Hi skywalker4:
Manual milling grade 5 titanium alloy is going to be a bit dicey on a floppy old Bridgeport, but it is possible and you can do a nice job too if you're willing to be a bit patient.
Here's what I'd do:
First I'd get myself a pair of 4 flute ball cutters, one that's 7/32" diameter and one that's 1/4" diameter for finishing.
I'd buy HSS instead of carbide.
Carbide likes a rigid setup to avoid flute chipping, so if your machine is tight and you're confident....Naahh, go with the HSS!
Run them slow, maybe 600 RPM for a 4 flute.
Find your start point for each kidney bean shape and slowly plunge to 0.005" of final depth with the 7/32 cutter.
Make sure when you do this that you have all the main axes locked, the rotary axis locked and the cutter choked up as much as possible, the ram back as far as possible, and the quill lock on enough to make the quill a bit draggy.
GENTLY peck it in with the quill, feeding the ball cutter as if it were a twist drill.
Use RapidTap or whatever other tapping fluid you prefer.
Use lots!...make a mess!!
Once you have the start holes in. you can unlock the rotary until it's also a bit draggy, then increment and plunge rough each kidney bean shape taking small bites until you reach the end point for each bean shape.
Once you've done that, move over in X or Y to within 0.005" of one wall, reset the depth, and walk around the periphery of the shape feeding continuously with the rotary ; then do the other wall.
Resist the temptation to try to climb mill this; a Bridgeport with a rotary is pretty floppy, and although Ti is pretty tough and not too grabby (unlike brass for example), if you try to climb cut you risk a big cutter bite if a flute does snatch at the sidewall.
Once you're within 0.005" of the walls, switch to your brand new 1/4" cutter.
Choke it up as before, set your depth and radial position and leave the rotary lock and the quill lock draggy again.
Now drop down to finish depth with the quill as you rotate the rotary at the same time to avoid a dwell divot at the start of your bean shape.
You want to keep the cutter moving as you work the quill down to the stop and swing the rotary together.
Practice it a bit until you're confident you can do it smoothly and repeatably without overshooting with the rotary.
There's a bit of a trick to it, but with a few practice tries well above the job you'll get the hang of it.
Once you have it mastered, walk the cutter into the first bean shape, run the rotary to the end position and then run it back all without stopping the continuous movement of the rotary except when you reverse direction and even then DON'T LINGER.
If you dwell, you'll make a divot, so don't stop!
Lock the shop door, banish the kids, throw the cellphone into the toilet if you have to...whatever it takes to concentrate fully on what you're doing.
That's it...all there is to it.
Before the days of CNC we used to do this kind of thing all the time as moldmakers.
If we fucked it up we had to hand stone it out with polishing stones so we all got really good at avoiding the divots.
It's been 30 years since I moved on to CNC, but I still remember the process back in the stone age.
Man it's soooo much easier now.
Cheers
Marcus
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