Hello! New to CNC work & first time posting on the community!
So far I have been using it for larger projects that mainly use a 1/4" bit or surfacing bits, but was creating some smaller items when I ran into an issue with a bit breaking during a pocketing operation running into a loose piece of wood. Note, I recently upgraded to Carbide Create Pro and this is my first time doing a pocket cut using it.
When designing the item in Carbide Create everything looked fine like in my previous work with the bit pocketing out each layer at a time when viewing the simulation/toolpaths. However while I was running the piece on my 5 Pro I noticed that the pocketing operation was working differently on the Illenium piece (file has only the affected toolpath enabled). Instead of running one layer of the piece at a time cutting to the bottom of the stock it first traced the inner outline of the pocket like a Contour (inner) toolpath until the bottom of the stock (Created an “Illenium Contour Example” toolpath to show how it cut).
At the time I thought it might’ve been a feature of Carbide Create Pro (or maybe a native feature I haven’t ran into before) to save time doing a pocket to stock bottom not having to cut the main pocket portion. However during it’s last cut the middle portion of wood came lose in the piece causing the bit to run into it causing it to break.
I tried looking at the toolpaths & simulation again to see if there was anything I might’ve missed that would’ve caused the pocket toolpath to cut differently & how to avoid it in the future, but looks like the toolpath would’ve cut the entire pocket layer by layer.
I know there is something that I’m missing & how to go about avoiding a similar situation in the future with a loose piece of wood in a pocket. Was curious if this is how the pocketing operation normally works (inner contour, then pocket the rest of the material)? Or is the best route for pocketing something small like this (or in general) to do an Inner Contour toolpath with tabs to cut out/flush trim afterwards to avoid cutting bulk of the material?
I ran into the same issue when using a 1/4” bit and having the pocket set to .3”.
However, if the pocket is .275” it works fine. There have been a couple of similar posts but no real explanation as to why it would behave differently with the wider pocket.
Carbide Create does pockets in steps. If you have a big area that you are cutting out for a pocket, then the program will have it as such that you can cut in layers or steps down to the desired depth. What it sounds like to me is that when you picked your pocket toolpath, you didn’t select your depth of cut per pass, thus meaning, you are going full depth in one pass and trying to cut everything at once. If this is the case, then you will run into problems when you have final cuts that make towers of wood and then it breaks over during the cut and slams into the tool.
Breaking tools sucks, but also a part of machining. You should be able to go into your toolpath for your pocketing and click on it to bring up the menu. Look into the depth of cut and see what you have there. Most depth of cuts are around .060, but you can pick what you want. But then again, I could be wrong at where I’m thinking you are having your issue as well. I have noticed not many people actually use Carbide Create and so those of us that actually have it, we will spend more time trying to understand how to use it in many of it’s functions.
Haven’t run into it with bigger projects or using the Pocket REST machining feature before. The pocket wasn’t very wide, ~.6" at the widest and ~.2" at the narrowest, so not a very large pocket at all. I usually don’t do a pocket straight through to the stock bottom, usually .25" depth most so I’m thinking it could just be some time saving aspect the software did vs my normal pockets.
That deffinately could cause it to happen, but I have the bit set to the manufactures specs with a .085 depth per pass which has been fine in the past with the bit. What you described is what normally happens whenever I use the pocketing function doing .085" passes along the whole pocket before stepping down to the next layer.
When I was monitoring the machine I saw it make a multiple passes for the inner contour of the vector like it should vs. the 1 deep pass. When it reached the final pass & close to completing that’s when the piece broke lose, jammed and broke the bit.
Why not go ahead and remove the pocket toolpath and replot it for a new toolpath? This might actually fix your issue as well. I had a vcarve project that I had plotted and the machine cut in one particular way. It was odd how it cut a little of one word, then jumped to different letters for different words. Then it would jump back to the rest of the letter to finish it and on to the other words. I made some adjustments to the project and when I went back and made a new toolpath, it changed where it started and finished. Might be worth a shot to redo the toolpath and it might actually fix itself in the program and not do what you are having trouble with. Just an idea.