Stug III Ausf.G from scratch

[Matias]

I have always wanted to build a model of the Stug as were used by Finnish troops during the WW2.
The first question when starting a new tank build is: "Where to get the tracks". I was planning to make a pattern of Stug track link and have them cast of aluminium, but then I managed to purchase readymade tracks from Armortek. And this was a "starting bang" for my project.


The tracks as arrived:



The beer can is there only to show the size for those not to understand the scale. (Well, later on also the contents of the can proved to be of help).



As always with my projects, I started the work making the wheels. In this case it ment to build the track wheels, sprockets and idlers.

For the sprocket & idler I made first patterns of Necuron, machinable plastics, which is very easy to turn, mill, saw and sand. From these patterns final wheel halves were sand cast professionally.

Idler pattern and cast wheel halves glued together and equipped with ball bearings:





The sprockets were made in a similar way. The "teeth rings" were first drawn with CAD and then laser cut from 4 mm aluminium. Finally they were fastened to the sprockets with M2 bolts and nuts:







For the track wheels I first made patterns from Necuron. Then molds for outer and inner wheel halves were cast of silicone rubber, and final wheel halves cast of PU resin. To strengthen the wheels, aluminium flanges were glued to each wheel half. Then they were equipped with ball bearings and glued together with epoxy using short lengths of brass tube, exactly the same way as originals were made.

First I tried to cast the track wheel tires out of flexible PU resin, but that didn`t quite succeed, so the tires were professionally built.

Track wheel pattern, mold and cast wheel halves:





Track wheels ready with tires:

[pangaloss]

You have my attention. I'm very interested in watching this build develop.

Cheers

Tim

[Matias]

Thanks Tim for watching!

Next I had to concentrate into the swingarms and their bearing into the lower hull. In original Stug the swingarms are located very low, almost on the hull bottom level. They are installed using "bearing blocks" which extend below the hull bottom:






I wanted my model to be as accurate as possible also underneath, so I had to make same kind of bearing blocks out of PU resin:



Small pieces of brass tubing were inserted into the mold before casting the resin. These tubes are working as slide bearings with swingarm shafts made of 8 mm silver steel.




The "skeletons" of swingarms were made of 8 mm silver steel & flat bar which were welded together. These skeletons were then inserted to silicone rubber molds, and outer form cast around them using again PU resin.

Swingarm "skeletons" and ready made parts:



"Guide plates" at the lower end of swingarms are also cast parts made of PU resin.



Ready swingarms with track wheels installed:

[viaad]

Nice detail! These builds on the forum are becoming very fun to watch.

[Warriorant]

Wow

I'm looking forward to watching this with interest. I'm always really impressed by the expertise on this forum with real scratch built models.

Keep the photo's coming and thanks for sharing.

Antony

[Falckner]

Looking forward to follow this
great to watch so talented builders.

[vehicle]

nicely done

keep us updated!!

vehicle

[TBowman]

Hi Matti

Glad to see your incredible Stug III project posted here. I love those swing arms and all of your scratch-built parts for this vehicle. Excellent detail and accuracy.

Looking forward to seeing the whole project story.

Thanks for sharing.
Kind regards
Tim

[Germanbilly1]

Now this is going to a build to watch. Your attention to detail is really showing.
GB

[Matias]

Thank you guys for your kind words! Nice that you want to follow my humble project. A little update:



Now I had to make a hard decision: Which material shall I use to make the model? The options are: Metal (steel or aluminium), polystyrene, or aircraft quality birch plywood.

Steel is too heavy, and difficult to cut and join with my equipment. Aluminium would be lighter but also very difficult to join. Polystyrene is light, easy to cut & machine, and easy to glue. And finally plywood is also light, strong, easy to cut and glue, it is cheap and a domestic (Finnish) product. Long discussions with people who have used plywood as main construction material for their 1/6 tanks got me convinced that plywood it must be. Also I wanted to keep the model as light as possible to be able to move it easily.

So I purchased full sheets of 5 mm and 2,5 mm thick airplane quality birch plywood and started to work.


