I keep seeing Titans of CNC videos and their parts look like they have a mirror finish. I’ve tried messing with speeds and feeds but can never get a smooth surface finish on sides.
Is there a way to calculate a starting point for a good finish on aluminum and different metals?
Your tooling end mill you use has a lot to do with the finish you can get. If it is a rough grind it will produce a rough finish.
Tooling will have more to do with it than one would think. The face mill in the Titan building block kit produces this mirror like finish, I was amazed as well as my students when we ran it the first time. Lol, lots of ew’s and aw’s when we did the first part. We also use the Kennametal 3 flute carbide endmills recommended in the kit. We get near blemish free finishes when we leave material for a finishing pass.
There a more factors than just the tooling that affect the surface. Each one is equally important. Run out is probably the biggest factor. If your using a face mill you will want to check the run out on the diameter and the face of the mill. Most likely unless you are using a brand new machine, new holder and new cutter your going to have some level of run out. When you do find your run out you will have to isolate it and get it as close as you can to zero. Clean the spindle taper check the spindle, clean the tool holder taper and check the tool holder run out. Check the collet if you’re using one and finally the tool. .001 may not sound like a lot of run out but what your actually doing is taking a 4 flute endmill and turning it into a single flute cutter. Other factors that affect backlash in your ball screws on each axis, rigidity of your setup sharpness of your tooling.