Clutch Knobs vs. the Gearbox Release Levers

Andrew J

I have a question about when to use the Clutch Knobs vs. the Gearbox Release Levers. I currently have a Mach1 in my observatory and when balancing or moving the scope to different park positions I typically just use the Gearbox release levers rather then messing around with the clutch knobs. I have Arthritis in my hands, and getting the clutch knobs tightened without using an Allen wrench can be difficult. So I almost never use the clutches. However, I have read somewhere that I risk damaging the gears if I let the mount axis slip while releasing the Gearbox levers. I try to make sure I always have a firm hold on the scope before I release the gearbox levers, but I suppose there is always a little movement when the axis becomes free. I have never really fully understood when and why I would use the clutch knobs vs. the Gearbox release. The Gearbox release is obviously much easier and I don’t have to mess around with an Allen wrench. I am hoping some of the gurus here can provide some guidance on when to use one over the other when adjusting the position of an Axis.


I just put down a deposit for a 1100GTO-AEL mount and before I start using the new mount after it arrives I would like to better understand the intended purpose of Gearbox Release vs. the Clutch Knobs in order to minimize the risk of damaging the new mount. At some point I may send in my Mach1 to have it inspected just to make sure I have not damaged the gears over the years.


I also have a related question. How tight do the clutch knobs need to be in order for them to function properly? Given the limited strength in my hands, I tend to hand tighten them and then use and Allen wrench to give them another quarter turn. However, I have no idea if this is the “correct” way of tightening the clutches. Without needing to get out a torque wrench, is there a rule of thumb to follow when tighten the clutch knobs? Another reason I almost never used them on my Mach1 is that I didn’t want to have to worry about getting them tightened down correctly. I would think they should be loose enough so if there is ever a pier crash (hopefully never happens… again) that the mount would slip rather than keep pushing the OTA into the mount. After I tighten the clutch knobs I generally push against the OTA and see if I can get the clutches to move but still tight enough that they would not move without a fair bit of force. Once I get the clutches tightened, I then use the Gearbox release knobs to put it back in a known park position before unparking the mount.


Anyway, this is something that has always confused me so thought I would ask before I start using the new 1100GTO mount.


Thanks in advance for the useful feedback.


Clear Skies,

Andrew J

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