The making of 26 inch Cassegrain-15, Telescope Body Done.

[Chanlunlun]

Dear ATMers,

Our work has put back in fast track again, after delaying and delaying for reasons of this and that. The optical tube is very long, so long that it just cannot be assembly inside our workshop. We had to carry everything in the roof to get the assembly done. Nevertheless we managed to finish the job.

The attached picture shows the scale quite correctly – yes, it is true, the telescope tube has a length more than twice the height of an average student. Don’t worry – the eyepiece is not that high. You can see from the picture – the diagonal cage is just at the right position and the zenith eyepiece height is quite good.

The next step is to star test the primary mirror. In this way we will first convert the optical tube into a Newtonian telescope and then star test the primary at the Newtonian focus. You will see an even longer telescope than this. (in case if you are curious – in Newtonian configuration the telescope will have a length of about 180 inches !)

Best regards
Chan Yuk Lun
9 Feb 2015.

[Eddy So]

[wtyu21]

congrad～Mirror God！

[Chanlunlun]

congrad～Mirror God！

Thanks !

But it seems that we still have a rather long way to go.

[anyone]

真系要爬梯看了。

[bingsze]

樹大會招風，到時候點解決搖擺的問題？

[wtyu21]

congrad～Mirror God！

Thanks !

But it seems that we still have a rather long way to go.

等待是美德～

[Carl Chan]

真系要爬梯看了。

不需要。那些學生的高度已經足夠了。

[Chanlunlun]

真系要爬梯看了。

Mr. One my friend, sorry for misleading you.

We design this telescope to be a Nasmyth Cassegrain. The eyepiece situates at the middle cage just a the right height of a student.

[Chanlunlun]

樹大會招風，到時候點解決搖擺的問題？

We don't have much wind here and the extreme heavy weight of the telescope itself also helps.

[bbsdma]

恭喜Chan Sir重炮进展顺利

有个疑问上次在design图也问过，但问题表述得不是很清楚

就是为何连接对角镜箱的上下两批桁架没有连接在同一点（比如说改成棕色所示的连接方法），以减轻对角镜箱的所承受的（OTA光轴径向方向的）弯矩和变形（绿色所示）？

谢谢

[Chanlunlun]

恭喜Chan Sir重炮进展顺利

有个疑问上次在design图也问过，但问题表述得不是很清楚

就是为何连接对角镜箱的上下两批桁架没有连接在同一点（比如说改成棕色所示的连接方法），以减轻对角镜箱的所承受的（OTA光轴径向方向的）弯矩和变形（绿色所示）？

谢谢

Thanks for your pretty drawing.

Upon finishing assembling the body was put into rigidity test. We didn't observe deformation as mentioned by you. The diagonal cage was pretty rigid and stable.

[lawrencemok]

With scope that big, I guess it has to stay in school? Can't wait to visit it in coming open day.

[Chanlunlun]

With scope that big, I guess it has to stay in school? Can't wait to visit it in coming open day.

Yes you are telling the truth. It won't leave the roof of QC. Come at open day and see.