until recently, I did a few CNC milling projects, using the stock Snapmaker CNC milling bits. I always needed to go shallow and slow, the toolhead flexing and struggeling a lot if I did not. Now I have a project running, where I need to cut 3 cm deep, and that’s just too much for the short Snapmaker bits. So I got myself a set of bits of mid-range pricing, among those a 6mm bit with 32 mm cutting depth capability. Fusion 360 calculated a feedrate of 2550 mm/min - so roughly 40 mm/s. That sounded a lot to me, but I thought: let’s give it a try. I started the job, my nervous hand hovering over the stop button, but - lo and behold - the bit cut through the wood like butter!
Here’s a video:
The spindle was a bit at its limit - instead of 12.000 rpm it managed 11.300 rpm at the deepest cuts.
So long story short: Better bits result in better results! Can only recommend to invest a bit into quality here.
EDIT: Just realize my text may be a bit misleading: Of course you cannot mill 3 cm deep in one go at 40 mm/s - here in the video it was only 0.5 mm stepdown, but I can tell that 2mm stepdown also worked, the spindle struggeling even more.
CNC go vrrrrrrrrrrrrrr. I regularly run a 1/8" down spiral @ 1000mm/m, 1mm stepdown and it never drops the RPM. I surely need to push it harder! The biggest issue I see is you will have to go back with a slower pass for any fine details or accuracies, since the tool runout is quite high, and the rigidity is a bit low on the snapmaker. Only if accuracy is required, of course. If you have plenty of tolerance and just need it to destroy material, you’ve got that. For being only 50W, the spindle is actually quite a workhorse, I’ve done the above speeds and feeds through solid red oak and maple with no issue.
On what type of wood and what amount of step-down?
Without knowing either of those quoting speed numbers is meaningless.
There’s a huge difference between speed you can go on soft pine vs. a hardwood like walnut or maple.
In my case it does not really matter - the wood is the same, the stepdown is the same, so the quality bits are just better than the stock Snapmaker ones, which is not too much of a surprise, since they cost considerably more. My point is: It is absolutely worth to invest in this better quality - jobs will be faster, and results more precise.
A bit of an update - the video shows the first of a set of four. Currently running #2, and decided to increase to 1mm stepdown. With the relatively soft wood no issue - until I hit a harder piece of wood where an embedded branch was. The spindle stopped dead and the toolhead got stuck. Fortunately I was just beside the machine when it happened and could hit the Stop-button.
So, the spindle is clearly a limiting factor with its 50W…
Back to shallow, but still going fast
…and happy to have the Stop-button