1. © Copyright 2014 by Lieven Persoons

January & February 2012

Photo gallery 3

At the end of january I made a third visit to my observatory in Verclause, together with Wouter, Karel and Martin. After studying the remaining problems for a few weeks together with Wouter we had a plan ready. We decided to replace pretty much all wheels that this dome is rich. We chose hard plastic wheels. These can bear bigger loads and have lower rolling resistance. As it turned out some of the original wheels were heavily damaged and even entirely deformed. I also changed the position of numerous wheels because their original factory placement caused them to rub and get damaged. To do this we had to make 10cm big holes in the base ring in order to get to some of the nuts and bolts holding the wheels. I also smoothened the edges where different parts of the dome joined. Before these often had some hard edges due to poor fit. As it turned out the most indispensable tool when working on this dome was an angled grinder. Another problem with this dome appeared that it sort of wobbles a bit, causing the gog rim to run off the gear driving the dome rotation. To solve this Wouter came up with the idea to make two guiding disks on the gear and also allowing it’s axle some axial movement in the gearbox. But I had to be careful because too much play could cause damage to the encoder on the other end of the axle. The problem of the motors stalling at low temperatures was solved by slightly heating the gearboxes. For this I used heating tracing for use on sanitary water tubes. As the tracing for the shutter motor was long enough i also ran it where the shutter wheels would run. This turned out very good because this keeps the tracks clear of snow. During all these works pretty much all equipment needed to be disconnected and lots of things needed to be disassembled. The only thing that could stay put was the telescope which was carefully covered with plastic film to avoid getting it covered with loads of fine fiberglass dust. With the help of Jacek Pala from scopedome I also managed to get the driver to work perfectly. The dome synchronisation is spot on now. Also polar alignment and goto calibration have been performed. Finally the dome is working properly. Only one thing is planned for the next time we visit; changing the oil in the gearboxes with one that has lower viscosity when temperatures are low. Finally I can start to enjoy the crisp and dark french skies.