The Skyliner 200P F/6 Dobsonian

[dweller25]

The 200P has enough aperture to make it useful for deep sky observing and with it's 23% obstruction it's very good for planetary observations too.

Being relatively light it can be easily transported for short distances as a whole unit (OTA plus base).

I believe the 200P is superb value for money but needs some small mods to make it really useable - at high powers at least.

Quite a few SGL members have this scope so I thought I would just share a few of the modifications I have made to mine......

1. Added a Lazy Susan Bearing to the base - This is a great addition and make s a BIG improvement to the azimuth movement. Tracking planets at x240 is no problem as there is no longer any "sticktion"

2. Polished the altitude bearings with Turtle wax - Another great improvement that gives really smooth movement.

3. Flocking - I flock opposite the focuser - an 8" square does the trick and I flock the tube all around the primary mirror and finally I flock inside the focuser tube. This definitely improves contrast as I can see the spider vane pattern on bright objects much better now - . Planetary contrast is slightly improved too

4. Added a fan attached to a baffle to the rear of the scope. This dramatically helps cool down and helps to remove the boundary layer from the mirror - it's amazing how much steadier planetary views are now - I always thought it was poor seeing !!

5. Replaced the rubber grips on the focuser with rubber O rings.

6. Blacked out the edge of the secondary.

I really like my 200P and will be using it extensively over the next few months for viewing and drawing Mars and Jupiter which should be great fun - even at -10'C in the snow

[NGC 1502]

Hi David. The 200P Dob just has to be the "best bang for the buck". I had one for a while and only got my OO 10" because it was as new, and going for a very good price from someone I know.

With the mods you have done, a very nice & portable scope. A couple of eyepieces to upgrade the originals, and it would take a lifetime to exhaust what one of these will do.

Hope you have lots of great nights, Ed.

[coffee_prince]

thanks for the review, those are a some mods i need to do in the future

[lexyastroman]

I plan on getting the 150mm version of the skyliner next month so some helpful tips for me already.

[ZEbbEDY]

whats the flocking process? is it just a sheet with adhesive backing?

where do you buy it from

also any pics on the fan mod i fancy doing this myself, have spare case fans here

[dweller25]

Got the flocking paper from here ......

Light Absorbing Black-Out Material - Edmund Optics

And here is a picture of the rear fan .....

[Damo636]

That's a very tidy job with the fan David. It's something i've been planning to do and have all the bits gathered up but just haven't gotten round to assembling it on the scope as yet. Do you leave it running all the time or just to speed up the cool down process?

[twotter]

A lazy susan bearing sounds like a plan to me. May I ask which size you bought and from where please?

[cathalferris]

A lazy Susan bearing means that the scope will act as a sail in any wind, and will find the downhill spot if the base is not perfectly level. Ideally you need the same friction levels in both axes, to better control the movement at high power. Instead of replacing the bearing, it may be better to change the surface area of Teflon that's in contact with the other bearing material, and possibly to change the other bearing material for the dimpled melamine-type stuff like Ebony Star. The objective is not to reduce friction to nothing, but to give the correct friction amounts. It's why you never see Dobs with roller bearings without a braking mechanism.

[cathalferris]

The calculations are in Kreig's book on building your own Dobsonian and are well worth working out, to better understand why certain things work the way they do.

[dweller25]

Damo - I run the fan all the time.

Twotter - 12" from here ... 12 Inch Round Lazy Susan Turntable Bearing Simply Bearings Ltd

Cathal - your right - I put a few CD's around the azimuth axis to slightly higher than the height of the bearing to add a little resistance.

[twotter]

Thank you

[coffee_prince]

does anyones base rattle? maybe it didn't come with a tefon bit but the screw doesn't go all the way in

[dweller25]

Mine rattles when it's not been tightened up enough.

[coffee_prince]

i am definitely mising something down there, must be a white/clear pastic/teflon circle bit, what can i do to get one?

[dweller25]

Try CD's

[paul schofield]

Thanks for the write up. I am at the stage where I want to make some small improvements for usage with my 200p Dob. Might hold off on the Lazy Susan for now but everything else sounds plain sailing. Thanks again.

[dweller25]

Glad to be of help

[cotterless45]

Nice mods, you seem to have hoovered up all the good advice.

Really wish that more serious beginners would get this scope. We are always amazed at the views. Newbies usually say "I suppose that's about £600 " after looking through the scope.

Nick.