AstroOlly Posted October 13, 2020 Share Posted October 13, 2020 Well here is a story... maybe of interest for other owners of original EQ8 mounts...Last year in October my EQ8 developed a fault as in the DEC clutch would not hold at all, so I stripped it down to find this, it looks like it was a flaw in the alloy cast, it’s very light weight and almost seems like it’s plastic...?So after thinking for a while I contacted the UK skywatcher sealer and asked about how this could happen and if there was a replacement for it, they told me it’s was the first time they had seen such an issue and said the only option was to replace it, and it would take at least four months to arrive from China, so I was gutted...☹️So after a few hours on the Internet I found a company in Ireland who have made loads of upgraded Larry and upgrades for this mount including spring loaded worms, bit more importantly and upgraded solid brass clutch ring, great so I got in touch and ordered one at a cost of £110 ??, but I needed it so I went ahead. It was a new type of design that the company had patented, and only used one bolt to secure and was slightly different design, as it clamped with small lugs that gripped the shaft in such a way as not to cause any lateral movement of the shaft when engaging the clutch, which the OEM one did, this in turn would lower backlash, so this new one was quoted to reduce backlash by up to 90%....hmmmm I thought...Anyway it arrived and I fitted, and yes it was superb and after re adjusting the backlash, I found I could adjust much more out with this new clutch, that I could before...the old clutch design grips the shaft only using 25% of the ring, due to the three fixing bolts holding it in place, as with the new one only one bolt was used, so now 90% of the ring gripped all around the shaft...It really is a great design and well thought out..you can see the two lugs on opposite sides, these are the bits that grip the shaft, and as they are opposite each other and 90 degrees each side of the fastening bolt they put equal force on the shaft with no lateral movement....You can see the split in the ring at the bottom which is so it can adjust and grip, this gap closes up... so off i went imaging again with no issues...Now nearly 12 months later, guess what’s just turned up....two new clutch rings from China...?? and free of charge....these are the same as the original ones and so very light weight and no where near on the same quality level as the brass one I bought.... oh well I have spares now... ?? Stew 1 Quote Link to comment Share on other sites More sharing options...
AstronomyUkraine Posted October 13, 2020 Share Posted October 13, 2020 That's some serious metal fatigue. My guess is the clutch is made from powdered steel. Still for the price of an EQ8, you would think a bronze or a clutch made from solid steel would be used. 2 Quote Link to comment Share on other sites More sharing options...
AstronomyUkraine Posted October 13, 2020 Share Posted October 13, 2020 Posted by: @AstroOlly but never understood why the hole at the bottom, unless it was a flaw in the metal... It’s a perfect hole... dry odd..It's a definite weak point in the construction, but the clutch could have had a fracture in it from the factory, but waited until your warranty run out before breaking completely. 1 Quote Link to comment Share on other sites More sharing options...
MarkAR Posted October 13, 2020 Share Posted October 13, 2020 Posted by: @AstroOlly but never understood why the hole at the bottomThat looks like it's machined. Counter bored hole sideways, through to a threaded hole looks like a clamping collar. Quote Link to comment Share on other sites More sharing options...
MarkAR Posted October 13, 2020 Share Posted October 13, 2020 Got sidetracked before finishing my reply.Was going to say that its completely the wrong material for something that's fairly constantly going to be loosened and tightened and prone to fatigue. The lower odd hole looks like a fracture. Material looks possibly like it might be sintered aluminium and hasn't bonded. 1 Quote Link to comment Share on other sites More sharing options...
MarkAR Posted October 14, 2020 Share Posted October 14, 2020 Trouble with certain Chinese materials, you don't need to abuse them, only use them for something to break. Quote Link to comment Share on other sites More sharing options...
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