Simply put, the overall design of putting the lead screws on the outside of the Y rail instead of on the inside makes the design more complicated and the overall working area smaller. This is because:
- The Y-rails get in the way of the X-axis gantry and other accessories such as the dust shoe, in most cases, losing about 3-4 inches in total working area.
- A longer Y-axis gantry is needed to avoid certain collisions, which adds additional packaging and cost.
- Drag chain routing becomes more complicated since it cannot mount to the rail directly, except with some significant modifications to the design and additional parts.
Putting the lead screws on the inside means that:
- We maximize the working area with the least amount of rail length.
- Simplify drag chain mounting since it can be mounted directly to the rail.
The LongMill uses ACME lead screws and Delrin nuts that are dust resistant and self-lubricating. Dust shielding is not needed. However, some customers may opt to shield their lead screws, so we created some integrated dust shields that can be purchased on our store. We felt that this was the most optimal solution, as the overall cost for the additional material, packing, and parts needed to flip the rail to the other side would eclipse the optional cost of the dust shields.
We promise that we’ve done a lot of design and testing to create the most optimal and cost-effective way to coordinate every part of the LongMill, including which direction the rails go!