Scratch built 1/32 Saab 210-2 Lilldraken

[Derek B]

Now that looks nice! Grat job, Derek.

 

Cheers

Rainer

 

Thanks Rainer - I am simply following in your Viggen footsteps.

 

Derek

[Christoffer Lindelav]

Hello Derek

Regarding the J21 I am having a dream of making a model out of that one but to be honest it´s a huge task I think. The first step is to actually complete the master and then we´ll see if it´s gonna be a one-off just for me or if I have the courage and time to make a model of it.

Carry on with your Lilldrake

/Stoffe

[Derek B]

Hello Derek

Regarding the J21 I am having a dream of making a model out of that one but to be honest it´s a huge task I think. The first step is to actually complete the master and then we´ll see if it´s gonna be a one-off just for me or if I have the courage and time to make a model of it.

Carry on with your Lilldrake

/Stoffe

 

 

Hi Stoffe,

 

Having made many full vacform and resin kits in the past, I can certainly attest to the dgree of difficulty invilved in developing and producing them. However, your J21 looks like it is well on the way to becoming a very nice little model in its own right.

 

Derek

[Derek B]

I am a bit of a modelling Magpie when it comes to collecting unusual bits and bobs as potential modelling and detail items, and I also believe in recycling materials and minimising the use of them when I can, so about 20 years ago, I found a discarded plastic slippery floor warning sign that I thought may be of use at some future point in time...I rediscovered it last night and thought 'I could make use of that'!

 

The plastic placard looks like it is made from some form of HIPS and will take liquid cement. It is approximately 1.4mm thick so is ideal material to form the basic keel shapes for my Lilldraken.

 

It's pretty amazing what materials you can use for scratchbuilding if you really put your mind to it

 

Basic fuselage side profile roughed out close to the required outline using a heavy duty Stanley knife

 

Shape sanded to the correct profile and is fractionally larger all around than the template

 

Can you see what it is yet? Good game of joining up the dots to form the plan profile shape of the Lilldraken

 

Plan profile shape cut out oversize

 

Profile shape roughed out with a heavy duty Stanley knife close to the scribed outline shape

 

Enough for one evenings work

 

Derek

[Derek B]

Spiffy yellow colour too!

 

Great progress Derek, looking good.

 

Dan

 

Thanks Dan

 

Derek

[Derek B]

Little more work on the yellow peril...

 

The plan form of the Lilldraken is now fully shaped and all of the black sign markings have been removed by sanding (which took ages). You will also notice the obligatory memorial banana milk shake (this build is for you Russ).

 

Close up of the cleaned up plan form keel. The three marks on the left intake area are indications of stress cracks in the plastic sheet - it is bent across the width of the fuselage diagonally. This is something that I didn't realise before I drew and cut it out. It has now been straightened out again with the aid of some hot water and a little brute force and ignorance.

 

Fuselage now keel fully to the correct size and shape. The jet pipe, compressor and intake and cockpit areas have been scribed onto the plastic.

 

Engine intakes, jet pipe, cockpit and undercarriage bays have been marked out on the plastic.

 

Close up of marked areas. Next will be fuselage cross sections.

 

Derek

[Christoffer Lindelav]

That´s nice Derek, don´t slow down now and keep the momentum going. Thanks for the info on the banana shake in that cup, I thought it was some kind of glue first...

/Stoffe

[Derek B]

Thanks for the info on the banana shake in that cup, I thought it was some kind of glue first...

 

...It can taste like it sometimes!

 

Derek

[Rainer Hoffmann]

Brilliant, Derek. I hope you start with the air intakes. They look a bit like the ones in the Viggen, so I would like to borrow some of your techniques

 

Cheers

Rainer

[Derek B]

Brilliant, Derek. I hope you start with the air intakes. They look a bit like the ones in the Viggen, so I would like to borrow some of your techniques

 

Cheers

Rainer

 

Thanks Rainer. I think that the intakes will be the most difficult part of the whole build!

 

I have an idea of what I want, but no clear idea of how to achieve it. I think that I will have to look at the Draken intakes again and see what they look like internally and see if I can get away with making them symmetrical for most of their length?

 

Cheers

 

Derek

[Derek B]

Thanks to the generosity of an LSP member (thanks trooper), I now have my new 1/32 Saab chief test pilot - Introducing Major Erik Falstätt, who has many hours of flight testing under his belt...If the aircraft he flies decides not to let him down!

 

I will need to modify his parachute to a seat type parachute and a few other modifications. He will be popping in from time to time to watch the progress of the Saab 210.

 

I have managed to find some scrap items to help with the detail work on the engine. The engine intake cone fairing is from some unidentified bomb tail section. The compressor fan is taken from a 1/48 S-3 Viking, the turbine blades are from an unknown source and the exhaust jet cone is from a 1/32 F-86 Sabre. All of the parts will have to be modified to be accurate for the Saab 210-2.

 

Close up of engine parts. The rear face of the compressor fan has been scribed to the required diameter needed for the Saab 210.

 

The engine compressor fan following reduction to the correct diameter.

 

Rear face of engine compressor following reduction in diameter.

 

Existing engine compressor fan nose cone removed and hole opened up for new nose cone fairing.

 

Another view. This fan will have to have every blade reshaped sharpened up following the sanding of the front face.

 

Derek

[Derek B]

A little more WIP. I was not completely happy with the engine turbine disk, so I selected another one. This one is slightly undersized in terms of actual blade disk diameter, but looks better.

