Modifying Skyliner 200p 8" Dob help

[SmoothOperator]

Hi all,

So my Skyliner 200p has finally arrived and im absolutely blown away by it! Cant wait for thee sky to open up over England!

I have read a lot about making modifications such as the use of setting circles or wixey alt guages, countersinking compasses or making a 'lazy susan' to make setting up and location of objects easier, however drilling and cutting up my brand new base to make mods seems like an extremely daunting task.

Can anyone provide me with some useful sources like a walkthrough on how to make such mods or even any other mod tips for a dob.

Also any other information sources like books (i have purchased left at orion already) that you think will ease my stargazing experience would be very much appreciated.

[Marci]

Most practical mods are whacking a fan on it’s bum to speed up cooling down the primary, flocking the interior if not already done to improve contrast, and grabbing a set of Bob’s Knobs for the secondary to make collimation easier. I then added a mobile phone mount alongside the finder scope and fired up Stellarium to deal with pointing & finding...

[Whistlin Bob]

I really don't think you can beat a 200p for starting to observe. I've had one for several years now and despite now owning three other scopes it still gets plenty of use- mainly due to the setup time being about 2 minutes. It's just a great scope.

I'd suggest you give yourself a bit of time to get used to it before making any mods to it, but the things that I did to help were:

- A Rigel finder for getting in the right neighborhood.

- A RACI finder for getting the exact location (I find the angle with the straight through finders just too awkward near the zenith)- use alongside software as per @Marci's suggestion.

- An adjustable chair- like an ironing chair or something.

Sorry- I know those things are all extra pennies when you've just made the main purchase- but they really helped me get the most out of mine.

 

[vlaiv]

+1 RACI - you can rotate eyepiece of finder to be in very suitable position next to main eyepiece - I found this very useful.

I also fitted 1:10 micro focus upgrade to mine - and I think it was very worth it - especially on planets. I did not go for whole focuser upgrade - this was simpler and cheaper.

https://www.teleskop-express.de/shop/product_info.php/info/p2625_1-10-micro-transmission-for-retrofitment-of-Crayford-focusers.html

I thought about settings circles and all, but decided against it. Alt/AZ coordinates change with time and you need a way of calculating current coordinates to be able to find stuff. This means either tablet or phone, and I don't like to use any of those while observing - plain ol' star hopping I like the most.

[Carbon Brush]

Use first. Find out the problems, restrictions, must have, etc. Then modify.

RACI finder has been mentioned. I think these are essential and I have always fitted to my (non refractor) scopes. Not everyone likes them.

Rigel finder has been mentioned. I think they are great. Not everyone agrees. In fact Rigel vs Telrad can be a contentious issue!

Observing chair. Why not a kitchen/bar stool to start off. Get a cheapies from Gumtree or car boot. Saw the legs down until the height suits your scope.

Hope this helps, David.

[Alan White]

+1 for the RACI
I would add a Rigel or Telrad finder too
Also warm clothes, lots of them are an essential part of observing in the UK in Winter.
A short stool or chair as also noted helps you be comfortable and observe, not just glance.

[Astro Imp]

Congratulations on receiving a great scope.

I agree with several posters, use your scope first and you will have a better idea of what you want/need.

The first task before taking your scope out at night is to align the finder scope. Do this during the day when you can see what you're doing, chose a prominent object as far away as possible (make sure you are not pointing near the sun). To get your finder accurately aligned  use the lowest power eyepiece, centre your chosen object in the eyepiece and then adjust the finder scope using the two thumb screws. Go back to your eyepiece and check nothing has moved, now use your highest power eyepiece and centre your object. Look through the finder and adjust as necessary, recheck in the eyepiece. BTW when using the finder at night keep both eyes open, you will see your object in each eye, move your scope until the two images coincide.

Good luck and enjoy, please keep us up to date with your experiences.

[westmarch]

I agree with the above suggestions for a red dot finder and RACI.   You need a good guide to what is up there - I tried loads of books, pocket atlases, etc  but found Sky Safari the best option - its so easy to overlay your finder view on the sky map and then flip the view, as seen through the main eyepiece.

