2.3mm drill bit
For ‘self-tapping’ holes to suit the screwmounting turrets
When experimenting with the screwmount turrets, I was delighted to find that it’s possible to get them to ‘self-tap’ into PTFE board. By using a 2.3mm hole, you do not need the M2.5 hardware to secure the turret on the underside. Instead, the pliable PTFE shapes itself around the screwmount turret’s thread and this holds it in place. This is a 100% unofficial option! 🙂
However, I’ve tested it thoroughly, and the turrets are definitely secure – they do not come out even with a 1kg transformer suspended from an upside-down board overnight. There’s one huge benefit: you can add extra turrets to a board that’s already bolted into place in a chassis, because there’s no need to remove it to add fixing hardware. Just use the 2.3mm drill to make the hole. The PTFE swarf comes out in one strand with no mess. Then screw the turret into place. So it’s an ideal way to add extra components to a board.
Note: I have NOT tried this mounting technique with other types of board! The fibrous and laminated phenolic boards may work, but my feeling is that they are not as suitable for this approach as the solid PTFE. Where the PTFE shapes itself around the turret’s thread, I suspect these other types may splinter or break up. Not recommended.