Quite small motor (QS-Motor) for fischertechnik

thingiverse

A quite small (QS) motor for fischertechnik with a size of 30 x 30 x 20 mm and three-way plug connectors. Part list: * [DC motor 130](https://duckduckgo.com/?q=130+dc+motor&t=vivaldi&iax=images&ia=images), preferably in a 9V version, contacts slightly bent upwards, so that they make contact with the two connectors when inserted into the housing. * white plastic [worm gear 0.5 M 6x10 mm](https://de.aliexpress.com/w/wholesale-6-mm-10-mm-worm-gear.html?SearchText=6+mm+10+mm+worm+gear) with 2 mm hole, cut the last two windings of one side off with a sharp blade, preserving only the stem * two connectors made from [3x3x0.3 mm square tube brass profiles](https://modellbau-schoenwitz.de/de/Messingprofile-/-Bleche/Messing-Vierkantrohr/Messing-Vierkantrohr-30-x-30-x-03-x-500-mm). Use the printed back part as a stencil to mark the side and top hole positions, drill with a 2.4 mm HSS drill, cut off to 9 mm length. Works nicely with any 0.5 M gear, or with the minimotor U-gear (U-Getriebe 31068). Can work with the Hubgetriebe (37268), but it's a tight fit as the Hubgetriebe's gap is just 6mm, so any imbalance will lead to friction. Won't fit with the smaller gears (Achsgetriebe 31067, Schneckengetriebe fein 31069,and Schneckengetriebe grob 31066). Print both parts as provided without support, the main part has a custom support for the side grooves included. Design note: To make the 6 mm worm gear fit to the U-gear, the motor's center is not aligned with the ft-grid size of 15 mm, but shifted by 0.75 mm up, so it's not at 7,5 mm measured from the motor botttom, but at 8.25 mm. If the U-gear is connected from below, as shown in the images, it will fit as expected. If you connect it from above, though, the U-gear will be shifted by 1.5 mm upwards, so that motor and gear will not be aligned (see image #5).