On Sun, Jun 20, 2021 at 01:47 PM, Chip Louie wrote:
Marc,
The original idea behind changing gearboxes was to eliminate the stock plastic gearbox uncorrectable periodic errors caused by the choice of internal gear ratios. There is no measurable hence observable advantage to increasing the mechanical advantage of the gearboxes on a properly adjusted mount.?
A properly adjusted Losmandy mount with the classic 2-piece straight drivetrain should never have zero backlash in a warm room or it will bind and lag as the mount acclimates to a colder environment. In Losmandy mounts with the classic drivetrain backlash shrinks the backlash as air temps fall. This is well known but poorly understood and has led to a zillion different people trying to invent or find ways to overcome a "problem" that is largely caused by not understanding how the mount reacts to its environment. To reliably resolve the changing backlash issue for most people the best solution now comes as standard equipment on all new Losmandy mounts namely the OPW Gen II spring loaded worm carriers.? Being spring loaded allows the worms to consistently maintain minimal backlash hot or cold which is just not possible with the classic 2-piece bearing mounts.? ?
If you need to power through lags or tight spots on the worm and worm gear you need to set your backlash correctly for these spots under the conditions which they occur.?
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Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astropheric Weather Forecast - South Pasadena, CA?
I agree with the clearance needed to account for thermal contraction with changes. There are areas on the transmission train that need to give like crumple zones. I'm still not sold on spring loading the worm meshing though. I need more time. . I'll get to that once I have sorted out my couplings between the gearbox and worm shaft.