Marvel's Hydra coupe 1/12 scale full scratch build

[François]

With the rear wheel covers done, that concludes the body printing phase of this project. I think I'll do the rear seat before priming the body. 

Edited May 10 by François

[François]

I did the rear seat today. Here's how it was done. 

I first made a paper template of the back rest.

Which was then transfered to a .015" thick plasticard

I 3d printed a bunch of domed strip to create the back cushion shape 

Which were glued to the plasticard

Next came the leather 

And once glued 

I then cut a piece of white foam for the seat cushion 

And covered it with leather 

But I didn't like the gap between the back cushion and the body so glued a 1/16" dia styrene rod to create a lip that will hide the gap. The rod will be painted the same color as the bodywork. 

I'm very happy with the result even though it's not final since I have to remove the seat for painting. 

And the last project for today was to make a new bigger spray booth. The hydra body didn't fit in the old one. At 28" wide x 14" deep, it will accomodate bigger parts.

[Mattilacken]

Looks good as usual! Great work with al of it!

[François]

All body parts have been primed,  wet sanded and primed again. They are now ready for final color. 

[Bugatti Fan]

This flight of fantasy is really going places now!

[François]

Did the leather on the door's inside panels. It's not perfect but I should be able to get it close with a bit of tweaking here and there and a bit of shoe polish.

[François]

Ok so I painted all the body parts with Tamiya's german gray spray paint.

As mentionned before, tamiya spray paints are no longer available in Canada but I was lucky enough to find 5 cans of the same color that was close to the gray I wanted. It took 4.5 cans to spray all the body parts (including the previously painted blower, wheels and front light brackets) so not much room for a error there (absolutely no pressure !!).  Next step is to clear coat the parts with Tamiya's LP-9 clear lacquer diluted 50/50 with Tamiya's lacquer thinner (the orange capped bottle, apparently it has a retarder in it). But before clear coating the actual parts, I did a test on a extra trunk lid. I laid 3 light coats at 5 minute intervals followed by a last wet coat. Once it's cured (no clue as to curing time but I figure an overnight cure should be good), I'll do some buffing tests with and without wet sanding. Hopefully,  I won't need to much wet sanding. 

After 2nd light coat (forgot the take a picture of the first)

After 3nd light coat 

And after wet coat

 

Edited May 21 by François

[François]

I'm on a fairly steep learning curve with the paint and clear process.

I cleared all parts except the fenders,  the rear trunk lid and the body. The result is ok, no more. I need to better control the dust (I got a tack cloth for this) and to better degrease the parts. After testing on a spare part, I decided to sand the cleared parts with a 3000 grit tamiya sponge pad first and then with a 5000 grit polishing pad (dry and wet). I will then re-apply a wet coat of clear. Once this coat has cured 48 hrs, I will see if another 5000 wet polish is needed or if I can just wax it as is.  It's a very slow process.

Tamiya 3000 pad

5000 polishing pad 

Second clear test on spare part 

I finished the of day by painting the shield on the inside of the trunk lid.  Still need to do a few touch-up and to apply the clear but I'm happy with the result. 

[Mattilacken]

Looks great!

[François]

This is the latest test, and hopefully the last, before I resume clear coating the parts. Here's what I did.  Starting with my test piece that had a coat of finish paint and 3 coats of clear,  the clear was wet sanded and received another coat of clear. This last coat was sanded it with the 3000 pad and wet sanded with the 5000 pad. I then buffed the left side using my 3M buffing compound, my 3M hand glace and finished with a polymere wax. These 3 last steps were done using a cotton wheel on my dremel at the lowest speed. The right side is as it was after sanding.

The result is quite nice and the waxed surface is slippery as should be.

So here's how I  will proceed for the rest.

All parts that had received 3 coats of clear have been sanded with the 3000 and 5000 pads. They will receive a new wet coat of clear and once cured, will be lightly sanded, buffed, glazed and waxed.

As for the parts not yet cleared,  they will get 3 coats of clear followed by the steps described above. 

I will pay more attention to the cleaning and dust control.

[François]

I printed the seats,  they will be covered with the same leather I used for the rear seat and door panels. If you look closely at the print, you will see a hole on the lower portion of the seat plus some striations (lines) on certain surfaces.  They should not be there. After some research,  it appears my LCD screen is shot and needs to be replaced.  Apparently,  an LCD screen on a printer is a consumable with a life span anywhere from a few months to a few years depending on use.  I was wondering with my prints where not as nice as before.  Thankfully, I only need to reprint the tool box covers since I now understand why they look like they do.  Live and learn...

