SkyWatcher Quality Control.

[wrinkly]

Bought a laser collimator yesterday to check the 150 mm Newtonian. Curiosity caused me to try it in the 90 mm Mak, laser came out dead centre of the front plate. Tried it in the ST80 and there was a large offset in the spot. Rotating the diagonal, gave a circle. Replaced the mirror diagonal with the prism diagonal from the Mak and the laser spot became dead centre of the lens, so obviously the mirror diagonal is out. Removed the four screws on the back expecting to find some form of adjustment but the mirror is stuck on the base with a double sided sticky pad. It is realised that the ST80 is a bargain basement 'scope but this seems ridiculous, perhaps they hope no one checks.

Now the question, which is the best option, try and adjust the mirror relative to the removable floor of the diagonal, adjust the floor by shimming or bung the diagonal in the dustbin and use the Mak prism?

Thank you in advance for all contributions.

[johninderby]

The diagonal that comes with the ST80 is the most basic you can get. It works, sort of, and at least you can try the scope out right away. I always recommend replacing these basic diagonals as the build quality is so poor. The mirror actually isn't that bad but it's not worth trying to collimate. You can get a decent quality brand new 1.25" diagonal for £25.00 to £30.00 and a dielectric one for £50.00 to £60.00.

John

[faulksy]

you can colimate the diagonal easy to do if you look on you tube theres a tutorial on there

[wrinkly]

Thanks guys. Managed to press the mirror onto the floor and it is better, but for how long? Good to hear Dion's voice on the video, always reminds me of Fred Dibner.

Oh well more expense but it is worth it.