B&K REF 20 volume knob

thingiverse

This replacement volume control unit is intended for use with B&K REF 20 A/V preamplifiers that need a reliable and sturdy knob. I personally required a new one because my original became loose over time, and initially believed the set screws had worn down to a point of being nearly unusable. However, after trying different Allen wrench sizes, it was discovered that none were sufficient due to using the wrong type, in this case, 1/16". With a suitable wrench acquired, further tinkering led me to fabricate an entirely new volume knob - purely for educational purposes. Key materials and tools required can be obtained via Amazon: * Brass Inserts for knife threads, featuring #6-32 internal threading with 0.375" in length (http://amzn.com/B0026GUEN4) * Plain Finish 18-8 Stainless Steel Set Screw (http://amzn.to/3u7xXb9) * Set of miniature Allen wrenches available from (http://amzn.to/38U2kOZ) Now let's proceed to the guidelines and instructions: ### Printing Details A standard set of parameters was utilized while printing the volume control knob with 0.2mm in layer height, normal shells speed and fill level set at 30%. The next steps involved mounting a new brass insert for future applications. * Screw in a brass #6-32 insert carefully by hand or using an object of adequate strength to secure the new threaded base into the printed knob with a high torque setting screw driver. * I opted not to utilize my print bed since I do not want any accidental scratch or scrape mark from heated glue. A heatbed would be helpful for making installation easier as glue stick will come up in place while inserting screws by this procedure but at least the plastic may stay firm. However, when I didn't test heating then screw in process with pre-applied adhesive (for sticking base knob securely together), that's my personal recommendation and precaution of protecting my equipment glass - not everyone must have that safety advice! Screw set-screws to tighten or loosen in an A/V device's face plate, just as required for a functional operation by making adjustments at your own pace. In case if there are issues during screw-in operations like I previously had trouble inserting inserts into metal housing because I am a beginner to using 3D printed components then try applying heat or other non-scratching materials that would reduce slipping while doing the job which results in successful print bed setup