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- Feb 8, 2014
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To expand on the above a bit, I am in the middle of a job today that illustrates rapid material removal.
First I outlined the profile by taking a 0.010 deep cut, this told me where the part was located in the chunk of steel, this could have been done by laying out the cut lines with a scribe also. Either way works.
Then over to the band saw to trim the excess material. When I did the layout pass I left plenty of excess material in case it didn't go back into the mill exactly the way is came out, a few thousands won't make any difference until after the finishing pass.
The excess is all trimmed off, about 20 minutes cutting time.
then over to the disk sander to knock off the high spots, could have been done on the bench grinder also.
Then back into the mill for the roughing passes, I made three 0.050 width passes because I didn't exactly know how high the high spots were and I didn't want to overload the machine by grabbing too much. Used a 1/2 inch cobalt rougher, 680 RPM (~80 FPM, material is 4150), 1.25 DOC (full material thickness), 4.5 IPM feed.
This would have been about 3 hours of spindle time had I not trimmed the part on the bandsaw. Spindle time was 26 minutes. So 20 min of saw time and 26 min of spindle time beats the heck out of 3 hours or so.
And here are the chips that come off of the rougher
The finish pass using a Harbor Freight 5/8, 4 flute is running as I write this.
First I outlined the profile by taking a 0.010 deep cut, this told me where the part was located in the chunk of steel, this could have been done by laying out the cut lines with a scribe also. Either way works.
Then over to the band saw to trim the excess material. When I did the layout pass I left plenty of excess material in case it didn't go back into the mill exactly the way is came out, a few thousands won't make any difference until after the finishing pass.
The excess is all trimmed off, about 20 minutes cutting time.
then over to the disk sander to knock off the high spots, could have been done on the bench grinder also.
Then back into the mill for the roughing passes, I made three 0.050 width passes because I didn't exactly know how high the high spots were and I didn't want to overload the machine by grabbing too much. Used a 1/2 inch cobalt rougher, 680 RPM (~80 FPM, material is 4150), 1.25 DOC (full material thickness), 4.5 IPM feed.
This would have been about 3 hours of spindle time had I not trimmed the part on the bandsaw. Spindle time was 26 minutes. So 20 min of saw time and 26 min of spindle time beats the heck out of 3 hours or so.
And here are the chips that come off of the rougher
The finish pass using a Harbor Freight 5/8, 4 flute is running as I write this.
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