Hi guys,


Can you please check if i am using this motorcalcs the right way?


(40kg moving gantry X+Z on hiwin type rails using 2* c7 type 2010 1500 mm ballscrews)
Really unsure about cutting forces (5N) and gantry weight distribution


Lets say i put this info in the sheet.
http://cnc4you.co.uk/resources/Stepp...1-03%204Nm.pdf

INPUTS OUTPUTS Version 1.2 - 30 Jan 2010
Units Metric

Load Calculations

Mass of Load 40 kg Load inertia 1,013E-04 kgm^2
Friction co-efficient 0,1 Load torque 8,937E-02 Nm
Cutting forces 5 N


Leadscrew calculations

Screw pitch 10 mm Screw mass 3,676 kg
Screw dia 20 mm Screw inertia 1,850E-04 kgm^2
Screw length 1500 mm
Screw minor dia 16 mm
Screw efficiency 80% %
Screw Fixing Fixed-supported Critical Speed 1066 rpm


Max linear speed 2500 mm/min Motor revs 250 rpm
for: Cutting
Total Inertial load 2,890E-04 kgm^2
(inc rotor inertia)
Proposed Motor Acceleration torque 0,504 Nm
Rated current 4 A
Winding Inductance 3 mH Total Torque 0,594 Nm
Holding Torque 3 Nm at 833 steps/sec
Detent Torque 0,04 Nm
Rotor Inertia 275 gcm^2
Ideal Voltage 55 V
Motor Usage Esitmated Motor
Supply Voltage 68 V Corner Speed 1082 rpm
Set Phase Current 4 A Estimated Torque
(at required speed) 2,081 Nm
The motor & operating conditions chosen have a good
margin and should be OK at the required speed
(subject to driver circuitry)



So what i am looking for is the following.
My design is 1500 mm of travel on the X-Axis.
Gantry weight about 50-70kg
There will be 2 ballscrews.

I am planning on using a timing belt reduction 1:2 ballscrew:stepper

I am not sure how to input a reduction in the sheet.
Filling out 2005 type screw makes the screw rev by a factor of 2
Filling out 2010 type screw makes the motor spin to slow so torque is off by a factor??



Will 2500mm/min speed be plenty fast for a 2.2 kw chinese R20 spindle using carbide bits on aluminium?
What would be a material that needs a higher speed rates over 2500mm/min???
Planning on machining hard/soft wood, aluminum, plastics.

(i have no idea what speeds and feeds are in the resonable range )
I tried filling in some diameters/types cutters and number of flutes in a speed and feed calculator for wood and alu

Looked like 2500mm/min is max any one would need in the hobby range, am i right here?


I am not sure if i can just reduce the gantry weight to 50% if i plan on using 2 steppers. (slaved X axis setup)


Please point me in the right direction.
Any help is welcome.