Technical Plans for 6" F/5 Newtonian

[ChaosKnight]

Something i did for fun during my free time.
Please feel free to use/reference.

[Airconvent]

Something i did for fun during my free time.
Please feel free to use/reference.

Hi Chaosknight,
Is this a conceptual plan or have you got a prototype made?
Do upload the pics here is there is a finished product...:-)

rich

[ChaosKnight]

It was a concept i thought about long ago.
Wanted to do it but in the end decided it's more costly than getting a newt of similar specs off the shelf.

[weixing]

Hi,
I think you forget to take the height of the focuser into consideration and also the diameter of the tube is a bit too large... you need to put in baffle if you use such a large diameter tube.

Have a nice day.

[laurentli]

you file the main mirror, or buy from market? I am trying to file the mirror myself, but I don't know where to get the thick glass, about 20mm thickness, and the plating service for glass

[weixing]

Hi,

you file the main mirror, or buy from market? I am trying to file the mirror myself, but I don't know where to get the thick glass, about 20mm thickness, and the plating service for glass

I think most DIY people in singapore buy the mirror instead of making one. It is not practical to make your own mirror in Singapore, because I don't think there are coating service at a reasonable price available in singapore.

Have a nice day.

[clittle]

I think forget about making your own mirror. If David Kriege, in his book, says better to buy the mirror, who are we to challenge him?

[ChaosKnight]

Oh no.....who dug up this old thread??

Anyway i had this idea to get a parabolic mirror by mechanically performing the equivalent of a 4-pt bending on a plane mirror.

It may be easier to obtain the required shape without too much grinding. However, this doesn't avoid the need for surface grinding for a mirror finish. The mirror material cannot be glass. A suitable alternative is metal.

The mirror can then sit in an adjustable cell, and variable focal lengths from the same optical system can even be obtained.

[Canopus Lim]

It is a good idea to DIY some stuff. But for optics I feel that it is not practical in cost. I have actually designed an achromat doublet and I have asked for quotation and it really cost a bomb; especially with such low quantity. Therefore I shelved the idea of trying to make or design the optics myself. Even if I designed an apochromat, the cost of developing (making prototypes) it and fabricating it is not reasonable.

[Tachyon]

Yes, we all had that dream of designing and building that 'Ultimate' killer telescope. However, reality sets in when you consider the additional costs of silvering and coating the mirrors. For that price, I could get a commercial scope of good quality, and without the risks involved. Unless you have your own workshop, getting a few pieces done to your specifications can be very expensive indeed!