A Sensitive Drilling Attachment

摘要

Having wondered for some time about buying a sensitive drilling attachment, I recently set to and made a unit using various items from "under the bench" - all of which "would come in handy one day".rnI found a 1/4in. capacity chuck of dubious origin, but which had a 1/4in. Whitworth female thread, a bearing of 24mm o/d - 9mm i/d - 7mm thick and also a tension spring approx 5mm diameter with an overall length of approx. 22mm including the end eyes. These three items determined the rest of the project.