What I find confusing is using the special bit for probing. After I take out the “probing bit” and install the actual cutter how does it know height difference? I use tiny bits so its bound to be quite a difference in Z (?)
I hate busting bits so I thought I’d like to understand how this works…
I have a v1 and not v2 but my understanding is the gauge pin is a known size. So the probe touches on the X and Y sides of the probe and by knowing that the pin is 1/4 inch it knows exactly where the corner is. A 1/4 inch like the #201 is not exactly 1/4 inch and because of the flute structure that can cause small inaccuracies because of where the flute might hit the X and Y points inside the probe. As Julien and Will said if you have a BitSetter as well Z zero is set and when a new bit is put in the router through the software interface the new bit is measured and compared to the last time Z was set and the length of the stickout of the new bit is calculated and the same z zero is maintained. The BitSetter is only comparing the new bit to the last time you either manually set Z or the last time you set Z with a BitZero.
So using the probe gauge is more accurate for setting X and Y because the gauge is more accurate than a random bit which is seldom exactly the advertised size and the flute structure can also cause inaccuracy.
I don’t have a “bit setter.” I only bought the zero because I was curious and it was on sale. After years of doing it manually I tend to miss the lack of control (plus Motion is really pretty crude compared to UGS).
I will send in a video. Basically I have a piece of 1/8 wood (baltic birch) clamped to the spoilboard. 1/64th Kyocera bit. Do a z probe. Start cutting, and the first cut is above the surface. 2nd cut is about 1/2 through the material. With UBS I would stop, hit “Return to Zero,” lower the bit a few .10s of a mm, rezro, restart. With motion…kinda screwed.
This can potentially happen if you have the BitZero placed on the corner of the stock with the lip overhanging when probing for Z only.
For XY probing you do need to have it positioned like that, but for Z-onlt probing you need to have the BitZero laid fully on top of the piece. If the error you are seeing is about 3mm / 0.1", it is a likely root cause.
What do you mean by “2nd cut” ? 2nd run of the same cut after re-zeroing (how?), or are you trying to run a single multi-tool job ?
This tends to tell me that you try to run a multi-tool job from a single file. You need a bitsetter to support that workflow. Without a bitsetter, you need to split the job into as many individual files are there are tool changes and re-zero Z manually in between (a.k.a the old way)
It is in the center of the stock. 5x7x1/8 One of the annoyances is that you have to hold it steady because it has this rim on the bottom that only covers 3 sides so it “tips” rather than sitting flat of the table.
By second cut I mean the stock is very thin so each cut is done twice–first cut is about 1/2 way through and the 2nd I should see the spoilboard underneath. If I don’t, I stop and drop the Z a little and restart. Vcarve tends to finish small parts of the path completely before moving on so you can tell right away if you’re on track (or not).
Single tool workflow for much of my stuff (scrollsawish pieces). Never felt the need for bitsetter. If I hit the lottery I might buy a machine that changes bits (and speeds) for me.
Or it was assembled incorrectly, or an off-spec component was provided by a sub-contractor, or too much adhesive was used, or something went wrong when a part was machined — we will do our best to work this out via support.