First the bottom plate, side plates & front and rear armor plates were drawn with CAD and cut with my CNC router:



The surface of the plates was handled to imitate hot rolled armor plate by spreading thinned carpenter filler (consistency like yoghurt) with a sponge, and sanded lightly when dry. This gave quite realistic look for the plate surfaces.
Then the lower hull was glued together, swingarm bearing blocks bolted to the hull, bottom plate was equipped with all bolt heads, hatches etc. and swingarms installed into their bearings:








And soon the lower hull began to look like a tank:

[Tigertiki]

Hi Matias,
Fascinated with your build of the Stug. I have a couple of questions. Did you thought about to spincast the track links out of Zamac ? And about the rubber, i casted successfully wheels for my 1/6 puma using Neukadur HS 55-30.Shore 55. Available in Europe.. That would be good for your wheels. And did you knew that aluminum can be soldered ?
YouTube - Durafix Aluminum Welding Rods i just discovered it a couple days ago but i welded Aluminum before and it was a headache.. I'm sure it will suit you in the project. You can use any burner for the weld. I saw your jeep project and i liked it a lot especially that you made the axels.. Is your router laser or mechanical ? I watch your project so i can learn some for myself too. Scratchbuilding it is not so impossible if you have some equipment available. A lathe and a cnc router is a must for pozitives.
Cheers
Attila

[johnro6659]

Awesome, The Stug is my second fav German tank. I always wanted to build one of these. Your masters and cast stuff look great.

[gimpy117]

very nice. are you a machinist?

[Sixth Vanguard]

Very exciting to watch builds like these! Thanks for sharing the wonderful work!

[Matias]

Tigertiki: Zamac and Neukadur are completely uncommon for me. I have to study more these materials. Maybe I can use them in my next project. Thanks for info!

Yes, I am aware that aluminium can be soldered. In fact I have the equipment and soldering rods, and have practized this a few times. But somehow I think this is not for me. Also it is a bit difficult to get thicker aluplates in a smaller quantity. And if you buy a full lorry is a bit expensive. Also I consider even aluminium a bit too heavy when compared to plywood.

My router is mechanical form a German company EAS GmgH. I have a Wabeco lathe and manual milling machine Optimum.


Gimpy117: No I am not a professional machinist, but a retired process control engineer. But I have made models for years and have learned machining skills only by "learning by doing" method.

[Tigertiki]

Thank you for the answer Matias. And about Aluminum :If you have a company in your area who builds small trailers or lorries they ususally have scrap Aluminum they pay to get rid of. And also the Al dealer who usually debit (cut) the aluminum has scrap too all the sizes. I got my materials from such a company and they give me for free and i feel like in haven..
Hope it helps, good luck with the project i enjoy to watch..

[Matias]

Again it is time for a little update. Next I started to work with details for the wheels.
A cover for final reduction gearing was made from Necuron and equipped with ball bearings. There are no gears inside, only a form piece:



Sprockets installed:



Next I made the guides for swingarms. They are fabricated of small plywood parts & handled with thinned filler to resemble cast parts. Bolts and nuts are M2 brass:




The next thing to do were the shocks. They are made of hydraulic pipe, PU resin castings, Necuron and small brass screws:



Upper track wheels are completely cast of black coloured PU resin. Rims are painted with grey car body primer:



First I thought to make the track tensioning system to work as original, but stresses would have been too much for tiny parts. This is why the outer parts are only fake, and track tension is adjusted inside the hull with crude but working mechanism:





kkk

[Falckner]

This is so good!
Please keep us updated .

[TBowman]

Outstanding!

Keep the photos coming Matti. Enjoy every post.

Best regards
Tim

[Germanbilly1]

I like the welds you are doing on the wood. If I welded wood I would have a Big Fire, LOL
GB

[Matias]

Originally Posted by Germanbilly1

I like the welds you are doing on the wood. If I welded wood I would have a Big Fire, LOL
GB

As you might already have quessed the welds are the same carpenter`s filler with which also the armor plates have been treated.

