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#2320 by roma847 on 11 Jan, 2023 00:11
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Thanks Mike for your estimation,
but somehow you misunderstood the classification of the steel ruler. On the bottom ruler, the long lines stand for 1 mm and the short lines for 0,5mm.
If you pay attention to that, you will certainly come to the measure that I need for the small snippets.
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#2321 by EG on 11 Jan, 2023 05:28
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Thanks Elmer for liking,
and what length do you guess? Do you have good sense of proportion?
I would say about .75mm... -
#2322 by roma847 on 11 Jan, 2023 12:19
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Thanks Elmer,
as I see, you both have difficulties with the mm scales because you are used to inches all your life.
Therefore take a look at my explanation for Mike and you'll see it better.
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#2323 by mike robel on 11 Jan, 2023 16:41
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I feel stupid. I use mm all the time. 1.45
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#2324 by roma847 on 11 Jan, 2023 17:23
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Hi Mike,
that's getting closer already, definitely < 1,5 mm, which is a bit shorter than this strut is supposed to be.
Since the frame is only 2 mm wide, the gap is 1,5 mm, which is why I need a total of 12 snippets of this length, wherefore I will use Evergreen Strips (0,25 mm x 0,5 mm) or the struts.
Therefore I initially set the steel rulers exactly to 1,5 mm, but I was surprised that the resulting snippet was 1,7 mm long when measured with the vernier caliper.
This fact is actually well known to me, but I fall for it again and again.
That's why I gradually approached the final dimension of 1,5 mm, which led to this special setting.
Here is the result with this setting by using the vernier caliper,
with which I can now cut off these snippets for the Screw Jacks.
And in addition to the 1,5 mm short snippets, I have meanwhile also cut off the upper Frame struts 2 (4 mm).
For the Vertical struts 1 (4 mm) I need the same length, which finally results in the total height of the frame being 4,5 mm.
Source: NASA (STS-125)
As one can see easily the squirrel feeds itself arduously ...
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#2325 by EG on 11 Jan, 2023 23:05
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Thanks Elmer,
as I see, you both have difficulties with the mm scales because you are used to inches all your life.
I'm quite familiar with the metric scale Brother, and scaling one is the same as the other... A simple mathematical ratio...
I went to your measured drawing and chose what I thought was the piece you are making and applied the scale factor to it... It was then I saw your explanation....
I guessed wrong... -
#2326 by roma847 on 12 Jan, 2023 12:03
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Nobody is perfect, Elmer!
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#2327 by roma847 on 12 Jan, 2023 14:18
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Hello everybody,
on this occasion I remembered my Mitre Cutter (RP TOOLZ), which I actually only use for larger quantities, like back then for the felt like 1.000 pins of the Crawler chains ...
But I have now tested this tool again for these 4 mm long frame struts by using a blade with only one chamfer. However, the difficulty also lies in the setting of the lateral stop to exactly 4 mm, which is why you have to test it before. But after I managed to do that, I was able to cut strips of exactly the same length.
One cut at a time, which is a bit tedious ...
or immediately several by fixing the strips with tape.
But one can also cut it through with the tape,
what's no problem.
Nothing is impossible!
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#2328 by roma847 on 12 Jan, 2023 21:44
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Hello everybody,
a far trickier component is this pivoted Double angle holder onto which the Worm gear is mounted, which functions as the drive component of the Screw Jack which provides the vertical movement of the trapezoidal spindle.
Source: NASA (STS-135)
Tricky therefore, because this double angle is very small, as one can imagine from its dimensions (1,7mm x 1,5mm x 1,0mm) in this image.
Source: NASA (STS-125)
Therefore it would be a clever solution if there was a suitable Styrene profile that would fall within this range.
Due to the width of 1,5 mm, I've immediately thought of my smallest Evergreen U or H Profiles, which are just as wide and after which I've been looking in my stock immediately.
From the H Profile (left) I've removed the upper webs and filed the inside a little thinner, which I like better than the U Profile (right), especially since the H Profile with 0,96 mm is also a bit higher, which would fit better into the overall picture.
For the protective tube of the Screw Jack spindle I will use a rod (Ø 0,5 mm). And for the black Folding bellows I could use this matching insulating tube Ø 1,3 mm,
which I have put onto the rod, and which I've tried out with the rod in a holder made of U Profile, what looks quite passable.
Most of all, with this solution I have something to touch, which will hopefully make it easier to glue the holder onto the fragile frame.
Let's wait and see ...
