Desperately need help/advice w/broken new scope

[Mai Ai Bing]

Got my new LUNT solarscope doublestack today.

However, to my horror it had "snapped" between the lens and the focuser during transport. So it came in three parts: lens, feather focuser and diagonal (see pictures).

There's only three tiny, tiny screws holding the diagonal to the scope itself. One had simple "fallen" out and was lying in the plastic wrapping, so my guess is that is was not properly assembled from LUNT and the two other screws could not hold it together during the transportation stress.

Anyway, I assembled the lens with the focuser using the three screws - all looked and seemed well.

BUT:

1) the focusser is so loose that it slides directly forth and back into and out of the scope. So it does not hold focus when looking "up". Feather focus or not - that has to be a mistake??

2) I can for the life of me not get any proper focus. I am a newbie, so it could be user error. But it could also be I made a mistake putting it together?

Have an automated setup - so the scope slews correctly into position. There's no problem "finding" the sun.

Whats's up? Have I assembled the focusser wrongly? It is just completely broken and needs to go back? There where no other parts lying around and everything seems and looks nice - its just not working.

Should add that the seeing was not the greatest in that it was afternoon and the sun was over an urban district. But I should still see something - right?

Thanks for any advice!

 

 

 

Edited November 11, 2020 by Mai Ai Bing

[Nigella Bryant]

If it's new I would get in touch with the supplier and ask for a replacement. Shouldn't have arrived like that. 

[Mai Ai Bing]

3 minutes ago, Nigella Bryant said:

If it's new I would get in touch with the supplier and ask for a replacement. Shouldn't have arrived like that. 

Will maybe be next step. But it was sent from the US to the Middle East - so I'd rather avoid that unless it's actually broken. Seems a lot of fuss for just re-mounting one little screw. But what do I know?

Edited November 11, 2020 by Mai Ai Bing

[Nigella Bryant]

I had to adjust the focuser on mine but it is eight years old. The focuser kept slipping which sounds like your problem. I did upload pics of the focuser on SGL. However mine is the ordinary crayford focuser. 

Focus shift on lunt 60mm Crayford.

By Nigella Bryant, June 12 in Discussions - Scopes / Whole setups

Edited November 11, 2020 by Nigella Bryant

[dweller25]

I think the three Allen head screws at the rear of the scope have come loose - these secure the feathertouch to the OTA

Just slightly undo the three screws to allow you to put the FT back in place and then tighten them up equally - not too much force though 👍

You may then need an extension tube after the focuser to achieve focus.

The FT slipping just needs adjusting.

Edited November 11, 2020 by dweller25

[Mai Ai Bing]

1 minute ago, dweller25 said:

I think The three Allen head screws at the rear of the scope secure the feathertouch to the OTA

Just slightly undo the three screws to allow you to put the FT back in place and then tighten them up equally - not too much force though 👍

Thanks. I did that. And it seemed that everything should be fine afterwards (I did use some - but not excessive - force. Just "tight"). Not sure why the focusser is running wild though.

[Mai Ai Bing]

11 minutes ago, Nigella Bryant said:

I had to adjust the focuser on mine but it is eight years old. The focuser kept slipping which sounds like your problem. I did upload pics of the focuser on SGL. However mine is the ordinary crayford focuser. 

Focus shift on lunt 60mm Crayford.

By Nigella Bryant, June 12 in Discussions - Scopes / Whole setups

 

 

Thanks for the pictures. What made your's slip? Is there something I can/should look for? Mine is super loose - like no hold at all. The unit seemed fine (unharmed) as I put it back onto the scope.

[dweller25]

I edited my post whilst you were typing....

You may need an extension tube to reach focus

The slipping FT should have an adjustment screw to allow to increase friction on the drawtube.

Edited November 11, 2020 by dweller25

[Mai Ai Bing]

11 minutes ago, dweller25 said:

You may then need an extension tube after the focuser to achieve focus.

The FT slipping just needs adjusting.

1) I'll see if I can get an extension tube and test it. Can it be my eyes needs the extension to focus? I am using the LUNT zoom, and it should fit nicely to this pre-configured package by LUNT scope/focusser/diagonal/eyepiece.

2) looked to see how to adjust the focusser play/slip (or anything), but could not see anything available to screw or tighten. Where do I look to do that?

(Sorry for all the questions, but I really hope to find a solution with the help of people here at the lounge)

 

[dweller25]

1. Reassemble the scope with the FT and the diagonal and point it at the Sun, then rack the FT all the way out, then loosen the eyepiece and slowly move that out of the diagonal whilst looking through it. If the Sun starts to get sharper you definitely need an extension tube.

2. There should be a tension screw that you can adjust - also your locking screw seems to be missing - it may have come loose in the packaging ? 
 

If in doubt contact starlight instruments for guidance

 

Edited November 11, 2020 by dweller25

[Peter Drew]

It sounds to me that the telescope has been subject to vibration somewhere during its transit which has loosened the focuser attachment and its motion adjustment.  There is a fine line between proper action and slippage on a Crayford type focuser regardless of the make or cost and correct adjustment is essential.  There will be a facility for adjustment somewhere on the body, if in doubt contact Starlight for the information. You shouldn't use the drawtube locking screw to stop the unit slipping, this could cause premature wear.     🙂

[Rusted]

The tiny screws are there to lock the focuser securely in place after it has been screwed into its main tube adapter.
If you didn't have these screws tightened gently, the focuser would unscrew if you rotated it anticlockwise.

FF focusers are designed to rotate smoothly in either direction.
All FF focusers have dedicated main tube adapters to allow this rotation by design.

