Re: Nice discussions leading toward perfection...
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This is a nice forum (especially for us insomniacs) to discuss improvement and diagnostic ideas.? I'm sure all the other owners are busy using their mounts to get great images.? That's the "silent majority"!?? I had great results from my G11T the other night when shooting M81 and M51.? Of course those are less of a challenge for tracking since they are close to the NCP.? Still, I was shooting at FL of ~2850mm.? I felt that I really didn't need auto guiding, though I was using an OAG in case my polar alignment was not perfect.? My 300 sec exposures were perfect...stars were all round dots.?? That G11T has been souped up.? I put on a 1:2 ratio belt drive, and McLennan 25:1 gearbox, so it is operating as a? 50:1 gearbox providing double the torque.? And any variation in the gearbox or belt is cut in half too.???I shimmed the RA worm case by very thin brass shims, to try and get the center of the worm exactly centered on the ring gear center.? I also just installed a?pair of back to back Belleville washers (30mm OD for the large worm bearings of the Titan) at the screwcap end of the RA worm, do the worm is not going to shift during temperature changes.? I reduced the weight hanging to 1 pound on the East side RA cord.? And I changed from Superlube to CRC caliper grease with MolyD, graphite, and teflon on the RA worm and ring gear.?? The system is running very smoothly.? The load is a 14 inch C14EdgeHD (~62 lbs) the 0.7 FL reducer (~5 lbs) QHY168C camera (~4 lbs), nautilus filter wheel, Celestron big OAG, and a heavy 80 mm refractor on rails on the top.? And 82 lbs of counterweights.? The total motor current running sidereal was ~ 0.25 amps at 17 volts into a high torque motor.? It's driving a total weight on the RA of about 165 lbs...well balanced but for the 1 pound hanging weight.? Incredibly, I could still see M81 center in the camera image through opaque sky clouds.? It was enough to test the mount and get the camera imaging working.? Here is a picture of the rig and sky conditions before I shut it down.? Anyone sensible would have packed up earlier.?? As soon as you get your system working perfectly, it acts like a magnet for clouds.? Better than iodide cloud seeding!?? All the best, Michael On Mon, Apr 5, 2021, 12:34 AM alan137 <acfang137@...> wrote: My opinion is that you need just enough clearance to allow the bearing to tilt inside the block by a tiny bit.? Maybe about 0.001 - 0.002" clearance |
Michael Herman