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#2329 by roma847 on 17 Jan, 2023 10:37
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Hello everybody,
meanwhile I've been thinking about how I could scratch the tiny Worm Gear and the Folding Bellows as well as the encased Coupling Rod, sitting on top of it.
For clarity, this time I've left out the confusing scaling of dimensions and just given the final dimensions of the components, making it easier to see the details to scratch.
Source: NASA (STS-132)
Then I looked around for suitable materials and found some in my inventory, including a suitable black insulating tube Ø 1,4 mm for the slightly thicker lower area of the bellows, which is directly sitting on the Worm Gear (Ø 1,0 mm x 1,0 mm) and then up to the coated Coupling Rod (Ø 0,5 mm x 1,3 mm) becomes slightly tapered (Ø 0,7 mm x 1,0 mm), which I at least want to indicate.
The following image shows the individual parts, whereby I put a black broom bristle (Ø 0,7 mm) into the insulating tube for the thinner bellows area. Next to it are the prepared Protective Tubes (Ø 0,5 mm x 9,5 mm), which are mounted under the double-angle bracket of the worm gear.
To the right the parts for the gear unit are to see, these are the punched-out small cylinders for the worm gears, and behind it the Housing of the output shaft, for which I'll use an Evergreen Strip (0,5 mm x 0,5 mm x 1,5 mm).
However, as can be seen in this image, it has a prismatic design,
Source: NASA (STS-125)
in contrast to this cylindrical form shown earlier.
Source: mechjacks.com
Then I thought of two more variants for the bellows, which can be seen here.
In the variant above the cent coin, a rod (Ø 0,5 mm) is plugged into the insulating tube (Ø 1,4 mm x 1,5 mm) above the worm gear, of which I could paint the tapered part (1,0 mm) black, while the remaining end (1,3 mm) would represent the coupling rod.
In the variant above it, a thin black insulating tube (Ø 0,5 mm) is attached to a pin for the tapering part (Ø 0,7 mm x 1,0 mm), which could be replaced by the white round rod, which would represent the coupling rod.
Let's see what I'll decide for, the variant with the broom bristle is eliminated anyway.
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#2330 by roma847 on 20 Jan, 2023 23:39
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Hello everybody,
well then let's get to the tricky Double-angle holders, on which the Worm Gears are mounted, which I've cut with the Chisel cutter from my prepared H Profile to 1,7 mm length.
However, since the shape of the sides of the angle is not an isosceles triangle, as can be seen in this image,
Source: NASA (STS-125)
I first had to attach these unequal slants to both sides of the tiny one, which was quite difficult because one can hardly fix the angle for it, but I managed to do this to some extent with the cutter and careful sanding. Then the Screw Jack protective tube (Ø 0,5 mm x 9,5 mm) could be glued at the underside of the angle, aligned and set aside to dry, 
which did complete the bottom half of the first Screw Jack.
And so to the Folding Bellows sitting on the top of the angle, which I had been racking my brains about for some time.
After careful consideration, I have now decided on the variant with insulating tubes of different thicknesses, with the lower part (Ø 1,4 mm x 1,5 mm and the part above (Ø 0,6 mm x 1,0 mm).
While pushing the thicker part onto the round rod (Ø 0,5 mm) did not cause any problems, I've first widened the thinner part with a pin (Ø 0,5 mm), although pushing it onto only succeeded under hot water.
And this bellows with the coupling rod now still had to be glued to the tiny Worm Gear (Ø 1,0 mm x 1,0 mm), to which I before still had to attach the Shaft Housing ( 0,5 mm x 0,5 mm x 1,5 mm).
This gear unit was then still glued to a small base plate (0,13 mm x 1,4 mm x 1,5 mm),
which shows that it is meanwhile about tenths of a millimeter.
Before gluing both parts together, I still wanted to determine the exact position of the Screw Jack on the still to be built frame platform,
since the position of the Shaft Housing must match that of the Bevel Gearbox of the door drive, between which the tubes of the Output Shaft are running, like one can see in this photo.
Source: NASA (STS-135)
For this purpose, I placed the gear unit with the bellows on the finished door drive in such a way that the center line of the Worm Gear and the Shaft Housing are matching, what was resulting in a distance from the wall of the canister of 2,7 mm, which I have to take into account when gluing the screw jack onto the frame pedestal so that both tubes are running aligned later.
Then I started scratching the upper frame by gluing the prepared struts (0,25 mm x 0,5 mm) together, what resulted to a frame 2 mm x 4 mm.
As one can see, the width of the screw jack base plate matches the width of the frame well.
