Replacement temperature knob for a Tefal Superglide 60 Steam Iron FV3161

thingiverse

My 94-year-old neighbor, Stan, dropped by earlier this week with his iron in hand, seeking my help to fix it. His fascination with my new printer had grown since he first saw it meticulously extruding another layer. He wondered if my new gadget could assist him. It turned out his wife, Ellen, an 89-year-old firecracker, had been a bit too forceful with the knob, and it came loose in her hand (I should have phrased that better!). However, it wasn't entirely her fault. Tefal's decision to minimize the amount of plastic on the knob boss likely saved them production costs, but unfortunately, this made it prone to breakage. I decided not to replicate the original design, as it would still be vulnerable to the same weakness that had killed the previous one. Instead, I took the opportunity to strengthen the design by filling in unnecessary voids and adjusting the length of the shaft hole for a better grip on the spindle. With the knob now reinforced, I noticed another flaw: The second part attaching directly to the thermostat shaft was also poorly designed, with only the top third of the control knob's hole making contact. I couldn't leave it like that, so I created a new one, lengthening it to utilize 100% of the available mating face. I'd already attached this piece (white) to the iron when taking the pictures, but the yellow one shown in the cover photo is an earlier PLA prototype. After reassembling everything, it worked perfectly on the first try... until the iron reached a temperature high enough for... Iron! D'oh!!! PLA's low melting point makes it easy to print with, but it's also susceptible to heat. The thermostat shaft's high temperature caused the plastic to elongate instead of turning the shaft. As a two-week newbie in 3D printing (Yeah, I know; it shows!), I decided to try ABS next. After ordering a reel and some trial runs, I finally got my settings right. I tested it all the way up to the iron's maximum temperature, and it seems to withstand the heat. Ellen might be disappointed that I fixed it so quickly – now she has to finish off the pile of Stan's shirts!