Bit slipping during cut

How To Machining
1

Appreciate some assistance from someone who can read the Carbide G code.

I’ll attach the gcode and design file and a pic of the crash site. My bit (1/4 roughing) did not creep out of the collet to cause this sudden plunge. Other info is my stock is 2.5" thick. The plunge is pretty much to the bottom of my stock. The machine was on a roughing pass, cruising along, no stress, smooth. Good thing I do busy sanding chores right next to the machine.

This has happened in Version 7 but I’ve not stopped and forwarded this kind of event till now. Makes me think of how I can afford V-Carve for the future.

Thanks again for any assistance. Spendy piece of walnut I just messed up.

RandomPlunge
RandomPlunge1512×2016 451 KB

20x9x2.5 Darleen.c2d (1.7 MB)
Darlene Top Side.nc (228.1 KB)

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I don’t have a Vectric tool path, that was just a comment, sorry.

My 1/4 tool is defined under a category I created. Just a simple endmill 1/4". I’ve selected this on many 2.5d projects.

I haven’t selected a 3d tool from the Carbide menu for this or any other projects. Are you thinking the random plunge could have been programed because of my manually created bit?

3

The lowest Z value in the G-Code is -48.551mm (-1.911")

image
image750×453 8.72 KB

There are a bunch of causes of unexpected Z plunges. (Will has the post bookmarked :slight_smile: )

1 Like
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1.911 sounds reasonable, the scale depth of my model is 1.95".

I’m going to keep the file as it exists and re-run to see of it crashes again at that point.

5

Scott,
Is your cutting height long enough to handle 2" wood? If you’re using a bit with a CH of 1" (like a 201) and you plunge down into walnut 1.9" (even if the shaft is also 1/4", the cutting height matters), it’s possible that your bit sticks to the side wall and you lose a step or two on it’s way out of the piece…and the next plunge goes through the bottom. I’ve had that happen to me with Walnut in particular.

I purchased 1/4" bits with 2" cutting heights after that happened and it never happened again

  • Gary
1 Like
6

I’m looking for my V8 Beta thread that got merged here today. Its was about my bit plunging on a file today.

I ran the file over again with no changes to the file. There was no plunging at the same spot. You mentioned you thought there we more then one reason why a bit would plunge without command. Today my bit remained secure in the collet, no slipping.

7

Undeleted and moved to this new topic.

Please let us know if you have any further issues.

8

Tnx Will, I don’t have anything else to report other then my bit did not slip on today’s problem. Its still a mystery why the bit took off and then plunged.

9

Note that we recommend using the button (on a trim router) only to hand-tighten things so that they will stay in place while one fully tightens with a pair of good quality wrenches.

Do you have a trim router or spindle? ER-11 or ER-20?

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I have a trim router and wrenches. Recently I started to pause my cuts and recheck the torque on the nut because my cuts are often couple hours.

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