[64SS350]

This build is amazing. From the engineering of the parts, fit, and functionality. 

Might I suggest though, sanding and filling some parts to eliminate the printing layer lines before painting?

Keep it going, looking forward to more progress!

[François]

Thank you 64SS350, glad you like the project. I always appreciate positive feedback even when said feedback reminds me of errors I have made. I say this with complete sincerity. Thank you for the feedback.

But, I feel I need to put a few things in context.This build as proven quite challenging on many fronts. From the design of a car from the ground up to mecanizing it at this scale.  Plus everything is 3d printed. Those of you with engineering background in fabrication design will probably now the difficulties linked to a large quantity of parts (probably close to 1000, I  haven't counted) working together. You might remember how the chain of dimension tolerance will effect the functionnality of a mecanism.  I had to dig out my old text books on this, especially when designing the motor. 

All of this work is then "wrapped" in the body which,  I know, is flawed in many places. I recently discovered (yesterday) that I have a major problem with my printer which accounts for some of these flaws. Being my first large 3d printed project,  I'm learning as a go along. I know certain boby parts might have requiered more care in the pre paint finish, again live and learn.  Like I mentionned in a earlier post,  I was lucky to find 5 cans of the color I wanted from tamiya.  I can't get anymore since this type of paint is banned from Canada (the shelves have been bare for many months since a replacement product seems to be difficult to find and other paint manufacturers can't keep up) so when I found these 5 cans I jumped on them knowing that I would be limited in the number of errors I could do. This is a huge model (25in x 8in x 4in) to paint so 5 cans is not alot.  Sadly,  some flaws were revealed only after painting. A more experienced painter would have known that, I do now.  I have about 1/2 a can of paint left so I have to choose which body part to redo and I decided to redo the tool box lids since they really look crappy and are small enough to be painted with the remaining paint. 

I do believe that when everything is done, and given the scope of the project, it should look quite good.

Keep on looking, the end is nearer then it was!!

[64SS350]

To build this piece from scratch, while understanding the engineering, design, and execution of it all, via a 3D print system....is amazing in itself! I haven't yet dove into printing,but I may contact you for advice if I do!! 

The added touches... like the leather on the seats....wow! Again..keep it up!!

[Funkychiken]

Looking amazing! Tha js for sharing all the detail and steps you are taking,  love reading  along!

[François]

So, all body parts have been clear coated (except for the 2 tool box lids, I have to repair the printer firts).

The main body after clear coating

Curing under dome. It was suggested that I cover the still wet parts with a box to protect from dust, quite ingenous 

Cured parts awaiting final buffing and wax

Test fit of both seat on floorpan

next up, leather covering of said seats

[François]

I did the windshield today. It's quite an odd shape to cut so I printed a template. To design the template,  I used the 'derived component' command on my 3d modeling program. I apologize in advance to all you non-3d modeling savy readers out there, this will get a bit technical.  Hopefully someone will know what I'm talking about, if not,  well it will have been another good english writing exercice. 

What this command does is that it can sudstract one or more form (the cutter) from another(the raw material). The resulting 'derived' part  is the difference of this substraction.  In this particular case, I needed the curved shape of the windshield so I could use it to cut a clear plastic sheet to the correct shape. Now, I already have the windscreen frame modeled.  So by substracting this frame (the cutter) from a larger form ( the raw material that the cutter cuts), I ended up with a derived part that has the exact shape of the windshield.  There's one other maneuver that had do be done but I won't explain it because,  well quite frankly, I don't know how to. 

Here are a few pictures to better explain

The windshield frame

The 'derived' part which is the difference between the frame and the raw form hence called the template

The printed template 

Clear plastic sheet on template 

Windshield cut to size

Windshield in windshield frame 

I also started to upholster the seats.  The leather is nice and soft but a little thicker then the leather I used on the Bentley.  It's a little harder to handle but the result is still nice.

[François]

And voilà the seats.

Seat adjustment rails

Backrest fold pivot

Airline Style seat support structure 

and in place

[François]

Now that the end is near, I'm starting to think about the display case. A few weeks ago, during walk,  I came across a bridge with an interesting structure.  I thought it might be fun to incorporate a few elements of this bridge in the display's structure. I'll also want to add so light fixtures of some sort. 

Here are a few pictures of the bridge 

to be continued...

[François]

I had 2 ugly grease stains on the back of the seats. I was able to clean the stains on tge right seat but had to replace the stained leather on the left one. While at it, I replace the Backrest fold pivot by folding lever.  Looks more appropriate. 

Stained seats

Repaired seats

Old backrest fold pivot (don't like)

New backrest fold lever