Opel (Vauxall) Kadett V8 GTR 1:10 scratch build

[Midnight Creep]

Hi,


My name is Peter and i would like to share this build with you.
I've already been posting it on a Dutch forum for a few months now but I like to share it with more people.


My interests are race cars and perticular in Hill Climb Cars.


I'm gonna split the first threads in some pieces to make them a little bit shorter and so i can give the threads a "NAME"


This threat will be named "Car presentation"



This car is also a hillclimb car.
It was build by a German team lead by Holger Hovemann.
He owns a garage in Germany for overall works at all type of cars and this garage also does car tuning.


Holger is also the driver of this spectacular car.






On the outside it is a Opel Kadett Coupe which were build from 1973-till 1977.
The actual car underneath the body is a Corvette C4 Chassis which was modified to fit the Kadett body.




The bare chassis from a C4 Corvette looks like this:






They cut of all of the above section and afterwards it looks a bit like the next picture (this is not the actual chassis from this car but just an example)








The engine is also not stock, stock engines from a Opel Kadett are max 2.0 liter with 115 Bhp.
This car is fitted with an engine developed by Chevrolet and Lotus, its a 5,7 Liter V8, non turbo with standard around 375 Bhp.


The Hovemann team increased the power of this engine to a stunning 805 Bhp als without turbo which is essential because that determines in which class the car is gonna participate in the races.




Many parts from this car are build or modified by the Hovemann team.
Some of those parts are :


Engine suspension, exhaust, engine cooling, the wide Body, the diffuser at the back of the car, and a lot of small other things inside the car.


This is the end of my first thread, I hope u like it.


The next thread will have the name "Research and Design"

[Midnight Creep]

Ok, lets continue with the next post.


Like I said in the first post this one is called "Research and Design"


The previous car models that I build are all at scale 1:24 but i like to try to make a bigger model to put in more details.
I have choozen to make it in scale 1:10 because it it an easy scale to calculate from original to my model and it will fit my workspace quite good because its not so big.


There are not many Opel Kadett Coupe kits for sale, most of them are die-cast cars in the scale 1:18 or smaller.


Recently the manufacturer Arenamodelli lanched a 1:24 kit, but like I said I want to make a bigger model.


That means I would have to make it myself and for that there a several options:


1: Make it out of resin, for that I will have to make a master first but this will take a lot of time and the results if u never done it before are mostly not that good.
So this is no option for me.


2: Vacu-vorm the body, for this also i would have to make a master and again like de first option the result will probably not satisfy what i have in mind.


3: Make a body like they make wooden boats.
This is als a way they create bodies from old (racing) cars by hand.
They use a wooden frame which has the shape of the body and fit all handmade bodypanels around this frame.


This is what i mean:






For this methode i will have to divide the car in several sections to make all the trusses which will have to be coated with strips of styrene.


To create a firm body i will have to coat the frame with at least 2 layers of styrene.
The first one over the lenght of the body and the second one across the first layer.


This 3rd methode is the one i choose and for that i will need sevreal drawing from this car , side drawings, front and back drawings and a top drawing.


The side, front and rear drawing were easy to find:






The top drawing was harder to find but i did find some original design drawings from the Opel Kadett Coupe.





This was just a photo from an original drawing so it wasn't straight.
I made a new drawing from it in scale 1:10 with a CAD drawing program.






I used the side and top drawing to determine were i should make all the different sections to make the frame.






I labelled the sections from A to U, the positions from the front and rear axle are also sections so i won't lose these measurements during the build.


During this design period i also collected a lot of information about the Corvette C4 so i could see how everything would fit.


For that I put the top drawings from the Kadett and the Corvette over ech other on one drawing to see the differences.






The red outline is from the Opel Kadett and the black outline is the Corvette.
U can see how much wider the body from the Corvette is according to the Opel Body.


The axels are (almost) at the same spot, later during this build i found that the wheelbase from the Corvette is a littlebit bigger than the one from the Kadett.


