Hi - I’ve spent a lot of time trying to figure this out with various calculators, and online searching, but to no avail. I’m afraid I just can’t wrap my head around it, so humbly ask if anyone can make a recommendation on what feeds and speeds setting to use for this particular bit, plunge rates, etc. It’s a 15º vee bit, and I plan on using it in hardwood, no metal. Shapeoko Pro XXL; Thanks in advance!
Vbit feeds and speeds are weird, there is basically no great universal formula or at least I was not able to crowdsource one from the collective brain on this forum, the best guideline that emerged at the time is what I captured in that section of the shapeoko ebook, and it has served me well:
In addition, here are two examples of (successful) vcarve jobs in hardwood and richlite (similar hardness) with one of my 25° vbits, you might want to dial down those settings slightly for a 15° vbit
Experimentation is key. To minimize the risk of breaking the tool, start with very conservative depth per pass, rather than slowing down the feedrate. The tip of a vbit spins at essentially zero RPM already, so moving too slow would rub the wood rather than cutting it. Depth per pass on the other hand is the perfect tuning parameter to go easy on the tool (slow depth per pass = very little deflection/ lateral force on the tool). Then incrementally increase depth per pass so that the vcarve jobs don’t take ages to complete.
Because the diameter at the tip is 0, the optimum spindle speed is ∞ (infinity).
How deep are you cutting? Calculate the diameter at the top of the cut & use that as your tool dia.
Consider your material. Too fast spindle speed can burn or melt material.
Keep your chipload up to a respectable level by increasing feedrate. Most of the materials we cut on these machines require at least a 0.001" chipload.
