Got lucky with a 2nd hand buy, but have questions

[Wizbit]

Hello, hoping someone can help with a couple of simple questions from a noob.

I had been searching the classifieds for something simple like an 80-100mm refractor when I spotted a skywatcher 200p on an eq5 came up at a price I had to jump at, even came with a copy of turn left at Orion. It's home now and seems to be in near perfect condition, only a couple a niggles.

1, there's a screw missing from the finder scope but I'll pick up a replacement tomorrow at work.

2, the focuser seems very loose. If I tilt the tube so that the focuser is pointing up or down it rolls in or out under its own weight with no eyepiece, is this right? Or can it be adjusted? I've attached pics.

3, it needs collimated. The instruction manual suggests using a 35mm film case with a hole as a tool but is it worth picking up something a little more precise before taking on this job?

4, I have no idea if the polar scope has been put in right or not. I've seen a vid that explains how to center it correctly but how do I know if it's orientated right?

Any help, pointers, links to instructions or videos would be greatly appreciated.

 

 

[popeye85]

Fraid I can't help with the polar scope but with regards to the focuser tightening up the thumbnail screw should 'lock' the focuser into place. 

I recommend that you get a 'cheshire collimator's to help with collimation. You can get laser ones but be warned these themselves require collimation and if they are wing it can lead to more trouble then they are worth. Oh, and have a look online for 'astrobaby guide to collimation' a fantastic guide that will see you right!

[Saganite]

Hi Wizbit,

 The underside of the focuser shows one silver screw, which is for locking the focuser, and four little set screws. If you adjust these little screws a bit a a time they will increase the tension, and you should be able to adjust the friction until the focuser slides smoothly. Have a play with that and you will soon see how it works.

As for collimating, have a look at Astrobaby's website. Any further questions just ask away.

 

good luck and enjoy a fine scope 

[Cornelius Varley]

2. The large knurled screw on the base of the focuser can be adjusted so that the focuser does not move under its own weight. Don't tighten it too much, just enough to stop the focuser from moving.

3. A 35mm film cap or collimating cap (similar commercial product) should suffice or a Cheshire eyepiece. Laser collimators will only work if the laser is correctly collimated in the first place, not all laser collimators are.

 

[rockystar]

Not quite popeye, the thumb screw will stop the focus wheels from adjusting the current position. there is a regular screw behind the thumbscrew (hidden by the thumbscrew in the phoo), tighten that up, until you can move the focuser without it slipping - i found I had to tighten it up about once every 5 or 6 sessions.

 

[ronin]

Can only help on No 2. It shouldn't slide under it's own weight but the missing screw may contribute to that. If I recall the 4 screws underneath control the resistance as they push the friction plate and the friction wheel together more (or less).

It will be worth looking for a simpke guide to taking it "apart". Sometimes the grease they use get on the plate and wheel and then getting it to not slide is more difficult. Just if that has occurred then it needs cleaning.

Collimation can be approximately done with a collimation cap (35mm film cannister+hole) and is likely worth trying before you spend out on a more expensive option. People have said that a "Posh Plug" from Astroboot with the AE sticker removed is good.

[Cornelius Varley]

Just now, ronin said:

Can only help on No 2. It shouldn't slide under it's own weight but the missing screw may contribute to that. If I recall the 4 screws underneath control the resistance as they push the friction plate and the friction wheel together more (or less).

It will be worth looking for a simpke guide to taking it "apart". Sometimes the grease they use get on the plate and wheel and then getting it to not slide is more difficult. Just if that has occurred then it needs cleaning.

Collimation can be approximately done with a collimation cap (35mm film cannister+hole) and is likely worth trying before you spend out on a more expensive option. People have said that a "Posh Plug" from Astroboot with the AE sticker removed is good.

The missing screw is in the finder bracket, not the focuser.

[Wizbit]

Thanks everyone, I see that hidden screw your talking about saganite and rockystar and just tried it, about a 1/16 of a turn sorted it. I'll try that guide

[rockystar]

This one - it's a allen screw, not a philips. the other four are for removing the plate which you shouldn't need to do

[Putaendo Patrick]

Looks like you should be able to control the tension on the focuser with the knob in the centre between the two wheels. Fully tightening this may also allow you to lock the focuser completely.

A film canister may be enough to get you going for collimation. Ideally however you may want to get a Cheshire eyepiece, cost about 30 pounds. Generally avoid cheap lasers, you often end up having to collimate the collimator!

