Tripod

[Craig2017]

Afternoon again everyone. Thanks you for the replies yesterday but I have another question. I have a dobsonion 200p telescope and it came with the spin base. If I wanted to get a tripod what would I have to get and also would I have to buy extra bit to get it fitted to the tripod. As I said I live in Devon and I have to travel about half an hour to be in the middle of exmoor but I don't really want to take the spin base as the telescope moves away from the object I'm watching by itself.

 

[Ricochet]

If you put the base on level ground it should not move in azimuth. If it spins too easily you can tighten the bolt through the centre of the base. In altitude the friction is adjusted by one of the handles. Tightening it up should be enough unless you've bought some really heavy eyepieces. If you are talking about the tendancy of objects to drift from right to left in the eyepiece this is not the telescope moving, but the rotation of the earth itself. All manual telescopes will have the object drift out of view. To counter it requires a motorised mount. 

To mount the telescope on a tripod you will require two tube rings, a suitable dovetail bar and a mount in the EQ5/EQ6 class or higher, preferably one of the AZEQ mounts so the you don't have to contend with eyepiece rotation caused by the combination of a Newtonian and EQ mount. I suggest that you try to rectify your current issues as the Dobsonian (spinning) base is superior for visual observations with this type of telescope in my opinion. 

[Craig2017]

Ok many thanks ricochet for you reply. If I tighten the handle it still seems to move so I guess I'll take it apart and see if I can make it more stable. Many thanks once again. 

 

[brantuk]

This is probably the cheapest way to to it with reasonably acceptable results. But note this is the 1000mm fl model as opposed to your 1200mm dob:

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-200p-eq5.html

But as stated above, you'd be better served by an HEQ5 upwards (or equivalent). Have a look on UK Astro Buy Sell website and you might find a used EQ5 (manual) for circa £280'ish with the scope, or £150-£180'ish without. All you'd need to add is tube rings to fit.

[Charic]

5 hours ago, Craig2017 said:

I don't really want to take the spin base as the telescope moves away from the object I'm watching by itself.

Is the telescope actually moving?  can you see/detect movement in the spin base?

I like the description you give to the base! but note that the spin base is called the 'Dobsonian' named after its inventor. John Dobson.
Mounted on the Dobsonian is your 200P Newtonian telescope, so  just for clarification, the  overall setup is referred to as a Dobsonian telescope, and the 200P you have is a good choice.

Now back to this base, does it actually move, as if blown by the wind, or moving  because the base is not level, and the scope is drifting under its own weight due to gravity. If its moving due to the wind, imagine how it will react up on a tripod type mount? Keep it simple, that was John Dobsons idea, hence the 'spin' base unit 

What I actually  think's happening, is that when you view an object through a non-tracking telescope like a Dobsonian, its not the scope thats drifting ( correct me if I'm wrong here ) but the target is drifting across the field of view when you look through an eyepiece. This is totally normal and acceptable, due to nothing more than the Earths rotation, which is more than noticeable when you magnify the view through a telescope.

If I point my scope at a Star or if I'm lucky to see Jupiter, I'll locate the target with the finder scope, then look through the focuser with an eyepiece fitted. If I watch for a few seconds, Ill see the image drift across my field of view, very quickly at high power, slower with low power. Its quite normal, and the only way to keep up with the image is to 'nudge' 'slide' push' track' whatever you want to call it, but you must move the scope manually in order to keep the target in the centre of the eyepiece. Use a wide angle low power eyepiece for less nudging, but nudge you must!

If you have disassembled the scope before reading this, just note that the bottom bolt through the base plates, just needs to be tight enough to allow the base boards to slide over each other, not too tight. The friction handle just controls the pitch of the scope or declination, holding it at the correct angle, but again, its something you will master, rotating the scope with the chin handle! and lowering/raising/locking with the friction handle. All becomes second nature with practice, but for me, I could never go back to a tripod mount, just for visual use, just too many things to adjust, and you think the spinny base is a problem!

HTH.

 

[Louis D]

If indeed it is the earth's rotation annoying you, build or buy an equitorial platform to put your dob on top of.  It will counteract the spinning of the earth for up to an hour at a time.

[Floater]

My first guess at this, Craig, would be that you're not on the level ... literally, not figuratively, y'understand? ?

[Craig2017]

Hi thanks for your comments. To be cruelly honest with you I did know it was a dobsonion base but I'm just worried about making myself look like a bit of a plank because I'm new to all this. Put it this way I sent my first message to a guy about some eye pieces the other day and put in new to astrology not astronomy and people picked me up on it. With the telescope moving by itself I put it on a table to view from it. But what happens is the telescope tilts by itself so I gave worked out. I set it on a fixed point yesterday  (a house) to see what is happening. So I will just play about with it so sort it. I'm not going to get a tripod for it either. Thanks for all your comments everyone. If you have anymore helpful hints or websites for a newbie please let me know. 

[Ricochet]

41 minutes ago, Craig2017 said:

 Put it this way I sent my first message to a guy about some eye pieces the other day and put in new to astrology not astronomy and people picked me up on it.

I wouldn't worry about it. It's the sort of thing that probably everyone here has done at some point.

41 minutes ago, Craig2017 said:

With the telescope moving by itself I put it on a table to view from it. But what happens is the telescope tilts by itself so I gave worked out.

I would advise placing the telescope on the ground so that it is most stable and then observing from an adjustable chair. I use an old drum stool with mine but you can use ironing chairs, observing chairs or anything else that gives you a range of heights (you can even build your own).

With the design of the 200p's Dob base I assume that the handle can be tightened all the way up to prevent any movement. Check that everything is seated and attached properly and that the "tension handle" is actually working and changing the altitude tension. You want to try to find a point where there is enough tension to stop it moving by itself but where you can move it smoothly and easily when you want to. If the altitude tension doesn't work then perhaps it is broken and you need to go back to your dealer for a replacement. If it is working and you still have issues then you can try adding weights at the appropriate end to counter the movement. The Skyliner 200p is a very popular telescope though and I do not recall reports of this being an issue with it until you start trying to use the heaviest of eyepieces so I would think it should work properly with the supplied eyepieces.

 

[brantuk]

Actually it's not the first time folks have had this problem with a 200P dob. What you want to achieve is enough friction so it doesn't move when placed on a target, but easy enough to nudge whilst you're tracking. Many dob owners have modified the central bolt in order to achieve the required amount of what we term "sticktion".

Do a search in the DIY section for "bottle top mod" and "lazy susan mod" and you'll see plenty of threads describing these simple and cheap modifications.

[Charic]

I'm right handed, and  from my seated position, the friction lever on my scope is akin to the throttle on a motorbike? throttle on to move/tilt the scope, throttle off firmly to lock the scope. Whichever way you see/imagine it, it all comes together with practice.

Ive not had any balance issues yet, even with a Nikon attached, just need to tighten the tensioner a little more!
This might seem obvious to some but there is only one tensioner handle per scope which needs to be on the side nearest the operator, its the one with the ball race set sandwiched between two grooved washers, maybe a cleanup in this area, but do inspect that everything is complete here, its possible something could come off whilst removed from the scope!.............here's one I prepared earlier,

If when you align the telescope to a house, and nothing moves, then its tensioned correctly or there's no wind! but if all seems ok, when  you point back to the heavens, the images will still drift across the field of view. 

And don't stop asking questions if your in any doubt, you/we are always yearning to learn new things everyday, even some quite comical?
I wonder who's still viewing through their 200P Skyliner with only the 2" aperture exposed!!!!!!!!