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Skylab, 1/100, Scratchbuild


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The Fruit Dish

 

Perched up on top of this Skylab contraption was a big circular dish thing that surrounded all of the instruments, black-boxes and other fruit that made-up the ‘Apollo Telescope Mount’. The ATM was the principle scientific tool on Skylab and will be a visual focal point on this model.

 

I am not a hoarder.  Not really.  My wife claims that I am but then I claim that she is a ‘clean freak’.  Sometimes however I do keep things that others might not. About a year ago I used the last contents of this aluminium shaving gel canister and noted its concave base. Ever since it has sat quietly in my shed awaiting this big moment.

xiRfrSn.jpg

 

Cut the base off.

tWODUeP.jpg

 

Chain drill a bunch of holes around the outside.

HTymxcS.jpg

 

Use a jeweller’s piercing saw to cut between each of the holes and thereby roughly define a circle a bit bigger than the required diameter.

dquc9k0.jpg

 

Resort to a disk sander to remove the majority of the remaining surplus and finish with hand-held sandpaper.  By the way, as aluminum is a very soft metal there's no real need for specialized metal-working tools for small jobs like this. This is just standard wood-work grade sandpaper for example.

3l0auwF.jpg

 

Voila! One dish thing for on top of the telescope – complete with a circular disk in the centre for mounting all of those weird-shaped little gizmos that did important things back in the day.

eKvzGRX.jpg

 

 

Now at this point I must concede that this is not especially accurate.  The original was not quite as concave as this. This thing is about the shape of a decorative fruit bowl, while the real thing was about the shape of a dinner-plate.  That’s a shame because I’m sticking with this one! There’s something very satisfying about having spotted something ages ago and kept it with a specific job in mind and then seeing that job complete. I'm putting another photo here just to make the point.

6fk5yTa.jpg

 

Right now I’m desperately trying to delay the evil moment when I have to start constructing the complex 3d network of struts and supports that hold the ATM in place. That’s why I think the next post will most-likely concern the rocket engine bell at the end of the CSM.

 

Thanks to everyone who’s following along.

See you soon,

Bandsaw Steve

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1 hour ago, Bandsaw Steve said:

There’s something very satisfying about having spotted something ages ago and kept it with a specific job in mind and then seeing that job complete.

       Gidday Steve, and agreed. Although not in quite the same context as your example here I put aside the not-required rocket launchers from two Airfix HMS KGV kits well over 20 years ago, specifically for my 1941 HMS Hood that I did just over two years ago.

       I love that new addition to your build here, she's quite a dish. 😖 (Sorry, couldn't help myself). But it is an ingenious idea for a use of discarded rubbish.

 

Oh, and BTW

1 hour ago, Bandsaw Steve said:

I am not a hoarder.  Not really. 

I really AM a hoarder. I've got to change.

 

Skylab is really shaping up well. Regards, Jeff.

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  • 3 weeks later...
19 hours ago, bianfuxia said:

how's this coming along?

Star Command this is Bandsaw Steve;

 

No progress to report as of Stardate 2023 10 18.

 

Anticipating some progress during next two-day recreational stand-down.

 

Bandsaw Steve out.

 

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  • 2 weeks later...

The Vacuum of Space

 

Sorry Karman team, I've been absent recently due to a combination of work, family commitments and spending most of my modelling time on the S.S. Xantho project.  As promised though, over the last few days I have made some progress.

 

Here's where we last saw this project, with no sign of any means of propulsion. 

eKvzGRX.jpg

 

As per these drawings the CSM needs a sizeable rocket bell.

bsIDcKz.jpg

 

Since it's a hollow structure I decided to vacuum form it.  I have found that sometimes the easiest way to describe some processes is to write them as if I'm telling you how to do something, so forgive me if this ends up sounding like a lecture.

 

The first step is to make a buck that's the correct shape. The easiest way, in this case, is to turn some suitable wood in a lathe. In this case it's just a piece of everyday dowelling.  At this early stage in the turning process use a wood-turning chisel. I did not photograph that because it's a bit tricky to control the tool and hold a camera at the same time. Anyway just work slowly and keep checking against your plans until you get the spinning lug of wood close to the correct shape.

tfkHzfq.jpg

 

Once the shape is close to correct, fine tune it to the  final shape using files and sandpaper. Then polish the buck with a sanding pad.

opgvQHc.jpg

 

Throughout this entire process you should be checking against a cut-out of the drawings to ensure the accuracy of the final shape.

The buck needs to be about 1mm too small in width to allow for the final thickness of the vac-formed plastic.

aYMW65e.jpg

 

Cut the buck off the dowl and sit it on a vac-forming plinth as shown below.

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My vac-forming machine is a small commercially-available unit that I bought online a few years back. Apparently its main use is in dentistry.  I don't use it often, but when I do I find it fun and effective. 

