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The DEC backlash I have is not exactly as what's showing in that video - my DEC axis can only move left-right, that is, if I hold the saddle plate and move it left-right; if I move the saddle plate forward-backward or up-down the DEC stays, nothing moves.?
However, I decide to follow that video and make the adjustments. With that screw backed off and the one with spring pushed in (till it stops), I can't turn the gear (too tight) but I can still move the DEC; from here I can adjust the 2 screws (per that video) to make the gear easily tuned by just 2 fingers, but the DEC backlash (if it is really a backlash) is still there.? Then I did a test, this time I pushed the spring screw little further in till the DEC 'backlash) disappears, and the gear became very tight and I can't make it turn at all, no matter how hard I push the other screw in (I thought I was going to damage the thread), I had to back off the spring screw (and adjust the other one) to make the gear turn; then the backlash reappears...
So, my case is that either I have a (seemingly) smooth turning DEC (gear) with a backlash, or I have no backlash but can't turn the gear... LOL
I'll go with the backlash for now :-) knowing all this is just dry-run, the moment of truth would be when I take it out tracking/guiding/imaging. Will post the result here.

Thanks again for all the good information here, really appreciated!!

Yue

On Wed, Dec 27, 2023 at 02:48 PM, <darkairmouse@...> wrote:

New to Losmandy - just received my first one today, an 811G and just doing some indoor tests after I assembled it.
I've noticed there seems to be quite a bit backlash in the DEC. I did tighten the clutch but still I can move the DEC by turning the counterweight shaft, and can even hear a sound when it moves, sounds like it is bouncing between gear teeth...
I understand this particular 'issue' has been reported probably too many times but still I'm a bit concerned - is this backlash normal, or I need to do some adjustments myself?

Yue,

Since you just received your mount, I'd recommend trying to use it first before making any adjustments. There will always be a little play in both axes. If it was set any tighter you could start stalling the motors. Try it in the field, see how it guides, and then see if you're satisfied. Redoing the worms takes some practice and I would not change anything until you find something functionally wrong. Chances are it was set well in the factory and will work as expected under the night's sky.

Good luck!

John
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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

Much like collimation on a reflector telescope, SLW adjustments should be something every owner should be comfortable with. Like Jim W. Said, being a new mount it should be pretty close to adjusted so the adjustments will likely be very small if at all. If one owns this mount for many years one will adjust the worm many times.?

my personal advice when adjusting either of the spring loaded worms is to take off the OTA and any weights. Ideally, like in the video, when you adjust the RA Spring Loaded Worm, remove the DEC axis (or make sure it is balanced and empty).

the last thing you want to experience is a worm gear chattering across the ring gear as the spring tension is reduced, thereby deforming your precision brass ring gear… forever. It isn’t rocket surgery, just watch the video, follow along, and go slow the first few times.?

On Wed, Dec 27, 2023 at 09:08 PM, Jim Waters wrote:

It should have been correctly adjusted during assembly.

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Jim W
Phoenix, AZ. USA

Losmandy G11G w/ L6, NINA 3.0 / ASTAP, ASI2600MC Pro, ASI533MM Pro,?Sky-Watcher Scopes, Canon L Lenses.

I’m sure it was just like mine. But then it was boxed and shipped. No telling how many times it was dropped hard in shipping. Scott made this video for a reason. I had the same thing when I got mine. The adjustment is simple.

Greg Morris

It should have been correctly adjusted during assembly.

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Jim W
Phoenix, AZ. USA

Losmandy G11G w/ L6, NINA 3.0 / ASTAP, ASI2600MC Pro, ASI533MM Pro,?Sky-Watcher Scopes, Canon L Lenses.

Adjust it.

Thank you both and glad to hear that is normal! I'll go find that post by Brian? :-)
I'll be imaging with this 811G whenever the skies are clear next time. and thanks for those PHD2 tips!

Yue

We got a very good explanation of this from Brian Valente maybe 18 months ago (I'm not sure).? Basically, you are feeling the effect of the spring-loaded worm.? It has some flexibility and is normal.

The other thing that will happen, when you are calibrating PHD2, is that the backlash will seem very large when calibrating, but actually, small corrections are made effectively.? Tell PHD2 to compensate for backlash in dec.? The effect of this particular mechanism seems to be that backlash seems to be large for large, sudden movements, but not for small ones.

I have a G11G and it has Dec backlash.? I have had it 9 months and have not adjusted anything.? I balance the scope so it is a bit camera heavy.? Sometimes, depending on where in the sky I am pointing at, after a dither it takes sometime to clear the backlash.? I think its a known issue and in gear box, not the worm.? Before calibrating PHD2 I move the Dec axis north.? After calibration I run the guiding assistant and it gives me a backlash of 1300ms or so.?

Hi there,
New to Losmandy - just received my first one today, an 811G and just doing some indoor tests after I assembled it.
I've noticed there seems to be quite a bit backlash in the DEC. I did tighten the clutch but still I can move the DEC by turning the counterweight shaft, and can even hear a sound when it moves, sounds like it is bouncing between gear teeth...
I understand this particular 'issue' has been reported probably too many times but still I'm a bit concerned - is this backlash normal, or I need to do some adjustments myself?


Thanks a bunch!
Yue

Merry Christmas to all and big thanks for all your efforts in making the Losmandy mounts the best!

Daniel

Happy Holidays and clear skies!

-Wayne

On Sat, Dec 23, 2023 at 08:20 PM, Paul Kanevsky wrote:

Happy Holidays and a Happy New Year, folks!

Hope you get to spend some quality time with your friends and family and many clear nights to enjoy the stars!

Thank you, Paul. And the same to you and the rest of the Losmandy community.

John
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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

A Blessed Christmas season everyone.

Joe

Thank you

Happy Holidays and a Happy New Year, folks!

Hope you get to spend some quality time with your friends and family and many clear nights to enjoy the stars!

Best Regards,

? ?-Paul

On Sat, Dec 23, 2023 at 04:19 PM, joe kuhl wrote:

So general consensus is it will be at the upper limit, but should be able to handle imaging at .6 and .75 arc seconds?? That's image scale of a 533mc at 1295mm and 1096mm with reducer.

Honestly, I'm thinking no, G11T is good but that's an awful big load of a scope, focal length wise if not moment arm wise.? Visual, yes, I think, but imaging I'm asking for trouble.

Joe,

My thinking would then be to look at other scopes with similar focal lengths that are not as long and heavy.? I also watched their introductory video, and this is a big jump in size compared to their older products. I agree you won't know how your mount performs with all that moment-arm factor until you try it.?

John
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Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, Sequence Generator Pro and PixInsight user

So general consensus is it will be at the upper limit, but should be able to handle imaging at .6 and .75 arc seconds?? That's image scale of a 533mc at 1295mm and 1096mm with reducer.

Honestly, I'm thinking no, G11T is good but that's an awful big load of a scope, focal length wise if not moment arm wise.? Visual, yes, I think, but imaging I'm asking for trouble.

Just me,? Joe

Hey George,?? The camera is an OSC, no filter wheel.? Just reducer spacers, OAG, camera.? What the spacing is I do not know at the moment.? A mini 12vdc computer on top of the scope where all the camera stuff is plugged into.? Simple set up.

Joe