Adding a depth stop required a few modifications.
SHOP OWNER: Alan Young
LOCATION: Ypsilanti, MI
Several years ago I got this nifty Mill Drill. It's been a powerful and helpful addition to my shop. Although it came with a depth gauge, the one thing it lacked was a proper depth stop. The gauge let you know how far you had gone down in the Z axis, but there was no stop for repeatable operations.
I decided to build a stop. Here are some CAD renderings of the new design.
I started by replacing the plastic cover with a shop-made aluminium cover, but I kept the scale from the original cover.
I made the fixed stop bracket to mount to the cover.
The new cover protruded out further from the Mill than the original plastic cover, which meant I needed to make an extension for the depth wheel.
The original interior threaded rod was 1/2-13. There was nothing to keep the depth gauge straight as it moved up and down since there was some slop in the threads.
So I replaced the interior 1/2-13 rod with a 1/2" acme threaded rod. Here is the original rod with a captive coupling that I wanted to use for the new rod. I cut it apart on the lathe.
I used a new 1/2" Acme threaded rod and I turned one end to accept the captive coupling.
With the new interior rod installed, I wanted to make a new depth stop "nut" that is captured within a yoke. The yoke would ride along the inside edges of the mill cavity keeping the stop stable as it travelled in the "Z" motion.
Here is the new piece. The "nut" is threaded for a 1/2" Acme thread with a tongue that will protrude through the scale on the aluminium cover. The nut is wrapped with a yoke that extends to ride along the inside edges of the Mill opening.
An exterior 1/2" Acme threaded rod gets mounted to the tongue of the interior nut.
Knurled nuts allow adjustability for the depth then are set together to fix the stop setting.
The new inside assembly is installed.
After the cover is installed the exterior threaded rod and yoke get mounted to the tongue from the inside "Z" nut.
The Drill Wheel along with the new extension is installed.
With everything assembled, the machine is ready to go.
For additional shots, which show more details of this project, click on the following link - http://alanyoungfurniture.homestead.com/MillDrillDepthStop.html
. . . Alan Young