Okay so I am a beginner and don't have much experience with the CNC systems. I am trying to build a custom system and for now I am just focusing on controlling 1-axis. And then will move to other 2 axis. So, I am using the Stepper Motor with lead screw: 14E17S0914FF3-250RS NEMA 14 Motor Step Angle: 1.8° and total steps per rotation = 200 Lead = 1.27mm Linear Travel/Step = 0.00635mm Amps/Phase: 0.91 https://www.omc-stepperonline.com/n...d-1-27mm-0-05-length-250mm-14e17s0914ff-250rs I have connected this motor to BlackBox X32 with latest firmware. Default microstep = 1/8. So based on my calculation, the step/mm should be: (200 x 8)/1.27 = 1259.84. I changed this value in the Grbl setting and the pulse width to be 100 µS. When I am commanding the motor to move 100mm, it is barely moving about 19mm-20mm. I tried fiddling settings but not is working and the motor is travelling way less than the desired value. Also adjusted the current in the blackbox but that won't do anything. Can anyone please help me what am I doing wrong or am I missing something? Thanks in advance
Hi Peter, not sure why 100uS was selected, typical default 10 should work fine. Paste you GRBL settings here. Cheers Gary
Parameter Value Unit/Type $0 (Step pulse time, microseconds) 100.0 µs $1 (Step idle delay, milliseconds) 255 ms $2 (Step pulse invert, mask) 0 mask $3 (Step direction invert, mask) X: Normal, Y: Normal, Z: Normal Reversed $4 (Invert step enable pin, boolean) 0 mask/bool $5 (Invert limit pins, boolean/mask) 7 mask/bool $6 (Invert probe pin, boolean) ✓ Enable $8 (Ganged axes direction invert as bitfield) 0 bitfield $9 (PWM Spindle as bitfield where setting bit 0 enables the rest) 1 bitfield $10 (Status report options, mask) 511 mask $11 (Junction deviation, millimeters) 0.020 mm $12 (Arc tolerance, millimeters) 0.002 mm $13 (Report in inches, boolean) ✗ Disable $14 (Invert control input signals, mask) 0 mask $15 (Coolant pins invert, mask) 0 mask $16 (Spindle pins invert, mask) 0 mask $17 (Control pins pullup disable, mask) 0 mask $18 (Limit pins pullup disable, mask) 0 mask $19 (Probe pin pullup disable, boolean) 0 bool $20 (Soft limits enable, boolean) ✗ Disable $21 (Hard limits enable, boolean) ✗ Disable $22 (Homing cycle enable, boolean / mask) 0 mask $23 (Homing direction invert, mask) X: Min, Y: Min, Z: Min Max $24 (Homing locate feed rate, mm/min) 100.0 mm/min $25 (Homing search seek rate, mm/min) 1000.0 mm/min $26 (Homing switch debounce delay, milliseconds) 250 ms $27 (Homing switch pull-off distance, millimeters) 5.000 mm $28 (G73 retract distance, in mm) 0.100 mm $29 (Step pulse delay, milliseconds) 5.0 ms $30 (Maximum spindle speed, RPM) 1000.000 RPM $31 (Minimum spindle speed, RPM) 0.000 RPM $32 (Laser-mode enable, boolean) ✗ Disable $33 (Spindle PWM frequency) 5000.0 Hz $34 (Spindle off value) 0.0 S $35 (Spindle min value) 0.0 S $36 (Spindle max value) 100.0 S $37 (Stepper deenergize mask) 0 mask $39 (Enable printable realtime command characters, boolean) 1 bool $40 (Apply soft limits for jog commands, boolean) 0 bool $43 (Homing passes) 1 passes $44 (Homing cycle 1) 4 - $45 (Homing cycle 2) 3 - $46 (Homing cycle 3) 0 - $62 (Sleep Enable) 0 bool $63 (Feed Hold Actions) 2 mask $64 (Force Init Alarm) 0 bool $65 (Require homing sequence to be executed at startup) 0 - $70 (Network Services) 7 mask $73 (Wifi Mode) 1 mode $74 (Wifi network