Chriske

Another picture taken in the entrance of our planetarium during work today.
in the background you see backlit pictures taken by HST. All these pictures are stacked 4 meters high 6 rows side by side. It's really awesome to look at.
Our manager is very proud..!

While hanging there still to do these very last items :
Frontcover
Backcover
Pointers
Astronauts
Wiring
 

This the last stage...
Standing on a scaffolding, HST hanging just temporary, inserting one solar panel, to measure how much we had to shorten the threaded rods on which HST hangs.  We don't want the solar panels or antenna hanging to low. One last time we had to remove HST and now it finally hangs about 3 meters high at the entrance of our planetarium. Urania members were rather impressed of it's size and all the details.
A few more days to add some smaller parts, solar panels and antennas.
 

Yep, but before I get into imaging, I need to build that thing first.
But most of all start asking questions 'how to' do that imaging correctly. From what I've seen so far here on the forum, there's a long way to go...😳
But I might find a person here on the forum who can tell me a thing or two about it all...😁

In the past, when dinosaurs were still roaming here, I've taken pictures of the night sky using 103aE, 103aF, 103aO  developer HC110, or MWP2. I also used TriX, Technical-Pan(Hypered).....aaah those were the days....!!
In those days I took pictures of the Moon with a 6x6 camera and made prints 3'x3'(yep foot). In those days you could buy paper on roll 1.27x10m. I still have a few of these roll as matter of fact. There out of date of course.

Busy designing my own type4 version.
It'll be a printed version(no slim line..!), I'll be using ball bearings instead of hinges.
I'll also replace the point of friction(between the two moving parts) by short linear bearing. Maybe I might use Teflon instead.
And last but not least, the driving threaded rod will be self made. Cutting my own thread assures me I have it absolutely regular. Almost all commercially made threaded rods are not.(construction of threaded rods is not what you would call a high precision process...🙄).

Point is I'm planning to use that tracker also with long telephoto lenses. So I need it to be very accurate.
 

Together with Falcon I'd like to build a Starlink satellite to scale.
Anybody have a link to more info to these Starlinks.
The only info I could find so far is a few drawings.

This is how these satellites are stacked in the Fairing during launching.

And this is what I made of it, so far. It's an estimate, I need to copy this from drawing in perspective. Details and smaller parts will be added later.

No no not at all, but I use to have a site of my own. I thought you were referring to that one.
It's still on line but nobody knows about it anymore. It has not been updated since 2000(or so) due to lack of time.

My site..? how so...?

It is...

Hi,

HST almost done now and already planning a new project, again for our local observatory.
This time I'm going to build/print a Falcon9, together with a Dragon or Fairy, and most probably a Heavy too.
It'll be build at the same scale as the SaturnV that I'm still printing right now. It'll take some time to print all these SaturnV's parts, especially Saturn's LUT, and crawler.
That SaturnV I'm printing is at scale 1:33, so Falcon at the same scale will be 'only' 2.1meter high.
Because of Falcon's shape there aren't to many parts that needs to be printed. It's in fact nothing more then a long tube with a few smaller parts sticking out of it's hull and also 9 small thrusters/booster. In my scale model that tube at scale 1:33 is only 110mm diameter and 1.6m high. The rest, up to 2.1m, is 'cargo'.

Ahhhh.....Remind me of school a few years ago now. My pupils made Stirling engines back then. One day I'm going to build me another, a bigger one...

The only way I can handle these small drill bits is in my lathe, see higher up(photos).
From 0.5mm I can drill with it holding it in my powertool.

I do. 17/100 is 0.17mm
I've got a 0.1mm drill bit, see higher up

Possibly, a friend has such a cheapo Chinese clone, and in his case the tail-stock's barrel is not centred with the chuck at all. And there's no way to adjust it.

Here I'm busy drilling with a 0.4mm drill bit.

You don't wont to know how many I broke until now...😱

These very small drill-bits need a Dremel of course.
0.7 and 0.8 are in use right now.

Drillbit 0.1mm is not visible because it is right above one of the tape measure's black marking.

Getting a bit closer....

Damn...!!! Making this picture I notice 0.2mm is broke..

But 0.1 is still ok. Using these small drillbits you need a Dremel it needs about 35.000 rpm. I made a special tool to hold my Dremel around the tailstock's barrel. Works perfect.
Why do I need these small drill bits...? : to make holes for 3D-printing nozzles.
The one I use the most is 0.25, 0.3, 0.35 and 0.4mm. But that is for friends. Except for the 0.4mm I never use these small drill bits myself because mostly I use very big nozzles. The biggest I use very often is the 1.5mm.  Busy building a bigger printer(on hold right now) to make very large parts using a 2.5(!)mm nozzle. But that's another story.

Some brands here start to sell 1.25x2.5m.

The only visible thing we still buy here is wood.
Buying a sheet of plywood, 95% we buy is still 1220x2440 mm, that is 8'x4' if I'm not mistaken.  Meaning, at a bigger scale lots of wood is lost because nobody works with Imperial sizes at this side of the channel...😁

I think the older guys here must be masters in using fractions.

When I was younger, even using metric units, I often would grab the wrong wrench for a certain hex-bolt I needed to fasten. After 'a few' years now I know what wrench to grab for any bolt.
Let's say you're working on a project assembled using Imperial hex bolts, different sizes. How do you know what wrench to grab when you took the wrong one in the first place.

Another thing, I do have a well equipped workshop. Among the many tools I have, also many drills. The smallest drill is 0.1mm. It goes up by 0.1mm per step, ending at 10mm. After that it continues to go up with 0.5mm per drill.
An example drill 5.0mm, next 5.1mm, next 5.2mm, next 5.3.....until 5.9, next 6.0....etc...
How do you(did you?) name these set of drills if it were imperial sizes only differ 0.1mm(equivalent)....?

I know you have that numerical system, but I'm talking before that system was used.
When I was at school we had to learn all about Imperial, The smallest we could measure with our calliper at the time was 1/128". There were even questions during exam about it....😡. At the time we all hated you....🤭   To be clear that was looooong before digital callipers existed.!

Waiting for the scaffold(next week), I'm busy making/finishing the last smaller parts for HST now.

- Painting frontcover
- Printing ESA logo(almost forgot)
- Making a few small counterweights to have HST perfectly balanced. In the future I'm planning to add a small motor to have HST very slowly rotating around a vertical axis. That's why the counterweights.
- Finding names to glue on the astronauts arm-patches.

14 hours ago, Michele Scotti said:

The accuracu targegt is a tricky question. Lambda/4 at least - anything les than that and it would be more of a light buck than anything

You need to make or buy a secondary far beyond that quality if you stop at 1/4, or you indeed will end up with a light bucket.

I'd go for at least 1/8.

On 08/06/2020 at 15:49, Glasspusher said:

 The slightest deviation from a regular support can result in astigmatism. 

yep.

To overcome this I use bubble-wrap or a soft carpet under the mirror(flat back) while working on my M-o-M.

Yep, and if I'm not mistaken they're mentioned in the original post higher up. (The picture)

Just kidding...😁