Finally ordered a combi microwave. Wanted a reasonably large one so went for a Daewoo 28L which had good reviews and had all the functions I need. Price was excellent at £90 with CO-OP Electrical online (£100 with Amazon and even more expensive elsewhere). Arrived today so decided to try it right away with a cup of water. Noticed the turntabe was hesitating at some points as it was going round and there was a vibrating/friction sound. Upon investigation I found the turntable is rubbing against the back wall.
Its a large 32cm glass turntable and there is a small dimple in the sloping bevel of the back wall to accomodate its large size. From what I can see there is a very slight warp in the glass turntable which is causing it to rub on the sloping bevel. The warp is so slight you wouldn't even notice if it wasn't rubbing
What sort of engineer designs something that doesnt allow any room for a slight difference in manufacturing tolerances. It really would not make a difference at all if that large glass turntable was 5mm smaller. When I was a design engineer in the motor industry I would always allow for manufacturing tolerances... plus a bit more if it didn't affect the performance of the part. I would always get the customers approval for this (Honda, Rover, Jaguar, etc.) It saved a lot of problems for us and the customer and kept customer returns to a minimum.
Spoke to Daewoo and they said they would pass my advice on to their design department and also offered to send out a new glass turntable. At that point I had not told them that I thought the turntable was warped so I'm guessing they have had this problem before, although they say they haven't. Decided instead to contact CO-OP just in case the back wall is also out of tolerance and the replacement is arriving tomorrow by special delivery at no cost to myself. So well done the CO-OP for excellent customer service. (">
The turntable inside the oven:
The dimple to accomodate the large 32cm plate:
Its a large turntable anyway so 5mm less would not make a difference to the performance or usability of the oven: