Is there anyone who can help with my inlays? I’ve been on this forum I dont know how many times trying to solve these CONSTANT issues. So to keep this short and sweet I did a practice piece of just a simple square. Pocket start depth 0, max depth .20 with a plug start depth of .18 and max depth of .20. I should be left with .02 gap above the material with .18 fitting snug in the pocket, correct??
It is way too loose and floats around in the pocket.
I zero my bits manually in the center of my stock and have a bit setter. I also have digital calipers and am measuring the cutouts which are equaling .20 depth for both the plug AND pocket.
I will literally pay someone to walk me through this like I am 5 or video chat.
You’re only leaving a half mm of “space” there. I bet you’re bottoming out. Try a start depth of 0.10" and leave everything else. With the 30deg bit, you’ll want to leave a bit more room. 0.1" might be too much, but it’ll be a good sanity check.
Ok, so I retried with .10 as the start for my plug and it was still loose, but tighter than the .18 depth. So I did a .05 start depth and it fits perfectly…
So my next question is why?? I’ve even brought this up on here before and people kept trying to tell me my start depth needs to be higher when I encountered problems like the plug not going deep enough.
Since the .05 start depth worked, shouldn’t I have a .15 gap on top? Because thats what everyone told me before and every video I have seen says the same.
This picture is the .05 start depth and .20 max depth… that gap is maybe .02
I appreciate it, and I think I’ve seen that one before. I understand how inlays work, what I’m confused about is why my start depths are so off every single time. Nothing is consistent. For example a .05 start for my plug now works, but past projects it sat way too high not inserting into the pocket enough. I do cutting boards so any gap is unacceptable.
Can you post a close-up photo of your VBit’s tip? It might be worn.
VBits are awkward. It’s easy to get the Z zero too deep in wood since they are so sharp, and - unlike other endmills - as the tip wears down, your pockets will get bigger.
Yes I was thinking the same thing yesterday, my 30 degree is slightly worn so I ordered one off Amazon, should have it tomorrow. I’ll see what kind of difference it makes!
When I have parts which need to fit together precisely I machine with a deliberate offset on the key face, put my calipers on the cut item to find out where it is on this bit, setup etc. and then adjust my extra offset down and re-run the finishing pass.
Can you find suitable measurement points on your inlay parts?
I had similar problems trying to get inlays to work on a cutting board. I spent a month experimenting with different depths and settings. I finally switched from a 90 degree bit to a 60 degree bit and everything worked as it should. On a cutting board, you definitely don’t want large voids under the inlays.
I’m not sure what you mean by offsetting the key face. Are you referring to the plug? If so what are you offsetting? Also, what would I be finding measuring points for?
If I’ve got, say a tenon and mortise to cut, I know that they need to fit together, that means there needs to be some sort of clearance. I also know that the diameter of my cutter and a bunch of other things on my machine are not perfect numbers so I won’t quite get the dimensions I asked for in the CAM (especially on V shaped bits which commonly have accidentally or deliberately truncated tips).
What I do in the CAM is I create a gap by tweaking the size of the mortise to allow clearance for the tenon. In Fusion there is the “Offset face” command which lets you push or pull a whole flat face. I start by making the mortise deliberately too small, say 29.8mm wide for a 30mm tenon, run the job and measure with the calipers. I can then adjust the clearance in the CAM and run again until I get the real dimension I was after.
If you are using a V bit things are doubly complex because any error in Z height changes the effective radius of the cutter in addition to the normal sources of error.
I’m not sure what CAM you’re using but if there is a way to program the two halves so that you can adjust the clearance between the angled faces when you insert the inlay into the socket you could start with a deliberately undersized socket for the inlay and then open it out until your inlay plug just fits.
