Hi Phil, I don't think you need to be able to see the reflective surface of the secondary mirror to check its alignment. From the front of the optical tube, you should be able to see if there is a consistent gap between the edge of the mirror and the PVC tube. That’s all this test is about. Is the secondary mirror "square " with the focuser axis?
You can adjust the spider, it should be square unless someone attache the secondary manually then remove glue or tape and align and re attach, but if it's not square it might be ur focuser not align Also if the back of secondary is worn out you may struggle to collimate and you can put a washer and it will be smooth again trust doesn't have to be perfect don't try to or u will loose ur mind and you will realize there wasn't that much of a difference between perfect amd close enough
Collimation of your scope's mirrors also requires the focuser to be perfectly square to the secondary mirror. That is why the secondary mirror has multiple degrees of freedom to be adjusted. The insertion of the plastic tube just provides a way of alerting you to the fact that your secondary mirror may not be square to the focuser. You could perhaps start moving the secondary toward true square alignment with the plastic tube inserted, and then remove the tube and finalise using a laser collimator.
I've never seen this done before - Top tip!
I would say to the newb watching this to be very careful to not touch the secondary with that pipe.
Haha
Thank you for the common sense logical solution
Very cool. I’ll be sure to remember this trick later down the road.
I took mine out with the spider vains lined it up with the vain that is inline with focus tube and put a black and white mark on all aligned parts
Very nice, but for closed Newtonian tubes you can only view from the top and the secondary mirrored surface is not visible.
Hi Phil, I don't think you need to be able to see the reflective surface of the secondary mirror to check its alignment. From the front of the optical tube, you should be able to see if there is a consistent gap between the edge of the mirror and the PVC tube. That’s all this test is about. Is the secondary mirror "square " with the focuser axis?
0:41 mine is skewed. It should be a little bit more „right“. What’s the solution? Can’t get it right with the 3 adjustment screws alone
You can adjust the spider, it should be square unless someone attache the secondary manually then remove glue or tape and align and re attach, but if it's not square it might be ur focuser not align Also if the back of secondary is worn out you may struggle to collimate and you can put a washer and it will be smooth again trust doesn't have to be perfect don't try to or u will loose ur mind and you will realize there wasn't that much of a difference between perfect amd close enough
nice idea, but this requires that your focuser is absolutely perfectly squared
Collimation of your scope's mirrors also requires the focuser to be perfectly square to the secondary mirror. That is why the secondary mirror has multiple degrees of freedom to be adjusted. The insertion of the plastic tube just provides a way of alerting you to the fact that your secondary mirror may not be square to the focuser. You could perhaps start moving the secondary toward true square alignment with the plastic tube inserted, and then remove the tube and finalise using a laser collimator.
Brilliant!
Thank you
All I can see is the cross in my 127eq