Also very important were the correct drawings from the Corvette Chassis.\
There were several chassis versions but these are the correct ones for my build.









This is the end of this post the next post will be the "Designing"

[hsmed]

This is going to be a very interesting build - looking forward to more posts 👍👍

[Midnight Creep]

Thx for your reply hsmed here's the next post.


With al the information from the previous posts i started to make section drawing with a CAD programm.


For sections A - L i put the front drawing of the Kadett as a template looking like this..




The drawing is already scaled to size 1:10 so the acual height will be around 130-140 mm .


All sections will have there own layer so i can print them al seperately.


First i started drawing the front of the car , headlights, grille, windshield, etc.
This will be the starting layer to line everything up.




To draw all the sections i used the drawing from the side and top to measure several cross points which will give me the exact line of the section.


The next drawing shows all layers A through L, in total there are 20 sections.





In all sections with the same color u see a offset line, this will be the thickness of the styrene i'm gonna use, 2 layers of 0,5 mm thick styrene.


After all the drawing were finished i printed them and glued them on cardboard with a thickness of 2mm.
All sections have there own label printed on them.



This will be the test to check if all the sections are correct or if i have to make some adjustments.



I cut out all the sections from the cardboard and made a groundplate from 2mm cardboard.


On that groundplate i made an exact copy of all the section positions which a had drawn on the side view of the Opel Kadett. labeld A through U.


I glued all sections in place, the front and rear section have a small angle like the 1:1 car but it will be 90 degrees up, that should also be angled but i will adjust that later.


When all sections were glued to to goundplate it looked like this:








and from the front:




Almost all sections were perfect, only a few i had to adjust , they are positioned at the windshield, i made some corners red where to adjust.




I adjusted it on the CAD drawings so every section is now ok.


For so far, next update will follow soon.

[Midnight Creep]

Hi everyone,



Here's already the next update from my build.
It's not that I build so fast but i already began this project in December last year to collect all the necessary pictures, drawings and documentation.


To get to the point of the cardboard version of all sections almost took me 2,5 months.


At this stage i'm going to make all the sections in styrene 2 mm thick.


To copy the master's in styrene i printed all sections on paper and used tape and white glue to stick them on a 2mm thick plate of styrene.
White glue because its easy to remove afterwards without leaving any residue.




I used a black marker to go around the outline of the printed sections to make a definitive line in case the paper edge will tear during the cutting.


To cut the plate easily in large sections i used a jigsaw with a pvc blade looking like this:




Then i cut each section roughly without touching the black marker line:




This was the first collection roughly sawed sections:




To make all the rough edges from the sections smooth in an easy way i made a handy sanding table from a piece of a wooden pallet and a drill with a sanding disc on it.




Sanding the sections, looking like this:




I simply removed the black outline making sure the sanding disc doesn't run very fast otherwise the styrene would melt.
Each section only took me 1-2 minutes to smoothen.


Left before sanding, right after:




After finishing up all the sections the paper prints could be removed.
I used a marker to write all section letters directly on to the styrene.




To make sure these sections are easy to remove after the body is finished i made holes in them.
(This was just out of precaution because i thought i would need to saw or doze off the sections to get them removed from the body.)


These are all the sections:




Then again i made a ground plate, this time from a 2mm tick styrene plate.
All section positions are drawn with pencil on the plate with the corresponding section letter next to it.




I made all the lines with a graphite pencil because i still have to glue the sections in place, i am not sure what will happen if i used a waterproof marker instead.


The placing and glueing off all sections was a precise job, i used a draw triangle to place each section 90 degrees up, lining it up with the section line and also exactly in the middle.




All the glueing went perfect, i'm using UHU styrene glue, that is glue thin like water so it spreads immediately along the side of the section which i had to glue.


Each day i installed 2 or 3 sections to make sure the glue hardens and also to make sure i could correct it wen something went wrong.


