Fixes

This page contains some suggested steps for some of repairs / fixes for Shifter devices.

OLT Terms and Conditions apply, OLT takes no responsibility for instructions below or Customer repairs.

1. Testing the Encoder Readout

This procedure is used to ensure (X or Y) encoders are working well and is used when re-adjusting the wipers or re-installing the encoders.

1.Make sure Crystal Shifter software is open and connected to the device via the USB cable. Make sure power to the device is switched off.

2. Now slide with your hand relatively slowly the (X or Y) carriage across entire length and watch the software screen at the bottom left where encoder points are shown (encoder points are denoted with “[enc]”).

3. You want to ensure there are no sudden jumps in values or areas where values cannot be read by the software as you move the carriage.

4. If you see the value jumps unevenly, e.g. if most of the length encoder increases by 1[enc] over 1[mm] of distance then if you see e.g. 10[enc] increase over 1[mm] this probably means the encoder is not working well and needs replacement.

5. If you see value jumping for a very large amount or “Err” shown on the software where [enc] points are normally shown (bottom left of screen). This means the wiper is not touching the encoder at that point – wiper should be adjusted (see section on wiper adjustment on this page).

6. If you are not getting any readouts, your encoder could be broken or wiper is not touching the encoder. Press the encoder with your finger and whilst holding the finger down see if the software is recording [enc] points. If it does, this means wiper needs adjustment. If it does not then it is likely the encoder is broken.

7. You should repeat this process using different speed of movement (e.g. slow or faster) and in different directions (moving left or right) to ensure there are no movement-related changes in wiper pressure to the encoder.

2. Replacing Encoders

These steps can be used to replace (X or Y) encoder. You may need soldering equipment and skills for replacing the encoders. You will need double-sided tape.

  1. Switch device power off. Ensure USB cable is not connected to the PC.
  2. Take some photos of the encoder being replaced for reference. Not the position of the encoder and encoder connectors. You can use a Sharpie pen to mark position of the encoder on Shifter’s surface.
  3. Carefully using solder, applying a gentle and quick touch, unsolder the red-white-black wires connecting the encoder strip to Shifter’s electronics (PCB) boards. The encoder strip should not be connected to the red-white-black wires anymore after this step.
  4. Note that the encoder should be parallel to the device frame and is at specific location within the device so the wiper can touch the encoder strip. You must put the new encoder as close to the position of the old encoder as you can. The wiper must be able to touch the working area (middle) of encoder in order to produce computer signal. Take photos and/or make marks with Sharpie pen if necessary to help you with this positioning. On some devices, an edged line or ruler on the device frame can be used to aid positioning.
  5. Carefully peel off the encoder. You may need to slide the (X or Y) carriage across to aid removal of the encoder.
  6. You should not need to remove the carriage to peel off the encoder but if you do then just remove one side of the (thick) timing belt to avoid unnecessary re-assembly later. If you do plan to take the belt off: a) check the tension of the belt in question with hand so you can re-tighten the belt to the same tension back again, and b) if you do this then you are likely to need to perform steps-per-mm calibration for the axis affected by the belt at the end of the procedure.
  7. Now that the encoder is off, use isopropyl alcohol to remove adhesive residue where the encoder was. You may want to use a flat object, e.g. a metal ruler or a flat knife to help with this.
  8. Take the new encoder. Slide it below the carriages and rest it roughly where it should be positioned.
  9. The encoder will have a self-adhesive bottom. Now that encoder is below carriage, peel off just a bit of the protective tape from the bottom (back) of the encoder. Peel at the edge that is further away from encoder’s connector (ie peel at right-most position for X or closest to the device user for Y). Press this (far) side of the encoder onto the device base so it’s now stuck down. Make sure it is at the same position as the old encoder was. Use previously taken photos or markings if necessary. Use engravings on the device (if available) to help you with positioning.
  10. Now slowly peel more of encoder’s backing tape as you are sticking the encoder to the base. You may need to move (X or Y) carriage again to facilitate this process. If you find this difficult you can remove the carriage as outlined above but this is more complicated in the end and likely to be unnecessary.
  11. If your encoder did not have a leading wire then you need to re-solder it back to the red-white-black cables. Apply only a gentle touch in place, applying too much heat or for too long will melt the encoder. Make sure to use heat shrink on cables first.
  12. Take a small amount (approx 2cm) of an insulating table or a double sided tape and position it below the encoder connector. This is to ensure connector does not touch Shifter’s metal surface where the encoder strip’s pins are. The connector has open terminals at it’s bottom that could touch device’s metal surface and interfere with signals. So it is necessary to put an insulating tape between encoder connector and base. Make sure the entire ‘blue’ area of the encoder’s connector is covered as the open terminals can be further away from the encoder connector. Consult your photos or call OLT if in doubt.
  13. Now that the encoder is replaced, use “Testing the Encoder Readout” process described on this page to check if encoder is working properly.

3. Wiper Tension Adjustment

These steps can be used to adjust Wiper tension on encoders. Too much wiper tension can damage the encoder and too little tension will not provide sufficient pressure on encoder to generate readout in software. Device surfaces are not perfectly straight so wiper will be applying different amount of pressure along the encoder. For that reason you must test wiper is pressing the full length of the encoder by sliding the carriages left and right as described below. You will need to use “Testing the Encoder Readout” steps outlined above too.

1. Switch device power off but leave USB cable connected to the PC and start Crystal Shifter software.

2. Take some photos before you start work on device so you can get back to them later.

3. Feel with your hand tension on the X or Y belt (depending on which wiper you are adjusting). You will need to tighten the belt to a similar tension later on.

4. Take thick (timing) belt off the X or Y carriage (depending on which wiper you are adjusting). The belt does not need to come off fully, you can just undo one end so you can lift the carriage up and access the nut that is fixing the wiper below the carriage.

5. Lift the carriage up or lift it at angle

6. Loosen the nut below wiper (I suggest not take it out as there will be small plastic spacers below which may fall out if you take nut out so may be a bit trickier to put back). If you do take the nut completely please make sure you do not loose the plastic washers (there may be one or two). You will need to return these washers back before tightening the nut at the end of this exercise.

7. Take the smallest hex key provided by OLT (0.7mm) and turn wiper by a small amount, e.g. quarter or half turn.

8. Put the carriage back (but do not fix/tighten the thick timing belt back yet! It should still be loose.)

9. Use “Testing the Encoder Readout” procedure outlined above to check if the wiper is touching the entire length of the encoder. You do not wish too much pressure or too little pressure so make sure the encoder is ‘just’ touching at the entire length of encoder.

9. Once happy with encoder tighten the nut (don’t over do it though) and test pressure on entire length of encoder again. When tightening the nut it is advisable to hold the wiper with the nex key in place as by tightening the nut one can easily rotate the wiper and change it’s pressure on encoder.  

9. Now tighten the (X or Y) belt again to the same/similar tension as it was before.

10. Test entire length of encoder again.

11. Because (X or Y) belt were re-tensioned you will need to run steps-per-mm calibration for the axis where belt was disturbed. If you have at the same time replaced the encoder, then first make sure you have calibrated the encoder before doing the steps-per-mm calibration.