I too would like the ability to set the spindle start point to an arbitrary location.
Not all the work I do with my Shapeoko 2 is cutting entirely new parts. Sometimes, I want to make modifications to an existing item. For example, I’m working on an underwater ROV project with my son. We want to modify our motor mounts (trimmed down PVC “T” fittings) with slots for fins. Basically, we’re talking about three linear cuts 1/4” deep along the line shown here:
In this case, the difficulty lies in accurately determining where the (0,0) “Home” position is relative to the existing part. In the picture shown above, “Home” is roughly the lower right corner of the oak board, but not precisely. Attempting to place the bit accurately over that (0,0) home point is almost impossible, and any initial alignment error results in the slots being offset on the existing part, sometimes rendering the part unusable.
What I’d really like to do is place the bit at a well known spot and tell Easel: “You Are Here.” Like this:
In essence, I would like to specify a location in the Easel drawing area that corresponds to the starting location of the bit. Then when going through the “Carve” dialogs, Easel would tell the user to ensure that the bit was at the specified starting location rather than at the regular (0,0) “Home” position, and then do its cutting relative to that location.
It would be nice if the “You Are Here” location would be displayed in the Easel drawing area as a cross-hair with a circle around it representing the diameter of the currently installed bit as specified in the “Machine” menu. Dragging the symbol interactively, specifying the position with text fields, and being able to nudge the position with arrow keys would all be useful interface features for accurately placing the “You Are Here” location.
FYI, as a temporary work-around, I tried to fake “You Are Here” by offsetting the cut lines in Easel so that the point shown above was at (0,0) in the Easel drawing area. However, when I did that, the job stalled at 10% completion, but never finished. Pressing Play / Pause repeatedly caused the cutting to advance in fits and starts, skipping large parts of the job. (I think what is going on is that negative coordinates are causing an error condition, and cutting is stopped when the negative coordinates are encountered. Pressing Play / Pause causes the G-Code interpreter to jump to the next segment, which may or may not cause another error depending on whether it has negative coordinates or not. But that’s just a guess.)