Last Telescope Build

[andrew s]

Hi, Here is my 400mm F5 Newt ready for first light if not yet finished. The design was constrained by the size of the existing observatory and that it sole use is for spectroscopy. This has allowed me to use a rail design with a large secondary (90mm) to shorten it considerably. The large backfocus this provides allows me to use a ONAG as well as guide heads on the spectroscopes. The optics were specially made by OO for me.

The set up shown is with the fibre head for my homemade echelle spectroscope (two orange fibres one for the image and one for callibration), but I can also accomodate directly attached spectroscopes.

I still have to add a dew shield for the primary and a metal aperture stop at the inlet to the focuser. Note the disk that stops direct sky light from entering the focuser. The dew shield is to stop my cats from trying to ride on the mirror rather than prevent dew!

I have made 2 x 200mm and 2 x 300mm Newts but this 400mm will be the last due to age and the size of the obs!

Regards Andrew

[Merlin]

With that beast Andrew, you should see the lunar dust mites.

[scotttumsh]

Great effort Andrew! its a Beast.

[Pan Euro]

Very impressive scope.

[andrew s]

Yesterday I found a problem with open tubed Newts.  I was collimating and suddenly could see and smell smoke. Looking to see who had lit a bonfire I realised it was me and the off axis Sun toasting the Obs wall! Lesson learnt - no leaving the roof open and the mirror cover off again.

[Mr Spock]

Lovely set up - and no tube currents!