My first real milling project - comments? - 1911 slide mod.

jmx66

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For years I've wanted to learn how to operate a vertical mill.
Long story short, I bought a little Grizzly G0704 a month or so and started learning on delrin and aluminum (anyone want a 1" square aluminum cube? :) ).
After three or so hours of tramming and a few test pieces, I mounted my Springfield TRP slide to do a carry cut.
6 flute 5/8 Promax AlTiN coated end mill loaded. 1100 rpm.
Here's off the mill:
Any suggestions on spindle speed? Could it have been better?
35484233601_cca69d341e_c.jpg

and cleaned up:
35575015146_2d254a92ec_z.jpg

Here's a "before":
35486050141_6a5e3d9f77_c.jpg
 
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For a start, what was your spindle RPM and feed rate of the end mill? What size end mill? How many flutes. What brand of end mill?
 
There's a vibration somewhere, leaving irregular cuts. Notice in your first picture each groove is different. No vibration, they would have been very fine and identical. Its possible you were feeding too slowly for the RPM.
 
That maybe too much end mill for that mill. I assume that is a carbide end mill your using? For your mill, I would limit end mill capacity to 1/2" diameter, not saying 5/8 or larger won't work, just my gut feel. I would also suggest to slow down the spindle RPM's, too until the squealing goes away or the ripples smooth out. If you leave a few thousandths for a cleanup pass, that may eliminate the tool marks. and climb mill on the finish pass. Oh, apply some good cutting oil to the surface, too. Remember, you're cutting (17-4 PH900 guessing) stainless steel there. It's much tougher! And will give you fits trying to cut it too! Oh, it will work harden in an instant, on you too, when you are not looking.
 
Yes, carbide end mill, Ken.
Thanks for all the advice. :)
 
.......................Remember, you're cutting (17-4 PH900 guessing) stainless steel there. It's much tougher! And will give you fits trying to cut it too! Oh, it will work harden in an instant, on you too, when you are not looking.
I found a reference where a manufacture uses 416 stainless steel for their slides. Machinability is a little bit better to machine than 17-4PH. Less likely to work harden. So I could be wrong on stating 17-4PH as being the material in the OP's slide.
 
Encouraged by my first effort, I decided to add "Ball Cuts":
Kennemetal 3/8" carbide 4 flute
Set-up:
34794543344_96da6d3bde_z.jpg

Right off the mill (better results than before :D )

35249096540_74670a0fb5_c.jpg

34794543224_6dfc073013_c.jpg


Cleaned up and ready to bead blast:
35470644682_d5a53c748e_b.jpg
 
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So....tell us about speed and feed for the ballmill...
 
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