Hello everyone,
I am on day 3 of trying to pick the right feeds & speeds for my first cnc part on a Tormach 1100. I am getting 3 different inputs from my sources. This is driving me nuts as it is the only part I am not confident on. This is all on a 3d adaptive tool path
I am cutting 6061 alu. with a HSS uncoated 2 flute 3/8 end mill which is pretty long. Below are the details of the end mill:
Cutting dia : .375
Flute length: 2.495
Overall length: 4.25
Body length: 3.1
Shaft dia: .375
I contacted the MFG for their recommendation and got it https://heritagecutter.com/BrubakerWeldon/PublicStore/Downloads/Brubaker M7-M42-PM End Mill-No...
CALCULATIONS FOR SPEED CALCULATIONS FOR FEED
RPM = (3.82 x SFM) / DIA. IPM = # of FLUTES x FPT x RPM
SFM = (RPM x DIA.) / 3.82 FPT = IPM / (RPM x # of FLUTES)
The Tormach 1100 does 5100 RPM and I was told to keep the RPMS up near max for alu. which means:
First I calculated the SFM:
(5100x.375) / 3.82 = 500.654 THIS IS SFM VALUE
Then, I calculated IPM
2 x .0041 x 5100 = 41.82 ( 2 flutes, what the mfg says FPT is, RPM)
So unless I am mistaken in Cam, my values should be:
5100 RPM
500.654 SFM
41.82 for lead in/out. Fusion recommends .00385 feed per tooth and when I enter the .0041 feed per tooth value the cutting feed rate goes up to 41.82 as my math suggests it should. I was comfortable with this, until I tried out G wizard and HSM adviser which recommended wildly varying values.
HSM says:
.4 DOC (maximum step down) .15 WOC (step over)
5120 RPM
1.37 in/min feed
502 in/min speed
.00013 chip load
.81 plunge feed
It also says .04HP used, .04 lb/ft of tq used, and tool deflection is in the red at .0020 deflection or 19.8%. I was told to keep deflection under .001?
G wizard says done at 50% between conservative and aggressive:
4504 RPM
14.627 IPM Feed
7.3 Plunge speed
442 SFM
.0016 chip load
.003 tool deflection? it has the % at 334%!!!
Please help me guys, I have googled, read and exhausted all my friends ears with this. I get very generic responses to the effect of " I just feel it out" that do not inspire confidence. What am I overlooking? Am I using these calculators wrong?
I am on day 3 of trying to pick the right feeds & speeds for my first cnc part on a Tormach 1100. I am getting 3 different inputs from my sources. This is driving me nuts as it is the only part I am not confident on. This is all on a 3d adaptive tool path
I am cutting 6061 alu. with a HSS uncoated 2 flute 3/8 end mill which is pretty long. Below are the details of the end mill:
Cutting dia : .375
Flute length: 2.495
Overall length: 4.25
Body length: 3.1
Shaft dia: .375
I contacted the MFG for their recommendation and got it https://heritagecutter.com/BrubakerWeldon/PublicStore/Downloads/Brubaker M7-M42-PM End Mill-No...
CALCULATIONS FOR SPEED CALCULATIONS FOR FEED
RPM = (3.82 x SFM) / DIA. IPM = # of FLUTES x FPT x RPM
SFM = (RPM x DIA.) / 3.82 FPT = IPM / (RPM x # of FLUTES)
The Tormach 1100 does 5100 RPM and I was told to keep the RPMS up near max for alu. which means:
First I calculated the SFM:
(5100x.375) / 3.82 = 500.654 THIS IS SFM VALUE
Then, I calculated IPM
2 x .0041 x 5100 = 41.82 ( 2 flutes, what the mfg says FPT is, RPM)
So unless I am mistaken in Cam, my values should be:
5100 RPM
500.654 SFM
41.82 for lead in/out. Fusion recommends .00385 feed per tooth and when I enter the .0041 feed per tooth value the cutting feed rate goes up to 41.82 as my math suggests it should. I was comfortable with this, until I tried out G wizard and HSM adviser which recommended wildly varying values.
HSM says:
.4 DOC (maximum step down) .15 WOC (step over)
5120 RPM
1.37 in/min feed
502 in/min speed
.00013 chip load
.81 plunge feed
It also says .04HP used, .04 lb/ft of tq used, and tool deflection is in the red at .0020 deflection or 19.8%. I was told to keep deflection under .001?
G wizard says done at 50% between conservative and aggressive:
4504 RPM
14.627 IPM Feed
7.3 Plunge speed
442 SFM
.0016 chip load
.003 tool deflection? it has the % at 334%!!!
Please help me guys, I have googled, read and exhausted all my friends ears with this. I get very generic responses to the effect of " I just feel it out" that do not inspire confidence. What am I overlooking? Am I using these calculators wrong?