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AZ goto mount - diy way to fix wobbles?


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My SW 130p is attached to its plastic (I know, right?) AZ goto mount by a small (dovetail) clamp and has the worse case of wobbles ive seen in a small newt. does anyone have any ideas as to how i can make it more stable?

:D

Advance thank you's, Aenima....

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Okay just realised how the above comes across. I dont mean to sound unappreciative of my scopes functions, but when i first got it for xmas i didnt know what any of the specs really meant - like focal length, fast/slow, eq mounts/az goto mounts etc. ~Now these things have clarified a little and i know astronomy is something i love, i need to adapt things accordingly. This means compromising in ways only experienced observers would know anything about. So far the people here have been extremely helpful and kind, but i feel i sounded a bit snotty in my last query thread hence this additional post.

I dont know if wobbles are just a thing with all AZ goto's or whether anyone else has remedied the problem, but i was thinking along the lines of duct tape or adding weight....

Anyone know?

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I used to have an Nexstar 102 STL and It was a little wobbly. I take it that i f you knock the scope it takes a few seconds, perhaps 3 0r 4 before everything settles down again? I learned to live with it for the few months I had the scope if thats what you mean. I have heard others talk about hanging sand bags underneath to stablise them.

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Just so you know, I slightly over tightened my tripod leg and completely snapped the fixing, luckily I managed to fix it easily using jubilee clips but I was lucky in the way that is snapped off. See pic. I also have the 130p on a Goto mount and because I only slightly over tightened the screw I thought I would give all on the legs the same treatment.

I just don't want you go add to much weight to your tripod only yo see it snap.

You might also want to so what I did just to add strength to your tripod as the last thing you want is for it to fall over when it snaps.

Regards

Jon

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Cheers, I was considering the extra weight but hadnt seen any one else use that method so was reluctant to just dump something heavy on and hope for the best. But it seems others have had similar ideas and were successful. Ta jon, the legs not as strong as they look, no? Your repair job looks great, did you mean it now holds steadier due to your diy work on the tripod?

Thanks ppl 4 the advice. I am starting to realise the limits of the AZ goto, despite rave reviews in magazines. What about the same kind of scope and budget but with a german equatorial? the basic ones? Are they simply too cheap or do the EQ's hold the scope better?

thnx -- Aenima

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A few things you could try

Don't extend the tripod legs fully, probably not more than half way which will make it a little more stable.

You might want to check you've balanced the optical tube properly, to do this attach your finder and the EP you will use most of the time, then carefully find the balance point using something like a pencil and hard surface, supporting the scope to make sure it doesn't roll off the side.

Mark this point on the tube with a bit of low tack tape (maybe masking tape) then when you attach it to the dovetail you can keep that marked point central.

And obviously make sure the surface you've placed the scope on is solid, I realised my decking was springier in some places than others.

If you find the view wobbles too much while you're observing you could experiment with turning off the tracking for short periods and just watching the objects glide gracefully from one side of the EP to the other (I find it to be strangely relaxing, in the end I switched to a manual AZ mount). Obviously you have to recenter manually and it's best left on when you have guests at the EP. You'd want to check your scopes manual to find out how to do this.

Hope some of that helps

Tyr

Edited by Tyr
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A few things you could try

Don't extend the tripod legs fully, probably not more than half way which will make it a little more stable.

You might want to check you've balanced the optical tube properly, to do this attach your finder and the EP you will use most of the time, then carefully find the balance point using something like a pencil and hard surface, supporting the scope to make sure it doesn't roll off the side.

Mark this point on the tube with a bit of low tack tape (maybe masking tape) then when you attach it to the dovetail you can keep that marked point central.

And obviously make sure the surface you've placed the scope on is solid, I realised my decking was springier in some places than others.

If you find the view wobbles too much while you're observing you could experiment with turning off the tracking for short periods and just watching the objects glide gracefully from one side of the EP to the other (I find it to be strangely relaxing, in the end I switched to a manual AZ mount). Obviously you have to recenter manually and it's best left on when you have guests at the EP. You'd want to check your scopes manual to find out how to do this.

Hope some of that helps

Tyr

~Yes, thanks tyr and everyone, some useful ideas. I placed small rubber coated womens aerobic weights on the tray and noticed an instant improvement without fear of overloading. But something i wasnt sure on was balancing the optical tube. I assume the two/three inch dovetail is already placed centrally otherwise i really dont know how to properly balance it. I cant picture the thing with the pencil very well, how do you work out the balance for sure?

Thank you, ppl ..

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~Yes, thanks tyr and everyone, some useful ideas. I placed small rubber coated womens aerobic weights on the tray and noticed an instant improvement without fear of overloading. But something i wasnt sure on was balancing the optical tube. I assume the two/three inch dovetail is already placed centrally otherwise i really dont know how to properly balance it. I cant picture the thing with the pencil very well, how do you work out the balance for sure?

Thank you, ppl ..

The pencil thing is taking your tube in to the kitchen and placing a pencil on the work top and then place the telescope tube on the pencil and try to get it so it sits in the pencil without touching the work top, when it's balancing you mark the tube with a piece of tape where the pencil is, that is the balance point, now mount your scope into the tripod so the tape sits in the centre of the dovetail joint of the tripod. (when balancing the tube, be sure the finder scope is attached too)

Hope that helps, if not, let me know and I will post a pic.

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This works for me.

Accessory tray lowered by 10 cm, plus 17AH battery placed on tray (doubles as stabilising weight and power supply)

All screws tightened up

Never extend legs by more than 21cm.

Inject "Superglue" into all joints you don't need to move.

With this "wobble" is cut to less than 2 seconds, even at mags of 150+

The mount and tripod can still be dissassembled for travel.

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~Yes, thanks tyr and everyone, some useful ideas. I placed small rubber coated womens aerobic weights on the tray and noticed an instant improvement without fear of overloading. But something i wasnt sure on was balancing the optical tube. I assume the two/three inch dovetail is already placed centrally otherwise i really dont know how to properly balance it. I cant picture the thing with the pencil very well, how do you work out the balance for sure?

Thank you, ppl ..

Apologies Aenima,

I've just realised I'd written "attach it to the dovetail" which makes no sense, as you say the dovetail is attached to the OTA already. I should have written when you attach the OTA to the mount using the dovetail clamp as jon1000 describes.

I would expect the balance point will be somewhere along the length of the OTA where the dovetail is.

Tyr

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Another thing to do is set your slew controls to a slower speed once you are on target unless you are using the GoTo and it's tracking of course in which case what I just said is moot. (I don't use my GoTo, just the slew controls, you can tell.)

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ah, yeah the pencil thing would, i assumed, only work if the attached mount is well placed to begin with. thanks i will give it a go. Also the lower tripod is a convenient idea as i was hoping to use it at lower positions due to using a chair rather than bending my back for too long at the EP. Using couple of rubber coated hand held weights for womens aerobics on the a-tray did loads to stabilise the whole thing but now i notice just how much the thin spider holding the secondary is responsible for majority of remaining wobble, dunno how to reinforce without affecting light passing through and even harder to collimate (which is already an issue!) but the wobble is much better thanks to the above ideas and advice.

Ever grateful, Aenima.

p.s i have so far only used the goto handset for manual slewing too. Still learning the whole set up thing and also finding objects easier than i thought when i first thought about the need for computer aided guidance. Now i think an eq mount would have been better, but you live and learn (and also spend huge money in process!)

Edited by Aenima
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