Posted by Grindstone Cowboy on 09/07/2022 17:12:38:
Or next best thing to an impact driver – put a well-fitting screwdriver in the slot and give it a sharp tap with a hammer. Sometimes that's enough to jar screws free.
Rob
+1 : Slotted screws are a pain in the rear end because it's important to use the right-sized screwdriver, Anything less than a blade that fits accurately into the slot, width, length and depth, risks chewing the screw-head so badly it has to be drilled out. A few things to try, maybe in combination:
- Build a dam around the head with modelling clay or bathroom sealant and flood the top of the screw with penetrating oil. Leave it for at least 24 hours and try the well-fitting screw-driver. Don't force it: there's a high-risk of mangling the slot or shearing the screw. If it doesn't move with moderate force, re-soak it, and repeat.
- Heat is good at breaking corroded and gummed up threads. Heat and cool the area several times with a blowlamp. Don't overdo the heat! If still tight after a few cycles, try penetrating oil again
- If still seriously stuck move to an impact driver or screw-extractor. Impact drivers force the blade into the slot whilst applying a powerful undo shock turn. Be careful not the break the casting! Screw-extractors have a left-hand thread that screws into a pilot hole drilled into the axis of the stuck screw: the harder it's turned, the tighter it grips except there is a risk it will strip the screw.
If the screw doesn't come out without fuss, I really don't recommend doing this just to fit a QCTP. At this stage I'd bet the farm a QCTP isn't needed!!! Later maybe, but it's not smart this early to get embroiled in a tricky screw-removal. Be aware the cross-slide is a brittle casting, not immensely strong, and the more brutal stuck-screw methods risk breaking it. They're hard to replace or repair, and without one the lathe is almost useless…
Dave