After a few days the groundplate looked like this:








In the next post i'm gonna start to coat this frame with small strips of styrene.

[hsmed]

Once again: This is great! It is very interesting that you describe your construction method so detailed. I have never tried to do anything like this - but your WIP is for sure great inspiration for having a go........one day when I have plenty of time :-)

[nugundam93]

wow. looks tedious but for sure it'll turn out great!

[ScratchBuilt]

Hello Peter,

Looks like you've got plenty of info and references for this build, so that's good! I'm certainly interested to see how it progresses from here - I'm a fan of foam and fibreglass myself, so it's good to see an alternative method of creating a full body shape. I used styrene strip to create some of the interior shell detailing on my Moby Dick, but I haven't used it for the exterior - won't you have potential problems over time with distortion?

I'm assuming you're going to make the C4 chassis to fit under the shell too? If so, very cool...!

Good luck!
SB

[Midnight Creep]

@Hsmed; Thx for your interest in my project and i'm hoping to inspire more modellers to give this a try.
It's a methode which u can use for several works, not only for cars.


@Scratchbuild: Hi, thx for your interest too.


I've seen your builds and they are stunning and for sure good material for every scratchbuilder to check.


The distortion problem, well i don't know for sure if it will happen.
I'm already busy with the boot of the body at this moment and in one of the next updates u will see that i have taken some precautions to prevent that.


And yes i will build the C4 chassis, i already made a CAD drawing from it in a way it should be "buildable".


The original C4 chassis is build out of a lot pre-shaped metal sheet welded to each other. (the newer chassis type is made from aluminium)



I simplified it a little bit but the main idea is to get the shape right to look like a C4 chassis and also to fit the body.

[Midnight Creep]

Ok time for the next update.


To fix the positions from the windows and fenders i made some styreen copies from 0,5mm thick sheet.


The copy from the fenders were easy to make from the sideview.





The front and rear window were a bit more difficult to copy because from every view they are angled so i took measurements from the side and the top view and i found a real picture from both windows in the internet to which i could compare the size and shape.


Side windows also from the side view;




The styreen frame should now be coated with small styrene strips from 0,5 mm thick.
Depending on the position were they will be glued the width will vary from 1 till 4 mm.


To make these strips i made a cutting board with an rvs ruler with a lenght of 50cm.
I fixed the ruler with a bolt and wingnut to the board so i could easily put more or lesss tension on the ruler.




Although the styrene is only 0,5mm thick i have to cut it by going along the ruler several times.
It is possible to cut such a small strip in 1 time but it won't stay straight because the knife will push the material to one side leaving a curved piece of strip.


The first strip i glued to the frame is all the way from the front middle to the rear.
This will give the frame more strength so in won't wobble.




Next were the fender positions, i marked them at the axle position so i could find the correct spot to glue them to the frame:




To get the front window in place i had to glue 2 support strips to the side;




I did't place the position of the rear window because it was too difficult to put it in the correct spot.
All strips around the rear window will get enough overlength so i could trim them back to the correct window position.



And then i started glueing strips to the roof and the bonnet, starting from the middle working to the side.
All these strip are between 3 - 4 mm wide.







Shortly before i got to the edge of the front fenders i stopped with the 4mm strips.
To get around the edge i made smaller strips from just 1 - 1,5 mm wide.
The first strip was placed along the whole body, following the natural curve on the side like the 1:1 car.


This first strip was important because all next strips glued to this one will follow the same line.




I glued some strips around the edge of the fenders and after thet i glued a strip at the widest point on the side of the car.
I also put a strip from the top of the front window along the roof towards the boot of the car.








After that i could use the wider strips again to cover more from the side of the frame, this went pretty quick and i side is almost done;








U can see already the line from the Kadett body at this stage.


For so far , next update will follow soon.

[Midnight Creep]

Hello everyone,


Before continuing the build i want to show u some pics from this car.


On the first picture u see the bare chassis from this car with the C4 chassis underneath it, the Hovemann team just replaced the left front part of the chassis (right on the picture) because they had an accident during a race.