Starlight Instruments use highly skilled staff to set up the degree of friction on the drawtube.
As Peter says, contact Lunt for further advice. Or, email Starlight Instruments for specific advice.
They are very customer friendly in my own experience.

 

 

[Nigella Bryant]

You shouldn't need to use the locking screw to keep the drawtube from slipping. As said, that's just to lock the drawtube in place when focussed if using heavy cameras, etc. You may need to take the focuser apart as I had to. In my crayford focuser the screws on the inner plate had worked loose and needed tightening but this was after eight years of use so not sure if this could be your reason. Only way to see is to disassemble the focuser. I'm not saying you should do that as it may invalidate any warranty if messed with.

[Rusted]

Sorry Nigella, but I was specifically advised NOT to dismantle my first FF by Starlight.

There is a procedure for getting the friction just right.

Starlight will be happy to advise by email.

Edited November 11, 2020 by Rusted

[Nigella Bryant]

1 minute ago, Rusted said:

Sorry Nigella, but I was specifically advised NOT to dismantle my first FF by Starlight.

There is a procedure for getting the friction just right.

Starlight will be happy to advise by email.

No worries Rusted, not offended, I was only saying what I had to do with an eight year old Lunt focuser.

[Mai Ai Bing]

1 hour ago, dweller25 said:

1. Reassemble the scope with the FT and the diagonal and point it at the Sun, then rack the FT all the way out, then loosen the eyepiece and slowly move that out of the diagonal whilst looking through it. If the Sun starts to get sharper you definitely need an extension tube.

2. There should be a tension screw that you can adjust - also your locking screw seems to be missing - it may have come loose in the packaging ? 
 

If in doubt contact starlight instruments for guidance

 

1 mio. thanks for the picture. Yes - there is a "locking" screw in the package. Had no idea what it was there for. One step ahead!

[Mai Ai Bing]

2 hours ago, Peter Drew said:

It sounds to me that the telescope has been subject to vibration somewhere during its transit which has loosened the focuser attachment and its motion adjustment.  There is a fine line between proper action and slippage on a Crayford type focuser regardless of the make or cost and correct adjustment is essential.  There will be a facility for adjustment somewhere on the body, if in doubt contact Starlight for the information. You shouldn't use the drawtube locking screw to stop the unit slipping, this could cause premature wear.     🙂

Thanks for the warning. I can see the smaller tension screw on the photo in the middle of the focuser beside the long locking screw (I guess that must be it).

Edited November 11, 2020 by Mai Ai Bing

[Mai Ai Bing]

28 minutes ago, Rusted said:

The tiny screws are there to lock the focuser securely in place after it has been screwed into its main tube adapter.
If you didn't have these screws tightened gently, the focuser would unscrew if you rotated it anticlockwise.

FF focusers are designed to rotate smoothly in either direction.
All FF focusers have dedicated main tube adapters to allow this rotation by design.

Starlight Instruments use highly skilled staff to set up the degree of friction on the drawtube.
As Peter says, contact Lunt for further advice. Or, email Starlight Instruments for specific advice.
They are very customer friendly in my own experience.

 

 

Don't remember I screwed the focusser on. It seemed to fit in a "grove" with the tiny screws. Have some homework now!

Edited November 11, 2020 by Mai Ai Bing

[Mai Ai Bing]

Thanks for all the great advice. I'll get to work by disassembling the focusser again and check that I got all these important details right. I'll be back tomorrow. Hopefully with a story of succes - or if not with some more questions.

For now you have all been of great help! 👍

[Rusted]

Let me repeat that I found Starlight to be very responsive in their communications.
So I would wait until FF has answered a first enquiry email just to get things moving ASAP.

Lunt, or their dealer is, of course, legally responsible for repairs or replacement.
Though this sounds as if it would be a rather slow process.
 While our OP is obviously keen to use their nice new telescope.
 

[dweller25]

12 minutes ago, Mai Ai Bing said:

Don't remember I screwed the focusser on. It seemed to fit in a "grove" with the tiny screws. Have some homework now!

That sounds right to me, here is a photo of the same setup - it appears to show the focuser held onto the OTA with the three small screws.

[Rusted]

From the OP's images I had assumed these were simple locking screws.
Unfortunately they have reversed the focuser in their images.
One can just see the white main tube beneath the focuser.

Now I think these screws are to retain the focuser as it rotates.
They project into the groove in the base of the focuser.
It may be these which came undone in the post.
Allowing separation of the components.

The image you have just posted is a private replacement for a worn helical.
It is not quite the same as images of the DS50 online.

Edited November 11, 2020 by Rusted

[Ricochet]

4 hours ago, Mai Ai Bing said:

Have an automated setup - so the scope slews correctly into position. There's no problem "finding" the sun.

I would not count on this. It is surprisingly difficult to find the sun and due to the nature of H-alpha, if you don't find the sun you will see nothing at all, well almost. In a double stacked scope there is a reflection of the sun that will appear blurry and out of focus. Adjusting the tuner on the double stack will shift this reflection around (and hopefully out of) the FoV. If you see only blackness (and there are no clouds), you're not looking at the sun. If the image you see is only blurry you may be looking at the reflection from the double stack. In this instance it is probably easiest to start in single stack mode so that you know that you are definitely looking at the real image of the sun.

 

[Ricochet]

2 hours ago, Rusted said:

Now I think these screws are to retain the focuser as it rotates.

I don't think this is the case. I've just had a play with mine and I can't find any tension level where the focuser can rotate and be securely held. If I slacken the screws to rotate the focuser it can fall off. 

Does anyone have one of these focusers where the focuser both rotates and is held securely simultaneously? 

[Xilman]

Personally I would RMA it.  Fiddling around with it and failing to make a successful repair gives the supplier an excuse to void the warranty.