Tilt issues on a newtonian?

[Ashen (Caleb)]

Anyone know how to fix tilt issues on a Newtonian imaging train? thanks

[rmuhlack (Richard)]

If you are having "tilt" issues due to mis-collimation of your newtonian, then that is the place to start first. My goto for achieving accurate collimation with my imaging newtonians is to use a laser (to get in the ballpark), followed by a cheshire eyepiece, followed by a Catseye auto-collimator (with the additional offset viewing port).

Then once your newtonian is perfectly collimated, if there was any residual sensor tilt that could be addressed using a tilt adaptor, like these: https://www.testar.com.au/collections/tilters

[Cosmic (Daniel)]

Originally Posted by Ashen

Anyone know how to fix tilt issues on a Newtonian imaging train? thanks

Hey Ashen, I just used shims recently to fix my tilt which showed 15% got it back to 5% simply using plastic shims I made myself. Used ASTAP and reevaluated refocused and repeated...bit of a process but just go about it logically

Cheers,
Dan

[mental4astro (Alexander)]

Tilt issues can caused by any number of reasons. The secondary isn't held securely in the spider, the spider assembly is too weak, too much load on the focuser, focuser isn't set square to the OTA, secondary isn't properly collimated, secondary's holder may be damaged & not hold collimation (a design & manufacturing flaw in mass produced Newts & a big flaw at that), just to name a few.

If you are only using a laser to collimate then there is the first source of your problems - a laser won't properly set your secondary mirror. The laser can be "telling" you that everything is kosher but the secondary can actually be way out even though the laser is coming back on itself. This is where a simple Cheshire eyepiece comes into its own. And depending on the laser you are using, the laser itself may need collimating too! The quality of fit of the laser in the focuser is another factor!

We need more info to be able to help you out. What scope you have, how you collimate (with what tools), the load you are putting on the focuser, the condition of the sec holder that the colli screws push on to. Once we know all of these then we can actually start working out where the source of the"tilt" is and possible solutions.

Alex

[By.Jove (Jove)]

Caleb, we need to know what the scope is, and a picture speaks a thousand words.

One common aspect is flexure, particularly if you have a thin tin-walled OTA, the focusers on these sag under the weight of the camera.