Some update

Tracks first time on:

[Tigertiki]

Truly amazing. Is the wood treated against moisture ? I assume that it will be RC-d ?
Regards
Attila

[Tigertiki]

Truly amazing. Is the wood treated against moisture ? I assume that it will be RC-d ?
Regards
Attila

[Matias]

Originally Posted by Tigertiki

Truly amazing. Is the wood treated against moisture ? I assume that it will be RC-d ?
Regards
Attila

Hello Tigertiki! The wood is first handled with this filler to get the surface look as rolled armor plate. Later the whole vehicle is sprayed with car body primer, and painted with camo colours. After that it is varnished with matt varnish. So I think it has been sealed enough against moisture. After all the aeroplanes made of this material are used outdoors too. And my intention is not to drive into water ponds.

Yes, it will be RC`d. My intention is to build a sound unit with original Stug sound & a smoker inside too.

[Matias]

"Forward" said grandma` in the snow.

Next I started the upper hull construction. It is also made of plywood, thickness 2,5 mm. Surface treated to look like armor plate:





The gun barrell was made of conical fibreglass fishing rod. Unfortunately it was not conical enough, so it had to be treated with car body filler and turned smooth in the lathe. The muffle brake came from my friend T.Bowman. Thanks Tim!

[pzrwest]

I see someone else has used old fiberglass fishing rods for barrels. To increase the diameter of the barrel I use butchers cord would around the rod section then soak the string with polyester resin and let it cure then lightly sand and add layers till I get the outside diameter I need. Old fishing rods are easy to find at yard sales.

[Matias]

Next thing to do were the mudguards. The originals are made of special plate which has thousands of small raised dots:



I tried to get similar readymade plate but couldn`t find anything even near. So nothing helped but "bite a bullet" and start making my own. After numerous attempts I finally found a useful method to produce these. A very thin aluminium folio was attached to the table of CNC router. Without the spindle running, little dots were pushed into the folio, and voila, I had the plate I needed. The folio was glued on thicker aluplate and mudguards were fabricated from this:



And they look quite original:

[johnro6659]

I really love the speed you building this at and work your putting into the Stug. I am not a big fan of using wood I prefer plastic but I have to admit I have seen several guys use wood and I think I will consider it and/or sheet metal at some time in the near future. Plastic is just getting expensive these days. I think my supplier has gone up in price several times now. Great idea on making the dimpled metal plate. What plans did you work from eventually I want to build a Stug and love to see what people are using for, or to make up plans. I have several books by Bradford with 1/35th scale drawings on just about every W.W.II vehicle both US and German. I can get them scaled up at my local Staples. I found that they do decent work for very reasonable prices. I have access to a machine shop actually three. I could have stuff done on the side but I need to learn how to make up the CAD programming so they can cut up the parts for me. It looks like your pretty much done a few details and some paint. I can't wait to see it finished.

[Matias]

Hello Johnro6659 and thanks for watching my build!

As you may quess, the project is at present almost ready, and everything I have shown is more or less history. This is why it seems that I am the fastest builder in the world. Until today I have used about 18 months for the build.

As a reference for my build I have used Walter J. Spielberger`s wonderful book: Sturmgeschütze, Entwicklung und Fertigung der sPak. The drawings in this book have been enlarged into 1/6 size and printed on paper. Then I have used Tamiya`s 1/35 plastic Stug kit for some measurements, and finally taken a lot of measurements & pictures of real Stugs at our tank museum: The Armour Museum, Parola,Finland - Home page where among others are a couple of Stugs in running condition.

For me the most important role in building has played my CNC router: EAS GmbH - Komplettpaket CNC-Frsmaschine / Graviermaschine - EAS(Y) 440

which cuts very easily plywood, plastics and alu. This company sells also a CAD/CAM package called Vector which is quite easy to learn and use.

[vehicle]

wow!!!! That looks great. very nicely done. Keep us posted.

vehicle

[bullit]

one of my fav's piece of armor....
amazing work you do there!!

best,
stephan

[Matias]

Thank you guys for your kind words!

And now it is time to make more details:



In Finnish Stugs the spare track wheels were installed on fighting compartment side walls:








Original machineguns were replaced by Russian Degtarjevs. These were nicknamed "Tank-Emma" by crews:



At the back there were big boxes for auxiliares where tools & tank crew`s personal effects were stoved:

[chavaTX]

Wow! Fantastic work all around! I like the Soviet gun as well.

[Falckner]

Its a real beauty.
Love you´r work on all the details.