 

Here's a brief run-down on how to use it (there are plenty of you-tube videos available if you want the full story)

  • Place the buck on the vac-base as shown below and build up the surplus wasted volume around the base of the buck with the small ball-bearings provided with the machine.
  • Insert a sheet of polystyrene plastic in the frame directly above the molding ensuring that it locks into the frame and leaves no gaps around the edge. (in this case I'm using 1.5mm evergreen styrene sheet and it worked beautifully).
  • Swing the blue heating cover into the position shown at the top of the unit. This cover has heating elements in it a bit like those in a toaster.
  • Turn the heat on and wait.
  • Watch the plastic carefully, after about a minute it will be warm enough that it's starting to soften. After about one and a half minutes it’s weakened so much that it’s starting to visibly sag under its own weight.  That’s what you have been waiting for!
  • Switch on the 'model' button to start the vacuum unit in the main body of the machine. It will draw air past the ball bearings and through hundreds of small holes in the vacuum base.
  • Now pull on the red lever (only half in the shot below) to lower the frame, and with it the plastic sheet, onto the buck.  The moment the upper frame engages with the lower frame a vacuum forms and pulls the soft plastic down to conform with the shape of the buck. The shaping is instantaneous.
  • Turn off the heat.
  • Turn off the vacuum.
  • Wait for the plastic to cool.

7eYciNO.jpg

 

With a bit of luck you will get something like this.

oFDYE0l.jpg

 

Remove the plastic from the machine and carefully cut out the required piece. Note that In this case I was wise and had not permanently attached the bell buck to the plinth. This made separation of the final product from the plinth considerably easier.

EGy355y.jpg

 

Now just clean up the part with sandpaper and drill a hole in the top of it so that it can be mounted in it's intended position.

V3cqfEb.jpg

 

And here is the result, temporarily fitted in place with the help of blu-tac.

wD9CdpY.jpg

 

I'm very pleased with this. The size and shape look about right to me and although it's suitably hollow, it's also quite sturdy.

VvBSjLp.jpg

 

That's it for now.  Next, I'm going to continue studying the geometry of the scaffolding, but to buy some time will probably move to the rear of the vessel where I need to make the odd-looking stack of ring-shaped and octagonal structures. 

OIPCGlM.jpg

 

See you soon.

Bandsaw Steve

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1 hour ago, Thom216 said:

Nice mini-tutorial on vac-forming. I bought one of those as well, but have yet to remove it from its box. Looking good!

 

Thanks,

 

Before I actually tried vac-forming I read a bit about it but I found that most of the written descriptions assumed a fair bit of prior knowledge so I tried to make this account as comprehensive and clear as possible. It’s probably a waste of type in the you-tube age though where you can just see it all happen.

 

I’ve been very pleased with my little vac-form unit and find it ideal for small jobs like this. The one observation I would pass on is that vac-forming white polystyrene plastic is easier than clear PTG, so I would suggest starting with white (eg Evergreen) plastic sheets until you have the ‘feel’ of the process.

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       Gidday Steve, you did very well vac-forming the engine exhaust bell. Sorry I somehow missed it on Saturday. Your method of demonstration is also very good. You said your buck was 1mm undersize (I take it 1mm on each side) but you used 1.5mm thick styrene. Is that because the styrene thins a bit when it stretches/forms over the buck?

       The method seems very wasteful of material though. Are the other bits (over the ball-bearings) reusable? If not then I guess that could be used as a rocky/pebbly stream bed in a diorama.

Regards, Jeff.

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On 01/11/2023 at 12:43, ArnoldAmbrose said:

       You said your buck was 1mm undersize (I take it 1mm on each side) but you used 1.5mm thick styrene. Is that because the styrene thins a bit when it stretches/forms over the buck?

       The method seems very wasteful of material though. Are the other bits (over the ball-bearings) reusable? If not then I guess that could be used as a rocky/pebbly stream bed in a diorama.

Regards, Jeff.


Yep. A visual guess of about 1mm was used in the knowledge that the plastic will be stretched and thinned out during the vac-form.

 

And yes. For small pieces such as this there is a high ratio of waste / useful product. On this piece I used about half of a $12 plastic sheet which is an outlay I’m OK with. The main thing here is that the shape formed correctly on the fist try, it’s when you have to try over and over again that the wastage and expense can get silly. 
 

On this occasion I thought about whether I could use the Bubbly shaped plastic that formed over the ball bearings but decided against it and biffed it out. Before I did that though I cut off the still flat sections that were between the two frames, so those scraps may well get used another day.

