Just a heads up on this issue; we have started shipping all new machines from here on out using the high powered driver on the Z-axis (instead of the X-axis) based on feedback we’re seeing in the field. We are going to release a PDF of simple instructions for current customers to make the wiring swap inside their own electronics boxes if they choose to make the modification. Below are some quick points.
- The Z-axis lead nut uses a heavy spring on the anti-backlash leadnut and also has a tight fitting thread on the ACME lead screw. We do this to ensure that backlash in Z is kept at a minimum for accuracy and floor finishing purposes which are very important for milling. Over time, this tight system breaks in better and the standard Z-axis driver has proven adequate for operation, even at rapids. That being said, any lost motion on the Z-axis has the greatest chance of causing damage to the machine itself (such as a vise or baseplate if the Z axis position gets off during a program) and we’ve decided that the high powered driver on Z provides significantly more margin for the broader customer base.
- We’ve had a half dozen folks with stalling issues on the Z-axis that have reached out to us. Switching to the larger driver has immediately solved these issues. We’ve never seen a stall event on the Z-axis on our own machines using the High Powered Z-axis Driver.
- Swapping the large driver inside the electronics cabinet from the X-axis over to the Z-axis means that the X-axis will use the standard sized driver moving forward. In all the years of testing that we’ve done on MR-1, we’ve always used the small standard driver on the X-axis without any issues (and we take much bigger cuts here than anything we’ve seen customers attempt so far
). The fact is that the X-axis uses a ball screw with significantly less rotating friction than the Z-axis lead nut. It also, doesn’t need to lift up the 60lb+ spindle assembly that is required by the Z-axis. In addition, the published Max Thrust values for the X-axis on our website spec table (135 lbs) was rated using the smaller driver on the X-axis. The Three MR-1 machines that we have sitting in our prototype shop that we run daily for rework and production all have the standard sized driver on the X-axis. - The High Powered Driver add-on option is still available for sale on our website. Users can choose to put these higher powered drivers in X or Y (need 2 drivers) if that is desired. In the not too distant future we are going to release the High Feed Speed Ball Screw upgrade option for MR-1 that increases the machine rapids up to 200 IPM. Having the larger drivers on the X and Y axes (3 total) will be required to run these new ball screws. This add-on feature will be great for folks running softer metals/plastics and doing a lot of 3D surfacing type of operations.
- Using the High Powered Driver on the Z-axis provides many additional benefits such as better drilling performance and better end mill plunging capabilities.
Hope this helps!