OpenFlexure Block Stage for SPIM

Fork of OpenFlexure Block Stage project.

Modification of the original Block Stage for SPIM imaging.

Department of Molecular Biophysics, Bogomoletz Institute of Physiology of NAS of Ukraine (Kyiv, Ukraine).

---

Setup overview

Part	#	Cost/unit	Link
OpenFlexure Block Stage	1x	$11	-
Arduino Nano compatible board	1x	$2.13	AliExpress
Arduino Nano CNC board	1x	$2.8	arduino.ua
Stepper driver A4988	3x	$1.3	arduino.ua
Stepper drive 28BYJ-48, 5V	3x	$1.45	arduino.ua
Joystick module	1x	$0.75	arduino.ua
Mini560 Pro Step Down to 5V	1x	$0.85	AliExpress
XT30 connector	1x	$0.6	arduino.ua
30 cm Dupont jumpers kit	1x	$0.95	arduino.ua
10 mm Spiral cable organizer	1x	$2.60	AliExpress
Total		~$30

Travel distances enlargement

Modification V0

The original OpenFlexure Block stage has only ~2 mm travel distances in each direction, which is not enough for large sample imaging. So, due to the parametric nature of the OpenFlexure Block Stage model, I just adjusted several variables in the parameters.scad file to obtain an STL model of the stage with enlarged travel distances. Additionally, I established a new variable platform_z_add which was just a constant in platform_z calculation (line 80) to control base high.

I am listing the changed parameters below:

Variable	Original value	Adjusted value
beam_height	75	100
stage_to_beam_height	12.5	0
xy_lever	10	30
flex_a	0.1	0.2
platform_z_add	7	20

Sample movement parameters:

• xy_reduction= 50 / xy_lever = 50/30 = 1.6
• z_reducion = 50 / z_lever = 50/10 = 5
• M3 screw pitch 0.5 mm

With selected parameters, we achieve next characteristics:

Axis	Travel distance	Travel per screw revolution (estimated)
X	~6 mm	0.313 mm
Y	~6 mm	0.313 mm
Z	~3 mm	0.1 mm

Materials:

Part	#	Cost/unit	Link
1.75 mm PLA filament	~200 g	~$4.75	Monofilament
Silicone O-ring kit	1x	$4.05	AliExpress
35 mm M3 screw	3x	~$0.5	Metalvis
M3 nut	6x	~$0.25	Metalvis
Total		~$11

Setup configurations

Stand-alone joystick control

Simple single speed stage control with joystick, sketch arduino/cnc_board_joystick_xyz.ino. Stage works in two modes, XY movement and Z movement, switching between them with joystick click button.

Stepper speed set up at 15 RPM, which achiwed travel speed 0.08 mm/s for XY axes and 0.025 mm/s for Z axis. Minimum rotation value set at 10 degrees per joystick activation.

Estimated movement parameters:

• ~9 um per joystick activation for XY axes
• ~3 um per joystick activation for Z axis

Joystick module case model avaliables on Printables (© @ZbychuM_510985).

μManager control

3-axis stage control with MarzhauserLStep device adapter, Inspired by CustomArduino vLStep Z-Axis solution.

Hardware modifications

Simple sample holder

Good practice for sample fixation during SPIM imaging is embedding the sample in agarose gel. 1 ml syringes are very suitable for large samples, so I designed a "lego figure hand"-like holder for a standard 1 ml insulin syringe.

Tip

Read about sample preparation for SPIM.

Sample holder model V0	Block Stage top view	Block Stage side view

R-axis arm

Moving platform modification with additional rotary axis.

in progress