For the gear train to rotate freely it was decided to use bearings. The bearings are ball races out of a hard drive and needed to be glued into the gears straight.

Super glue was used to attach the bearing into the gears and the shaft was used to keep them straight and aligned in the gears while gluing. First all the gears were already drilled out to 5mm (the same diameter as the shafts) so the shaft fitted into the gears tightly. The bearing holders which are round pieces of the clear plastic, cut about 3mm bigger than the bearing with a 13mm hole board in the center which was a snug fit for the bearings. The bearing were then pushed into these holders without glue and along with the required gears and spacers ( clear plastic with 5mm hole board in the center, to space gears) were assembled onto a 5mm shaft to keep them all aligned.



To keep the gears perpendicular to the shaft while gluing, a 5mm hole was drilled in a flat machined piece of wood, with the drill press. This gave a vertical hole that the shaft with all the gears and spacers were pushed onto, went into. Now the glue was places between the required gears and spacers, being careful not to glue the bearing or the shafts in, then they were pushed together onto the flat surface of the machined wood the shaft is pushed into. This ensured the gears are all perpendicular to the shaft, and that they would rotate without a wobble.

After 10min to let the superglue set, the shaft and bearing were removed from the gears and the original 5mm hole which kept the gears aligned, was drilled out to 6mm so only the bearings came into contact with the shaft, this means there is very little friction on the shaft. The bearings and shaft are now put back in and the bearing are glued in to prevent them coming off. Use the shaft again to keep the bearings straight while gluing into the gear.



It was important before the glue fully dry’s on the bearing to make sure when the gear is spun; the gear does not wobble sideways and is also centered. if it isn't, take out the bearings and try correcting the errors.

For the power gears, which are the first gears in the gear train, they can’t be mounted on ball races unless you have a 3mm thick bearing with a 12mm inside diameter. Small bronze bearing are made for this part. These were done on the lathe and had a 12mm inside diameter for the ratchet and were just over 3mm thick so it stopped the ratchet or gear scratching the clear plastic frame. the outside diameter was 18mm and was a press fit into the clear plastic frame.