>I'm going to try this question again, as there have been a couple of threads on it, and I still have problems with my set-up.
Dave Smith showed pictures of, and described, a method that attaches a laser to a FLEXIBLE holder, and then you point the laser so that it hits the tip of the rod (or cutter).
As Rick R pointed out, The laser should be aligned perpendicular to the rod, for best accuracy especially on bowls with a wide base.
Is there a way to do this somewhat simply? I can get the laser to point at the tip of the rod with no problem, but when I put the rod into the bowl, it is obvious that it is not perpendicular (in two planes) to the rod. Maybe it's just me. Any tips will be greatly appreciated.
To be accurate the laser needs to be perpendicular to the surface of the bowl. If you are measuring the bottom this will be parallel to the lathe bed but if you are measuring on the curved portion of the bowl near the bottom the laser should be set perpendicular to that side.
On my lazer attachment to the boring bar I place a large rare earth magnet on the bottom of the cutting tip. It has a line drawn with graduated markes. I angle this line until it's perpendicular to the area on the vessel that I want to measure and adjust the laser point to the thickness that I want.
If we call the bottom of a bowl 12 oclock then I might be measuing at 11 oclock or 10 oclock to get the sides near the bottom.
I would take a photo of the set up but I've loaned the boring bar to a friend who is trying to get ready for a show.
I am assuming you are using this setup to measure or check the depth of a bored hole, as that was the original discussion a few days ago. I'll also assume you have a drill chuck that mounts into your tailstock. My memory is that the flexible magnetic arm you mention is attached to the tailstock body.
Mount a length of strait metal rod (or a stiff wooden dowel) in the chuck to use as your "depth probe". If you take a small piece of scrap wood, say about 4" long, and drill a hole in it, perpendicular to a flat side, that fits the diameter of the depth probe, you should be able to set this over the end of the "depth probe", and adjust your laser beam to just skim the flat wooden face and arrive at the tip. Remove the wooden guide, and slide the tailstock assembly, with laser attached, to measure the depth of your hole, bowl, or whatever. This should show the laser spot on the outside of your vessel in a useful way.
Alternatively, scrap the flex mount, and build a rigid arm to hold the laser using 90 degree corners, like the Jamieson-type boring rigs, so you are always perpendicular.
