D_II_X-Y-stage unit

X-Y-stage unit; D_II

For technicians and sales managers

This section describes the components, functionality, handling, installation and checking instructions of the X-Y-stage unit for the scanner Pannoramic DESK _II (D_II).

Contents

General

Components and construction

Maximal hysteresis in Y-direction

Adjustments

Find the hardware limits

General

The X-Y-stage unit is used to position the slide at loading or unloading action, it moves the slide in X- and Y-direction during the scan process.

The movements are realized by stepper motors. The slide insertion is done manually, in the slide insert and removal position.

The X-Y-stage unit is mounted fixed; a remove or exchange procedure requires several checks and adjustment procedures, so a prophylactic remove is strongly not recommended .

The exchange of the X-Y-stage unit is possible

If the shape of any part is deformed or a part is broken and this can not be exchanged separately.
If the X-Y-stage unit has any fault and the exchange of the unit was explicitly recommended by 3DHISTECH's Service and Support.
In any cases, please refer first to the chapter 'Before you start to replace units'.

Requirements

Service program for slide scanners ('SlideScannerService.exe') with the actual license file.
Slide scanner and Slide Viewer software ('SlideScanner.exe', 'SlideViewer.exe') with the actual dongle.
1.5, 2.5, 3 and 5 mm hex key wrenches.
Hardware and construction knowledge of Pannoramic scanners.

See also: Dismount the focus unit

X-Y-unit mounting above

Mount the X-Y-stage unit

1. Insert the X-Y-stage unit into the cutout of the scanner plate and rotate the L-shaped mounting elements into the mounting position.

2. Drive in the mounting bolts and tighten these.

3. Connect the cables of the X-Y-stage unit..

4. Insert the focus unit until it stops.

5. Tighten the fixing bolt by turning it counter clockwise.

6. Connect the cable.

For more information, see 'Scanner plate',

X-Y-carriage system

The carriages are used to move the specimen holder and so the slide in X- and Y-directions.

The unit mounting plate is mounted to the scanner plate from beneath. This ensures the proper mounting and fixing of the X-Y-stage unit.

X-stage unit

The static part of the X-stage consists of:

X-direction mounting plate
X-motor
Dovetail foot (mounted from beneath)
X-rails
X-minimum limiter
X-maximum limiter

The moveable part of the X-stage consists of:

X-stepper rotor
Spindle
Transport nut (module)
Y-stage unit

The transport nut module is driven by the spindle and is mounted onto the Y-stage unit (the X-carriage).

Watch video: X-Carriage; D II

Y-stage unit

The static part of the Y-stage consists of:

Y-direction mounting plate (X-carriage)
Y-motor
Y-rails
Y-minimum limiter
Y-maximum limiter

The Y-motor is mounted to the mounting plate.

The moveable part of the Y-stage consists of:

Y-stepper rotor
Spindle
Transport nut
Y-carriage
Parallelogram
Specimen holder

The transport nut is mounted to the Y-carriage.

Watch video: Y-carriage; D II

Carriages

The carriages are mounted and lead with rails for each direction.

The X- and Y-rails ensures a slippage-free movement of the carriages in X- and Y-direction. The X-carriage contains the entire Y-part. When the motor starts rotating, the spindle, it drives the carriage in the direction, defined by the rotating direction of the rotor. The mechanical dimensioning of the X-Y-stage allows reaching nearly each part of the slide by the objective, except the barcode area (restrictions are given by the slide holding mechanics of the specimen holder; see also the scan area).

X-and Y-spindle

The spindle (together with the transport nut module) is used to transform rotation of the rotor into slippage-free longitudinal movements. The four threads on the spindle guarantee a precise movement, increase the torque of the mechanical drive and help to reduce or eliminate slippage and hysteresis.

The X- and Y-spindle are connected to the stepper motors by the help of the spindle mounting. On the thread of the spindle the transport nut module is situated and this is mounted onto the X- respective Y-carriage. To eliminate slippage in the connection between rotor axle and spindle mounting, the spindle mounting is hold on the motor axle by a pressure connection.

Transport nut module

The construction of the carriage transport nuts ensures a slippage-free movement of the carriages. The early used transport nut solution with transport nut, spring and counter nut is now replaced by an integrated module solution. Adjustments, regarding the counter nut position are now done by rotating the spindle separated from the motor axle (e.g. if the motor axle stays in Home 1,2). This way, the hardware limits may be adjusted easily and more precise.

The use of the stepper motors micro stepping mode, combined with the accuracy of the mechanics allows achieving a resolution of 1µm longitudinal movement per rotor step.

