I created a cheat sheet detailing how profile and pocket toolpaths behave when allowance offsets (both positive and negative) are applied (a concept I have to relearn every time I need to use it). Thought I would share in case anyone else struggles like I do, trying to remember whether they need a negative or positive offset.
Joe
Wow, I was just trying to figure this out. Thank you. I am just 4-weeks in and suddenly it’s beginning to click. But this is a great help thanks. Tom
Sorry to Rehash an old thread, but trying to keep topics together What’s a typical Pocket allowance people are using for a Wider Gap when slotting pieces together? The pieces I’m using are 1/8" thick, I was guessing (-.005) might be a good amount to ensure they fit together smoothly but just curious what others were using.
Well The the 1/8" pieces I’m using are slotted at 1/16" depth just to hold the other in place for accurate placement before gluing and would be straight and perpendicular to eachother.
@AndyP Just curious does that 0.1mm allow just enough room for the box lid to lightly spin without much friction?
@JoeT Thanks for your input, I plan to do inlays that was one of the reasons for getting a CNC, and would have eventually asked that question. You stated that .003 is a “starting” point, how many times do you do the carve and find out the .003" isn’t enough and have to re do it all? or has that never been an issue?
I typically prototype new inlay designs on scrap wood to make sure everything works as I planned. I can make any offset adjustments based on my prototype, but usually an offset .002" or .003" works just fine. I want the smallest offset possible to reduce glue line visibility, but not so small that assembly/glue-up becomes a pain. I find .002"/.003" offsets are a good compromise. I have tried .001", which look great, but can be a challenge to assemble. Here are some pics of inlays using the offsets I mentioned.