Here is another HF just finished. I was asked to go over the process of making your own hollowing tool so I will try. You can get M2 square cutting bits here for less than buck. I like to use 1/4" bit or samller. http://www.use-enco.com/CGI/INSRAR2?PMSECT=747&PMADID=SI0000053221&PMAVID=36
I then buy a 5/8" cold rolled rod 36" long. I use a hacksaw to cut it into two 18" pieces. You then need to get a drill bit that will drill a hole that the square bit will just fit in. Make sure it is a bit that will drill steel, don't try you brad point bits. I then mount the bar in my lathe with just a inch or two sticking out of the chuck. In our school shop an old rockwell lathe and the 3520B both have a hole in their spindle that the 5/8" rod will fit thru. One then mounts the drill bit in a jacobs chuck in the tail stock and slide it up to where it almost touches the end of the rod. A slow speed and plenty of oil helps to keep the heat down while drilling the hole into the rod. You do this by turning on the lathe and using the tail stock to feed the drill into the rod slowly using a lot of oil. drill the hole about 2/3 the the length of the square tool bit. After this is done I drill and tap a hole into the side of the rod about 3/4" from the end of the rod. This is to screw a set screw which will hold the bit in. I then put a set screw in the hole below the surface and use a grinder or sander to taper the end down. after you have got it looking the way you want the set screw can be backed out to clean up the threads. All you have to do now is to put it in a handle and your ready to go. I keep both ends of the bit sharp so that I only have to turn it around to get a sharp edge. I have less than $7.00 in one of these tools. I put a couple pics of how I drill out the hole for the tool bit and what the end of my hollowing tool looks like.
Good Luck,
Jack
I then buy a 5/8" cold rolled rod 36" long. I use a hacksaw to cut it into two 18" pieces. You then need to get a drill bit that will drill a hole that the square bit will just fit in. Make sure it is a bit that will drill steel, don't try you brad point bits. I then mount the bar in my lathe with just a inch or two sticking out of the chuck. In our school shop an old rockwell lathe and the 3520B both have a hole in their spindle that the 5/8" rod will fit thru. One then mounts the drill bit in a jacobs chuck in the tail stock and slide it up to where it almost touches the end of the rod. A slow speed and plenty of oil helps to keep the heat down while drilling the hole into the rod. You do this by turning on the lathe and using the tail stock to feed the drill into the rod slowly using a lot of oil. drill the hole about 2/3 the the length of the square tool bit. After this is done I drill and tap a hole into the side of the rod about 3/4" from the end of the rod. This is to screw a set screw which will hold the bit in. I then put a set screw in the hole below the surface and use a grinder or sander to taper the end down. after you have got it looking the way you want the set screw can be backed out to clean up the threads. All you have to do now is to put it in a handle and your ready to go. I keep both ends of the bit sharp so that I only have to turn it around to get a sharp edge. I have less than $7.00 in one of these tools. I put a couple pics of how I drill out the hole for the tool bit and what the end of my hollowing tool looks like.
Good Luck,
Jack
