A couple of takeaways that some of you may find useful:
Use an air blast to clear chips and help keep the tool cool. I use an air blast that’s built into the lower mount. I’m sure it’s a bit overkill but I’m running 40PSI through the air blast with a 25 gal compressor.
Measure the diameter of your end mill with a set of calipers. I’m not sure if this is unique to the stuff I buy from aliexpress but some of mine came out to 2.9mm instead of the advertised 3.18mm. It looks like the shank is 3.18mm prior to being ground but the flutes are a bit smaller. I had to kind of “spin” the end mill in the calipers to find the largest diameter of the flute. I was initially using very high stepover for roughing the block into shape and I couldn’t figure out why it was leaving ridges between passes. Turns out that if your tool diameter is ~9% less that what you tell your CAM software then this sort of thing happens /s.
Never plunge straight into the material and avoid plunging altogether if you can. Id you must plunge into the material take if very slow. I still got some chatter during plunges using trochoidal milling’s helical pecking plunges.
Make a ton of test cuts to get things dialed in first. the majority of the time spent on this project finding the right settings for this machine. Christian’s advice is a great starting point for trochoidal cuts.
Spend the time to get your machine set up as square as possible. Foot height, rail squareness, gantry squareness, z axis, all of it. I used Ryan’s tool and shimmed the router as best I could but still got the slightest of ridges on my finishing passes. I, regrettably, didn’t set up dual end stops from the beginning so I use clamps on my rails and lock steppers to keep the gantry square before every cut.
Take care to get the vise mounted properly. I locked a new spoil board on to the table and surfaced it prior to mounting the vise. Fingers crossed that the base of the vise is perpendicular to the fixed jaw and parallel to the flats. I didn’t have the proper tools to check. Jogging the machine around probing things proved good enough.
Vise mounted to the surfaced spoil board.
The last piece of the puzzle was getting the fixed jaw parallel to the X axis on the machine. You could get this close enough for most work by jogging the machine around and making sure that the end mill just makes contact with the jaw at either end. I cheated by 3d printing PLA soft jaws (100% infill for sure) and getting things close. I then took a skim cut across the length of the fixed jaw. You’re more or less guaranteed to have the fixed jaw and machine parallel to each other that way. I’ll have to get a clip of this… Machining PLA without turning it into a gummy mess was a challenge and, if I’m being honest, I probably didn’t need to go through the trouble here. Oh, and never trust the movable jaw on cheap vises. Jaw lift sucks.
Other useful things:
Mounting a vise on a large CNC machine: https://www.youtube.com/watch?v=cn05fX55pqc
This Old Tony on squaring stock: https://www.youtube.com/watch?v=tW8HNAlUXxU
Hopefully some of you will find bits and pieces of this info useful