Just got my olympus BHMJ from ebay (listed 200USD). It move smoothly but when inspected closely i realize inside ring which depress when tighten screw from outside to mount on pole is only partially available, i don't own any of these so not sure if it suppose to be this way? here is picture if anyone can advice?
Don't remove it (if working well), it provides a better grip for the clamping bolt without damaging the rod. I have systems with and without it and the working difference is clear, the maker put it for a good reason.
And do not force it without rod, unscrew the bolt few turns to maintain it relaxed.
Lee, your BHMJ inner ring appears to be quite correct. This part isn't really a ring--more like a quarter ring.
I have several BHMJ blocks, and have examined additional specimens that passed through my hands. Every one has been like yours, with a quarter ring. The sole exception is one of mine, which arrived lacking this part entirely. But my fabricator, Don Wilson, quickly and inexpensively made me a perfectly-functioning replacement, after measuring and copying a quarter-ring from one of my other BHMJ blocks. I found it easy to remove the quarter ring from this block for Don's inspection, and equally easy to put it back in place afterward (it's held by a single screw) and to install the custom-made replacement in my other BHMJ block.
ChrisR, if my experience is any guide, I doubt one can rotate this quarter ring. There is a screw holding it in place. If there were reason to rotate it--other than perhaps flipping it 180 degrees--one would need to drill an additional hole in the block for the holding screw.
Pau, if you would like a replacement quarter ring for your BHMJ block that is missing one, feel free to contact me. I can ask Don Wilson to make one for you. Just guessing, I suspect the cost would be about $60 USD for time and materials, plus shipping.
Pau, if you would like a replacement quarter ring for your BHMJ block that is missing one, feel free to contact me....
Thanks so much, but my only BHMJ has it and works like a charm with a custom made aluminium rod.
I was referring to other similar mounting systems found in lab supports, cheap chinese stereoscopes or my DIY camera holder in my vertical macro rig.
I'd like to add a question to this thread instead of starting a new one since it is kind of relevant to the topic.
What size are the threads for the bolt that is used to secure the focus block to the rod? My BHMJ focus block has three threaded holes. The top and bottom one are threaded 1/4"-20. These do not have that inner ring (locking collar) being discussed here. The centre hole does, but the thread is not 1/4"-20.
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