stepconf.lyx

CNC 的开放码,EMC2 V2.2.8版

 The second time the switch closes, the home position is set.
\newline 
Choose 
\begin_inset Quotes eld
\end_inset 

Opposite
\begin_inset Quotes erd
\end_inset 

 to have homing slowly back off the switch.
 When the switch opens, the home position is set.
\layout Description

Time\SpecialChar ~
to\SpecialChar ~
accelerate\SpecialChar ~
to\SpecialChar ~
max\SpecialChar ~
speed
\begin_inset LatexCommand \index{Time to accelerate to max speed}

\end_inset 


\layout Description

Distance\SpecialChar ~
to\SpecialChar ~
accelerate\SpecialChar ~
to\SpecialChar ~
max\SpecialChar ~
speed
\begin_inset LatexCommand \index{Distance to accelerate to max speed}

\end_inset 


\layout Description

Pulse\SpecialChar ~
rate\SpecialChar ~
at\SpecialChar ~
max\SpecialChar ~
speed
\begin_inset LatexCommand \index{Pulse rate at max speed}

\end_inset 

 Information computed based on the values entered above.
 The greatest 
\series bold 
Pulse rate at max speed
\series default 
 determines the 
\series bold 
BASE_PERIOD
\series default 
, and values above 20000Hz may lead to slow response time or even lockups
 (the fastest usable pulse rate varies from computer to computer)
\layout Description

Test\SpecialChar ~
this\SpecialChar ~
axis
\begin_inset LatexCommand \index{Test this axis}

\end_inset 

 This will open a window to allow testing for each axis.
 See section (
\begin_inset LatexCommand \ref{sec:Testing-Each-Axis}

\end_inset 

)
\layout Subsection

Spindle Configuration
\begin_inset LatexCommand \index{Spindle Configuration}

\end_inset 


\begin_inset LatexCommand \label{sub:Spindle-Configuration}

\end_inset 


\layout Standard


\begin_inset Float figure
placement H
wide false
collapsed false

\layout Caption

Spindle Configuration Page
\begin_inset LatexCommand \label{cap:Spindle-Configuration-Page}

\end_inset 


\layout Standard
\align center 

\begin_inset Graphics
	filename stepconf-spindle.png
	scale 70

\end_inset 


\end_inset 


\layout Standard

These options only appear when 
\begin_inset Quotes eld
\end_inset 

Spindle PWM
\begin_inset Quotes erd
\end_inset 

, 
\begin_inset Quotes eld
\end_inset 

Spindle A
\begin_inset Quotes erd
\end_inset 

 or 
\begin_inset Quotes eld
\end_inset 

Spindle PPR
\begin_inset Quotes erd
\end_inset 

 are chosen in the 
\series bold 
Parallel port pinout
\series default 
.
\layout Subsubsection

Spindle Speed Control
\begin_inset LatexCommand \index{spindle speed control}

\end_inset 


\begin_inset LatexCommand \label{sub:Spindle-Speed-Control}

\end_inset 


\layout Standard

If 
\begin_inset Quotes eld
\end_inset 

Spindle PWM
\begin_inset Quotes erd
\end_inset 

 appears on the pinout, the following information should be entered:
\layout Description

PWM\SpecialChar ~
Rate
\begin_inset LatexCommand \index{PWM Rate}

\end_inset 

 The 
\begin_inset Quotes eld
\end_inset 

carrier frequency
\begin_inset Quotes erd
\end_inset 

 of the PWM signal to the spindle.
 Enter 
\begin_inset Quotes eld
\end_inset 

0
\begin_inset Quotes erd
\end_inset 

 for PDM mode, which is useful for generating an analog control voltage.
 Refer to the documentation for your spindle controller for the appropriate
 value.
\layout Description

Speed\SpecialChar ~
1\SpecialChar ~
and\SpecialChar ~
2,\SpecialChar ~
PWM\SpecialChar ~
1\SpecialChar ~
and\SpecialChar ~
2
\begin_inset LatexCommand \index{Speed 1 and 2}

