8" dob vs the n00b...

[elusiver]

well.. the dob arrived yesterday.. i am now a dob owner YAY! opened the OTA box and was surprised, it was ALOT bigger than i had imagined, and the guys at work were impressed. End of the work day came and I excitedly carried out the OTA box to my car.. but lo and behold.. it didn't fit. I ended up having to transport the OTA out of the box, and the box with the base squeezed along side it...

Finally got it home.. opened and checked all the box contents.. and layed them all out on the floor. There really isn't alot to the dob, 6 main pieces including the OTA.. simple. Assembly took just over half an hour, i expected it to take alot longer. There were no missing pieces, and almost everything went together very very easily. I only really had 3 issues when I assembled the dob.

1. The tensions springs I found were tricky to get on. And took a fair bit of 'strength' to strectch out and hook on.

2. I don't think my ota is balanced.. it seems more heavier towards the rear, so it doesn't 'hold' it's alt position well.. i'll hopefully fix this up tonight by attaching to magnets to towards the front of the OTA.

3. Being a n00b.. there had to be a stupid moment. I wanted to see the inside of the tube.. but the lighting in the room wasn't enough.. so i shone a torch in it. DON'T SHINE A TORCH DOWN THE OTA! it was not a very bright thing to do and it was hurty for my eyes.

Saw a break in the clouds saw I crab walked it out just to get a quick glimpse of the moon. Seeing and transparency were terrible.. but it still was freakin AWESOME!!!


I took some photo's along the way.. so i might make up abit of a diary of the process.

Tonight, i'll hopefully be centre spotting a collimating the dob... which should be interesting. As with assembly i hope to take photo's of that process too.

With centre spotting is the folded paper method the 'best' way to go? I don't really want to use the ruler thing as it looked kinda harsh.

Also, should i use a solid spot or a 'ring' type arrangement. Went to officeworks this morning but they didn't have any of the white type of reinforcement rings only transparent.. which i thought would be pretty useless. So i bought some of those black round stickers, and i figured if the ring way was the way to go i could gut a hole in the middle of the sticker.

When taking out the primary.. is it just the six screws(on mine the screws are kinda chromy coloured) on the outside edge near about 1cm or so away from the bottom of the ota? I'm assuming the mirror 'falls' out of the OTA, rather than in. So could stand the OTA upright.. like this

_
| |
| |
| |
- <--- Primary mirror

with the primary mirror end on the floor.. undo the six screwn then lift the OTA off the primary mirror??


soo many questions.. i bet there will be more to come.

thanks,
el
now a member of the 'get a dob brigade'

[slice of heaven]

Congrats, another dob to the fold.
Check out Starklers how to on the mirrors. It pretty well covers the method for removing the mirrors. May as well check the secondary while your at it.
Balance is an issue youll have to work through till your happy.

[rmcpb (Rob)]

Ahhh, such excitement

For the centre spotting, mine has a black texta mark in the centre with a white reinformement ring around it to make it easier to see. I think the folded paper trick is the way to go. To get the primary out is simply remove the six screws and out the whole cell comes. Putting it back in can be tricky, the first time I did this I thought the whole tube had gone out of round BUT I hadn't lined up the slot in the cell with the folded seam in the OTA. When that is lined up it almost falls into place. At this stage I wouldn't bother with the secondary, just get your primary spotted and recollimate the scope then enjoy it for a while, its a beauty.

Cheers

[acropolite (Phil)]

Congratulations on the new toy elusiver; Just what we need; another (wannabee gotoer) dobber. The torch thing is also relevant when viewing the moon, I thought I'd permanently damaged my eye after viewing the moon in my 8".

[vindictive666 (John)]

i wouldnt stand it up

check this link out although it doesnt tell you how to centre spot its a good guide i used it the the other day :

http://www.iceinspace.com.au/index.p...63,206,0,0,1,0

ive attached a dot zip its over 300kb to download but the pics are self explantary

[iceman (Mike)]

I'd do the secondary while you've got it in pieces.. it's really not difficult to check and remedy, if it's tight.

I lay the OTA down when taking the mirror out, but resting on 2 of the foam packing semi-circles. That keeps the tube round.. and as Rob said, be careful to line up the notch on the mirror cell with the notch in the tube to ensure it slips back in easily.

The mirror won't really "fall" out when it's laying down, it just needs to be pulled backwards but of course be careful when you undo that last screw and be ready just in case

And prepare your work area BEFORE you take the mirror out.

[elusiver]

thanks heaps for the link and the zip file vindtictive.. and all the advise guys.

guess this a reason to clean up the workbench in the study.. it's a mess.

cheers for the tip on the round foam bits iceman. i'll have to take those home as they're here at work cause the box and stuff wouldn't fit in the car.

el

[elusiver]

another quick question.. if anyone online has they're scope near them. Would anyone know the outside circumference of the big end of the finderscope. Got an idea for something but i may need parts that i could pick up from bunnings on the way home.

el

[slice of heaven]

Between 18.5 and 19cm

[vindictive666 (John)]

gday

just had a measure of my finders scope is approx 180mm in circumference

its an 8x50 (12 inch Dob)