LXD75 10" SN - advice needed please...

[martinss]

Hello everyone,

I took the plunge and bought an LXD75 10" plus loads of other bits and am over the moon with excitment waiting for it's first light with me. There are a couple of things I would like some advice on though and hope that someone here can offer some suggestions...

As the scope is second hand (but not used in 10 months), the primary mirror has some marks on it and would like to clean them off. They are extremely obvioud and will affect its performance. How easy is it to clean the primary mirror of the 10" SN??? I've got experience in cleaning other newt mirrors, but have read that the mirror set-up on the LXD75 series is a bit 'odd'.....that's the first question...

The second query is....I've been recommended to change the focusser to a JMI crayford which apparently is basically a 'straight swap' with the existing one....so will have to remove the corrector plate to install it I guess....can anyone let me know the part number or name of the JMI focusser as I can't find the right one for looking - there are so many and I wouldn't want to order the wrong one! Also, does anyone know how are the Moonlight crayfords for the LXD75....I quite fancy one of tose if someone would recommend one....

Thanks for your time and I look forward to any advice you may have!

Cheers,

Martin

[jazzmeister]

Hi Martin,

I have the same scope, and it was left in my observatory, I think a slug or something crawled in through the back of the scope (behind the mirror) and left a residue on my primary mirror. So I had to clean it off. Looked on the web and found a few links, and basically the procedure is to carefully remove the primary mirror, (be careful with the Rubbish bolts holding the mirror in place, they are easy to thread), try to remember which screws go where and at what orientation the mirror was in, you will still probably have to recolliminate but the less the better.

Use a blower (not compressed air or your mouth as this will cause you more problems) to blow off any loose material or dust and then using a mixture of isopropyl alcohol and purified or de-ionised water, use cotton buds to clean the mirror in lines out from the centre, using a different cotton bud on each line (you will get through a lot so buy a pack) continue cleaning in line sections until you have gone around the entire mirror. BE CAREFUL however as the coatings can easily scratch, so do not exert to much pressure and like I have already said use a different cotton bud on each stroke.

Once clean carefully put the mirror back in and recollaminate as neccessary (see LXD75 manual for instructions, if you don't have one it can be downloaded on the web)

Hope this helps you, sorry I don't know the answer to your other questions.

Are you using your scope with the LXD75 mount? If so you will find that it is too small for your 10 inch scope, get yourself an EQ6Pro if you can afford it. I have had 2 frustrating years of using the scope with the mount, and have discovered that it is futile to try, everyone will recommend that you upgrade the mount. Sorry if this is bad news for you, but to save you a lot of frustration and heartache, like I have had, I thought you might like to know.

The scope itself is fantastic however, so well done on choosing a really nice scope, you will not be dissapointed with the views you will get with this and it is great for astrophotography.

Cheers

J