By JamesBuckle
FSWizard/HSMA Vastly different F&S
I'm new, but not totally fresh to CNC, have just set up my small VMC, it's a fairly light machine and I've tended to drop my feeds while maintaining the max 3000rpm in Alu, but I've had a couple of tool breaks making me think I'm not feeding fast enough and I'm rubbing/sticking. So I ran the tool info in FSWiz:
12mm End Mill, 2 flute, 17mm flute length 36 stickout
3mm DOC
12 WOC (slot/pocket)
Limit RPM to 3000 (machine limit - this drops the calc'd F&S)
Results:
Surface Speed 113 (limited to the 3000), feed at 883mm/min
chip load 0.14mm
Same items entered into HSMA return:
873rpm (32.9m/min) and 241mm/min feed.
chipload ~0.14mm
Seeing as I know I'm cutting 6061-T6 and I'd expect SFM of 100-200m/min, I'd assume both are correct (based on chip load being close) but I'm wondering why HSMA is suggesting much lower F&S. It's not even coming close to my max torque, breaking torque or deflection?
Thanks for any advice, I could do with breaking fewer cutters and I'm struggling to figure out where to start!
Eldar Gerfanov (Admin)
Updated by: Eldar Gerfanov (Admin)July 21, 2015, 5:04 pm
Please download a latest update 1.161
There was an issue with metric machine limits in the previous update.
But i am not sure it affected you.
Hmm... could you attach some screenshots?
This is what i am getting in HSMAdvisor:
Tool: 12.000mm 2FL HSS None Solid End Mill
Speed: 113.0 SMM/ 3000.0
Feed: 0.1383 mm/tooth 0.2766 mm/rev 829.82 mm/min
Chip Thickness: 0.1383 mm
Reference Chip load: 0.0922 mm
Engagement: DOC3.00 mm WOC12.00 mm
Effective Dia: 12.000 mm
Cross Section: 0.25 x Dia.
Power: 0.4kW
MRR: 29.87 cm^3
Torque: 1.30 N-M
Max Torque: 6.56 N-M
Cutting Force: 216.4 N
Deflection: 0.02 mm
Max Deflection: 0.04 mm
Also see the first attached image.
Perhaps your machine definition is limiting things for you?
Edit: Make sure to use some sort of lubrication as aluminum is very sticky.
JamesBuckle
Sure, would love to learn why my mistake is (which is far more likely than a code issue!). Attached are my two screenshots taken just now.
I think I have got a little closer. After you mentioned it I went back in to the machine definition and re-saved it with a new name. When I set the max feed rate to 2000mm/min, all in metric, (78.74in/min), I go back to the main sheet and it warns me that the max feed rate is exceeded and the RPM has been limited to match max feed rate, but that's now set to 78.74mm/min. Looks like it/me might have some confusion with the conversion of machine limit.
Eldar Gerfanov (Admin)
Please download and install the latest update.
Also go to Edit Machine and make sure "Calculations Stick to RPM Values from the table below" is off.
That option forces your calculations to math the closest table value.
See the attached screenshot:
JamesBuckle
I updated and restarted HSMA, re-checked/corrected the machine info and hit save. Back to the main screen changed the material then changed it back (in case it was a variable update issue) but I still get the same results. I expanded the panels a bit to show the rest.
Eldar Gerfanov (Admin)
Updated by: Eldar Gerfanov (Admin)July 22, 2015, 11:19 am
Ah I see it now.
You have Custom Cutting speed set up in your Manufacturer Speeds and Feeds panel. That is an override that people usually use to set starting speeds and feeds supplied by the manufacturer.
Click on "Speed" label to set it to deafult.
In the future you should use Reset button, Located on Tool Data panel to reset every parameter to default when you see something does not make sense.