I also found these DIY mods useful when I first got my dob.

John

[Steve]

Warm socks and a woolly hat ?

lit is probably best you use the telescope a while before considering mods. You will then have a much better idea of what will be useful to you. 

[SmoothOperator]

Thanks for the info guys, much appreciated as always.

So it seems an RACI is highly recommended so think i will look at some of the options for them.

With regards to a Telrad or Rigel, i personally really like the 2x magnified finder the 200p comes with, not necessarily the quality of it but the fact that it is 2x magnified so im not sure about the fact that both these finders are unmagnified, can anyone provide some piece of mind on this front?

[westmarch]

Most of us use the tetrad or red dot to get into the general area.  The telrad has a variety of circles that project onto your direct view of the sky, as such, it does not generally have magnification.  You are then able to match these to what your map says you should be looking at.

The RACI, when properly aligned in daylight, then shows a more magnified, wide field, correct way up view to allow you to identify fainter stars.  The illuminated cross hairs can be switched on and off to centre on particular stars.  You can then star hop to your target.

The final stage is to invert your map and check that what is in your scope field of view corresponds with it.  This will again be more magnified and Your target should hopefully be somewhere in the field of view.

In the end it has to be what works for you.  If you like what you have, stick with it.  Over time, you may wish to try out other options if you are having problems finding targets.

Good luck and congrats on a great purchase.

John

 

[Astro Imp]

IMHO if you use a RACI you will need either a Rigel or Telrad, I prefer the Telrad although it has a much larger footprint.

[SmoothOperator]

1 hour ago, Marci said:

Most practical mods are whacking a fan on it’s bum to speed up cooling down the primary, flocking the interior if not already done to improve contrast, and grabbing a set of Bob’s Knobs for the secondary to make collimation easier. I then added a mobile phone mount alongside the finder scope and fired up Stellarium to deal with pointing & finding...

Appreciate the pointers Marci, have just downloaded stellarium and think its brilliant, could you just explain a little bit about what you mean by flocking?

[Marci]

See http://www.deepskywatch.com/Articles/flocking-newtonian.html - details it nicely.

[SmoothOperator]

1 minute ago, Marci said:

See http://www.deepskywatch.com/Articles/flocking-newtonian.html - details it nicely.

Much appreciated!

[niallk]

Just start using it, and get a Telrad very soon   No need to be thinking about drilling or cutting anything.

Get the cheapest Sky Safari version on your phone if you have one, and set the red nightvision option, with the screen dimmed down as much as it will go!  Be careful about ruining dark adaption unlocking a phone - just charge it and set up the screen to not time out.  Ideally it is best not to use a screen at all, but it can really really help you getting to know the sky initially, imho.

FWIW I never flocked my 250px.

[SIDO]

A dobknob is a simple and inexpensive addition that can go far to make the bump tracking method more accurate, some prefere the knob bottom scope but I like it nearer the focuser as pictured. A RACI and a redot, recital or laser finder is an awesome combo on these scopes as somewhat formentioned.

        Best of Luck...

                      Freddie ?

[SmoothOperator]

10 hours ago, SIDO said:

A dobknob is a simple and inexpensive addition that can go far to make the bump tracking method more accurate        

Hi Freddie, thanks for info!

I’m very much an ametuer astronomer, having just got my scope a few day ago and looking through it a couple of times, so I’m just trying to get as much advice as possible. Any chance you could briefly explain what you mean by the bump tracking method and what the use of the dobknob is as I can’t clearly make it out in the pic. 

Again, thanks a lot! 

[Ricochet]

8 minutes ago, SmoothOperator said:

Hi Freddie, thanks for info!

I’m very much an ametuer astronomer, having just got my scope a few day ago and looking through it a couple of times, so I’m just trying to get as much advice as possible. Any chance you could briefly explain what you mean by the bump tracking method and what the use of the dobknob is as I can’t clearly make it out in the pic. 

Again, thanks a lot! 

The dob knob is the knob at the front of the tube you can hold on to. You've bought a Skyliner so you've already got one fitted. 

