PSA: ATC pick and place Z position setting

Spindles and ATCs
1

I just wanted to raise community awareness on a recent issue I discovered with my ATC system, which could potentially have been dangerous to the machine or me… or both.

NOTE: This was NOT an issue with the ATC or it’s design… it was a setup issue on my end.

I recently purchased the 3/8" Jenny compression bit that Cody from Cadence Manufacturing recently came out with. I was cutting some plywood parts in 3/4" ply, and specified that bit for the profile cuts. The machine picked up the bit and came forward to continue running, at which point I did a feed hold and stopped the spindle, so I could swap out for a different dust boot brush length. When doing so, by chance I happened to bump the bit and noticed it wiggled. Upon further inspection, I saw the spindle had not fully picked up the tool holder. It seemed like the top of the nipple on the tool holder was pinched in the spindle clamp. When I wiggled the tool holder it popped up fully into place and I could hear the spindle clamp ‘snap’ shut. Obviously, had I not noticed this and started the spindle back up it could have went badly.

I could be wrong, but my working theory as to the cause was that I did not have my pick and place Z height set low enough. Up until that point, I had only been using 1/4" bits, and so it had not been an issue. The little bit of added weight of the solid carbide 3/8" Jenny bit made the difference between whether the ATC could fully pick it up or not. I lowered the setting and have not had the issue since.

Moral of the story: Make sure your pick and place setting is as low as you can possibly get it and still have everything work properly.

Mike

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2

Thanks for sharing, i haven’t observed that myself

3

I have had the same issue, it is vital that all tools pick-up Z height be consistent and that the setup Z height be low enough to consistently pickup your tool correctly.

What I found interesting is that the drawbar sensor was still saying “tool picked up” in that case…

To our PWNCNC friends, this would be a good note to make sure your customers read before one of them gets hurt and decide to come after your hard earned money.

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4

I’m surprised that no alarm signal was raised due to the clamp not closing completely.

5

As was I. And I never even thought to look at the Masso to see if it was showing clamp closed or not. Maybe it would have alarmed before it spun the spindle back up? Not sure.

6

I also had this issue. It was unsettling and haven’t seen it since I adjusted the Z downward. Had forgotten about it until seeing this thread.

Would it be helpful to adjust the air pressure on the control box? I see the knobs on the box but have no idea what behaviors different pressures will bring.

8

Thank you for the feedback. Based on what was said it sounds like the sensor doesn’t report partially open occurances. On mine the sensor is hardly operable as the flash from low to high as the jaws are closing nullifies the tool absent when should be present alarm, and even getting it intentionally was burdensome.

https://support.pwncnc.com/kb/article/444-failure-to-retrieve-not-resulting-in-error/

Another thing to ensure is that the acorn nut on the top of the holder is screwed in all the way.

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