Replacement temperature knob for a Tefal Superglide 60 Steam Iron FV3161

thingiverse

My neighbour, Stan - a sprightly 94 year old - popped in to see me earlier this week, bringing his iron to see if I could mend it. I'd shown him my new printer, and he was fascinated (as we all are when we first see a printer meticulously extruding another layer). He wondered if my new toy would be able to help. It seems his wife, Ellen - a mere whippersnapper of 89 - had been a little bit heavy handed with the knob, and it had come off in her hand (I could probably have phrased that a little better!). Turns out it wasn't her fault. Tefal had pared the amount of plastic on the boss down to the bare minimum - presumably to reduce production costs - and there was so little material there that it's a wonder it lasted as long as it did. I could have simply replicated the original. But this would have left it prone to the same weakness that killed the first one. So I took the opportunity to design something a little tougher. I filled in all the unnecessary voids, and tweaked the length of the shaft hole to improve the grip on the spindle. Now the knob was stronger, I could see a further flaw: The knob has a second part that attaches directly to the thermostat shaft and, once again, thanks to penny-pinching design, only the top third of the control knob's hole actually made contact with it - It would have been even less if I hadn't lengthened the knob boss. Well, I couldn't leave it like that, so I made a new one of those too. Only this one was lengthened appropriately to use 100% of the available mating face - I'd already fitted this piece (white) to the iron when I took the pictures, so the yellow one shown in the cover piccy is an earlier PLA one. I put it all back together, and was thrilled when it all worked absolutely perfectly, first time. ...Right up to the moment the iron got hot enough to... Iron! D'oh!!! PLA is, of course, a very low melting-point thermoplastic. It's part of the reason it's so easy to print with. But the heat on the iron's thermostat shaft is high enough to make the plastic... well... plastic! So instead of turning the shaft, it was just elongating the hole. I'm still a two-week noob with 3D printing (Yeah, I know; it shows!), but I fancied having a try with ABS. So a reel was swiftly ordered, and soon put to use. Boy, It's a tricky bugger to work with! But I persevered and, after 2 or 3 goes, finally managed to get my settings right. I've tested it all the way up to the iron's max temperature, and it seems to be able to stand the heat. I think Ellen was disappointed I fixed it so soon. Now she has to finish off the pile of Stan's shirts!