axis bed. We wanted to improve the rigidity of the Y axis, while allowing for more flexibility for wasteboard mounting and workholding. With this new two-part bed design, users can easily remove and switch out Y axis beds, and users can make their own beds if needed.
The steel Y axis gantry plate which will come with all V3 machines is far stiffer than the HDPE, which means a more rigid machine. You can see below based on some simple testing with a dial indicator and a 2-3 pound aluminum block, the difference in the amount of deflection that each machine experiences.
V3 deflection: Around 1-2 thousandths of an inch
V2 deflection: Around 5 thousandths of an inch
Testing was done on a very simple setup of a dial indicator pressing against the right side of each machine. The vice was lined up against the right edge of the bed for consistency. An aluminum block was placed on the opposite end. This allows us to compare the amount of deflection between the two designs.
One thing to note is that the Y axis gantry was an aluminum prototype that was milled out on the Mill One. Production machines will come with a laser cut steel gantry which is stiffer that aluminum. Because of this, we should be able to expect even better rigidity from production machines than from our prototypes.
Have a V2 machine but want to upgrade this part? You can get a kit that will update your machine here: https://sienci.com/product/v3-y-axis-bed-kit/