DMF_TomB
Diamond
- Joined
- Dec 13, 2008
- Location
- Rochester, NY, USA
i am curious what other experienced machinist use to determine an end mill depth of cut.
.
for example i use the 2x longer then 2 square (2x2) rule. that is a end mill sticking out 2 times longer then 1/4 depth of cut.
.
i ordered 1/2" end mill with 1.25" LOC but received 1.625 length of cut. Formula says with aluminum and HSS end mill
0.80" stick out from collet then 0.684" max depth of cut
1.40" stick out from collet then 0.223" max depth of cut
1.88" stick out from collet then 0.125" max depth of cut
.
even at 0.100" DOC and climb milling i was getting vibration marks with 0.005" to 0.008" thick chips. Of coarse i could slow feed and lower depth of cut but even doing this vibration marks were still seen.
.
my point is i never realized before how much a slightly longer end mill could seriously effect machining rates. at first it would appear better to have a longer end mill just in case you might need it but if you do not need the length it can really increase the time to machine a part.
.
just wondering if anybody has studied this before?? you would think during a war time when producing arms like during WW2 somebody would have studied this. Or the Automakers would have studied this, although they might not publish the info and treat it as a trade secret.
...... Just wondering what formulas others use other than trying things and increasing til vibration is too severe. But doing this you might not realize the vibration is more from the end mill length than anything else.
.
for example i use the 2x longer then 2 square (2x2) rule. that is a end mill sticking out 2 times longer then 1/4 depth of cut.
.
i ordered 1/2" end mill with 1.25" LOC but received 1.625 length of cut. Formula says with aluminum and HSS end mill
0.80" stick out from collet then 0.684" max depth of cut
1.40" stick out from collet then 0.223" max depth of cut
1.88" stick out from collet then 0.125" max depth of cut
.
even at 0.100" DOC and climb milling i was getting vibration marks with 0.005" to 0.008" thick chips. Of coarse i could slow feed and lower depth of cut but even doing this vibration marks were still seen.
.
my point is i never realized before how much a slightly longer end mill could seriously effect machining rates. at first it would appear better to have a longer end mill just in case you might need it but if you do not need the length it can really increase the time to machine a part.
.
just wondering if anybody has studied this before?? you would think during a war time when producing arms like during WW2 somebody would have studied this. Or the Automakers would have studied this, although they might not publish the info and treat it as a trade secret.
...... Just wondering what formulas others use other than trying things and increasing til vibration is too severe. But doing this you might not realize the vibration is more from the end mill length than anything else.