Chriske

There is indeed some surface roughness but very easy to remove. Astig is very easy to detect even with Foucault. In the position the mirror is now in I don't see any astig at all. Shadow is coming nicely in from the right(iow horizontal as it should). Now rotate the mirror on it's stand for about 45° and take another picture. If the shadows do come in horizontal again, so in your case from the right, there is no astig. BUT, if the shadows come in at an angle -not parallel with the movement of the knife- then you do have astig. btw best is to place the knife at the 70% zone, so you have a far better idea of the surfaces shape.

Looking good..! Around the inner perimeter you could add a few teflon strips to make the action smoother. To get rid of the wobbly action a few springs or even small bolts pushing against these teflon strips.

Still at it... Optics nearly finished so we can work on the scopes wedge, its angle and the width. We decided to also print the rest of the scope, tripod, wedge/fork. This is how the tripod will look like, V1 not quit finished. Busy adding some improvements. A small container is in the making. All printed parts are very thick. The aluminium legs of these tripods are a gift from an old amateur. He gave us a box filled with these legs.

If the pitch has to go why put it in a freezer. When it has cooled enough, take it out of the freezer the pitch will slide of very slowly. The trick is to wait until the pitch start making soft cracking sounds. This will only work with a full glass tool, not with a tiled tool.

To be clear on this one, I have no problem whatsoever with my rather moderate alcohol consumption. as a matter of fact I don't even like Gin or any other strong drinks...🥴

Hi, This little scope is about 30 to 40 years old. Out of the bottom of a Gin bottle I grinded a 100mm (square) f/4(about) curve. Back then we had lots of laughs when I showed this little scope during our open door. Especially when we had a little sip of water from that bottle. It was btw not a good idea we thought to leave the original content and drink that. The original content was in fact not really Gin but Bokma, a Dutch Gin equivalent. And no, we did not waste the Gin but drank it afterwards when open door at our observatory was finished...🤪 Anyway, back then I made the 'tube' out of wood and called the little gimmick 'Parabooze'. Owning a few printers these days I'll replace the wood with printed parts, it'll be a complete overhaul. There's one little problem while using this little scope. Optically it is ok. But while slowly emptying the bottle the central point of gravity of the telescope does shift towards the top... so I need to find a solution for that ....🤔 Collimating the primary mirror was done by bending the steel wires at the neck of the bottle. Going to replace it with a more professional solution of course. Back then the operator of the aluminium-coater asked me whether this was a joke or not when I asked him to aluminize and coat the bottom of my bottle. The man really thought I had a few 'loose screws' or drank to much of that liqueur... Cheers..!

I know Peter, but I was not planning to build a 77mm bino. In this case I stumbled upon these two, lucky me a thought, why not...?

In fact it is merely a toy and not what we would call a telescope...😧 So these two will go to the scrap heap...sigh...!

hmmm...🤨 its a BLITZ

While cannibalizing the two refractors I saw a few baffles in the tubes. Nothing wrong with that of course but the holes in these baffles are way to small. Looking through the hole, were the eyepiece supposed to be, I could not see the spacers of the 77mm Fraunhofer lenses at all. I even needed to shift my head to the very perimeter of the eyepiece barrel to see these spacers. Seen from the eyepiece location I expect to see these spacers.Could it be that using (to) narrow baffles, these scopes cover up mediocre optics.???🤔 I've seen it before in some very cheap (50€ or so) telescopes sold in warehouses. One time I took apart such a cheap 70mm f/10 scope and found very close to the lens, about 25mm or so, a 50(!) mm diameter baffle. A few moments later I found out that the lens was only '1' lens. And that single lens wasn't even a doublet. It was nothing more the a convex/flat piece of glass...😳. I expect to see nothing more then the Moon or so with that kind of 'scope'. On the box were the scope was sold in, there were lots of promising markings, one of them was that the largest magnification was 600x(!!) Furthermore you could see the portholes of a ship that was miles away.

Thanks for the tip Stu...👍

one word : A-MA-ZING...!!

This an old one from last year, forgot all about it, anyway.. Scope 400mm RC eyepiece 35 + Samsung smartphone(somewhat older) Single shot, handheld no stacking nor processing. It's a very first attempt from me and my son Steven. Planing to continue taking more SP images in the future.

I will use the same setup as in my 150mm binocular. And I'll add a readout apparatus so I can see on a small screen how far apart the eyepieces are. I will also make a handheld measuring device so the observer can read what his IPD is. Have to think about this, how to make it.

This is a first idea There are in fact two cradles. The brown is fixed in the mount. The red one is attached to the two scopes. The upper part of the brown cradle can be removed and locked with bolts. So the bino itself can be removed for easy transport. As I said before I will mount the complete unit into an old Celestron forkmount. While tracking the scopes, in fact the eyepieces, needs to stay horizontal. That is why the red cradle will rotate in the brown one. Smooth gliding will be done on Teflon pads. The Focusing and IPD unit (busy drawing) is completely selfmade. For that I need 4 small diagonals(31mm). To have an idea how big this is ; the diameter of the brown part is 230mm --> fits exactly in that Celestron fork.

There's not to much work involved this time. Both the tubes and cell's are in good condition. So that only leaves me the support unit(cradle) and also the focus/IPD unit to build. My goal(as aways) is our open door mid Sept, so plenty of time. After open door I'll 'release' it in the hand of our youngsters... I hope they take good care of it...🤨

Bino's...story of my life, and I'd rather call it an addiction...🤭 Busy drawing parts already. Not far from that refractor I also found a very old C8 fork, it's a first generation I think(very ugly green). I'm thinking using that fork to support that bino. I'll make a system to keep that bino horizontal all the time while tracking.

A few months ago I posted something about restoring a 77mm refractor During cleanup in one of our 'forgotten corners', believe it or not, I discovered (covered completely with dust) exactly the same refractor as the restored one. Needles to say these two scopes are candidates to make another binocular... Except for the serial nr, these two are identical

Ordered a 40mm Omni from Celestron, just one to see how it performs.

redesigning, well we discussed it and a 2" eyepiece is a bit overkill for a scope this 'thin' we think.

Hey...! What about this one...?

Hi guys...'m new here in this section. Our group is busy building a few(6) Delmarva Schiefs. The scopes we're building will be 108mm f/29(about, still busy grinding the optics) We all have 'a bunch' of eyepieces from older projects and want to buy one more. The reason for that 'one more' is we want to see the entire Moon in the FOV using a 1"1/4 eyepiece. So we need a wide angle eyepiece with a long FL. Assuming the scope has a FL of 3100mm and using this eyepiece we have a magnification of 125x That gives us a true field of 0.51°, so about the size as the Moon. In the eyepiece 'world' there are a few other candidates to do the job, but they're rather expensive. Does anyone now were to buy other long focus 1°1/4 eyepieces with an even larger AF...? Thanks...

I have no manual and do not know if it's complete or not. Do not know how old it is. Does anyone know what it is and how it works...?

Zenith prism ready, a 5.5 hour print.