Dorchester — Oct 11th 2016
We were delighted to welcome back John L’s friend Jenny who spoke to us last year about building a 3D printer under the auspices of U3A. This year she came armed with that printer and had persuaded her U3A friend and engineer Charles and his wife to bring his 3D printer from Rugby to join us. Their enthusiasm was infectious. Jenny ran through the building of her printer which clearly needed Charles’ engineering skills to make it functional. Inexpensive domestic 3D printers are not for the faint hearted and require patience and the desire to experiment. Essentially educational, Jenny’s machine has the print head move horizontally on the X & Y axis and the support table provides the vertical movement. The fourth ‘axis’ is the print head temperature. Charles’ machine is different, with three arms, each with one end connected to the print head above a fixed circular bed and the other ends hanging down from three vertical sliders positioned at 120 degrees round the bed. The whole three-axis movement of the head is controlled by the relative up and down movements of the three vertical sliders—very elegant to watch. Jenny’s original intention to use a Raspberry Pi to drive the printer proved impractical as the CAD software and output to the printers are written for Windows and require a PC intermediary. Jenny and Charles brought several samples of the items they had made using PLA (Polylactic Acid) filament feeding to the print head. These included a very effective filament drum holder Charles had made on his printer for Jenny’s, a desktop pen holder, and some little model robots (watch out Lego!). Although we saw the printers running there wasn’t time to get any output established. Jenny and Charles showed CAD software that you can use to design your own components, but there are also plenty of off-the-shelf CAD designs to make a wide range of objects. Jenny showed how to use her CAD software to design a case for a Raspberry Pi starting with four cylinders representing the four corners and developing it from there. A similar smaller shape hollows out the interior.
Jenny is now busy setting up a new larger capacity printer (200mm x 200 mm output table). She hopes to use this to build the one-piece body of a robot and plans to use a Raspberry Pi to drive it. It was fascinating, and we hope to see them here again.
After the break John gave a hands-on demonstration of recovering data with Time Machine with his external disc drive containing a Time Machine backup. He deleted a file, and making sure to empty the trash so the file was unrecoverable from his Mac. he opened Time Machine which displays a time line stack of Finder windows. By selecting a window from an earlier date the file he had just deleted was made available. Clicking on that file and selecting ‘recover’ brought it back to the Mac’s internal drive. On the right hand side of the Time Machine window there is a vertical timeline. Clicking on this shows a flag with the date and time, and where data is currently available.
Georgia wanted to know the best way to be able to connect remotely to her mother’s Mac. Mick recommended her to download the full “TeamViewer” app, and for her mother to download “TeamViewer Quick Support”.