Limiters

The movement range of each carriage is limited by two limiters, one for the upper and one for the lower limit. Limiters are used for both, the X- and Y-directions. With the limiters the mechanical construction gets a start and an end position.

When the mechanical limiter is reached by the carriage, the carriage movement stops. If more steps are entered in the service program, those steps are lost - this behavior creates 'lost steps'.

The defined limit position is a part of the real movement range!

During the detection of the hardware limits the creation of lost steps is used to find and determine the upper and lower hardware limits. The first number of steps that do not create lost steps is used as hardware limit; the accuracy is 100 steps (0.1mm).

Example:

· If the step number of 1200 steps in negative direction after Home1 and Home2 does create lost steps (more than +-2 steps) and

· The step number of 1100 steps in negative direction after Home1 and Home2 does not create lost steps (not more than +-2 steps) the negative hardware limit will be -1100 steps.

To define the upper limit, the same principle is used. First we create lost steps then we decrease the number of steps to go by 100 steps until no steps are lost during the movement.

During slide insertion or removal actions and sample scanning process lost rotor steps are unwanted, because the counting and reporting of steps mismatches the real number of steps gone. Therefore, the limits are defined by using the last possible number of steps without lost steps and an accuracy of 100 steps (=0.1 mm).

For more information, see chapter 'Adjustment procedures'.

The home position does not define the mechanical limit. Either in -X- and in -Y-direction there are several hundred more steps possible. The absolute limits are defined as shown in the figures 'X-direction; D_II' and 'Y-direction; D_II'.

Note! The unit (or its adjustment) is faulty, if there are more than 1600 steps possible in negative direction from Home 1,2.

The unit (or its adjustment) is faulty, if there are more than 1600 steps possible in positive direction after 57600 steps in +X-direction or 73600 steps in +Y-direction.

For more information, see chapters 'Adjustment procedures', 'How to define the hardware limits' and 'Check or define the hardware limits of the X-Y-stage unit'.

Specimen holder

Allowed slide dimensions

Single width

Length: 75.00 to 76.00 mm

Width: 25.00 to 26.00 mm

Thickness: 00.95 to 01.20 mm

Double width

Length: 75.00 to 76.00 mm

Width: 50.00 to 51.00 mm

Thickness: 00.95 to 01.20 mm

If the first character of the serial number is an “S” the tool is used to check the slide dimensions of single width slides; thickness = 0.95 ... 1.05mm.
If the first character of the serial number is a “P” the tool is used to check the slide dimensions of single width slides; thickness = 0.95 ... 1.20mm.

Please check the slide dimensions before insertion of slides!

During scanning, the assembled arm is not in contact with the release pin and so, the assembled arm is in the 'Hold' state. The slide is tightened by the 'Strong spring' to ensure, that the slide does not change its position in the frame. The force of the 'Strong spring' is 2N ±0.5N. Through the 'Assembled arm' and the 'Inverter', the 'Strong spring' forces the 'Assembled clamp' sideward (in the image downward) in relation 50.5 : 8 (the 'Assembled arm' amplifies the force of 'Strong spring') and in relation 17:22 the 'Inverter' attenuates a little bit this force, but its main task is, to invert the movement. This way the force of the slide clamp against the slide is nearly five times more than the force of the 'Strong spring'.

During slide insert and removal operations, the 'Assembled arm' is moved sideward against the Release pin and so, the mechanics, driven by the 'Assembled arm' releases the 'Slide clamp' (Adapter) via the 'Inverter' mechanics. Only the force of the 'Soft spring' holds now the slide in the frame. Because the force of the 'Soft spring' is not much, the slide can be inserted or removed manually.

· Please do not exceed the allowed slide dimensions; otherwise, the slide clamp may be damaged!

Watch video: Release pin and supporter

Slide holding and scan area

The slide is hold by the specimen holder on the longer, lower edge and with a slide clamp on its upper edge, on the barcode area; see the red lines on the right. As you can see, the definition of the limits X-min and Y-max are critical. X-max and Y-min are given by the maximal usable slide size and are not critical; they could be the slide edge.

· Never touch the specimen holder with the objective or the focus pin during movements!

See also: 'Areas of the slide', and 'Define the scan area''

Single width slide adapter and sensor

As mentioned above, the specimen holder may hold slides with single width and double width.

If single width slides should be inserted into the specimen holder an adapter is used.

To tell the software, that the adapter is present, a Hall sensor, mounted on the preview unit's sensor mounting plate is used.

If the sensor shows the active state in the slide insert position, the adapter is present, slides with single width will be inserted.

Adjustment

Move the X-Y-stage with the service program to the Home1,2 position and insert and remove the adapter more times. During these actions, the presence or absence of the adapter have to be signaled surely and correctly.

