The Surplus Shed is to blame. They dangled this 127mm achromat in front of me and I was gone. So it's their fault. One thing led to another and it wasd then Andrews' fault for having a decent 11:1 focuser by Long Perng. But the result has been a 5" short-focus widefield refractor. FL is 700 so it works out at about 5.5.
The objective from Surplus Shed came in a ruddy great cage that I retained and the scope was largely built around it. The dust-cap in the picture below is actually about 50% optical tube since the objective actually sits about half-way along its length.
The engineering challenges have been in fashioning an accurate leams of scaling down from 150.. aluminium pip to 80mm and then down again to accommodate the focuser. That being overcome, the remaining task was painting and voila, we have a telescope. The dovetail bar underneath is fastened to the tube in 3 places and is very rigid.
I can't wait to get some light into this baby.
Photos to follow.
Peter
Looks real neat. Does it really matter if it does not work as good as top grade refractor. The experience gained will be worth more than the price of the best and the satisfaction of rolling your own is great. In any case it will probably produce excellent results.
I made my first refractor when I was at school. An old spectacle lens with a FL of about 40 cms, a couple of carboard tubes and the viewfinder lenses out of a box brownie. It showed Jupiters moons and craters on the moon. It probably would have just shown saturns ears if I had been able to point it at Saturn.
Well done Peter, it looks good, I hope you get plenty of clear skies soon!
I'm waiting on the Surplus Shed 127mm F9.45 lens to come back into stock. I'm on the back order list and have been assured that I will get one from the next batch, due any day now!
My first attempt will be a folded light path design, using optical flats previously purchased from SS, and a 2 speed Crayford focuser. Everything has been built, just waiting on the lens!
I built a modded PST and a Ha double pass system with the 90mm objective.
A laser collimator and a Cheshire definately help in the final alignment and collimation.
Thanks Anil. I recall looking at your scope and being totally impressed by the detail. The hand-grips and the texture of the paintwork were nice touches too.
The seeing with this scope has been better than I expected by a fair margin. I'm still struggling with mount issues so the few photos I've taken so far are not good enough to show. But I'm as pleased as punch with it.
thanks again.
Peter