Right from initial assembly I have felt pretty uneasy about the fine pulley set screws in my 3XL. It wasn’t the screws that bothered me but the fine hex key required to tighten them. I was frightened of stripping the key in the hex socket and combined with this not being able to tighten it enough - resulting in it coming loose.
My modification is not original having noticed it on the Inventables forum some time back. The idea is to replace the original set screw with a Socket Head Screw and their suggestion was this
Very nice I thought especially with its inbuilt thread locker. Some would know from my earlier posts that I live in Australia and our range of many things including screws is somewhat limiting to what you folks in Europe and the US have available (probably to do in part with our much smaller population). I have not been able to find these screws or their equivalent here so I dashed off an order the McMaster-Carr after all their web page says they have no minimum quantities. The next day they cancelled my order with the following reason:
Due to the cost of complying with extensive US export regulations,
Can’t blame them I suppose but how extensive can the regulations be for a small packet of 25 screws?. Anyhow I obtained locally similar screws without the nylon insert and installed them with a dab of thread sealer. Now I have a little more confidence in the tightness of the pulley screws. A couple of images may be helpful.