For the lathe? I use the old fashioned approach of pushing a straight piece of metal up against the work and looking to see if it's vertical. I adjust up or down until it is.It's time for me to make one, but before I do, I want to see what you guys use.
For the lathe? I use the old fashioned approach of pushing a straight piece of metal up against the work and looking to see if it's vertical. I adjust up or down until it is.
For the mill I haven't yet arrived at a tool height setter. I tend to move the tool closer until a piece of paper is grabbed. Measure the paper and tweak it that much closer. So far nothing I've done requires anything better.
I did try to buy one from China but that fell through. Should really try again.
For the lathe, I have a dedicated dial indicator with a pin point tip. It takes a little while in the beginning to set up the exact height to center, but you do it once, and you're good as golden, unless you drop it. You just move the indicator tip to the cutting edge. If its too low, I shim it up by that amount. You can see in the photos, that the cutting edge is 0.008" low of center, so I'll put an 0.008" shim underneath the tool.
It might be my own interpretation of hobby lathe history but I think when people were putting cutters into non-repeatable tool posts & diddling with shims or tool angle in the lantern style posts, it made sense to have an independent gage or standard to check the tool tip against independently to avoid disturbing a part in progress. But seems like most everyone has a dovetail tool post these days & a small collection of inexpensive knockoff holders. What I find quickest with a new tool is just turn the end of a scrap bar & adjust height until the nib is gone. Usually (ideally) once set, the height should remain that way with other tool changes.
I use to have a 'standard' which was just a bar turned to match my center height. Then I just used DTI on Noga type mag base to reference that height like you would on a surface plate & compare to tool height using the lathe bed datum. This was quite accurate especially on more steeply angled tool edges because you are measuring the very extremity of the point. Having said this, I have tweaked some cutting tools up or down a smidgen if it decides it likes to cut better there. Tool height setting to 0.001' doesn't factor when the tool is loaded, things can bend & deflect a bit. The suspended ruler method is quick & dirty but I've also seem some so-so inserts that have quite rounded profiles in side view & can get tricked by this method.
For the milling machine, x and y axis, I use the Starrett edge finder. In Z-axis, raise the column until the endmill is close 1/8" away from touching and lock the column. Move the cutter away for the piece, unlock the quill, and move it up and down a couple times to free it up.
Move the endmill to your part, put a feeler gauge on top of your part, lower the quill until it touches. Lock the quill, move off the part, let the endmill drag the feeler gauge off. Lower the quill, or raise the column by the thickness of your feeler gauge.
If I've done it right this link should point to a short video, hand held cell phone, of my CNC router doing homing. It's a short script in MACH3 that moves down until the contact is made. It then adds 0.062" (PC board thickness) to that point and sets that as 0.000" for the Z axis.
I can set up the big camera on a tripod along with some lights and do a better job if someone wants.
And this is how I find the edges now on the mill with LinuxCNC.
Thanks.Your videos are just fine as is John.
The feeler gauges are hardened, and you only use light pressure to touch off, so no digging in. Do a test. Machine a piece of aluminium flat, then using the same set up, move off, and try my method.I like this. I will have to try it. I have a set of feeler gauges that I had to use as shims and have a lot of them left that I could use for this task.
Did you ever measure how much the end mill digs into the feeler gauge when you this? Or is that my job since I'm wondering about it.......
Ive been wondering about an electronic method that works the same way with an insulated pad on the part connected to an E-box with a sort of continuity tester in it.
The feeler gauges are hardened, and you only use light pressure to touch off, so no digging in. Do a test. Machine a piece of aluminium flat, then using the same set up, move off, and try my method.