That's a disc coupler from Ruland.? I have one on my own mount on the Dec drive axis.? I've been trying to find a replacement for my own coupler, which has loosened up a lot (to the point of introducing a ton of backlash) and even after tightening the tiny, tiny disc screws may not remain tight.? I can find an almost-exact replacement on Ruland's website, but it doesn't have set screws but is rather a collar tightening model.? And it's priced at USD $108 for one.? I suspect that Losmandy may have had a custom-made model, or else the set screw version is no longer being made by Ruland.? ?I'm waiting (after more than 4 days) for Losmandy to return my call / voicemail to see what they can offer me.? The $50 Oldham coupler on their website does not appear to be long enough.? The Ruland disc coupler is about 24mm long and I have not found an Oldham coupler anywhere that is long enough to fit both the worm axis and the gearbox axis, and even the one on Losmandy's store website looks too short.? There are a couple of options I've identified but I still want to hear back from Losmandy in case they can offer the original Ruland coupler or at least guidance on the best replacement.

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-- Patrick Freeman

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