Are mount fixings universal?

[NotSoSuperNova]

I think the title is fairly concise. I'm looking at joining the dobby brigade with a big Skyliner 250. However, I'm very aware that these are essentially a stand alone unit, never to be upgraded or swapped and changed unless with maybe a GOTO kit. Standard newts on EQ mounts (200p on an HEQ5 to be specific) have recently caught my eye and I'm wondering if I could put say...a Schmidt Cassegrain scope on one if I were that way inclined at a later date?

I may be thinking slightly long term but I think making an informed decision would make me feel better. At the moment I'm pretty sold on the 250PX as I'm after bang for my buck, I think

[E621Keith]

Most German equatorial mounts are universal. You just need a set of tube rings and the right dovetail to attach the scope to the mount. Some Celestron SCT comes fitted with dovetail. Actually it is possible to defork a dob and put it on a GEM provided you find a suitable set of tube rings

However, there are two common standards of dovetail. The Vixen dovetail is lighter and narrower and is used in smaller scope and mount. The Losmandy dovetail is wider and heavier and is used in heavier scope and mounts.

[NotSoSuperNova]

Wow, thank you very much. So you can fit any OTA to any other GEM as long as you have the correct tube rings and the weight, size of dovetail etc is accounted for?

[dmahon]

Pretty much as you say, yes.

You need:

Tube rings to fit your scope

Dovetail (Losmandy or Vixen are by far the two most common)

Saddle on mount to match dovetail (or one that takes both)

Mount that will take the weight

If you're thinking of adding a camera, try to only use 2/3 of the maximum weight to improve stability and remember that the dovetails, camera and assorted bits & pieces weigh in as well.