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Fantastic build and a great subject as well. Also some very useful info on vac-forming - I do believe I have the same machine as yours - I haven't got around to using it yet but your info has given me a new incentive to roll up the sleeves and get on with it :)

 

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Jabba's Palace

 

I'm running out of big components to build but am still desperately trying to stave off the evil day when I have to build that weird gantry that holds the ATM in position.

Luckily there are a couple of biggish bit's left. Including a distinctive octagonal radiator and a bulbous thing that housed gas bottles (oxygen?) at the rear of the ship. These things looked very simple to build so one evening I just waded in.

It involved more lathe work - which is a fine thing as far as I'm concerned because this lathe is just so much fun to use.

U9ITP9r.jpg

 

 

IbuMsa2.jpg

 

Pretty soon I had turned out a great model of Jabba the Hutt's palace, although if you are a brainless computer algorithm it might look a bit like something that 'violates Imgur's community standards’ so I suspect this photo might disappear soon. 😬 (Exactly that happened to a photograph of Xantho's hull recently).

jP2uyHv.jpg

 

Anyway - after cutting the dome off the top of Jabba the Hutt's desert hut I had a suitable shape to add to Skylab's rear end.

FO8yYHc.jpg

 

Then I started on the octagonal radiator that sat on top of Jabba's dome.

J9FqrhM.jpg

 

This structure was absolutely featureless on the outer-facing surface but a bit more involved on the surface facing back toward the ship so I had to do some detailing work.  I tried using 'Tamiya Airbrush Cleaner' as an extra thin cement for some of the non-structural details and it worked beautifully.

pyLozfu.jpg

 

HYfv5BE.jpg

 

Here is the finished bit ready to be plonked onto the 'top' of the dome piece.

DU0Kh7J.jpg

 

The dome was a bit rough so got treated to a couple of rounds of fill, sand, fill, sand etc.

TRG4m9F.jpg

 

A pretty easy step forward in the great scheme of things, but...

TxD3ALJ.jpg

 

If you look closely directly under the Apollo Telescope Mount you can see that the first exploratory brass work has begun on the gantry.  

8ettF81.jpg

 

The era of procrastination is coming to an end.   Soon this gantry must be tackled and I'm anticipating that it will be the single-most difficult thing I've ever scratchbuilt.

 

I need some suitable, ideally relevant,  'Jabba the Hutt' quote to finish on but can't think of one right now.  Feel free to throw ideas about.

 

Best Regards,

Bandsaw Steve.

 

 

 

 

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Delaying Tactics

 

I am currently still trying to work out how best to build the complex, geometrically weird & irregular gantry that holds the ATM in place. I’m starting to formulate a plan that I think is worthy of an attempt but I am not sure that I’m fully prepared for it just yet. 

While dwelling on this, the clever idea came to me that there was one way that I could work on this project without actually working on the model. Sooner or later this thing will need a display stand.

 

Here is a racy looking base marked up on 16mm MDF.  I thought I’d go for something a bit more ‘space-age’ looking than just a straightforward oval.

KCFyqNp.jpg

 

And here’s the start of the upright pillar.

sN8PHz8.jpg

 

With the base cut out this looks a bit like the Orion Space Clipper from 2001. Is this a happy accident or is something deep and subliminal going on in the background of this old 2001 fan’s brain?

z2RZ01v.jpg

 

A dry run with blu-tack and a – still painfully incomplete – 1/32 Mirage III balancing on top looks promising.

mCRpbjQ.jpg

 

With two dowel prongs drilled into the top of the thing the stand is ready to go.  Note that in this case the rear prong is about 1cm longer than the front one. I’ve found that if you make one prong longer it’s easier to mount the model on the stand. Just connect the model onto the longer prong and then turn it until the second prong / hole is aligned, then lower the model into its final position. If the two prongs are the same length you have to line them both up at the same time.

cHSnMFi.jpg

 

Drill two vertical holes at exactly the correct size and spacing in the base of the model.

4vt5o8W.jpg

 

Test Fit. Here’s the result!

i6Lvywn.jpg

 

I’m happy with this!👍 

 

This step has been especially pleasing since my elder daughter, who just on Saturday was telling some of my mates how tired she was of me going on and on about ‘Bloody Skylab!’, told me she thought it ‘looked pretty cool!’

:speak_cool:

High praise indeed! Enough to warrant another photo.

 

Cm6Mb7e.jpg

 

So, delaying tactics have been successful for another week.  With a bit of imagination I might just be able to hold off starting the gantry until about December 4th, which is just long enough to see out this group build. 😊

 

Best Regards,

Bandsaw Steve

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23 hours ago, Bandsaw Steve said:

holds the ATM in place.

I know it's not that, but my first thought on reading that was "do they need cash in space?" :cwl:

 

The stand is really good, Steve, nicely done there. Is the Mirage made from metal, or just foiled?

 

James

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