Hole-in-One

Every now and then in woodworking, like anywhere else where one practices a hobby or profession, there is a tool - purchased or acquired a while back in case it is needed - that finally is put to use.  Router bits are a case in point. A long time ago I thought it was worth investing in a rabbeting bit set for a variety of depth of cuts depending on the size of the ball bearing on its tip. It is one of those  things that though seldom used it is worth its price once the need arises. 

Here though is a task that may surprise anyone who may run into enlarging an existing hole. It is almost an impossibility to pull off with precision and accuracy to achieve the proper diameter of the new bigger hole.

This bit will only cut to the depth that the bearing will allow it. With the bearing as guide it will run along the inside diameter of the existing hole while the bit cuts a rabbet on half the thickness of the board.

Shown above with the board turned upside down after the cut where a larger diameter had been cut precisely.

Then comes along a flush cutting bit, where the diameter of the bearing is exactly the same as the cutting bit. The bearing will now run along the wider hole, thus allowing for the bit to cut into the remaining rim of the smaller hole

The whole operation is best done on the router table (another reason why a router table is an essential part of the work shop). The whole board (work piece) is much too large if the router fence remained in place. The fence can be easily removed by taking out just two locking knobs.

The photo below was taken while the bit was spinning to show the enlarging new diameter hole. Holes can be enlarged almost ad infinitum by simply repeating the process over and over until the desired larger hole is achieved.

What was all the fuss about? I needed to relocate one hole (see where it was finally covered with a square 1/4 inch plywood) from an existing location to the center of the top board shown below. The smaller hole was the limit of my spindle drill cutting bit.

This is my 5th generation design of a saw dust interceptor. This intermediate element of the dust collection system allows for much of the saw dust and other waste debris to be caught by the cylinder in between the tool and the dust collector. The aim is for air, mostly air anyhow, to go all the way to the impeller and filter of the collector shown below.

NOT SHOWN  INSIDE AND BELOW THE TOP IS MY DESIGN THAT ALLOWS FOR THE DUST AND OTHER PARTICLES TO SETTLE DOWN WHILE DUST-FREE AIR IS DRAWN TO THE OUTLET HOSE INTO THE DUST COLLECTOR.

Fine dust and coarse debris were trapped at the bottom

So far, I'd say 99 per cent of dust and debris were intercepted. Need to make certain over a longer period of use, but so far so great! This could be something ⦽💡

So far, the dust collector - filter and receptacle looked empty, free of dust!