Hobbymat Md65 Accessory Base An Update

摘要

As originally designed, alignment dowels and the securing stud were fitted to the accessory base rather than the steady to avoid swarf entering holes that may not always have been plugged when the base is not in use. Another thought was that repeatedly tightening and loosening a steel screw in the 5mm thickness of cast iron may wear the thread. On reflection, this should not cause a problem for many fittings and removals; after all, the majority of model aircraft compression ignition (diesel) engines use cast iron pistons running in steel cylinder liners. The only issue with the original arrangement that came to light in use was the possibility of opened chuck jaws catching the protruding stud if the base was inadvertently moved out from its stowage without being noticed. The first couple of occasions when this occurred came as a bit of a shock. No damage was done apart from slight bruising of the thread; easily remedied. The third time the bruising was more severe and stud replacement considered. After three times, however, a pattern could be seen developing that must be stopped! I suppose it was time to accept that the original design was flawed and introduce a modification.