I’m making some catch all trays and I’m noticing a small issue in some of the corners where the toolpath completes but leaves a little uneven ridge. I thought my speeds and feeds were pretty conservative but I can’t think of what else would cause this. Any ideas?
Usually this sort of thing is caused by deflection when plunging — best fix seems to be to leave a roughing clearance larger than the deviation, then take it off with a finishing pass (which usually requires adding inset geometry in Carbide Create, see: Adding geometry to cut as a pocket with a finishing pass )
What I do when using large bits is I will tell the computer I am cutting the pocket with a bit that is ~0.050" wider than it really is. It cuts the pocket at however many passes you do, like 0.100" passes. . . This leaves 0.025" all the way around the pocket to clean up and remove the layer marks in the wood and the chunky corners. (like /u/WillAdams wrote)
Then I go back and tell the computer I am using the actual size of the bit, do an inside profile at full depth pass and have it do the last bit of cleanup at a single cut (provided the cutting depth of the bit is greater than the pocket depth) and it should clean it up nicely.
To follow up to my question, I tried your suggestion but it didn’t seem to help any. The strange thing is, that I just noticed actually, is that the little uneven ridges are occurring only on the top left and bottom right corners of the pocket. Any idea why this would be?
But I’m stumped as to fix the below issue now.
The first picture shows my pocket toolpath, running clockwise.
The second picture shows my outside-right toolpath which is inset .75”, the same diameter as my bowl bit.
But as you can see, there is a small amount of material in the corners that won’t be reached by the second toolpath.
Any ideas?
Can you tell what I mean from the two images. You can see the second one doesn’t cut the same amount of material as the first one. First is pocket, second is outside right
I feel like this is super simple but I’m just missing something. I just need a finishing pass to run counter clockwise that matches the outside oath of my pocket.
First picture is a pocket of the larger rectangle. This is the area I want my pocket to be.
Second picture is an outside right offset of the smaller rectangle in the center, thus creating the finishing pass going counter clockwise. The issue is that this path does not cover the same area as the first path.
I cannot make the smaller rectangle any larger as it will cause the outside right path to exceed the area of the pocket rectangle.