Leveling a board

Newbie question. Just getting started with CNC and I want to level off a board I want to use and not sure how to created the tool path for this. The board is 8.5 X 15.25 X .75 . I have a 1" surfacing bit. My question is how to I create a tool path in Carbide Create to do a one continuous run back and forth on the board and do the entire board. I guess similar to levelling a waste board. I know it is a stupid question but just getting started with CNC and sometimes the simple beginning stuff can be the hardest, lol.

I will sometimes do this manually by setting the Z to the proper height and just run the machine in Jog to make passes back and forth.

The automated way (and probably better way) is to just draw a rectangle slightly larger than your piece and set up a toolpath to pocket it.

4 Likes

Thanks I think that is going to work , now have to add my tool to the list of available tools .

Just put the size of your board in cc and run a pocket tool path. That should take care of it.

2 Likes

Thanks, that is basically what I did and got both sides done, took a few rounds on the first side since I was being very conservative but the second side was done in two passes with higher speeds and a little more depth , now just a little sanding to get rid of some ridges and it will be a new board.

2 Likes

Marty, when I do a flattening side, I run the last path 0.005” completely with the grain. That at least hides some ridges.

1 Like

As mentioned, keep your pass depth to a minimum, (0.1in or less), do a lass pass but the other important thing, for better results, is to keep you stepover relatively small, probably in the 25% range.

1 Like

Thank you, I appreciate the input. I still have a lot of learning to do but it’s fun.

2 Likes

Another newby…Any update on this topic? i have a 1" flattening bit and but not sure about using the bitsetter. Can you somehow by pass that step and just set bitzero? I assume in CC you make a rectangle just a little larger on all sides than the material to be flattened…correct? and then use a pocket tool path with settings mentioned above. My starting thickness of my material will be about 1" and then use some spacers to get it stable…fairly flat to start but still some wobble. This should get one side flat…then flip and flatten the other side and should not need spacers if the fist side is flat. comments welcomed.

You can disable the bitsetter in the settings menu in CM. You have to re-initialize the machine and depending on your model you may need to power cycle. I have found that is required on the Pro.

Depending on you bit you may not need to disable though. The McFly seems to work just fine with it.

Using a rectangle and a pocket path will work but causes the bit to start in the center and work outward so it will plunge. Probably not a big deal if you are taking a tiny bite. The other strategy is to draw a zig zag type pattern (90 degree corners of course) that will have your bit reach the edges of the material and use a contour pass with no offset.

2 Likes

How would you draw a zig zag pattern?

@Tod1d has a good graphic illustrating it but I can’t locate it now.

Basically just draw a line across the bottom and then up your stepover amount and the back to the other side and up and back over and over.

Or draw one line across the bottom and repeat it up through the top and then connect every other pair on each side so that you end up with one continuous vector.

I can show an example later when I am at my computer.

2 Likes

Set up the Stock Size to match what you wish to cut:

Then set the grid size to match the desired stepover:

image

Then draw one element of the pattern:

Then use Linear Array to duplicate as necessary:

OK

Join Vectors:

and draw in the last/missing line:

Join again:

2 Likes

I have a test underway with a small board….working fine. Question…can you adjust the width of the cut on each pass? It is taking a very small bite and taking well over an hour for a 5”x5” board.

The width of cut would be determined by the grid size used to draw things.

cleanup_CC_6x6
I think this may be the image Cullen eluded to. I set up the workpiece to the size of my stock or just a bit larger, Then divide by an odd number to get the stepover within a reasonable range for my cutter so I’m always climb cutting along the edges. Then I extend beyond the boundary of my workpiece & add filleted/rounded ends to make smooth transitions.

I typically set my depth to 0.0001", which will round off to 0.000 in the G-code. Then I can control my depth on the machine by setting my Z zero.

Another way to program it is to set your depth to the max amount you think you need to remove plus a bit, and then DOC on the tool to how much you want to remove per pass, say 0.010". Then just stop the program once it’s cleaned the whole surface.

3 Likes

So for a 1” diameter surface bit, what would be the recommendation for grid size?

This really depends on your tramming, and how level your cutter is. If I’m only taking 0.010" with my 1 1/2 planer bit, I will step it over 1" or more. If you’re nice & level with a 1" bit you can probably get away with a 3/4" stepover.
I always run the zig-zag/raster path with the grain to avoid tearout across the grain. And I try to get the tool off the part before stepping over. The round/smooth transitions allow you to maintain a constant higher feedrate without jerking the machine.

3 Likes

I haven’t used the semicircular turnarounds before. Will try that next time.

Sorry, new here…where do you set the step over?