scratch build Robocop ED-209 by RandomDesign

[RandomDesign]

 Hey its RandomDesign,

finally CMWS is back.

Lets first have a look at the hardware that should be used for the project:

Motherboard: MSI MPG-B650I-EDGE-WIFI
CPU: AMD Ryzen 9 7950X3D
GPU: MSI Geforce RTX4070 Super 12G Ventus 2x White OC
Memory: Trident Z5 Neo RGB DDR5-6000
SSD: Kingston FURY RENEGADE SSD 2TB
PSU: Cooler Master V850 SFX Gold

Water cooling: Alphacool

 

 

The concept:

For this years competition, I am planning to build a version of the ED-209 robot from the movie Robocop.
Most of the hardware and watercooling components will be placed in the head section.
By doing that, the hardware should be included into the design as if it is one part of the construction
and might fit a specific purpose.
I will also try to include some LED effects and moving components to match the design of the original as close as possible.

Many parts will be 3D printed, but most of the parts that I need multiple times, will be mold in silicone and then cast in a urethan resin.
I am also going to use a cold cast technique with real metal powder to create all the metal looking parts.
Detailed descriptions will follow as soon as that parts will be created.


Now lets see the original design. I got some images from the latest Robocop game, directly from the publisher Nacon.
Its a good starting point to get high resolution images of the machine, as it has not changed from the one used in the movie.

 

 

 

 

I used this images to create my own 3D model to get not only all the parts for 3D printing, but also a good reference on size
and where all the hardware components should be placed.
It also helps to get a better idea on how I want each part to be fit together and how a stabilizing core construction can be included.
In total the entire 3D model has about 209 individual parts that need to be fabricated, post processed and assembled.
 

 

 

 

And of course some final renderings of the 3D model

 

 

 

 

 

Edited June 10 by RandomDesign
picture upload

[RandomDesign]

To make it easier to follow my progress, I will always mark the areas in the 3D model I am currently working on.

Starting at the bottom, the first part to work on was the feet section.

 

 

The middel construction of the feet is 3D printed in PLA. I already included all the holes necessary for mounting them later to a base and for
the stabalizing aluminum core.

 

 

 

Cause I need all the "toe" caps multiple times, they will be mold and cast in a urethan resin.
The templates were first resin printed to make the post processing a little easier and faster.

 

 

 

Then all parts for the feet were 3D printed and ready for post processing. You can also already see parts of the inner leg construction.

[cyg]

I am excited for this one, I really liked your matrix build. 

[RandomDesign]

The advantage of the resin printed toe parts is the easy post processing compared to PLA.
Just took some 280 grid sandpaper followed by 400 grid wetsanding to prepare the part for the next step.

 

 

Cause I need each piece of the toes at least two times, and I wanted to make them a bit more sturdy, I decided to not use the resin print.
Instead I am going to cast all the parts in a urethan resin. That way they wont be as brittle as the resin print.
Unfortunately, I missed taking pictures of the mold making process for this piece, but I will come back to the technique later in more detail.
For the molds , I used Mold Star 30 from Smooth On.

 

 

To save material and weight, the parts were rotocast. I just filled some resin into the mold and than rotated it until the resin was set. 
 

 

 

Here is one test piece I made to see if the thickness of the wall was enough. In total, I made five pours of the urethan resin to slowly build up to the desired thickness.

 

 

 

To further stabilize the part, but not add unnecessary weight, the parts were filled with an expanding foam.

 

 

Looking good so far.

 

Edited June 27 by RandomDesign

[RandomDesign]

The next part is the the main section of the lower leg.

 

 

This section is a combination between an inner core that will be responsible for the stability and an outer shell.
The inside parts are already equipped with holes for the aluminum profile and the metal rods that will hold everything together.

 

 

For stabilizing i will use a 20x20 mm aluminum profile and some 6 mm threaded rods.