Here is an image to illustrate the size of the parts from the normal viewer perspective of approx. 30 cm.
Next, however, the upper frame must first be completed with the remaining struts, because only then the complete Screw Jack can be glued onto it.
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#2331 by roma847 on 23 Jan, 2023 12:54
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Good morning friends,
so let's continue with the remaining struts on the frame for the Screw Jack.
After all four top frames were done,
the vertical struts were glued, for which the frame had to be fixed again in order not to be able to slip, which can otherwise happen very quickly, 
whereby had to be rechucked again and again.
The test fitting on the sketch fits quite well so far,
and the frame so far looks stable too.
So it could now continue with the gluing of the diagonal struts, which were cut on this sketch.
While the first strut could still be glued in relatively well after the appropriate fixation,
gluing the other strut was a bit more difficult, which is why the framework had to be fixed differently in order to have reasonably free access without the frame being able to slip. But I found a solution for that too.
Now only the slightly longer struts had to be glued onto both long sides of the frame.
For this I have adjusted the stop on the ruler in such a way that there is an overhang of 1 mm at the top,
behind which I then glued the framework.
Then the strut was glued on the other side.
This was followed by a fitting on the Payload Canister, which was okay so far.
For gluing the Worm gear on the Folding bellows I first have tested the clamping option of the Protective tube with the Double angle holder and tested the seat of the gear.
However, since I was not able to check the alignment of the protective tube with the upper spindle with this clamping and correct it if necessary, I decided to clamp into the scissor tweezers, which was clamped firmly on the table top.
And thanks to my steady hand, the gluing of both parts worked right away,
and the fit of both parts was also perfect.
However, trying on the Screw Jack on the frame turned out to be a blatant number, since the clear opening of the frame and the width of the double angle holder with 1,5 mm are identical, causing the part kept slipping through.
But on the 10th attempt it worked and stayed stable for a photo, which made up for the effort.
And that's exactly why the two small lateral holders must now also be attached to the double angle, but which are only 0,13 mm x 0,4 mm x 0,5 mm in size.
Source: NASA (STS-135)
But I'm still trying to make it,
for which I have already found a suitable thin strip in my hodgepodge. 
Let's wait and see.
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#2332 by roma847 on 25 Jan, 2023 14:11
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Hello everybody,
an exact re-measurement of the small angle holder on the double bracket of the Screw Jack resulted dimensions of 0,4 mm x 0,5 mm, which is why I did not use the initially selected 0,5 mm wide strip, as I would have had to cut 0,4 mm long strips from it, which is almost impossible to do it reproducibly.
So I've cut a new strip out of Evergreen Sheet Styrene (0,13 mm x 0,4 mm), although it was difficult to get the width (0,4 mm), which took me several attempts.
This gave me the advantage that I could set the length (0,5 mm) on the ruler and only had to cut off the pieces.
And now please buckle up!
These angle holders are by far the tiniest bits I've ever had in front of me to scratch, 
which I now somehow had to glue onto both sides of the double angle, which is why I was curious whether I would be able to do that at all. 
Here one can see that the snippet just about fits on the tip of the tweezers, but then really grabbing it, holding it and sticking it to the angle is almost impossible.
If at all, this only works with one of my patented Tape tweezers, who have often helped me in similar cases, hopefully this time too.
Here I have already tapped and picked up the snippet with the tip of a new tape tweezers, and the acupuncture needle lays already in place to dab a tiny droplet of Revell Contacta-Professional onto the underside of the double angle.
And here the first snippet is already glued, but you can hardly see it because these white plastic particles offer too little contrast, which is a well-known phenomenon with such macro shots.
Maybe one can see it a little better on this shot, although it always depends on the incidence of light.
That's why I chose a lateral position here, where one can now see the midget relatively well.
Then the angle holder was also glued to the other side, which resulted in a width of the double angle with these holders of 1,8 mm, which is actually enough to stand on the frame, which has a clear opening of 1,5 mm.
And after drying, the Screw jack was put to the test on the frame, what can be seen in this image,
which has completely convinced me and so I could go to bed last night full of satisfaction ...
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#2333 by roma847 on 28 Jan, 2023 20:01
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Dear friends,
on this memorable day in 1986 with the Challenger Mission STS-51-L took place the first launch from the just finished Launch Pad 39-B,
Source: wikimedia.org
which ended in a disaster 73 seconds after lift-off, in which the seven-person Challenger Crew lost their lives.