The offset on the polar scope is only necessary for very precise tracking, for example photography. There should be setting circles on the mount to find the correct position according to date and time, but there are also programs available on the Internet and apps for phones which are a lot simpler.

[popeye85]

7 minutes ago, rockystar said:

Not quite popeye, the thumb screw will stop the focus wheels from adjusting the current position. there is a regular screw behind the thumbscrew (hidden by the thumbscrew in the phoo), tighten that up, until you can move the focuser without it slipping - i found I had to tighten it up about once every 5 or 6 sessions.

 

Every day's a school day!

[Cosmic Geoff]

1 hour ago, Wizbit said:

 

4, I have no idea if the polar scope has been put in right or not. I've seen a vid that explains how to center it correctly but how do I know if it's orientated right?

A

There is plenty of advice on this forum about how to use the polariscope, if you search for it. But for visual use you don't need to bother with it at all. Just ensure that the latitude is set correctly on the mount (it probably is, if the last user was local), and aim the RA axis at the pole star by eye, and it will be good enough. I didn't get a polariscope with my EQ-5 and it has never been a problem. 

[alacant]

Hi. I'd recommend not reading too much about collimation. When I first started, I wish someone had given me the film canister with the hole in it you mention and told me to make it look like this. It really isn't the horror story many guides put you through! Just my €0.02. HTH.

This snap is from through the canister on a 200p. Copied from the astrobaby site mentioned above. 

[Dave In Vermont]

Astro_Baby's website is missing-in-action for quite awhile now. I hope she's okay...

But here's a copy of her collimation guide:

Astro Baby's Collimation Guide.pdf

Just 'Save' it to your computer. When it's time to actually do the deed of collimation, come back here with any questions. And try not to rip all your hair out! The 'first-time' is usually a scary and mysterious chore. After that - it's like riding a bicycle - you'll wonder what all the fuss was about and find it to be 'second-nature.'

Get that focuser squared away, that's a fine telescope!

Dave

[Wizbit]

Quick update:

Sorted the finder scope, tightened the focuser and collimated the mirrors (seems like Ive managed a not bad job of it too!).

Then last night the clouds cleared for about 45 mins so rushed out to the back garden quick set up and there was the Orion nebula! Looked great in my 25mm eyepiece. I'd like to get a wider one as well as maybe replacing the 10mm one I have as it just didn't seem right, although maybe that was just the turbulent sky, any suggestions on brand/types? I've seen a few reviews of some but several of the good reviews have the caveat that they were no good on f5 scopes and I don't want to waste my limited funds.

Thanks for the help, now hoping for some clear sky's so I can try it out on a few more targets.

[Ricochet]

How limited is limited? I think the BST Starguider and Celestron X-cel LX ranges are supposed to be ok at f5 if £50-60 per eyepiece is not too much. 

[Wizbit]

That's pushing the budget but if pay it if it was getting me a better product, but.. the x-cel only seems to go as wide as 25mm and I can't find bst anywhere.

Are the zoom eyepieces worth looking at at all? Or just a waste?

[Ricochet]

BSTs can be had in the UK from Alan at Skies the Limit (Skies unlimited on eBay). Both the BSTs and X-Cel LXs stop at 25mm because at a 60° apparent field of view you're almost at the limit that a 1.25" barrel can show. If you want a noticably wider true field you'll need something in a 2" barrel which is going to be even more expensive. The Explore Scientific Maxvisions are probably your best bet but then you're talking £100+. You'll also need to make sure you've got the 2" eyepiece adaptor for your focuser, I think that it is a separate part on your scope. If you don't have it then astroboot tend to have them fairly regularly. 

[Wizbit]

Thanks, I hadn't thought about the physical limit of what the 1.25" tube could show but it makes perfect sense. I do have the 2" adaptor but that is getting a bit much.. for now

[Waldemar]

Step by step does it. Grant yourself the time to learn from experience, as you did with your focuser.

[BritAngler]

The 10mm eyepiece isn't really a good bit of glass, so I would replace that one soon(ish), the 25mm however is good for the price so you could stick with that one for a while longer. Zoom eyepieces are good when it comes to convenience but cannot beat the quality of a prime eyepiece. Considering the price of a zoom (£70+ for the Celestron 8-24mm), I would instead consider buying 2 or 3 prime eyepieces instead. One thing you might like to buy is a twistlock adapter, it fits into the 2" adaptor and self-centres your 1.25" eyepieces. At about £25 for the SkyWatcher version, it's not a bad price.