 

 

 

 

To fit the outer shell on my 3d printers and have a good orientation, I needed to split it into different sections.
Next up is the post processing on those parts.

[RandomDesign]

After all parts for the next section were printed, I started by sanding them down with 120 grid sandpaper.

 

 

 

Afterwards, all the parts were assembled. I just used super glue, that will be more then enough to hold all pieces together.

 

 

And of course I made a first test fit with all the other parts of the leg that I have done so far.

 

 

Next up, I need to start and fill in all the gaps and imperfections. Will show that process in the next post.

[RandomDesign]

In the next step, I filled in all the remaining layer lines and gaps with a two part epoxy putty.

 

And of course, everything was sanded again.

 

 

For the back side, I printed a cover to hide the inside of the leg structure.

 

 

In the original design, there is some kind of metal detail parts inside the back cover. To replecate it, I first resin printed the part.

 

Although, resin prints are already pretty smooth, I still gave them an overall sanding.

 

Then, I applied a couple thin layers of sprayfiller and wet sanded the entire part.
Now its perfectly prepared for the next step that will follow soon.

[RandomDesign]

I needed both parts multiple times, so I decided to make a mold and cast them in resin.
In addition, this allowed me to use a real metal effect. That way all metal parts will not only look the same, but
they are also made out of real metal. At least the outer surface

So first I build a simple mold box from card board. It will be a  block mold to just pour the resin in later on the other side.
For this there was no need to make any kind of fancy mold design.

 

For the silicone, I used Smooth On Mold Star 30 (I know its 20T in the picture, but I decided to change last minute).

 

 

 

Before filling the mold box with the silicone, I degased the Mold Star 30 in my vacuum chamber to get rid of all the air bubbles introduced while mixing.

 

After pouring the silicone, I like to let everything cure under 60 PSI in a pressure pot.
That way even the last air bubbles will be removed.

 

 

And just 6 hours later. the mold was done.

 

 

For the cast I had several options for the resins. In the end, I went with Task 2 from Smooth On.
To get the metal effect, I used real aluminum powder, which I brushed into the mold before pouring the resin.
In addition, I tinted the resin black and added some of the powder to it.
The result was a dull metallic looking piece.

 

 

To bring out the shine, I used some 0000 steel wool and polished the surface. This already gave a slightly worn look.
 

 

 

For an even more used and grimy look, I applied a brown and black metal wax, that I polished down again.
The remains were just enough for a nice ralistic dirty metallic look.

[RandomDesign]

There were two more detail parts for the leg missing.

Those were also 3D printed in resin.

 

 

 

Although the surface was already pretty smooth, I gave it a slight sanding and a layer of spray filler.

 

 

 

For these parts, the back side was also inmportant, cause I needed a flat surface to glue it later. Also I wantet all the parts to be the same thickness.
Thats why I opted for a two part mold.

So I needed to embed the parts in a bed of clay for the first half of the silicone mold. I tried to get the edge as clean as possible, so save time on the
clean up of the seam line later.

 

 

 

 

Made a quick and easy mold box from card board and poured in the silicone for the first half.

 

And the the first half came out nicely. Now I just neet to make a mold box again, and pour the second half.

[RandomDesign]

Then, the second half of the silicone mold was done.

 

 

For the casting process, I started with the larger detail piece. Here I used Task 2 from Smooth on and tinted it with a little black to already get a greyish color.
That way, all the parts that need primer at the end will have almost the same color to begin with.

 

 

 

Then those parts were already painted in the final color. In addidtion, I added some self made decals that resemble thge one used in the movie.

 

 

The part that will sit on the inside was done a little different. I again used the cold cast technique.
I brished some aluminum powder into the mold before casting it. After some polishing the parts had a nice metalic shine.

 

 

There, I also used my vinyl cutter to make the lettering like in the original one.

 

 

Of course it still looked way to clean, so I applied brown and black wax to make it look dirty and grimy.

 

 

 

Couple screws were added as a final detail.