my cabbing machine...
by Eric Mitchell
...can grind, sand, polish and with the aid of a keyless chuck, carve and buff, a versatile homemade cabbing machine
A versatile homemade machine. The machine costs about 1/3 the cost of a commercial machine (or even less). If the cost of a machine has put you off cabbing I hope this brief description with pictures will show ho
w easy it is to make one. The essential part is the spindle, I got mine from Picador Engineering. When I refurbished it I forgot how deep cat litter trays are and the result made the machine a bit awkward to use. You can’t get a shallow tray so the only option was to raise the height of the spindle.
The spindle is a shaft, machined and threaded at its ends (to allow wheels to be secured) and mounted in plummer blocks.
Picture 1 Shows the motor, which is a continuously rated 230V A/C 1/4 hp motor. This is mounted on a small platform itself supported on two lengths of timber and bolted to a chipboard base. The base has a strip of timber fastened the rear edge to tilt it forwards. The bolts also secure two lengths of angle iron which carry the spindle. To the right of the motor is a piece of timber mounted vertically, this supports the back board.
Picture 2 shows the cat litter tray in place.
Picture 3 the backboard in place.
Picture 4 shows the spindle (with its drive belt) mounted on the angle irons. The drive belt runs in two pulleys, one on the motor and the other on the spindle. The ratio of the motor to spindle pulley is such that the shaft rotates at about 1800 rpm. Multigroove pulleys could be used to give different shaft speeds. However a quick and easy means of releasing and reapplying tension to the belt would be needed, otherwise repositioning the belt would be difficult.
Picture 5 shows a grinding wheel left and an expanding drum right (with a sanding belt in place).
A belt is necessary at all times as unrestrained expansion of the drum can damage it. At the right hand end of the shaft is the keyless chuck, only mounted when required.
Now fully assembled with the enclosures which prevent water spraying all over. Above the machine is the water container (Tesco) and the plastic tube, with tap (local home brew shop), to allow a steady water supply to either wheel. An ‘eclipse’ magnet is used to hold the tubes in place. A piece of sponge (hidden by the enclosure) both wipes the wheel and makes sure it is wet.
The sides of the expanding drum are recessed and the nut that holds it in place is cut so that it is flush with the drums outer surface. This allows discs to be mounted for sanding, polishing etc.
EW & JP Mitchell
Rough Rock, Cut Stones & Jewellery sold
in aid of the
(Reg. Charity 221124)