[inxsone]

Really beautiful work and attention to detail...

[Tigertiki]

Hi Matias,
It was suspicious to me as well how quick this Stug was built but there are no miracles in scratchbuilding. I love the brass parts too, did you made them ? I like the iddea of the Alu plate forming with the CNC mill since i have to do some flooring for the SdKfz 251. Keep up the nice work. This is the actual stage ??
Cheers

Attila

[Matias]

Thank you ChavaTX, Falckner and Inxsone !

Tigertiki: Yes, I have made all brass parts too. The actual stage of the project is: Motors and electronics installed, painting almost done. Weathering still to be done.

[Germanbilly1]

That is one perfect looking Stug. Detail is museum quality.
GB

[TBowman]

I'm speechless.

[Panzercommander HOH]

Agreed - this is simply AMAZING!

I don't know where to begin - I'm extremely envious of your skills!

GREAT JOB!

Fred

P.S. I'm kitbashing a Lagus Division tanker figure in my head for your Stug...

[toychest]

Very nice indeed ,wish I could get such detail as you have. Will be great to see it painted.

[Matias]

Thank you all for your kind and encouraging words! As far as I have seen, your models are also of very high quality. I have only tried to follow the quality and detailing shown here on this forum.



Next thing to do was to install the motors. I have used Chinese electric scooter motors with 12 V 150 W and nominal speed 2600 rpm. Motors have very high torque, so there is no need for high reduction gearing. Primary gearing is made using worm and wormgear with 15 teeth. Secondary is made using roll chain and sprockets with 15 and 30 teeth. This gives total reduction of 1:30, which should be about right to give the model scale speed.
It is very easy to change the sprockets, if different reduction is necessary.

On this picture you can see also the suspension of track wheels. First my intention was to build a torsion bar suspension, but it was very hard to know, which material and diameter torsion bars should be used. This is why I decided to use this simple and crude suspension system made with coil springs. If not suitable, the coil springs can be changed very easily.





Smoke generator came from Mr Richie Wignall. Exhaust pipes are made of pieces of copper piping, and mufflers from Necuron:



Smoke generator installed to the rear of model:

[Matias]

And then the electronics. I decided to use the 12 V 12Ah lead battery because of it`s high capacity. It is quite heavy, but luckily the model is light, so total weight is reasonable.

Up left in the picture is the battery. beside it are the loudspeakers. Middle left is a 2x40 W amplifier for sound unit. In the middle are 2 relays for steering. These cut power from appropriate motor so that the model will turn. Middle right is the Benedini TBS5 sound generator packed with Stug original sound.
Below left is the RC receiver. In the middle is electronic 2 channel switch to control the steering relays. And below right is the ESC: Castle Creations Mamba Max.






Components installed into the hull:




Under the engine compartment`s left side hatch are the fuses, charging socket for battery and main on/off switch. Under the right hand hatch is the filling hose and voltage control potentiometer for smoke generator:

[Matias]

And now finally to the painting.

First the whole model was sprayed with car body primer to have a good surface for all materials like metal, plywood and plastics, where the surface coats can adhere.
The camo scheme was brushed using Vallejo Model Color acrylics. Shades 892 (green), 941 (brown) and 821 (sand) were used, because according to specialists these are the nearest that were used during the war.
This was followed by clear varnish, onto which transfers were attached. After dry, a few vashes were made with black, brown, green and yellow oils diluted in turpentine.
And the final layer was sprayed with matt varnish. Onto this some more weathering was applied with Mig`s Dry Mud pigments.

"Tank-Emma" was brushed first with Vallejo Gun Metal. When this was dry, a thin layer of Gunze`s dark Iron was applied, and brushed lightly with stiff brush. This gets the shiny outlook of metal.

The tracks were brushed with a mixture of matt varnish and Mig`s Dark Mud, and when dry surfaces were brushed with steel wire brush to get original shiny metal appearance.

And finally the model looks like this:

[pzrwest]

Vey nice Finish Stug III. Do you have any vids of the Stug? Love to see this gem in action

[Tigertiki]

Hi Matias
Amazing work, it is standard setting for me ! True museum quality ! Would love to see some video of it. And how about gun elevation and some pyrotechnics w/ recoil ?
Cheers
Attila

[TBowman]

Truly an amazing work of art Matti.