\end_inset 


\begin_inset LatexCommand \index{PWM 1 and 2}

\end_inset 

 The generated configuration file uses a simple linear relationship to determine
 the PWM value for a given RPM value.
 If the values are not known, they can be determined.
 For more information see section (
\begin_inset LatexCommand \ref{sec:Determining-Spindle-Calibration}

\end_inset 

)
\layout Subsubsection

Spindle-synchronized motion (lathe threading)
\begin_inset LatexCommand \label{sub:Spindle-synchronized-motion-(lathe}

\end_inset 


\begin_inset LatexCommand \index{spindle-synchronized motion}

\end_inset 


\begin_inset LatexCommand \index{Lathe Threading}

\end_inset 


\layout Standard

When the appropriate signals from a spindle encoder are connected to the
 parallel port, EMC supports lathe threading.
 These signals are:
\layout Description

Spindle\SpecialChar ~
PPR
\begin_inset LatexCommand \index{Spindle PPR}

\end_inset 

 Also called 
\begin_inset Quotes eld
\end_inset 

Index pulse
\begin_inset Quotes erd
\end_inset 

, this is a pulse that occurs once per revolution of the spindle.
\layout Description

Spindle\SpecialChar ~
A
\begin_inset LatexCommand \index{Spindle A}

\end_inset 

 This is a pulse that occurs in multiple equally-spaced locations as the
 spindle turns.
\layout Description

Spindle\SpecialChar ~
B
\begin_inset LatexCommand \index{Spindle B}

\end_inset 

 (optional) This is a second pulse that occurs, but with an offset from
 
\series bold 
Spindle A
\series default 
.
 The advantages to using both 
\series bold 
A
\series default 
 and 
\series bold 
B
\series default 
 are increased noise immunity and increased resolution.
\layout Standard

If 
\begin_inset Quotes eld
\end_inset 

Spindle A
\begin_inset Quotes erd
\end_inset 

 and 
\begin_inset Quotes eld
\end_inset 

Spindle PPR
\begin_inset Quotes erd
\end_inset 

 appear on the pinout, the following information should be entered:
\layout Description

Cycles\SpecialChar ~
per\SpecialChar ~
revolution
\begin_inset LatexCommand \index{Cycles per revolution}

\end_inset 

 The number of cycles of the 
\series bold 
Spindle A
\series default 
 signal during one revolution of the spindle
\layout Description


\begin_inset Note
collapsed false

\layout Description

Maximum\SpecialChar ~
threading\SpecialChar ~
speed The maximum spindle speed at which threading will
 be used.
 Like high motor speeds in Hz, high 
\series bold 
SPINDLE A
\series default 
 speeds require a low 
\series bold 
BASE_PERIOD
\series default 
 setting (TO DO)
\end_inset 


\layout Subsection

Machine Configuration Complete
\begin_inset LatexCommand \label{sub:Machine-Configuration-Complete}

\end_inset 


\layout Standard

Click 
\begin_inset Quotes eld
\end_inset 

Apply
\begin_inset Quotes erd
\end_inset 

 to write the configuration files.
 Later, you can re-run this program and tweak the settings you entered before.
\layout Section

Testing Each Axis
\begin_inset LatexCommand \index{Testing Each Axis}

\end_inset 


\begin_inset LatexCommand \label{sec:Testing-Each-Axis}

\end_inset 


\layout Standard


\begin_inset Float figure
placement H
wide false
collapsed false

\layout Caption

Axis Test Window
\begin_inset LatexCommand \label{cap:Axis-Test-Window}

\end_inset 


\layout Standard
\align center 

\begin_inset Graphics
	filename stepconf-test.png
	scale 70

\end_inset 


\end_inset 


\layout Standard

With Stepconf it is easy to try different values for acceleration and velocity.
 First, enter the correct figures for 
\series bold 
Steps per Revolution
\series default 
, 
\series bold 
Microstepping
\series default 
, 
\series bold 
Pulley
\series default 
, and 
\series bold 
Leadscrew
\series default 
.
 Then enter a provisional value for 
\series bold 
Velocity
\series default 
.