Front: Michael Smith, Francis Scobee, Ronald McNair; Back: Ellison Onizuka, Christa McAuliffe, Gregory Jarvis, Judith Resnik
Source: wikimedia.org
Let us take pause in silence and keeping their legacy alive forever.
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#2334 by roma847 on 30 Jan, 2023 22:50
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Hello everybody,
for the remaining three Screw Jacks I came up with a different solution.
In order not to have to glue the tiny Angle holders to the sides of the Double angle holder last, which was a pretty tricky affair, I have this step this time brought forward.
That's why I first drilled the holes for the Spindle protective tubes in the brackets, first with Ø 0,3 mm pre-drilled, and then with Ø 0,5 mm re-drilled.
Then the sides were beveled,
wherefore this time I fixed the holders between four rulers and then cut off the slants on both sides one after the other with a razor blade.
And in this position I also glued the tiny angle holders onto the front side.
To glue the angle holders to the back, however, they had to be carefully re-clamped and precisely aimed with the tiny one on the Tape tweezers.
But now the Double angle holders are finished,
and I can glue in the protective tubes and then move on to the Worm gears and Folding bellows.
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#2335 by roma847 on 02 Feb, 2023 17:58
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Hello everybody,
and thus to the Folding bellows, their assembly sequence I've quickly recapitulated in my former Reply #2330.
First, I glued the Lifting spindle protective tubes into the holes in the Double-angle holders. In order not to break off the already glued tiny Angle holders on the sides, this time I clamped the holders at the front and back between the rulers,
as well as aligned their seat in scissor tweezers and let dry.
This was followed by the well-known tricky threading of the black rubber sleeves of the bellows onto the sharpened spindle rod (Ø 0,5 mm).
After the tricky insertion of the tip into the 1,0 mm long thinner upper sleeve (Øo 0,6 mm), it was pushed up to 1,5 mm in front of the rod end.
Then the 1,5 mm long lower sleeve (Øo 1,4 mm) was pushed on, which was much easier.
After gluing, the round rod was cut off flush, with which the 2nd Folding bellows was finished.
In the same way the two remaining bellows followed. Once you know how it's done, it's only half as bad.
Then I've still scratched the three Worm gears in the known way.
As next step the assembly of the Screw jacks can follow now,
and following this the gluing of the missing frame struts.
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#2336 by roma847 on 03 Feb, 2023 15:21
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Hello everybody and thanks for liking friends,
I can be honest, it is a new challenge every day to sit down at my craft table because I know what is waiting there again for me ...
A little fun on the side.
In our German forum, a friend was astonished at that my components are narrower than the protruding edge of the 1 Cent coin.
And if he really means the width of the protruding edge of my constant companion, then according to the current measurement it is 0,46 mm wide, which shows, that some of my parts are meanwhile smaller indeed. 
Today I was satisfied with gluing the vertical struts to the frame,
what was also the same stressful business as last time (Reply #2331), 
especially since immediately the first strut dropped out of the tweezers when dipping into the glue blob and was therefore scrap.
The squirrel laboriously feeds itself and is hopping from strut to strut...
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#2337 by roma847 on 03 Feb, 2023 22:39
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Hello everybody,
this was followed by gluing the lower small cross struts (0,25 mm x 0,5 mm x 1,5 mm) at the end of the vertical frame struts.
For the gluing of the Diagonal struts I had to scroll back and look at the special arrangement of the steel rulers for fixing.
Due to the modest artificial light conditions, I've set up my improvised Object lighting with a Headband LED,
which, together with my Headset magnifying glass, gave me the perfect view.
For the gluing of the opposing diagonal struts, the frames had to be fixed non-slip as usual using the super magnets.
And then the frames were finally done.
Next, the Worm gears and Folding bellows can be glued to the Double angle holders. Always nice one thing at a time.
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#2338 by roma847 on 07 Feb, 2023 22:57
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Good Evening everyone,
today in a quick way some images of the gluing of the three remaining Screw Jacks without many words.
After gluing the Gear units onto the fixed Base plates (0,13 mm x 1,4 mm x 1,5 mm)
the Folding bellows were glued onto the Worm gears one after the other.
And here they are standing in rank and file like the tin soldiers,
and can next be glued onto the Double angle holders.
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#2339 by roma847 on 08 Feb, 2023 19:50
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Hello friends,
and thus to the final gluing of the Gear units with the Folding bellows on the Double angle holders.
Next the gluing of the vertical braces to the remaining three frames will follow,
and then the four Screw Jacks are glued to the frames, wherewith finally would be complete this complex subassembly.
