I bought a 6-frame radial extractor with manual drive from Dadant in 2011. The first day I used it, the lower wheel slipped from the central shaft when operated at high speed, causing all the frames to twist (since the upper wheel remained stationary), damaging some of the frames. This was caused by the fact that the two set-screws in the wheel were not sufficient to hold the wheel to the shaft. I subsequently filed a flat spot on the shaft and tightened the set-screws as tightly as possible. As a result, I have not had this problem again. This potential problem should have been corrected in the factory during design and construction.
The more significant problem I experienced with this extractor however was that one of the six feet in the lower extractor wheel that hold the weight of the frames was not aligned symmetrically with the other 5 feet. Its alignment was twisted by approximately 3/8 inch. This caused the associated frame to be slightly twisted radially, resulting in one side of the frame not having its honey fully extracted. The weight imbalance due to this un-extracted honey caused the extractor to frequently spin out of balance. I called Dadant about this to complain and they had me talk with the manager of their factory. The factory manager told me that this issue was related to the alignment of their welding jig and he made it clear that he considered realigning the jig to be too time-consuming a task for him to bother with. He did, however, send me a new lower wheel, which to my surprise also had one of the 6 feet misaligned, exactly the same as the original. I called the factory manager again and he insisted that this must not be a problem since they had sold these extractors for years and he had never received a complaint. Fortunately for me, I have a friend who is a professional welder. I took the lower wheel to him. He ground off the misaligned foot and re-welded it symmetrically. The extractor now works fine (except for needing to tilt it to empty it – which is another design flaw in my view). In summary, I cannot recommend buying this extractor. This extractor should have been sold without these simple design flaws and no beekeeper should be expected to re-weld his extractor in order for it to work correctly.