\series bold 
 Next
\series default 
, click 
\series bold 
Test this axis
\series default 
.
\layout Subsection

Finding Maximum Velocity
\begin_inset LatexCommand \index{Finding Maximum Velocity}

\end_inset 


\begin_inset LatexCommand \label{sub:Finding-Maximum-Velocity}

\end_inset 


\layout Standard

Begin with a low Acceleration (e.g., 2 in/s^2 or 50mm/s^2) and the velocity
 you hope to attain.
 Using the buttons provided, jog the axis to near the center of travel.
 Take care because with a low acceleration value, it can take a surprising
 distance for the axis to decelerate to a stop.
\layout Standard

After gauging the amount of travel available, enter a safe distance in Test
 Area, keeping in mind that after a stall the motor may next start to move
 in an unexpected direction.
 Then click Run.
 The machine will begin to move back and forth along this axis.
 In this test, it is important that the combination of Acceleration and
 Test Area allow the machine to reach the selected Velocity and 
\begin_inset Quotes eld
\end_inset 

cruise
\begin_inset Quotes erd
\end_inset 

 for at least a short distance--the more distance, the better this test
 is.
 The formula d=.5*v*v/a gives the minimum distance required reach the specified
 velocity with the given acceleration.
 If it is convenient and safe to do so, push the table against the direction
 of motion to simulate cutting forces.
 If the machine stalls, reduce the speed and start the test again.
\layout Standard

If the machine did not obviously stall, click the 
\begin_inset Quotes eld
\end_inset 

Run
\begin_inset Quotes erd
\end_inset 

 button off.
 The axis now returns to the position where it started.
 If the position is incorrect, then the axis stalled or lost steps during
 the test.
 Reduce Velocity and start the test again.
\layout Standard

If the machine doesn't move, stalls, or loses steps no matter how low you
 turn Velocity, verify the following:
\layout Itemize

Correct step waveform timings
\layout Itemize

Correct pinout, including 
\begin_inset Quotes eld
\end_inset 

Invert
\begin_inset Quotes erd
\end_inset 

 on step pins
\layout Itemize

Correct, well-shielded cabling
\layout Itemize

Physical problems with the motor, motor coupling, leadscrew, etc.
\layout Standard

Once you have found a speed at which the axis does not stall or lose steps
 during this testing procedure, reduce it by 10% and use that as the axis
 Maximum Velocity.
\layout Subsection

Finding Maximum Acceleration
\begin_inset LatexCommand \index{Finding Maximum Acceleration}

\end_inset 


\begin_inset LatexCommand \label{sub:Finding-Maximum-Acceleration}

\end_inset 


\layout Standard

With the Maximum Velocity you found in the previous step, enter the acceleration
 value to test.
 procedure as above, adjusting the Acceleration value up or down as necessary.
 In this test, it is important that the combination of Acceleration and
 Test Area allow the machine to reach the selected Velocity.
 Once you have found a value at which the axis does not stall or lose steps
 during this testing procedure, reduce it by 10% and use that as the axis
 Maximum Acceleration.
\layout Section

Determining Spindle Calibration
\begin_inset LatexCommand \index{Determining Spindle Calibration}

\end_inset 


\begin_inset LatexCommand \label{sec:Determining-Spindle-Calibration}

\end_inset 


\layout Standard

Enter the following values in the Spindle Configuration page:
\layout Standard


\begin_inset  Tabular
<lyxtabular version="3" rows="2" columns="4">
<features>
<column alignment="center" valignment="top" leftline="true" width="0">
<column alignment="center" valignment="top" leftline="true" width="0">
<column alignment="center" valignment="top" leftline="true" width="0">
<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text

\layout Standard

Speed 1:
\end_inset 
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text

\layout Standard