6.4.2 BLOX with Linear Actuators

BLOX can be used with all the OpenBuilds Linear Actuators available at OpenBuilds Partstore: Linear Actuators as well as 2-axes motion platforms like the ACRO

If you want to move something, lift something or slide something this is the way to go!

See Wiring BLOX: Stepper Motors

Before you can use an actuator, you need to set it up so the controller knows how to control it correctly. Make use of the Initialization Blocks to configure them for use with the BLOX:

Drag the “Set Stepper Motor max current to” and “Set up Linear Axis” blocks into the Initialize input of your BLOX Block

Use the table below to find some default values to use for Current settings, Steps-per-mm and Acceleration

Linear Actuators	Details	Initialization Blocks
V-Slot® Mini V Actuator	Belt Driven GT2-2M Timing Belts 30T Pulley NEMA 17 Motor	Steps per millimeter: 53.33 Recommended Acceleration: +-900mm/sec² Recommended Feedrate: 0-250mm/sec Recommended Stepper Current: 1.0A
V-Slot® NEMA 17 Belt Actuator	Belt Driven GT2-2M Timing Belts 30T Pulley NEMA 17 Motor	Steps per millimeter: 53.33 Recommended Acceleration: +-900mm/sec² Recommended Feedrate: 0-250mm/sec Recommended Stepper Current: 1.0A
Belt and Pinion NEMA 17 Actuator	Belt Driven GT2-2M Timing Belts 30T Pulley NEMA 17 Motor	Steps per millimeter: 53.33 Recommended Acceleration: +-900mm/sec² Recommended Feedrate: 0-500mm/sec Recommended Stepper Current: 1.0A
Belt and Pinion NEMA 23 Actuator	Belt Driven 3GT-2M Timing Belts 20T Pulley NEMA23 Motor	Steps per millimeter: 53.33 Recommended Acceleration: +-900mm/sec² Recommended Feedrate: 0-500mm/sec Recommended Stepper Current: 2.2A
V-Slot® NEMA 23 Belt Actuator	Belt Driven 3GT-2M Timing Belts 20T Pulley NEMA23 Motor	Steps per millimeter: 53.33 Recommended Acceleration: +-900mm/sec² Recommended Feedrate: 0-500mm/sec Recommended Stepper Current: 1.5A
V-Slot® NEMA 17 Lead Screw Actuator	Lead Screw Driven TR8*8-2P (4 starts) Leadscrew NEMA 17 Motor	Steps per millimeter: 400 Recommended Acceleration: +-300mm/sec² Recommended Feedrate: 0-100mm/sec Recommended Stepper Current: 1.2A
V-Slot® NEMA 23 Lead Screw Actuator	Lead Screw Driven TR8*8-2P (4 starts) Leadscrew NEMA 23 Motor	Steps per millimeter: 400 Recommended Acceleration: +-500mm/sec² Recommended Feedrate: 0-80mm/sec Recommended Stepper Current: 1.5A
C-Beam Actuator	Lead Screw Driven TR8*8-2P (4 starts) Leadscrew NEMA 23 Motor	Steps per millimeter: 400 Recommended Acceleration: +-500mm/sec² Recommended Feedrate: 0-800mm/sec Recommended Stepper Current: 1.7A
C-Beam XLarge Actuator	Lead Screw Driven TR8*8-2P (4 starts) Leadscrew NEMA 23 Motor	Steps per millimeter: 400 Recommended Acceleration: +-500mm/sec² Recommended Feedrate: 0-80mm/sec Recommended Stepper Current: 1.7A
C-Beam Double Wide Actuator	Lead Screw Driven TR8*8-2P (4 starts) Leadscrew NEMA 23 Motor	Steps per millimeter: 400 Recommended Acceleration: +-500mm/sec² Recommended Feedrate: 0-80mm/sec Recommended Stepper Current: 1.7A
C-Beam Tension XLarge Actuator	Lead Screw Driven TR8*8-2P (4 starts) Leadscrew NEMA 23 Motor	Steps per millimeter: 400 Recommended Acceleration: +-500mm/sec² Recommended Feedrate: 0-80mm/second Recommended Stepper Current: 1.7A

Before you can also be used as a 2-axis system. You need to set it up so the controller knows how to control it correctly. Make use of the Initialization Blocks to configure them for use with the BLOX:

TIP: For more advanced 2-axes Motion control, check out grblHAL as an alternative

Drag the “Set Stepper Motor max current to” and “Set up Linear Axis” blocks into the Initialize input of your BLOX Block, set it up for both axes

Use the table below to find some default values to use for Current settings, Steps-per-mm and Acceleration

2 Axis Actuators	Details	Initialization Blocks
C-Beam XLarge X/Y Table	Lead Screw Driven TR8*8-2P (4 starts) Leadscrew NEMA 23 Motor	Steps per millimeter: 400 Recommended Acceleration: +-500mm/sec² Recommended Feedrate: 0-80mm/sec Recommended Stepper Current: 1.7A
OpenBuilds ACRO System	Belt Driven GT2-2M Timing Belts 14T Pulley NEMA 17 Motor	Steps per millimeter: 114.29 Recommended Acceleration: +-1200mm/sec² Recommended Feedrate: 0-500mm/sec Recommended Stepper Current: 1.2A

Its beneficial to add the “Home Stepper Motor” block to the initialization as well, that way later moves can make use of absolute positioning

TIP: Remember to install a Limit switch at the minimum (Zero-end) of travel

During initialization, the controller will move the motors until it hits the homing switch. Then it will perform a pull off and finally set its internal coordinates to ZERO. You can then perform absolute moves relative to this zero point.

Single Axis Homing	2-Axes Homing

Use the “Move Stepper Motor” blocks to move the actuator(s). You can do Relative moves (“Forward” or “Reverse” by some distance from current location) or Absolute moves (“To” a specific position, relative to the Zero point set by homing). If you make use of the “Apply Analog Sensor Value” block and place the “Move Stepper Motor” block inside it, you can map the sensor value to the Motor as well.

The “Wait for move to complete” tickbox will force the code to wait for the actuator to reach its commanded position before continuing with the program. That is usually the option you need. With an analog sensor application you may want to untick it - that way as the sensor changes the value, the position of the actuator can be changed in near realtime to match, rather than waiting for the last move to complete first.

Absolute Positioning example	Relative positioning Example	Position relative to sensor value

You can also rotate the motor a number of partial and/or full rotations using the “Rotate Stepper Motor” block, in applications where the logic does not apply linearly, for example with a Stepper motor spinning Pan Head on a camera slider or similar

Initialization:

Moving a rotational axis: