Improved Drill Depth Stop

The main improvement of this depth stop over the original was that it was quicker to adjust.

It was a simple pinch bolt which was free to slide on a plain rod, rather than the original threaded rod fitted with lock nuts.

The sliding rod was made form 10mm silver steel and the pinch bolt was a stainless steel off cut in a cast iron housing.

The old depth stop was removed and the existing hole in the drill casing was filed to give a flat reference surface.

The plastic collar fitted to the quill was retained.

Original depth Stop

A 'top hat' bush was turned from brass which was drilled and reamed to 10mm.

The bush was a loose 'floating' fit in the hole in the casing so that it could be aligned later.

A length of 10mm silver steel was slotted along its length with a 3mm slot drill. It was reduced at one end to take a 6mm thread.

This photo shows the rod fitted to the quill collar with a 6mm nut and located in the brass datum bush. Once the quill collar and bush had been aligned so that the bar was vertical and quill travel was unaffected, the bush was glued in place with epoxy resin.

The housing for the depth stop itself was made from a block of cast iron. It was drilled and reamed off-centre to 10mm to fit on the sliding bar. Then it was cross-drilled in the side and tapped with a 1/4 32tpi thread, to take the pinch bolt.









The thumb wheel was made from 20mm stainless steel. It was knurled and a section reduced and threaded to match the housing.

The end of the thread was drilled and a brass insert was turned to fit the hole. The brass would grip the sliding bar without marking it.

Once complete, the depth stop was used more than the original one because it was quick to adjust and could be set with one hand. The brass bush gave a positive stop.