Thursday, January 3, 2013

Home Made Cut-off Blades for the Lathe

One of the holders which came with the quick change tool post was a cut-off tool holder.  These are used to part off a piece after its been turned.  You can also use them to cut narrow grooves for anything.

Usually the are made with a carbide tip on a steel shank.  An idea came to me the other day.  Why not cut out a rectangular section of a scrap circular saw blade?  Cut it so that a carbide tooth remains on the end, and you have a great edge and since the teeth are thicker than the blade, it won't bind either.

The result:

This last picture shows some grooves I began to cut.  I will be parting off three segments, but first they need a hole bored through for a project...

Not bad.  The cutter took a minute to cut out with an angle grinder and the carbide tooth cuts the aluminum like butter.  Nice shavings come off.

This worked so well that I will have to find a thicker blade to make a cutter which can handle deeper cuts.  Its an excellent reuse of old saw blades, which often still have a few sharp teeth to use.

A Quick Change Tool Post

My parents bought me a quick change tool post for Christmas.

As you may have gathered from the picture, its made in China.  Nonetheless, it seems like a decent tool post.  Close tolerances and nice ground surfaces leave me impressed.  

The tool post came with a rectangular slab of steel 1/2 an inch thick.  You machine the T nut for the lathe.  That was an interesting process.  I reinforced a piece of angle iron, secured it in the groove, used a fly cutter to mill it vertical, mounted the steel blank on this.  An end mill went into the chuck.  With this setup, I milled the T-nut down to size.  More on that later.  I have some videos that will go up on my youtube channel.

Here you see the other holders that came with it.  From left to right:  A 5/8" boring bar holder, a knurling tool (Its also serving to hold my dial indicator), my threading tool holder, a cut-off tool holder, and my right-hand tool holder.  The left-hand bit is in the mounted holder.

The beauty of these tool posts is that the nut on each holder keeps the position of the bit.  To change bits, you just turn the handle, remove the current tool, and slide the new one on.  Once you've set all the proper heights once, its done.  Changing tools no longer takes time.  The height is set.

This tool post allows me to take advantage of brief periods of time.  I can go out to the garage after school, spend 45 minutes, and actually accomplish something because of the time it saves.