Next picture shows the V8 engine..




And this is the detachable lightweight front of the car:




And like all race cars this one also has a flat bottom panel to create drag.
Two members of the Hovemann team are preparing/building it, there will be an aluminium frame on top of this plate.







And now back to the build, glueing more strips, now on the right side.
First starting with the small strips in the middle along the whole body.




Next picture seen from the top view. U can see that all the strips around the rear window have som overlength.





To coat the body around the side window i put the template i made earlier with some tape on the right spot.
Now i could easily see what part needs to be coated.
I also trimmed the overlengths around the wheel areas.





On the next picture the right side of the car completely coated with strips.
With the rear window mask i drew an outline onto the body and trimmed some of the overleght as well.







Next 2 pictures shows the curves on the side of the car.






And one from the rear.




Before applying the second layer of strips the body must be sanded to smoothen it, not too much because it is only 0,5 mm thick.

This way the second layer will stick better.


This is how it looks like after the sanding:








Now it was ready for the second layer of strips.
I started in the middle of the bonnet straight over the axle line.




Going to the front of the car....
To glue the strips like this i pre-shaped them with the roundings from the fenders before i glued them in place.
This way there won't be any tension on the strips when i glue them.




And the last part i did for this post is the roof, with some overlength on each side so i could trim it back later.




Thx for watching,

[Midnight Creep]

Hello everyone,


Continuing this build with all the strips.


A difficult part of building the body like this are the small window posts at the front and rear window.
I could'nt go straight across them like the rest of the body so i decided to make the strips for the second layer wider than the first layer so there will still be overlapping.


U will see this on the next pictures were i continue at the back of the body.





All strips at the rear window have overlength like the first layer.




On the next picture the 2nd layer of strips is finished.
Some strips were custom made to fit the gap, it was quit a puzzle..




I used the paper masks from the windows and wheel arches to draw them onto the body.








Now i used a dremel with a small round saw to cut most of the overlenghts.
The whole body was sanded to smoothen all the strips.










Now it was time to separate the body from its underground.
I used the blade from an iron saw for that, its small and bendable to into all the places were i need to cut the sections.





And then the separation is a fact.




From the under side:




Now i had to remove all the sections.
I thought i would have to used a dremel to cut them out but by putting enough side power to the glued part of each section i was able to "break" them out without leaving any damage to the body.


First 8 sections are removed:




This is a picture from the removed sections:




And another few sections were removed, everything is ok..




On the next picture they are all removed, looking good.




And now the body looks like this:







On the inside of the body i glued 2 strips from left to the right along the B-pillar to give it more strenght.




Last picture for now.

[ScratchBuilt]

That's fantastic! It must be easier to use this technique in a larger scale like 1:10 or 1:8, even though it needs more styrene. Less potential for mess than using fibreglass, although I'm looking at all those strips and wondering what the smell was like while you were gluing it all together! My worry would still be the potential for the shell to distort over time, but I guess once you've got the chassis and rollcage fitted inside it'll be supported again. What are you planning to use for the floor panel?

Very, very impressive, and I'm looking forward to seeing this continue.

All the best,
SB

[Kjenjak]

Simply amazing, model building in its purest way!

[Midnight Creep]

@SB: Thx for your comment.
Well this is 1:10 i am building and this technique is also very suitable for 1:8 or larger.
Making a model smaller as this one (1:10) is still be possible but u would be needing smaller strips and going around corners is much more difficult.


About the smell during the gluing, i'm not complaining because i only glued just a few strips each time (max 5-8 per day) so what u saw in my update took several days.
And i must say that the glue i'm using doesn't smell that bad.


The distortion problem will be fixed in one of the next posts.



The floorpan will also be made out of styrene but i'm not busy with that at the moment.
Right now the trunk is under construction.


@Kenjak: thx for ur reply, i'm pleased u (and probably more people) like my building.