 

Picture of the new turbine disk and the tubine shock cone fashioned from the F-8 Sabre item.

 

It required reducing in diameter at the base, so here you see it being checked with a circle template to ensure that all is good during the sanding process.

 

This gives some idea of how it will appear upon completion.

 

Similar attention was net given to the compressor an end of the engine intake cone. The front has yet to be shaped and modified.

 

I have not been able to find anything suitable for the jet pipe (which has an 8mm ID), and as I could really do with making it seamless, it means that I really have to put my thinking cap on (I do have an idea, but I have never tried it before - this is the fun part of scratcbuilding; experimentation!).

 

I also have to make a jet pipe cone for the turbine end, which in itself is a little challenge as I have to make two separate sets of cruciform turbine shock cone supports to go inside it.

 

Derek

[Rainer Hoffmann]

Hi Derek,

 

I just had a closer look at your drawings - and what must I see? Metrical measurements! I'm in awe But then, it's the 21st century and may be even you guys on that island in the north sea can appreciate that invention from the continent...

 

Great work, Derek. I'm really enjoying this.

 

Cheers

Rainer

[Christoffer Lindelav]

Mmmmm... Metrical, I like that.

/Stoffe

Hi Derek,

 

I just had a closer look at your drawings - and what must I see? Metrical measurements! I'm in awe But then, it's the 21st century and may be even you guys on that island in the north sea can appreciate that invention from the continent...

 

Great work, Derek. I'm really enjoying this.

 

Cheers

Rainer

[Derek B]

A little more WIP. The cntre of the turbine disk has been drilled out and a disc of plastic fashioned to act as a mounting platform for the shock cone assembly.

 

The intake nose cone has also bee shaped at the front and a cooling hole made from a plastic lolly stick tube, kit sprue plug and another plastic tube insert - the whole superglued to the front of the cone and sanded to shape.

 

Another view.

 

So, I needed a suitable tube for the long jet pipe with an 8mm internal diameter. The only problem is that I could not find anything to hand that was suitable for the task. The solution, form my own from Milliput. This is an experiment, so at the start of this process I had absolutely no idea whether the plan would work or not...all part of the fun .

 

I found that my aluminium modelling knife handle was a fraction under 8mm in diameter, and more importantly, long enough for the task. I started by working out how long I needed it and marking this out a little oversize with two windings of masking tape on the handle. This served two purposes. the first was to made two neat ends. The second was to build up the masking tape windings to a sufficient amount that they became my depth guage for the eventual wall thickness of my Milliput tube.

 

I mixed some PVA wood workers glue with water and applied this as a non-stick layer to my handle. Once dry, I applied a layer of vaseline petrolium jelly to the surface as additional non-stick lubricant. I mixed a good sized ball of Milliput from my 5 year old pack of Milliput and squeezed it around my handle then rolled it loke a rolling pin to create an reasonably even layer then left it to harden overnight. If it works I will end up with a thin seamless tube or if it fails, I will gain a new illiput grip for my handle!

 

Here it is after I have filed and sanded it down to the masking tape and removed the masking tape from the handle. Now is the crunch time...Will it work or not?

 

I could not budge it by hand at all, so I had no recourse but to use the very risky technique of having to use brute force to shift it. I put one end of the handle in a vice and using a pair of pliers clamped around the Milliput tube cushioned by a thick sheet of rubber (and a few prayers) I applied a torque force to it to break it from its hold on the handle. A audible crack ensued and the tube moved. Once I had removed it from the handle I could see that the seam where the Milliput joined had come apart. I applied a layer of superglue to this seam on the outside of the tube and sanded it smooth. What you now see id the end result. I still have to clean the inside of the tube and shorten it to the correct length and sand the ends square, but at least I noe have the jetpipe that I need.

 

End view of the Milliput jetpipe tube showing how thin I ended up sanding it. The masking tape diameter was approximately 9.2mm, so I thought that it would be about 1mm wall thickness when finished, it actually came out about 0.6mm in the end.

 

I decided that I needed an engine casing around my compressor fan to mount my five nose cone support frames onto as well as reducing the fan diameter (I know that it is actually a turbo jet and not a by-pass fan engine, but forgive the errant description). To do this I found an old till receipt roll plastic inner which matched the outside diameter of my fan, so I recduced the diameter of the compessor disk to match the internal diameter of the till roll tube after first cutting a slice off it.

 

So, this is where we are at the moment with the engine cold and hot ends.

 

Did the jetpipe tube experiment work? My conclusion is yes and no. I did not achieve the seamless tube that I wanted, however, I now have a jet pipe that is the correct size and will be satisfactory once I have cleaned it up and made it the correct length. With some more thought and development, this method might work for my intakes as well. If I were to make another one tomorrow, what would I do differently?

 

I would:

 

a. Apply more masking tape (Make it 2mm larger than the ID size)

b. Apply at least two or three coats of watered down PVA glue to prvide more if a non-stick cushion between the Milliput and the handle and apply more petrolium jelly.

c. Once my Milliput is mixed, put a hole in it (like a donut), insert the hndle through the hole and squeeze the Milliput into place - this should avoid any seams being formed in the final tube.

 

When I said that this GB is all about pushing your own limits and developing skills and techniques that we can all learn from (myself included here), this is exactly the sort of challenges that I expected and wanted to share with you all.

 

Derek