Bump tracking must be what we normally call nudging. Due to the earth's rotation stars will appear to move from one side of the field of view to the other. You have to routinely push the scope a little bit to keep whatever object you are observing in view. 

[SmoothOperator]

 

2 hours ago, Ricochet said:

The dob knob is the knob at the front of the tube you can hold on to. You've bought a Skyliner so you've already got one fitted. 

Bump tracking must be what we normally call nudging. Due to the earth's rotation stars will appear to move from one side of the field of view to the other. You have to routinely push the scope a little bit to keep whatever object you are observing in view. 

Ahh I see, just not used to the lingo yet lol! Thanks for that. I have already noticed with the Skyliner that the base isn’t quite as smooth as I’d like it to be (even with the centre bolt fully undone, I think the pure weight of the tube is to blame) any suggestions on how to improve this ie some sort of bearing or just a way of decreasing friction suitable 

[Ricochet]

2 hours ago, SmoothOperator said:

 

Ahh I see, just not used to the lingo yet lol! Thanks for that. I have already noticed with the Skyliner that the base isn’t quite as smooth as I’d like it to be (even with the centre bolt fully undone, I think the pure weight of the tube is to blame) any suggestions on how to improve this ie some sort of bearing or just a way of decreasing friction suitable 

You might want to consider the lazy susan mod. If you search the forum you can probably find a post where someone details how they did it. Amazon is probably as good a place as any to get a lazy susan. 

You will probably want to fit the lazy susan inside the existing bearings. You need some friction or the base will turn too easily. You might find that after a while the az bearing wears in and runs more smoothly. 

[John]

There is a mod involving washers cut from plastic milk cartons that works well to smooth the azimuth motion. Here is a discussion on this mod:

Having owned a few dobs including the Skyliner 200 I'd say that the most useful mods are moving to a 9x50 RACI finder in place of the straight through stock one and adding a Telrad or a Rigel Quikfinder alongside of that.

The "dob knob" might come already fitted to the scope these days but does provide a useful handle when tracking the scope manually.

Other than that, I'd not rush into other modifications until you have had a few chances to use the scope and start to get a feel for things that you might like to improve.

I've had a couple of dobs with "lazy susan" bearings but I much prefer the feel and opertation of well placed and balanced teflon pads. The "Milk carton washer" mod I mention above should help with smoothing the azimuth motion, if it needs it.

Learning about collimating the scope is well worthwhile as well.

Have fun !

[SIDO]

The last two dobs I purchased have had the Lazy Susan style bearings and previously to that the market was mostly Teflon style bearings, I do like the Lazy Susan style but only after installing adjustabile feet on the base so the scope can be easily leveled and a bit of swapping thrust bearings to get the right tension uniformity...with my old dobs that used Teflon bearings I used to sprinke a bit of graphene a dry lubricant and at one point even replaced the Teflon with sheet plastic to get motion just where I liked it.

As John stated his preference it is a matter of personal preference as too the azimuth motions of a dobsonian and getting it just right will indeed make your observing more comfortable.

                       Freddie ?

 

[pregulla]

When I got mine the AZ motion was "sticking" I even thought about doing the "lazy Susan" mod. The I came across a "bar soap mod". Just wet a bar of soap, apply it to the surface Teflon bearings run against and let it dry. Made things much better for me.

[Chefgage]

On 15/12/2018 at 12:09, SmoothOperator said:

Hi all,

So my Skyliner 200p has finally arrived and im absolutely blown away by it! Cant wait for thee sky to open up over England!

I have read a lot about making modifications such as the use of setting circles or wixey alt guages, countersinking compasses or making a 'lazy susan' to make setting up and location of objects easier, however drilling and cutting up my brand new base to make mods seems like an extremely daunting task.

Can anyone provide me with some useful sources like a walkthrough on how to make such mods or even any other mod tips for a dob.

Also any other information sources like books (i have purchased left at orion already) that you think will ease my stargazing experience would be very much appreciated.

Heres the modifications to my 8" dob that i did