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.
Offset Allowance.pdf (445.1 KB)
Really useful, I can never remember
So thoughtful of you
Happy to hear I’m not the only one who has trouble remembering this!
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
You’re very welcome Tom! Enjoy your Onefinity! Joe
I am new to the cnc world and have had my machine for a short period of time. Thank you for sharing this as it certainly will help me going forward
Thanks @JoeT. I printed the cheat sheet for my notebook. It’s very well done and illustrative of how to set up the offsets in the proper direction.
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.
For a round box with lid I allow 0.1mm in diameter for a tight with oak or walnut.
For inlays, I use .003" offset allowance as a starting point.
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?
Snug when oile. Does turn but not easily.
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.