Sit with me by the HSM fire, stay a while and listen

[Sherpa (Jon)]

would you say this is dust or chips? i am confused

Morning Folks - doing some HSM with a DOC 6 mill WOC 1.27 mill 40% on a straight 2 flute 3.17mm end mill

I have not be running my machine right, by that i mean i think i can push the machine way harder, my cuts are conservative and everything i do is “Safe” i would like to nudge it up a little bit.

I think the 3+ years time and motion i have done, i must have spent a good deal of time at the table side that i could save by refining inefficient toolpaths.

Plus this is so relaxing honing our craft! and because well you know science!

So here are the Details of the cut (if you need more let me know)

Cutting was good, really happy with the finish on the bottom, almost no tool marks at all - blown away by this since the machine stood for nearly a year without any love at alll.

Side walls are good too but i need to add a final wall pass to clean it up a bit, but finish and speed is amazing 1min 3secs to clear out 5cm x 3 cm @ 6mm deep.

But i am confused and would appreciate some thoughts.

(Evidence 1) This shows some of the bed chips again i am happy with these as they look good to me?

(Evidence 2) this was taken from within the cut, i paused the machine and turned off Vac and Spindle and these look awesome too, nearly the 6mm length of the cut so again really happy.

Top Tip Do not, and i repeat DO NOT get your buttons mixed up and turn spindle off thinking it is the Vac when the machine is still running - I didn’t do this, i heard it somewhere, of someone called… ok yeah fine it was me, so they got ladled real quick, also again sowing that A) didn’t need labels before as i was using it so often, and B) CNCing can get a good heart rate at any time!!

(Evidence 3) Again happy with this little pile too. Chips as i would expect, side note, is it wrong this made me smile, and i mean it i pinched this lot out of the cut and was like “that is a fine chip” also these had some heat to them, not a huge amount but enough for me to think hmm that is doing its job as a chip.

(Evidence 4) Now a little deeper in the cut we have this chip pile, not happy with this, apart from looking a little to pixie dust like for my taste, the other noticeable characteristic was its heat compared to pile 1 (Evidence 3 pic) this was significantly hotter, rubbing was the first thing that came to mind, but what is confusing me is there are some good chips in here too.So if it was rubbing i would not be getting Chips?

This leads me to think that this could be a re-cutting of chips problem, if the Suckit Dust Boot is not able to extract the chip quick enough this would result in creating Pixie dust?

I would love what peoples thoughts are on this and how can i prevent it.

So to sum up for today:

Pro’s

1. Cut time dramatically on my MRR
2. Had fun
3. Clean Cuts
4. Wriggle Room to speed cut up another 5%
5. Heat in chips not on endmill
6. Never used a straight flute Endmill (Tick to bucket list)

Con’s

1. Refine toolpath for side wall clean-up
2. Chips inconsistencies
3. LED workshop lights making documenting my work hard, need to address this
4. Need to look at 2d Adaptive and 3D adaptive to see what i should use and what is better for this toolpath
   Re-Label Power Box (might even make a new one!!

Well thanks all for your time reading this, would love your thoughts on anything here, especially around the chips?

Will post up my findings on the next run!

Best Wishes
Jon

[Julien]

I’m happy to see I’m not the only one obsessing over how chips look/feel
Here’s a my favorite curly chip pic, for no reason:

Joking aside, I wouldn’t worry about the chip/pixie dust transition as long as the cut looks and sounds good. 80ipm@18000RPM on a 2 flute is 0.002" chipload which sounds perfectly fine to me. It may well be chip recutting if you are cutting deep AND in narrow spaces (show us your toolpath?). I’ve been wanting to experiment with a combination of using an air blast AND a dust shoe at the same time, to get the chips out of the cut fast and let the dust shoe collect everything while it’s in the air)

I did not get if you were using a helical 2-flute endmill or really a straight router bit ? I don’t use those so I won’t comment but there are a couple of threads about it.

#AllChipShapesAreBeautiful

[Sherpa (Jon)]

Hi Julien it is a true straight i think this is it straight endmill cheap but good, doing slotting tomorrow so will update all tomorrow, also interested about your air pump idea would that be run from a pond pump / compressor or something else?

[Julien]

I ended up using an air brush compressor, for quietness.

[Sherpa (Jon)]

Toolpath as requested: -