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Skywatcher 250PX Dob Mods

Rob

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Moonshane

Moonshane

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right, but what is this black matt material used for exactly?

hi there, it's a matt material usually self adhesive, which reduces light scatter inside the tube. this increases contrast. it's basically in sheets and glued to the inside of the tube and sometimes the focuser drawtube too.

some more info here

http://stargazerslounge.com/diy-astronomer/107834-lining-newtonian-ota.html (scroll down) and here Telescope Parts UK

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Moonshane

Moonshane

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it definitely would. flat black paint is actually quite reflective at low angles. flocking being a rougher surface 'traps' light a lot more.

the difference is not dramatic but every little improvement counts. it's something I plan to do to my 6" dob and although my 12" is flocked with felt (as it was when I bought it) I am going to redo that with protostar in the new year when funds allow (I have a couple of EPs on my hit list first).

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starman345

starman345

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Wow, you've been busy! Some nice work there. So far I've replaced my sloppy rack and pinion focuser with a Moonlite, put milk carton discs behind the secondary between the mirror and spider, and I have Bob's knobs for the secondary on order. The Moonlite made a big difference, I can actually get some detail in Jupiter now, before it was either focused in or out too far.

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johnkirkpatrick

johnkirkpatrick

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I really want some mods done. Flocking mainly, Is there anywhere I can take my scope to get it done for me? I'm not brave enough to attempt it lol, I'm not even brave enough to blacken the secondary mirror edge's with a sharpy pen, ( cant ever collimate it back, So never touch it. Might try it without removing the mirror though, MIGHT!!

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starman345

starman345

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I really want some mods done. Flocking mainly, Is there anywhere I can take my scope to get it done for me? I'm not brave enough to attempt it lol, I'm not even brave enough to blacken the secondary mirror edge's with a sharpy pen, ( cant ever collimate it back, So never touch it. Might try it without removing the mirror though, MIGHT!!

I'm the same as you John, I would like to do those things but I would like to use the telescope for a while first, just in case I totally hose it. One of these days I'm going to strip it apart...it can't be that complicated.....I"m trying to convince myself:confused:

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starman345

starman345

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I have a skywatcher 250px Black diamond Auto Dob, and i just love it If you click on my profile you'll see some good photos of it

Really nice telescope Robert! Someday I would like to have one like that. I have a 10" but it is quite basic. I really like your dome observatory, is it easily moveable? What is it made of?

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Moonshane

Moonshane

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I really want some mods done. Flocking mainly, Is there anywhere I can take my scope to get it done for me? I'm not brave enough to attempt it lol, I'm not even brave enough to blacken the secondary mirror edge's with a sharpy pen, ( cant ever collimate it back, So never touch it. Might try it without removing the mirror though, MIGHT!!

seriously. don't do this. the chances are you'll cause more problems than you solve.

if you can wire a plug/change a light bulb etc you can easily take your scope apart, flock it and recollimate but I understand your caution.

use the scope and then when confident you can collimate normally then you'll be happier. I took out my three secondary knobs, removed the secondary and replaced the secondary with a washer behind it, and new collimation knobs and recollimated everything in less than half an hour so it must be straight forward?

the main things are go slowly and don't touch the mirror surfaces / drop anything. ensure the secondary centre screw is far enough in - put a sharpie pen dot on the bolt and count the full turns to get it off. do the same number of turns approx when you replace it.

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Robert Watson

Robert Watson

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Been away for a few nights ,The obby made of 1/8" ply on 3+1 1/2 frame it's 7 foot wide around 8 foot high covered with fiberglass and gellcoat Loft ins inside the frame and sheeted with 1/8" ply inside The dome runs on 6 casters and is just hand turned at the moment. I hope to get a few more photos fo the inside as ive just about got it finished.

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Robert Watson

Robert Watson

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Brill obby love the dome,have you got any type of heat in it. I put a 8 watt Greenhouse heater into mine its on a timer so it comes on morning teatime and around 11.00 it just takes the chill out of the air keep,s the damp out but not that warm to upset the scope + I have the dod covered with a quilted cover. I've had trouble finding red bulbs for my light's. Any weard looks from the neighbours or peeking over the fence

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spaceboy

spaceboy

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No weird peeking over the fence but the neighbors are a bit weird! They had a BBQ the other week ??? it was freezing :)

No heater as I have enough problems with the neighbors BBQ's & Baxi boiler fluming hot air in my direction with out me adding to the air turbulence. To be fair it doesn't get too cold as I'm protected from most the elements.

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