Check this behavior more times.

If checks failed, adjust the sensor position more precise

Adjustment procedures

Adjustments for the X-Y-carriage unit

The following procedures are described for Pannoramic SCAN especially. In Pannoramic MIDI and Pannoramic DESK the adjustments are logically identical, but some pronunciations like 'up or down and left or right, horizontal and vertical' may differ. Please take this into account if you are adjusting DESK or MIDI.

Find the hardware limits for the X-carriage

· This procedure must be done if the scanner unit or the X-Y-stage was changed; the parallelogram was adjusted, the specimen holder mounting was altered or the drive unit was manipulated.

· Insert a medium large slide and set the focus motor to 500 steps.

Find the negative limit in -X-direction

1. With the service program set the Y-carriage to Home1,2.

2. Set the X-carriage to Home1,2.

3. With the service program go forward to the X-motor position -1200 steps.

4. Go backward +1200 steps.

5. Press Home1 (only). There should be not more then +-2 steps difference to Home1. If there are more steps lost, decrease the actual absolute number of steps by 100 and repeat from step 2. In the steps 3 and 4 use the actual absolute number of steps!

6. If there are not more then 2 steps difference to Home1, increase the number of steps by 100 and repeat from step 2. In the steps 3 and 4 use the actual absolute number of steps!

7. The negative limit is found correctly if the motor movement has no steps lost and the actual absolute number of steps, increased by 100 would produce lost steps. The found negative limit can differ by more 100 steps from unit to unit. The reason is the tolerance of the components.

8. Update the value of the parameter 'ObjectGuideXMin' with the found number of the actual steps in the file 'MicroscopeConfiguration.ini' section [HardwareLimits] and save the file.

Find the positive limit in +X-direction

With the service program set the X-carriage unit to Home1,2.

9. Go forward to the X-motor position +29700 steps.

10. Go backward 29700 steps.

11. Press Home1 (only). There should be not more then +-2 steps difference to Home1. If there are more steps lost, decrease the actual number of steps by 100 and repeat from step 9. In the steps 10 and 11 use the actual number of steps!

12. If there are not more then 2 steps difference to Home1, increase the number of steps by 100 and repeat from step 9. In the steps 10 and 11 use the actual number of steps!

13. The positive limit is found correctly if the motor movement has no steps lost (max. 2 steps) and the actual number of steps, increased by 100 would produce lost steps. The found positive limit can differ by more 100 steps from unit to unit. The reason is the tolerance of the components.

14. Update the value of the parameter 'ObjectGuideXMax' with the found value in the file 'MicroscopeConfiguration.ini' section [HardwareLimits] and save the file.

· Check the found limits by using the number of steps, used as parameter value in the file 'MicroscopeConfiguration.ini' section [HardwareLimits]. Lost steps must not occur.

Find the hardware limits for the Y-carriage

For SCAN: Move the X-carriage +29000 steps from Home1,2; this way, the slide tightener can not collide with the magazine unit and the focus pin does not collide with the lower edge of the specimen holder.

For MIDI: Move the X-carriage +6400 steps from Home1,2; this way, the focus pin does not collide with the slide stud of the specimen holder.

For DESK: Move the X-carriage +6400 steps from Home1,2; this way, the focus pin does not collide with the slide stud or the slide rails of the specimen holder.

Find the negative limit in -Y-direction

Repeat the steps, described in the procedure above 'To find the negative limit in -X-direction' logically with the Y-carriage.

15. Update the value of the parameter 'ObjectGuideYMin' with the found number of the actual steps in the file 'MicroscopeConfiguration.ini' section [HardwareLimits] and save the file.

Find the positive limit in +Y-direction; DESK_II

Repeat the steps, described in the procedure above 'To find the positive limit in +X-direction' logically with the Y-carriage. The positive limit is found correctly even before the +Y-limit is reached or before the specimen holder will be touched.

16. Update the value of the parameter 'ObjectGuideYMax' with the found value in the file 'MicroscopeConfiguration.ini' section [HardwareLimits] and save the file.

Further information can be found in: 'How to define the hardware limits'.

Sample scan process

The software divides the sample to be scanned, seen by the preview camera into fields of views; the size of the FOV depends on the resolution of the scan camera and the magnification of the camera adapter. Each field of view contains a small part of the neighbor FOV. In this way, stitching becomes possible. Because the capturing of the FOV’s is done on a meandering course, the Y-direction is often changed. If the hysteresis in Y-direction is too much, stitching will not work correctly; therefore, we have to check the hysteresis in Y-direction. The maximal allowed hysteresis is 4μm (=4 motor steps). We comment that this hysteresis decreases itself by some motor steps after some sample scan procedures, even if the X-Y-stage is brand new.

