Previously mentioned from another post, we have a bench sized mini-mill for quick prototyping and parts creation. Back then we purchased some scales and setup DRO on this milling machine but never have a chance to document the process for sharing.
The DRO unit and scales were purchased from LittleMachineShop. They used to have everything bundled in one DRO package but looks like they now have different versions. Our DRO package included the following:
- 12″ scale on Z and X axis
- 8″ scale on Y axis
- DRO unit, power supply and cables connecting scales to DRO unit
- No mounting instructions
Upon close examination and investigation of products, we figured out there maybe no modification required to mount the scale. Picture can tell thousand words and lets get started.
Lets start from Z axis.
First off the top Z-axis plastic stop has been replaced by this aluminum support bar. This bar does the Z-axis stopping as well as the mounting point for the 12″ digital scale (300mm).
Cut a piece of aluminum “L”, mount the scale on one side, the other side attached to headstock using existing set screws and bolt for pointer. (See below)
Next, Y axis
The two pictures showed the Y-Axis scale is kinda “float” mounted using modified aluminum “L” brackets, nothing special and there is no drilling needed on the mill base.
X axis last and it’s a bit more complicated.
First, we need to fabricate a mount on the left end of the table, this mount provides a secure clamping of the scale. Don’t worry about the extra holes (a.k.a. wrong measurement)
Next (See below) is to fabricate an aluminum plate to attach the scale, the bottom of plate is to attach to the saddle (Note the shape of the plate). The plate can be mounted by using the existing screws used for plastic skirt.
Now tie the Y axis scale to the same plate by using a “L” bracket. From photo below, note that there is an extension aluminum block used at the back of the scale. A small piece of “L” bracket is then fastened onto the block on one side and the other side to the plate.
That’s pretty much it, here is another view
Final task is to route and properly hook up all cables, make sure no tension to cable when milling at any direction and have fresh batteries on the scale. Power up DRO and have fun milling. I hope this document gives you another alternative way of mounting scales for mini-mill DRO purposes.