[alistairsam]

Hi,

I initially used longer springs and longer collimation bolts to move my primary up. that got it to focus.
But then I moved to a low profile focuser as I was able to move my primary back and that helps avoid the need for a bigger secondary.
when you move the primary up, you might lose some light if its the standard 50mm secondary. so its common to change the secondary to a 62mm or so.

Low profile focusers are a very good alternative, but they're a bit hard to find and tend to be a bit expensive.
there are a few on ebay, andrews sells the long perng focuser that has a low profile, but easiest fix would be the springs and longer collimation bolts.
just get some broad enough springs.

here's a pic of my collimation bolts and a comparison of the normal and low profile focuser. yours could be different, but just giving you an idea.
that 30mm or so that you save with the low profile will mean you don't need to touch your mirror as the slr can go 30mm inward.

edit: you will most likely need an extension tube to use an eyepiece once you move your mirror up or use a low profile focuser.