Dymo Tapewriter Drive Wheel

thingiverse

A replacement gear and drivewheel ratchet for a 1960's dymo tapewriter. These were made to the same design for many years, it's likely if yours looks like this it will fit! The gear had cracked, and the original steel+leather drive wheel had disintegrated. This part replaces both the gear and drivewheel, providing direct coupling between them. The gear has 15 teeth, as per the original - the text spacing comes out about 4mm. It's a bit closer than modern equivalents but looks very period (see photo). Usage: Used in combination with a slice of ID14 x OD22 mm silicone tubing as a tyre (which you might substitute for anything similar - even 3D-printed TPU, for example). A model of the tyre is included in case you need it. Center bore is D 3/16" (D4.8mm). It's D5mm in the model, intended to be drilled after printing for a clean accurate fit. You can reuse the old #5-40 (1/8") set screw (if you have a thread tap to match). I only had metric, so used a new M3x4mm. Anything from 3-5mm long will work fine. Make sure you do tap the D2.5mm hole! For consistent text spacing, you need to ensure the drivewheel runs freely with the pinchwheel and tape fitted, so the detent spring is able to work correctly. This does depend on the tyre material and dimensions used. If it's too tight, consider adjusting the diameter of the drivewheel (model is D14 mm) to reduce the pressure applied to the tape.