BLT27C Specifications and Instructions

Model BLT27C Translator

        The BLT27C has cantilevered flange supports with wraparound flange brackets (see drawing). A total of six locking screws (three for each flange) hold the flanges within the brackets. The advantage of this design is that these screws can be loosened, even while the translator is installed, and the actuator portion of the translator can be repositioned radially around the flange. This allows positioning of the BLT to clear things like ion guns and other equipment. Another feature of this translator is that the guide rods and actuation screw are set back from the flange to give maximum access to the flange bolts. Despite its modest price, the BLT27C will provide years of trouble-free service, especially if the simple maintenance is performed.

         As delivered, the screws are coated with baked-on molybdenum disulfide. This coating will degrade over time, due to moisture in the atmosphere. After bakeout, lightly relubricate the screws with the (provided) silicone-based molybdenum disulfide grease. Be especially careful not to use a hydrocarbon grease such as Felpro C100^TM unless you perodically clean the oxidized residue from all load-bearing surfaces.  The normal bakeout temperature is 150^oC, but higher temperatures can be used if needed. For bakeouts between 150^oC and 210^oC, increase the frequency and thoroughness of lubrication. All BLT ball bearings are lubricated with MoS₂ grease for low friction and long life. All parts are field replaceable. All translators are also available with long strokes, motor drives, linear encoders, tapped flanges and special heights.

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Maintenance Instructions:

        The BLT27C needs only minimal maintenance. The linear bearings used in Model BLT27C are self-lubricating and the guide rods need only be kept clean and free from dirt, dust and debris. The jacking screw and bearing do, however, need periodic lubrication. As delivered, the screws and ball bearings are coated with baked-on molybdenum disulfide. This coating will degrade over time, due to moisture in the atmosphere. After bake out, lightly re-lubricate the screws with the (provided) silicone-based molybdenum disulfide grease. Be especially careful not to use a hydrocarbon grease such as Felpro C100^TM unless you periodically clean the oxidized residue from all load-bearing surfaces. The normal bakeout temperature is 150^oC but higher temperatures can be used, if needed. For bakeouts between 150^oC and 210^oC, increase the frequency and thoroughness of lubrication.
 
To thoroughly re-lubricate the bearings while the translator is under vacuum: 

• First move the translator to its fully compressed position.
• Remove the bearing retainer flange on the lower bracket.
• Turn the knob counterclockwise to extract the bearings from the lower bracket.
• Work the factory-supplied grease into the bearing. Remember: a little goes a long way!
• Replace the bearing, retainer and screws.
• Do science.

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