Because the X-direction is never changed during a sample scan process, the X-hysteresis is not critical and can be some steps more (max: 8 steps).

Watch video: 'Tissue scan process' (P250)

Check the maximal hysteresis in Y-direction

Start the program 'SlideScanner.exe' with the service password. In the tab 'Focus' produce a sharp live view.

In the tab 'Service' select 'Microscope control' and check the option 'Cross line on image'. In the part of the X-Y-control select a step size of two steps and go upward, until the tissue moves.

Now go in opposite direction and count the clicks until the tissue moves. If more then 3 clicks are required, the hysteresis is too much.

See also: 'Stitching' and 'Exchange the Y-drive unit'

Carriage drive unit

The following adjustments are done only, if the motor has to be exchanged, the X-Y-carriage drive unit was removed.

The resolution of the stepper motor by 3200 steps/revolution and the construction of the spindle together with the transport nut allow a resolution of 1μm longitudinal movement per motor step; the transport nut eliminates the slippage if the rotation direction changes.

The only difference between the Y-carriage drive unit and the X- carriage drive unit is the length of the transport spindle; the spindle of the X-unit is shorter.

Transport spindle; Multi (4) thread spindle

The spindle (together with the transport nut) is used to transform rotation into slippage free longitudinal movements. The four threads on the spindle guarantee a precise movement, increase the torque of the mechanical drive and help to reduce or eliminate slippage and hysteresis.

Spindle mounting

The spindle is mounted to the rotor axle by a pressure connection solution.

Disconnect the spindle

· Set the appropriate motor to Home1,2.

· Move the rotor by about +16000steps (5 revolutions).

· Loosen the spindle mounting bolts and move the spindle mounting from the rotor shaft.

To mount the spindle

· Set the appropriate motor to Home1,2.

· Move the rotor by about +16000steps (5 revolutions).

· Move the spindle mounting onto the rotor shaft and tighten the bolts.

· Check the hardware limits for the carriage.

· By loosening the spindle mounting and rotating the motor shaft with the service program, the movement range of the carriage can be adjusted.

1. Loosen the spindle mounting bolts.

2. Rotate the motor's rotor some revolutions or some 100steps forward or backward as desired and tighten the mounting bolts.

3. Check the hardware limits.

· Repeat the procedure until the requirements of the hardware limits are fulfilled.

See also: Limiters and define hardware limits

Transport nut module

The transport nut moves the Y-carriage (or any other, connected peripheral) to the desired position; the thread of the spindle and the nut moves the peripheral by 3.2mm if the rotor (and the spindle) have done one revolution.

To reach the appropriate limits of the mechanical drive, the rotation of the spindle in relation to the Home1,2 position of the rotor can be adjusted with the spindle mounting.

The limits have to be less then 1600 steps in negative direction counted from Home1,2 and less then 1600 steps after 23revolutions of the spindle (if Y-carriage); see also 'The hardware limits' and 'Find the hardware limits for the Y-carriage.

Watch video: Y-Drive unit; D II

Rotor slippage

Rotor slippage is defined as the longitudinal movement of the rotor axle in its bearing. If the rotor direction has changed this slippage may increase the longitudinal position fault drastically, even if we try to reach a longitudinal movement resolution of 1µm /rotor step. To eliminate this slippage, the adjustment bolt with counter nut 'Eliminate slippage' can be used.

Important

This adjustment is already done during the component implementing procedure; please do not drive the bolt or the nut!

Dismount the carriage drive unit

· Set the appropriate motor to Home1,2.

· Move the rotor by about +16000steps (5 revolutions).

· Remove the mounting bolts of the appropriate transport nut and pull it out of its holder.

· Remove the motor mounting bolts from the rear.

· Remove the motor mounting bolts from top.

Pull the motor together with the entire carriage drive unit away from the carriage.

Mount the carriage drive unit

Set the motor to Home1,2.
Move the rotor by about +16000steps (5 revolutions).
Fit the transport nut module into its mounting.
Fit the motor mounting to its carriage and drive in the bolts from top, the unit should be even a bit moveable.
Drive in the bolts from rear of the motor, the unit should be even a bit moveable
Drive in the bolts of the transport nut module.
Set the motor to Home1,2.
Check the optimal movement of the carriage from limiter to limiter with the service program, it should move smoothly, evenly and noiseless.
Tighten the motor mounting bolts and the transport nut mounting bolts correctly.
Check and /or adjust the hardware limits.

Watch video: D_II_Dismount_Y-Drive unit