More dialog work

I tidied up the pocket dialog.

I noticed that if the viewing units are in mm, but the NC output units are inches, then all the values in the dialog are in mm ( which is what I expected ) except for the tool description. I am reluctant to change it because the tool decription is used in the comment in the NC code comments, so maybe it should be in NC code units for that.

Pocket operation now uses a dialog

I have added a pocket operation dialog. When you select a sketch and add a new pocket operation, you get this dialog. When you OK it, the pocket operation gets added. When you double click the operation in the tree, you get the dialog again. When you select a different control, or press Tab to go to the next control, a different picture is shown.

opencamlib operations working again in HeeksCNC

The 3D operations weren't working in HeeksCNC because of some changes that had happened to the syntax in opencamlib . They work OK now. Here is an "attach operation" modifying the toolpath of a pocket operation.

zig zag option for pocket operation

I added a "use zig zag" check box to the pocket operation in HeeksCNC. It seems to work really well. It works by making a rectangle for each slice of the area. It does a boolean "intersect" of the rectangle with the area to pocket. Then it loops through the resulting spans. It starts with the straight line at the bottom of the result and adds all the spans until it gets to the top of the slice. I also added a "zig angle" value too.

Keep tool down

I changed the pocket operation to keep the tool down whenever possible.
I have changed the "area" module to make Subtract work again.
This is my function in area_funcs.py

def feed_possible(p0, p1):
....obround = make_obround(p0, p1, first_offset_for_pocket)
....a = area.Area(area_for_pocket)
....obround.Subtract(a)
....if obround.num_curves() > 0:
........return False
....return True

P.S. how do I get the spaces to stay at the start of the line in blogger?

Attach operation

I have added an "Attach" operation.
You select a solid before making it.
Any other operation done, after an attach operation, will have its feed moves dropped down on to the solid ( or solids ) specified by the attach operation. This can be cancelled by an "Unattach" operation.
In the picture, an existing "Pocket" operation is attached to the cone.
This is not finished yet. I need to add a "minimum z" value to the attach operation; currently it is set to 0. Also, I need to decide if the z height specified in the existing operation should be taken into account. For example, if the pocket operation is trying to cut to z-1, should I make this be 1mm below the surface contact point?

End Plate

I made another part from aluminium alloy.
There were a few lessons learnt here. The most exciting one was where I hadn't tightened the 16mm tool holder into its collet enough. I noticed the tool was cutting deeper than it should, so I paused the machine and set the z lower so it would cut higher.
I started again but it continued to cut deeper as it went. I stopped and adjusted the z value again. I assumend that something was going wrong with the Z axis drive of my machine. I continued to cut until the tool holder fell out and wedged over at an angle!
Fortunately nothing had been damaged, as far as I can tell, and the part had been cut oversize, where it went wrong, so it should be OK.
I had to stop there, yesterday. I came back this morning and tried again. I looked at various positions of the part on the computer and then set the x, y, z of the machine by touching the tool against already machined faces of the part, with a piece of paper. However, as soon as the tool started cutting metal again, the part came unglued. The coolant had unstuck the super-glue, overnight.
I pressed the big red button, took the part off, cleaned it up, machined a new area in the wood, with some islands to locate the part. It was a bit of a tight fit, so I hammered the part down to glue it down. This probably isn't good for my machine, although it is resting on a lump of wood.
I am happy with the finished part. I did have to hammer it straight again afterwards though.
Another thing, I have seen before, is where I am cutting a sharp inside corner ( or one the same radius as the tool radius ). On the finish pass, the amount of material taken off is quite accurate because there is not much deflection or vibration until it gets to the sharp corner. It then momentarily squeals as it cuts the entire corner in one instant. You can see from the last picture how there is a lot of deflection ( I gues about 0.3mm on my 6mm tool. A solution would be to change the shape of the pocket so that the internal radiuses are at least a bit more than the tool radius, or to use a smaller tool.