Note: groups.io will be down for maintenance on Monday, September 26th, starting at 9AM Pacific Time (4PM Monday September 26, 2022 UTC), for approximately one hour.
- Helical milling drill holes with endmill
toggle quoted messageShow quoted text
I'd forgotten how tedious and terrible development is without a
debugger and the ability to step through code and inspect
On 8/10/22 2:45 PM, John Johnson wrote:
I've been thinking about and working on the long-requested (ca.
2018) feature that would let one mill holes of different
diameters using an endmill.
I would like your input.
- Is this useful?
- Do let me know if you have suggestions on gcode. My
knowledge on this is limited. I would like to support as many
controllers as possible (TurboCNC (happy to see
TCNC is still around!), Mach3,
etc.), so make it as generic as possible.
- I'm thinking G03 (counter clockwise) for all holes.
- From what I've read, using IJ is preferable over R, and I
recall from my experience R arcs can get whacky.
- I'm thinking 4x 90° arcs to make a circle. Again, to
accommodate as many controllers as possible.
- I'm concerned about holes that are larger than 2x the tool
- For example, in the image attached, the tool is
0.015"/0.381mm and the holes are 0.020"/0.508mm,
0.035"/0.889mm, and 0.050"/1.27mm. There is a 0.005"/0.127mm
post in the center hole, and 0.020"/0.508mm on the
- The debris left in the center (see attached pics), which
could potentially become ensnared by and break the tool.
- One way to eliminate this is as two (or more) holes, a
smaller one to full depth, then larger ones.
- This would probably need "pecking."
- I could also use a sort-of center-out strategy, where the
cutter starts in the center, then mills at increasingly
larger diameters until the desired size is reached. Rather
than the helical path shown, I would probably just plunge
some amount in the center, then start milling the concentric
circles at that depth out to the max diameter, plunge at the
center a bit deeper, rinse and repeat.
- How do we control chip load?
- Step down for Z axis as an absolute amount (e.g.
0.25mm/0.010") per pass?
- What about increasing the diameter if concentric holes or
multiple passes are used?
- Could be a fixed maximum, I suppose, or some percentage
of the tool diameter.
- Code that generated the images is attached.
- Let me know what you think about it too. I just generated
it in Excel for the time being.
Would appreciate your input and expertise!
Join firstname.lastname@example.org to automatically receive all group messages.