Re: OPW Adjustment Steps with Belleville Washer
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Hi Taylor, Some comments...I hope help. Once you assembled the OPW, and in doing that you squeezed the Belleville washer flat, and so the worm will stay compressed.?? If your OPW has a cover that you can leave off, so you can see the Oldham coupler, do that.? You ideally want to see how the Oldham coupler parts look when the drive is slewing.? ? There were 2 forms of OPW for the G11 (RA in the GM811): a)? Older long style (about $350?) has provision for the gearbox to bolt on.? This type requires a longer Oldham coupler (because the gearbox is further from the worm).? Prefer this type of you can get one, because the gearbox can be kept lined up with the worm ahead of time. b) Newer shorter style (~$150?). The gearbox does not attach to this one. Like the original design, the gearbox bolts to the mount.? This one takes the (original) short Oldham coupler.? Like the original drive design, the gearbox is fixed in position, so it's necessary to line up the? gearbox with the worm after the worm is positioned.?? If you have the older style OPW that has the Oldham coupler and gearbox attached, install those while the OPW is off the mount.? If you have the newer type, leave the gearbox off for now. Now attach the OPW and just lightly force the worm into the teeth of the ring gear.? The Losmandy instruction is to rotate the axis so you use the ring gear teeth to force the worm toward the gearbox.? If you have the Belleville washer in place, the worm isn't going to move at all.? Just a very light force of the worm toward the ring gear is all you need.? Too much pressure could cause "stall" messages on the Gemini, which senses motor current. Now allow the Oldham coupler ends to be loose.? You will want to slide the Oldham coupler in and out between the gearbox and the worm shaft, to center the gap between these.?? Now attach the gearbox and try to line up the shafts.? Gently lock down the gearbox...you may have to shift it's mounting once the Oldham is installed. Now attach the two metal ends of the Oldham coupler, so that the white center is tight between the metal ends, and tighten down the setscrews in the metal ends. Now attach the motor and run the drive and inspect the Oldham coupler as it rotates.? If the metal parts are not shifting in the plastic part, that's what you want...pure rotation.? If not, you might have to enlarge the gearbox mounting holes to shift it's position to try and line up these parts.? (The drive will work if the coupler shifts,? but you want lowest PE and absolutely no glitches in the drive.) Shifting the gearbox is a pain because the motor is attached to it.? This can be work taking it apart and putting it back. Once it's done, you don't mess with it.? It should stay in the right position, and work properly for (forever?)... (Or email me privately and call me if you need to...!) All the best, Michael On Fri, Jan 17, 2020, 2:06 PM taylor waber <taylorwab@...> wrote: My mount is a GM811 with a OPW, no springs. I added the Belleville washers as recommended by Michael H. but have a question about the steps for adjusting the worm.? |
Michael Herman