Hexy 635mm bino update---tubes skywards

[twinhexydan]

HI guys ,

finally got hexy pointing towards zenith--minus secondary cages and cells

[swamp thing]

Kin hell. That's Big.

Is that your new grab n go.

What a tool that's gonna be.

Great stuff

Steve

[kniclander]

either you are extremely small or those are very big. awesome is all i can say...

[Gina]

SO... it's not dust that might bother you it's dead birds! That is HUGE!!

[twinhexydan]

Hi guys,

I,m a bit tired from doing this project !!!

it,s only 10 feet long x 7 feet wide

am anticipating a mass exodus of bats when I set up for the night.

was trying to make equipment to match the scenery--- (sky,s a big place) did you know??

This is not quite my new grab n"go, I prefer to call it my new go n" grab

might need some eyesocket forceps to get the view. He he !

I,m hoping someone will go bigger than me cuz the next project will be a 36 inch bino !!!

keep watching DAN

[tonyh66]

haven't got a clue what your building, but its big. where are you getting the mirrors and how big are they?

[twinhexydan]

Hi tony,

I,m building a binoscope---basically two reflectors side by side in a binocular format. left eye looks into left scope and right eye looks into right scope--at the same time --your head is in between the two scopes so you merge the two images just like in an ordinary set of binocular,s each focuser has a 90 degree diagonal mirror to allow the bino viewing,

I am making the mirrors myself--slumping multiple glass disc,s in a kiln to produce two mirrors 40mm thick x 635mm (25inches) each.

I have made a grinding/polishing machine to form the parabola needed.

a specialist will aluminise the mirror,s .

this format----2 x 25 inch will give an equivalent light gathering power of a 36 inch single mirror----the binocular view merged by the brain adds 40% to the basic optic size, if that makes any sense to you.

glass rubber Dan

[mdstuart]

I bet M81/82 will be awesome in those!

Mark

[mdstuart]

My boy..Josh wants to know if you are taking them to SGL8?

He also asked me if you are a millionaire!

Mark

[michael.h.f.wilkinson]

Imagine asking an airline company if it is OK to bring your bins as carry-on luggage, and then turning up with these

Awesome project.

[twotter]

I thought you were standing next to two daleks

[Beulah]

I am speechless.

[twinhexydan]

Hi to md stuart,

I,m gonna need an antiglare filter to dim the stars in those two galaxies--what think ye ?

sgl8 ? I might come as [removed word] whitington if I can get the balance right. lol

these will have a permanent home on a trailer eventually so they might turn up anywhere.

money is not a problem but I,m not wasteful, when all,s done my bank will be £1500 lighter that,s all.

expensive pair of binocular.s eh!

I,m rich in enthusiasm Dan

[twinhexydan]

re; michael wilko,

they are more likely to bolt them to the fusilage and aim the jet at warp factor two

people keep calling them awesome (mispronunctuation) it,s eyesome!!

but thanks anyway Dan

[twinhexydan]

Twotter,

I thought I heard a double echo !! faint , dim , and squinting "YOU WILL BE EXTERMINATED"

bright eyed Dan

[twinhexydan]

Well Beulah,

that,s because my project is another language.

next year I,m going to embark on a 36 inch lightweight bino project

36 x 2 that is.

while I,m still young enough eh !

evolving Dan

[tonyh66]

don't suppose you fancy doing me a 20inch blank in your kiln?

Have you thought of slumping the glass to somewhere near the correct parabola to reduce the grinding/polishing? i used to work in glass and know how to make moulds to do this.

[twinhexydan]

Hi tony,

Have you made a mirror yourself before ?

they are doable at that dia. but if it,s your first I would suggest messing around with smaller dia. first imho if not then Yes I could slump a 20 disc , this would be 38mm thick (2 x 19mm) pilkington float.

Man you would see things with that you aint seen before.

Yes have thought of slumping to near spherical shape , so might have a bash.

send me an elaboration on your mould method if you would

regards Dan

[tonyh66]

I used to slump glass for bullet resistant windscreens, the moulds used for those were made from steel section - not a super accurate way of doing it, but it worked and was cheap.

The other stuff i used to do was laminated glass for CRTs and radar screens and the like. the moulds were made from a high silica cement which were made using wooden formwork. Basically if your wooden formwork(mould) was accurate then the mould for bending the glass would be accurate. Bending/forming the glass in the kiln was the real dark art, you just have to make sure you get no gas trapped between your layers which creates bubbles, forming gas vents into the mould helps.

[twinhexydan]

Thanks tony I,ll log that one.

Looking at late april/ early may to start the glassworks as hexy needs finishing first , which is basically adding on all the bits I,ve made ready.

will post an update when done

Dan

p.s. Wouldn,t mind a bit more mould info ,if you have any----if you would

[Peter Drew]

Annealing your kiln slumped glass blanks is another issue worth investigating at an early stage.

[twinhexydan]

Thanks peter for the warning, what exactly were you referring to regarding the annealing ?? if you would thanks

Dan

[Peter Drew]

Annealing glass is an art on its own. The basic principle is that the glass is cooled gradually over a period of time by carefull controlled reduction of heat. This should prevent stresses within the blank which could affect the final figuring of the mirror. My suggestion was to try and research a suitable method of controlling the kiln and the best temperature gradient for the type of glass used.

[tonyh66]

Peter got there first, annealing can be built into the fusing and slumping program, as he says its just a case of holding the glass at a particular temperature to release the internal stresses before ramping the temperature down slowly to avoid re stressing the glass. You don't say what kind of kiln your going to use but you really need to control temperture, ramp and dwell times accurately.

with regards the moulds, it was over 7 years ago since I left the glass forming job so its a bit fuzzy. As I remember the stuff we used was silica cement, a quick recce of the internet found that a 50/50 of silica and plaster has been used to make mirror moulds and there is an interesting piece out there where the mirror has been formed with a 'waffle' back to make it lighter. I will knock up a couple of sketches and description of detail when I have finished this set of night shifts im working at the minute. i will also throw out the question of fusing and slumping 38mm thick glass on the art glass forum I frequent to see if they can come up with a rough kiln program.

[twinhexydan]

Thanks peter , I will fill the brain with annealing info.

In passing I,ve noticed a 12 inch reflector on ebay item number 120885903867 , format of tube looks exactly like my 12 inch which you made back in the 90,s

Was wondering if you could say if all these scopes had david hinds mirrors ?

if they do and it is the same as mine was wondering about compatibility of the two mirrors for a bino format ?

thanks dan