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souls33k3r

Lakeside focusing issue

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Hi there, 

I've been having issues after issues tonight with various things but one thing which is bugging me is the auto focusing routine. Screenshot_20190215-213354.thumb.jpg.09b9df7e45473d873ea010cc89741328.jpg

As you can see, the HFR value remains zero and some times it would jump up and down like a zig zag come up with weird value or starts low HFR value and then goes up but in the end it throws an error message (will see if I can get a screenshot of that later). 

Any ideas? It's getting super frustrating. 

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Can you see the focuser moving, check those little grub screws haven't come loose.

Dave

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And then if I start somewhat closer to the focus point, I get this. 

received_1165284067014726.thumb.png.95a40bd838fb238a33558ca6ce4d9b25.png

Please help. 

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Just now, Davey-T said:

Can you see the focuser moving, check those little grub screws haven't come loose.

Dave

Cheers Dave, the focuser is indeed moving. Let me go out and check the grub screws. Give me 5 min and I'll report back. 

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Have you got your backlash set high enough ..  that can cause the flat spot on the way in

Dave

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And also the HFR tolerance warning you are getting..   something like 250 or 300 might be enough by the look of the graph

Edited by Laurin Dave

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Ok I've checked and all the screws are tight. 

Backlash compensation is set to 100, should I make that higher? 

HFR tolerance? 

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2 minutes ago, souls33k3r said:

The weird thing is, it was all working fine last night. 

Sounds familiar :grin:

Dave

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I'd set it to 300 and see what happens ..  the graph shows it moving in 200 with no effect on focus so it needs to be higher than that.  Was it doing that flat bit consistently. 

 

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I've set it to 300 and IN compensating direction and still not any better unfortunately

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Its got to be something come loose.

Mounting bracket - grub screw onto focuser shaft - something in the focuser - focuser to scope mounting ???

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I've literally checked everything and all is tight and made sure all gets even more tighter. 

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1 minute ago, Laurin Dave said:

No other ideas I'm afraid..  hope you get it sorted 

Dave

 

Cheers matey :(

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IMG_20190215_231313.thumb.jpg.dd1d87a56e5c1c21b01b38d7f7ac3b45.jpgI really don't know what to make of this. It's like the focuser doesn't move in between the focus runs but when I move the focuser to say 500 steps (manually), it moves. Now all I'm getting is a straight'ish line between HFR 5.7 AND 5.9

Edited by souls33k3r

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Yes, the horizontal steps at the start of the auto-focus and the validation frame being way out are indicative of severe backlash problems. Can you move the manual focus knob on the other end of the focus shaft. It should just move a small amount in either direction like 2 degrees which is the normal mechanical backlash. If it's way more than this then that's your problem. Perhaps the screws that mount the focuser shaft to the scope body are loose though I'd have thought that would have been noticeable. The other thing is one of the gears in the lakeside reduction drive may have come loose from its shaft. It'll mean taking it off the scope and dismantling it though I can't think what else to suggest. My lakeside backlash on two rack and pinion scopes is just 30.

Edited by symmetal
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2 minutes ago, symmetal said:

Yes, the horizontal steps at the start of the auto-focus and the validation frame being way out are indicative of severe backlash problems. Can you move the manual focus knob on the other end of the focus shaft. It should just move a small amount in either direction like 2 degrees which is the normal mechanical backlash. If it's way more than this then that's your problem. Perhaps the screws that mount the focuser shaft to the scope body are loose though I'd have thought that would have been noticeable. The other thing is one of the gears in the lakeside reduction drive may have come loose from its shaft. It'll mean taking it off the scope and dismantling it though I can't think what else to suggest.

Cheers mate, I'm going to bring the scope in now and inspect and then possibly take off the focuser and put it back again and see how it behaves. Clutching straws here really. :(

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If it turns out to be the motor I can stick you one in the post, be quicker than ordering one especially from Ian as he's just gone on holiday.

Dave

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If it's the lakeside motor which has come loose from its gearing shaft it will still feel good and tight when you try and move the manual focus. I don't know how they are fixed to the gearbox shafts but if its grub screws that may be the problem.

Have you re-seated the ribbon cable from the lakeside controller to the motor if you're using that. One of the contacts may have gone high resistance causing the motor to stall.

Alan

Edited by symmetal
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Ok so the fine focus known I can turn about a quarter of it. The coarse knob(?) I can move about 2 degrees, ermmm slightly more I guess more like 12 o clock to half 12.

10 minutes ago, Davey-T said:

If it turns out to be the motor I can stick you one in the post, be quicker than ordering one especially from Ian as he's just gone on holiday.

Dave

Cheers mate, you're too kind. I'll contact Ian in the first instance if it is the focuser because when you pay good money towards it, you expect it to work :)

9 minutes ago, symmetal said:

If it's the lakeside motor which has come loose from its gearing shaft it will still feel good and tight when you try and move the manual focus. I don't know how they are fixed to the gearbox shafts but if its grub screws that may be the problem.

Have you re-seated the ribbon cable from the lakeside controller to the motor if you're using that. One of the contacts may have gone high resistance causing the motor to stall.

Alan

I'm using Pegasus Ultimate Box as the control box. 

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Sorry the 2 degrees or so movement was with the fine focus. My course knob doesn't move at all. Your coarse movement does indicate something is loose somewhere, though that isn't enough to account for your severe backlash problem. Ah! you use a Pegasus. Does the Pegasus have a D9 connector like the lakeside motor end which is better than the IDC connector on the lakeside controller.

Alan 

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9 minutes ago, souls33k3r said:

Cheers mate, you're too kind. I'll contact Ian in the first instance if it is the focuser because when you pay good money towards it, you expect it to work

He'll supply a replacement no problem just thinking about keeping you going in the meantime.

Dave

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Dave, I know I can always count on you mate, you're too kind and I sincerely do appreciate your offer. I mean it from the bottom of my heart. 

OK I've take the focuser apart and noticed that the coupler that connect to the scope focus spindle was rattling a bit. So tightened it now. Shame I won't be able to test this under the stars right now since I've brought all of my gear in now. 

IMG_20190215_234559.thumb.jpg.2bef63ebd67bdd34a4ee6c2e519c6ed2.jpg

I'll put it all back on and then try moving the fine and course focus knob and see if it moves. 

Edited by souls33k3r
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You should be able to test it indoors. With your original backlash setting just tell it to focus out by 100 or so and watch the fine focus knob. It should show a small movement in the in direction at the end of its outward travel which means its taken up the backlash OK. :smile:

Alan

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