SSID) ssid - $75 (Wifi network PSK) psk - $100 (X-axis steps per millimeter) 199.100 steps/mm $101 (Y-axis steps per millimeter) 1259.840 steps/mm $102 (Z-axis steps per millimeter) 199.100 steps/mm $110 (X-axis maximum rate, mm/min) 2500.000 mm/min $111 (Y-axis maximum rate, mm/min) 2500.000 mm/min $112 (Z-axis maximum rate, mm/min) 2500.000 mm/min $120 (X-axis acceleration, mm/sec²) 500.000 mm/sec² $121 (Y-axis acceleration, mm/sec²) 500.000 mm/sec² $122 (Z-axis acceleration, mm/sec²) 500.000 mm/sec² $130 (X-axis maximum travel, millimeters) 1000.000 mm $131 (Y-axis maximum travel, millimeters) 1000.000 mm $132 (Z-axis maximum travel, millimeters) 100.000 mm $300 (Grbl) ? - $302 (IP Address 1) 192.168.5.1 - $303 (IP Address 2) 192.168.5.1 - $304 (Subnet Mask) 255.255.255.0 - $305 (Port) 23 - $306 (Port 2) 80 - $307 (Port 3) 81 - $341 (Tool Change Mode) 0 mode $342 (Tool Change probing distance) 30.0 mm $343 (Tool Change Locate Feed rate) 25.0 mm/min $344 (Tool Change Search Seek rate) 200.0 mm/min $345 (Tool Change Probe Pull Off rate) 200.0 mm/min $346 (Restore position after M6) 1 bool $370 (Invert I/O Port Inputs, mask) 0 mask $384 (Disable G92 Persistence) 0 bool $396 (WebUI timeout in minutes) 30 min $397 (WebUI auto report interval, milliseconds) 0 ms $398 (Planner buffer blocks) 35 blocks $481 (Autoreport interval) 0 ms Sorry if I made this extra long, just pasted all the settings in case it helps.
Also when I changed it to 10µS, the lead screw won't move at all. Seems like motor is trying to move but not enough torque at this speed.
only using a Y axis? is the only one set for 1259.. steps per mm, also change to a whole number (round up to 1260). Gary
that's interesting, might be hard to hit this speed with such fine lead. also whole number on steps per mm, while decimals are supported they can lead to issues. Gary
Yes, I am only using Y-axis for now. So I have just connected 1 stepper motor at this time. Once this issue is resolved, it will connect other two axis motors. Update: Changed it to 1260, still it travels about 19mm for the command of 100mm
that's a 0.9A MAX motor. BlackBox's bare minimum is around 1.2A - it will overheat and stop working shortly - that motor is far underpowered for BlackBox It has Lead Travel/Revolution: 1.27mm(0.05") 1260 steps per mm is close enough Way too fast for such as a high resolution screw. Our 8mm pitch screws, run around 150mm/sec² Also quite possibly too high, our 8mm pitch screws run at 2500mm/min Try far lower numbers for Acceleration and Max rate, its probably stalling part way through moves Not even keeping in mind a NEMA14 is way less powerful than our NEMA23s, just talking about the outright increase in resolution (more precision, more torque, less speed) 1.27/8 * 150 = 23,8125mm/sec² acceleration 1.27/8 * 2500 = 396,875mm/min max rate Probably far lower because the motor is also weak All the way down is still 1.33 times the motors max rating (and max rating usually about 50% above recommended current setting for a motor)
As per your suggestions, I changed the max rate to 400 mm/min and acceleration to 40 mm/sec^2 and seems like it is moving about 100mm for the set value of 100. But as you said that the the current stepper motor at 0.9amps is not enough for Blackbox and yes it heats up a lot. So, I will try upgrading it to NEMA 17 or 23 with higher rated current.
