Z axis calculation

[adstaggs]

NEWBIE!

I need help trying get the right calculation for my Z axis.

Nema 23 Bipolar 1.8deg 1.26Nm (178.4oz.in) 2.8A 2.5V
5 inchs travel
4" WIDE
machined from 3/8 plate 6061T6 alu.
3/8-16 SCREW WITH anti-backlash ACETAL NUT (16 turn/inch for high torque), ACETAL=delrin
DOUBLE STAINLESS BEARING ON ONE END
1045 ground SMOOTH ROD

 

[masso-support]

So are you looking for values on how to calibrate the motor settings in MASSO so that it moves the Z axis right distance?

 

[adstaggs]

yes please

 

[masso-support]

You basically need two things:

1. Depending on your stepper motor drive settings, please find how many pulses you need to give to the drive to make the motor rotate exactly one full turn. Then enter this value in the Z axis setup in MASSO Drive: Pulses per revolution.
   
2. Next depending on the pith of your screw, we need to enter the Motor: Distance per revolution value. For example if rotating the screw one full turn your axis moves 5mm then enter 5 for Motor: Distance per revolution.
   

 

[adstaggs]

1. 200 steps
2. not sure so how would I calculate 16 turn/ per inch

 

[buschbwbusch]

16x200= 3200 ppr

Most stepper drives are chopper drives though and will multiply the pulses going to your motor. Some are called out in the multiplier and some will just tell you the ppr going to the motor make sure to read and understand the label on the drive

 

[adstaggs]

All I know is that it is a Nema 23 Bipolar 1.8deg 1.26Nm (178.4oz.in) 2.8A 2.5V

and the label reads this.
23hs22-2804s

I have googled trying to find out how to calculate distance per revolution but found nothing.

 

[buschbwbusch]

The signal from the Masso first goes to drive then from drive to stepper motor. What stepper drive (not motor) are u using?

 

[buschbwbusch]

So the motor turns the screw the screw is 16 you...which literally means u must revolve the threaded rod 16 times to travel one inch. This is rotation to translation. In order the revolve the motor 1 time around it will take x number of pulses which is a factor of the stepper drive. Thus pprx16= pulses Masso must create to move 1 inch

 

[adstaggs]

so if there 16 turns in one inch then could I not convert 1" inch to 25.4 mm then divide 16 into 25.4 = 1.5875 and get the distance?

 

[adstaggs]

I purchased them from CNC4PC Stepper Driver 5056
settings
4.3A
Microsteps 40

 

[buschbwbusch]

Are you setting it up in inches or mm? I set mine up in inches, essentially you are just telling the controller how many pulses it needs to go to move a certain distance be it inches or mm. So if it is MM then yes the 1.5--- would be pulses per MM. Please post a pic of the drive you are using along with a pic of the nomenclature that should be on the drive or the manual for the drive. The easiest way to do this is a common sense method using a tape measure and then an indicator to dial things in better. Put in a number to the setup screen. Go to MDI and command the machine axis to move a certain amount. Compare the amount it actually moved to the amount you commanded. Set it up as a ratio, from there edit the pulses per. The simple fact is if the machine travels too far then there are too many pulses, of it doe not travel far enough then you have to few. I would never just trust the fact that you typed in the correct information into a wizard and it set things perfectly. Yes use the wizard, but also verify as well. Doing this will also perhaps show you the amount of backlash your machine may have, but that is another topic.

 

[adstaggs]

Thanks for all your help.

I have attached a pic not sure about nomenclature so if you need more info just let me know. I will try what you have suggested.


This stepper driver is based on a DSP with an advanced control algorithm. It brings a high level of system smoothness, providing optimum torque and nulls mid-range instability. Motor auto-identification and parameter auto-configuration technology offers optimum responses with different motors and is easy-to-use. The driven motors can run with much lower noise, less heating, smoother movement than most of the drivers in the markets. Its unique features make the driver more attractive.

Multi-Stepping allows a low resolution step input to produce
a higher microstep output for smooth system performance
Microstep resolutions programmable, from full-step to 51,200 steps/rev
Can be set by Dip switch (2,4,8,16,32,64,128,256,5,10,25,50,125,250)
Supply voltage up to +50 VDC
Output current programmable, from 0.5A to 5.6A(Can be set by Dip switch too)
Pulse input frequency up to 200 KHz
TTL compatible and optically isolated input
Full or Half Current , Sw4: Off= Half Current
Suitable for 2-phase and 4-phase motors
Support PUL/DIR and CW/CCW modes
Over-voltage, over-current, phase-error protection

 

[buschbwbusch]

It look like ur switch setting are set to 4.3a and a multiplier of 8...so

16X200x8=25,600--Pulses per INCH. That is going to be pretty slow most likely look at the switch settings and change them on switched 5-8 to be as small as possible.

 

[buschbwbusch]

Sorry looks like 2.7a and the same multiplier. Set switch 5 to off and 6,7,8 to on, and the multiplier should be 2 instead. Than
16X200X2=6400 pulses per in or do the simple math to change it to be MM or M CM whatever it is asking for

 

[adstaggs]

That helped greatly now it move smoother and faster and everything seems to home ok, so the Z homes to the top 0.00 but when I try to move it down it sets off the z limit switch alarm and the only way to clear is to home it again. is there any way to override the alarms?

 

[buschbwbusch]

Is your Z axis home switch NC or NO? If you go to the setting page you can change the state of the switch by tabbing over to it and hitting the space bar on your keyboard. The most likely reason is you have an active low setting or vice versa and the homing switch is switching to the opposite for a split second and confusing the controller.

 

[adstaggs]

it set for NC but very cheap switches maybe this could be an issue, I was thinking about purchasing the homing sensors would this be a better solutions?

 

[masso-support]

I think its a setup issue and not a switch issue. Please check that all homing inputs on MASSO F1 screen only show L (low) when the switch is not pressed, it should only show H (high) when pressed. If you see the signals the other way then select that input and press space key on the keyboard to invert that input.

Have you watched this video, it has some good info about homing setup:

 

[adstaggs]

I am still trying to dial in the settings but I notice that the Z motor is so hot to the touch that I can not keep my hand on it, also the Z when it homes it will not back away 5mm that I have set but X and Y work fine, do you think the motor is over heating and cause issues. Also the MDI command do not work when I issues a command nothing happens.