Finished photos look real and it can't get any better then that. Thanks again for sharing this project here. It's fun to see it posted as a whole project so quickly while I know you have been working on it for some time.

Just beautiful.

As others have said, looking forward to the video.

Kindest regards
Tim

[Hammer's Africaners]

Fantastic work!

[gary1930]

Great work! You should be very proud.

[Germanbilly1]

Very Nice, really did like your build photos. The finish is perfect.
GB

[The_Dutchman]

I can't but agree with all the other comments. An excellent build report on an excellent vehicle!

[Falckner]

Totaly amazing build !
You did a tremendous work
and should be real proud off you´r
self.


3 things about it that I like,and make it stand out
in my mind.

1. Not a Tiger 1, Panther or other Tank
You choose to do a Stug III
2. You do a Finnish Stug and a very fine one
3. You did most off the things/parts you´r self .

My salute for you´r build

[sgtbilko]

Great build

[Sixth Vanguard]

Pretty amazing vehicle Problem with posts like this is it makes my feeble plans seem even more feeble

[Hoffner]

That thing is really bad ass.

[Matias]

Thank you all very much for your kind and admiring words! This encourages me to start a new project. Well what should it be? I don`t quite know either, but somehow I just like the old tanks like Renault FT or T-26...

Pzrwest, Tigertiki and Tbowman: I intend to make a video of the model, but it must be done outside and now we have here -20 degr. Celsius and about 50....100 cm snow. So we have to wait for a couple of months that the snow melts.

Gun barrel hoisting is made with a regular servo, but there are no pyrotechnical functions or barrell recoil systems. Maybe in the next model....


Falckner: Thanks for your words! Somehow I just love these older Finnish vehicles used during the last wars. Maybe because my father used to fight "somewhere there" in both wars.

Amaral: After all I spent about 18 months building the Stug. I issued this thread only when it was almost ready.
I would like to have a crew, but there is a problem of right clothes. Ready Finnish tank crew clothes are not available, and so far my wife has declined to make them. And I cannot use the sewing machine...

Sixth Vanguard: I had exactly same feeling when starting this build and watching other people`s wonderful projects. But you only have to start building. And have good references. The rest is easy.

[xacto11]

Matias,
I would first like to congratulate you on a extraordinary Stug! I love the fact that you used wood to construct the hull and gives me hope that the PzIII that I have started in plywood will be a success. I think the finish of the paint and weathering is also very good.
As for your next project possibly being an FT, I just wanted to say that long ago I sent Panzerwerk masters for track links but unfortunately he indicated that while they could be cast, the molds would not last long. Maybe if we ask real nice we can get two sets of tracks cast for us. C'mon Steve you know you want to
I also like the idea of a T26. I enlarged plans few years ago. That will be a big tank simple suspension though.
Looking forward to seeing your next project, no matter what it may be.

[johnro6659]

AWESOME! Love it!

[Matias]

Originally Posted by xacto11

Matias,
I would first like to congratulate you on a extraordinary Stug! I love the fact that you used wood to construct the hull and gives me hope that the PzIII that I have started in plywood will be a success. I think the finish of the paint and weathering is also very good.
As for your next project possibly being an FT, I just wanted to say that long ago I sent Panzerwerk masters for track links but unfortunately he indicated that while they could be cast, the molds would not last long. Maybe if we ask real nice we can get two sets of tracks cast for us. C'mon Steve you know you want to
I also like the idea of a T26. I enlarged plans few years ago. That will be a big tank simple suspension though.
Looking forward to seeing your next project, no matter what it may be.

Thanks xacto11! Now that I have gathered experience of airplane quality plywood, I just love the material. Strong, light, keeps it`s measures good and very easy to work with. I`m sure the next project will be made of this material too.

Concidering the track links for FT I would be very interested to hear more. And the enlarged drawings for T26, do you still have them? Would you like to sell them for me?

[Squidley]

That is just a fantastic build. Stug III has always been one of my favs, and you've done it justice.

Truly a museum quality piece.

[vehicle]

That came out great!!!! thanks for taking us thru your build.


vehicle