Couple of questions for my first real project (toolpath, multiple bits, efficiency changes?)

Hey guys hope this is right place. Since getting my machine I have created a few small project/training cuts (mounting holes for t-track inserts, bit holder, couple of square and circle test cuts, etc…) but nothing super fancy. Planning on being a super basic “guy with a CNC” and making some trays for some family members for Christmas. Designed one for my house first. I drew it up and I believe setup up all the paths in an order that makes sense but had a few questions before I hit load and run. OK let’s do this…

So here are my paths and my preview. I know the preview is not super accurate especially when adding bits that arent in the library (amana 45982 tray bit and amana 45771 30* v engraver). It will be going into some ambrosia maple my buddy gave me (is that considered hard or soft?). The way I have it set up is like this

  1. using a carbide 201 to hog out all the middle stuff using a pocket path down .7in.
  2. switch to the amana tray bit and do a contour pass (no offset) along the same perimeter down to .75in.
  3. same bit run the pocket path from step one but from .7in down to .75in .
  4. switch to engrave bit to do artwork in center from .75in down to 1.05in.

So here are my questions:

  1. Since I am changing bits, and don’t have a bit setter, I will have to save each path that uses a different bit as a separate g code file and rezero after bit changes correct? (or was that just older versions of CC/CM)
  2. It’s showing a little over 2 hours just to clear the middle using the stock settings. Is this because those settings are fairly conservative? could I bump the depth or feed rate up and be safe? I know this is a vague question and a lot of variables but just curious. (other than that what are some good clearing bits for remove lots of material quick)
  3. Is there a way in CC to change the direction of the toolpath from moving around the shape to across the shape? Would like the third toolpath to go across the bottom of the tray side to side instead of around. I have seen this with other way more involved programs but I am not trying to learn all of that right now…
  4. Lastly, for some reason the preview isn’t showing the vertical sections of the “R”. I am guessing since the vertical parts of the “G” show up this is just an issue with the preview, or I entered the tool properties wrong. Any ideas on that one?
  5. Do you have any suggestions, cautions, or anything at all before I do this thing?

Apologies for all the reading, but thanks for taking the time! I have read/watched so many articles/threads/videos over the past month or so trying to prepare for this. A lot of the stuff has blended together in my head so I may have this all wrong and if so please feel free to me straight!

Here are the files since I sometimes see people ask for them.
Catch Tray.c2d (24.8 KB)
Catch (36.8 KB)

I don’t have experience with the tray bit or v bit you are using so cannot provide much feedback there but can answer some other questions.

According to the internet ambrosia maple is a soft maple category with a Janka hardness or 700 to 950lbf so you can consider that a softwood for the 201 toolpath since that hardness is similar to a pine, should save you some time also since your d.o.c will be deeper.

Also looking at your design it will not cut as designed. If you zoom into the corners of the bowl you will see that because your using round bits it will not cut the corner angles.

Onto your questions-

  1. Yes you will have to save seperate files since you don’t have a way to rezero z after changing bits. Remember to only rezero the z and to also use the same place each time. Meaning don’t zero your vbit in the bottom of the pocket.

  2. Yes carbide feeds and speeds are conservative. But if you change the 201 path to a softwood feeds you’ll see it cuts a great amount off your time.

  3. There is no way to modify the toolpath with carbide create.

  4. It appears to be cutting all you selected. If you rotate your simulation and look from the bottom view you will see your toolpaths for the r.

My only suggestion would be to modify your design for those corners I discussed before.


I knew they wouldn’t be exact corners, but I wanted to mess with the chamfer setting and see what it looked like with an inside cut. this statement got me thinking though that the original chamfers were already shorter than the radius of the bit so if I had cut them there wouldn’t be any sort of chamfer just a round corner. I just changed them to be a bit longer and modeled it in ketchup (since I am better and quicker with that) and it looks like I can still get them to work albeit not sharp transitions. THANK YOU FOR THIS!!!

as for the other answers thanks for clarifying/backing up what I thought.

  1. I thought I read somewhere that CM was going to start allowing bit changes in one file but maybe that was only with a bit setter. also good call on the not zeroing to the bottom of the bowl. don’t think I would have done it but who knows… when I get working things get crazy.

  2. switching to softwood cut it in half, and changing the size dropped a little more :+1: :+1: :+1:

  3. that’s what I figured, guess it’s time to start learning fusion360. Is there an off chance that CC-PRO will et you change them?

  4. GENIUS!!! I never even thought of that, but what do you know, there it is!!!

Always start with the least invasive cuts first. Group the same bits together. Save the cutout with tabs for last. In the toolpath list you can change the order by dragging the toolpaths around.


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