A while a go inventive Italian Kapper ‘SMAC’ posted that spent laser printer toner cartridges have some really useful components inside. My magenta cartridge failed the other day and, after the pain of paying HP for a replacement, I decided to forgo the recycling fee (£1) and see if I could make use of the innards. Sure enough the break down produced 3 neat helical gears. 1x 44/32 tooth, 1x 19 tooth, 1x 22 tooth. The larger 44/32 tooth gear will easily serve as a pan drive: all for a £1! The 19 tooth is a snug fit on a micro-servo shaft: The 22 tooth is a good fit on a ‘standard’ servo shaft: To reduce the height of the bigger gear I cut off the 32tooth flange (a bit of a shame because it would give a faster ratio but it had to go). The drive shaft (m3 bolt) needs a guide: a micro servo disc ‘arm’ is a perfect fit. I’m unsure how many hours of operation these gears are designed for, the plastic is very soft under the hacksaw so the ‘near enough is good enough’ mesh might cause rapid wear, the teeth are much finer than the KAPshop gears so the alignment is much more exacting… The pan gear guide is made up of 2 parts, the servo mount and the ‘Z’ plate to support the top of the pan axle. The ‘Z’ plate is 2 L sections overlapped, riveted, and cut to size: The driven gear and its spacers are fixed on the shaft with ‘nyloc’ nuts which saves weight and space over the lock-nut method I have used previously, a small refinement this rig will test out, if they slip I’ll go back to the double nut method, I can afford to trash these gears to find out. To get the extra offset centre of rotation to fit the EosM I used 30mm wide aluminum for the top frame, the offset centre is crucial to avoid overloading the tilt servo. I decided on a micro pan servo to keep the weight down and found 360 degree continuous rotation micro servos to be a tad rare. It is possible to hack a 90deg one but there is very little room in the case for my ‘knife & fork’ style soldering so I used a Feetech FS90R which does the job. The build was done with a ‘dummy’ servo while I waited for the 360 item to arrive from Germany. To get the most out of the bargain the rig fits both EosM and S95 cameras under clickPanPro control. This is tricky as the centre of balance of the 2 cameras are very different. I resorted to using the battery as counterweight to level things up. Despite using heavy gauge (2mm) aluminum strip the weight saving of the micro servo is noticeable, all up with the S95 this version of Tim’s rig weighs just 350g (150g sans camera). So now I wait for the post from the mainland before I can see what happens when I try to catch the light on the sensors from the skies. Will the gears strip their teeth? Am I expecting too much from them? How will they fare in their new thrashy environment?

B