CETAC Z-Drive Assembly Replacement Guide Manual Part Number 610144 Rev 1, 2012 CETAC Technologies, Printed in USA
Overview This guide describes the necessary steps to replace the Z-drive assembly on your autosampler. Do these instructions apply to my autosampler? These instructions apply to CETAC ASX-500 series autosamplers, including (but not limited to) the ASX-520, ASX-260, ASX-130 and XLR-8. The pictures in this guide show an ASX-520 autosampler. Your autosampler may look different, but the instructions apply to all autosamplers with Z-drives like the ones shown. How does the Z-drive work? The Z-drive is driven by a length of cable (line) which is made of PEEK tubing. A rotor on the back of the autosampler moves the cable, which slides the probe up and down on the Z-drive. A mounting block on the back of the autosampler pivots back and forth to allow free motion of the cable while preventing the cable from kinking. Tools Required You will need the following tools: Wire cutters, for trimming the black positioning flag. Philips screwdriver. 3/16 inch nut driver or small wrench. The Z-drive parts kit may contain additional parts, such as a guide plate, depending on the type of probe and on the autosampler application. You can remove thumbscrews with tools if necessary, but do not tighten them with anything other than your fingers. How should I care for the Z-drive? CAUTION Do not allow the cable to bend sharply. Avoid pushing up on the slider or pushing on the Z-drive cable. Do not tighten the thumbscrews or nuts with anything other than your fingers. Cleaning instructions and other maintenance information may be found in the Operator's Manual for your autosampler. 2
Replacing the Z-Drive Assembly WARNING Ensure the power cord is not connected before proceeding with installation. 1 Place the autosampler on a flat surface and turn the unit off. Figure 1. Front view of the autosampler. 2 Remove the two Kynar thumb screws from the Y-axis home block. Figure 2. View of Y-axis home block with Kynar thumbscrews. 3
Figure 3. Z-drive removed from arm assembly. 3 Remove the old Z-drive assembly. 1. Remove the PEEK or nylon line from the rotor by loosening thumbscrew on rotor (Figure 4). 2. Remove 2 thumbscrews from mounting block (Figure 5). 3. Pull the whole Z-drive assembly forward and off the autosampler arm. Figure 4. Removing block from back of autosampler. 4
Figure 5. Removing cable from rotor (nylon cable). 4 Remove new Z-drive assembly from the packaging. Sleeve (Protects Z-Drive Cable) Sample Probe Will Be Installed Here Z-Axis Slider Parts Kit (Varies) PEEK Nut Mounting Block Y-Axis Slider Z-Drive Cable Home flag Figure 6. Typical Z-drive assembly. 5
5 Slide the Z-drive assembly onto the autosampler arm. Figure 7. Sliding Z-drive on arm tube. 6 Slide the Z-drive assembly onto the Y-axis leadscrew nut (the black block which moves back and forth along the arm). Lift the bushings with your fingernails to get them over the edge of the leadscrew nut. Figure 8. Lifting the bushings over the edge of the leadscrew nut. 6
7 Secure the Y-axis slider to the Y-arm by tightening the thumbscrews. Figure 9. Tightening the thumbscrews. 8 Locate the two holes where the old mounting block had been installed. In the lower hole, install a screw. This screw will act as a stop for the new block as it swivels. Figure 10. Installing the screw. 7
9 In the upper hole, install the standoff. Use a 3/16 inch nut driver to secure the standoff. Figure 11. Screw and standoff after installation. 10 Place the new mounting block on the standoff. Install a truss head screw and Nylon washer. The screw should be snug, but the standoff should be able to rotate freely. Figure 12. Installing the mounting block. (Shown with cable for reference. You will install the cable in the next step.) 8
11 Feed the cable through the rear guide block, then tighten the PEEK nut to secure it (Figure 13). Figure 13. Tighten PEEK nut for cable casing adjustment. 12 Turn the rotor clockwise as far as it will go (Figure 14). Rotor Pin Stator Stop Figure 14. View of rotor with rotor pin at stator stop. 9
13 Slide the cable onto the rotor on the back of the autosampler (Figure 15). If needed, loosen the thumbscrew on the rotor to allow the cable to pass through the clamp. Figure 15. Sliding Z-drive cable into rotor groove. 14 Gently move the Z-axis slider until the gap between the slider and cap is approximately 3/32 (~2mm) (Figure 16). 3/32 (~2mm) Figure 16. View of gap between probe bracket and cap. 10
15 Hold the cable flat against the rotor and secure the cable by tightening thumbscrew on the rotor (Figure 17). Maintain the 3/32 (~2mm) gap while the rotor pin is making contact with the stator stop (full clockwise rotation of rotor). The thumbscrew should be as tight as possible using just your fingers. Figure 17. Securing cable to rotor. 16 Rotate the rotor back and forth to ensure that it moves freely. Ensure that the full width of the cable is under the clamp (Figure 18). Clamp Figure 18. Verifying cable movement and cable clamp 11
17 Center the Y-arm tube in the autosampler X-travel slot in order to properly adjust the drive cable (Figure 19 and Figure 20). This step applies to all models of ASX-500 series autosamplers. X-travel slot Figure 19. Arm centered for cable casing adjustment. Figure 20. Proper cable orientation. 12
18 Install a sample probe. 19 Turn the autosampler on, wait for it to initialize and move the probe to the "home" position, then turn the autosampler off. 20 Check that the probe is centered over the tube of the rinse station. Manually lower the probe by gently turning the rotor on the back of the autosampler. The probe should be centered in the tube of the rinse station. If the probe is not centered, move the Z-drive assembly to a convenient position and use wire cutters to trim off a narrow strip of the black positioning flag (Figure 21). If you trim off too much, replace the flag (extra flags are supplied with the Z-drive assembly). Repeat steps 19 and 20 until the probe is centered precisely over the rinse station. Figure 21. Adjusting the home position flag. 21 Turn on power and use your instrument control software to move the probe to several rack positions to make sure the probe is hitting positions correctly. 13