Reticle in polar scope

[sublime_mick]

can anyone help me out?

Mine is off centre and I read in another thread about using o rings to centre the reticle.

I couldn't make sense of the procedure and would be grateful if anyone has done this themselves and could provide simple instructions.

cheers

Mick

[Freddie]

Does it not have 3 grub screws you can use to adjust?

[MG1]

Astro Babys HEQ5 Polar Alignment

Scroll down to aligning the reticule...

also: http://www.astronomyshed.co.uk/forum/viewtopic.php?f=19&t=4006

HTH

[Valley]

The o rings are to take the slop out of the eye piece if you've unscrewed it slightly to achieve focus, this isn't what you need.

As others have said you need to adjust the reticle using the 3 grub screws.

[sublime_mick]

this is the thread I read and was hoping someone would be able to give even more basic instructions:

http://stargazerslounge.com/diy-astronomer/166595-permanent-polar-scope-reticle-centring.html

[Rob L]

Hi Mick,

I saw that thread and thought it was the perfect solution to the trouble I've had with centering the reticule.

I have an EQ3 polar scope and it may differ to the ones for the EQ5/6 but the idea is you unscrew the foucser then remove the three thumb(or grub) screws holding the reticle in place once it drops out you find a perfect fit o-ring for the reticle, put it back in and the o-ring will ensure the reticle is perfectly centred.

That's the theory anyway. But I can't find an o-ring that is the right size, it's either to big and I can't get the reticle back in without the o-ring coming off, or it's too small and the reticle just slops around. I got a set like this one 419 pc RUBBER O RING SET METRIC TZ | eBay

but still couldn't find one that would fit.

Rob

[sublime_mick]

know what you mean Rob.

I got a box of rings from Maplin - only about £3 for 225 of them - some fit nicely round the reticle - but are either too thin or too thick.

I tried a combination of 1 that is too thin and the thumb screws - seems easier to work that way as there is much less movement from the reticle.

will try halfords for more o rings

or even try and trim 1 of the rings which are too thick with a stanley knife.

remind me to buy plasters for when i slice the fingers off myself.

i'm hopeless with fidgety things - and this reticle mullarky sure is a pain in the ass. at least if i find an o ring that fits it'll be a problem i'll never have again.

[glowjet]

I can see where you guys are coming from but the best way is find an O ring that fits the reticule but is slightly to large for the tube, don`t trim with a Knife as this will not be accurate enough and the fingers may suffer, instead push the ring onto a wood mandrill, piece of dowel etc, put it in an electric drill and you can then sand the outer edge down to a perfect fit, you will find rubber sands quite well if you are gentle with it, don't be to eager or the rubber will burn as it gets to hot. Hope this helps solve you dilemma

[sublime_mick]

I can see where you guys are coming from but the best way is find an O ring that fits the reticule but is slightly to large for the tube, don`t trim with a Knife as this will not be accurate enough and the fingers may suffer, instead push the ring onto a wood mandrill, piece of dowel etc, put it in an electric drill and you can then sand the outer edge down to a perfect fit, you will find rubber sands quite well if you are gentle with it, don't be to eager or the rubber will burn as it gets to hot. Hope this helps solve you dilemma

great idea glowjet - now all i need is a drill and some dowel lol

i surprised myself knowing what dowel is.

will definitely give that ago.

though i'll have a look at the o rings in halfords and check their sizes and compare those sizes to the ones i have.

if i find the right size - i reckon with clever marketing a 1p o ring could fetch £50 - just with a fancy "astronomical" name.

retailers seem to be doing it with all astronomy stuff

[Broady67]

I have seen the video from astro baby about adding gub screws instead of the adjustment screws. My question is what size are they and where can i get some from?

Andy

[glowjet]

Grub screws are what you use with an Allen key, the size will I think be 3mm, as 2mm would seem to small and 4mm to large ( astronomers deduction ) Try Boltmeup.com they have a massive range of stainless goods at very reasonable, small quantity prices, often post free HTH

[AndyH]

Whilst researching o rings for a different job, I came across this thread.

This shop on fleabay, may be of interest. Sells o-rings and rubber cord that can be cut to the desired length....

2MM DIAMETER NITRILE RUBBER O-RING CORD BUY4GET1FREE items in Equip Store Ltd store on eBay!

Andy.

[Photosbykev]

Whilst researching o rings for a different job, I came across this thread.

This shop on fleabay, may be of interest. Sells o-rings and rubber cord that can be cut to the desired length....

2MM DIAMETER NITRILE RUBBER O-RING CORD BUY4GET1FREE items in Equip Store Ltd store on eBay!

Andy.

Just what I was after for shock proofing a Baader 110mm diameter D-ERF

[sublime_mick]

anyone know what size we need for the reticle?

mine is an eq5