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

[François]

Alan, I'm no suspension expert but I think it would be these things. The 2 black link bars would prevent the forward/backward mouvement while permitting the up/dw mouvement. This design is based on the Mercedes G4 suspension but I didn't but every details in.

 

[Alan Smith]

Thank you Francois, that was what I was looking for but didn't see, They are known in the UK as 'anti-tramp links' - " Axle tramp is a self-sustaining vibration in a vehicle's driven axle that can occur when the vehicle is accelerating or braking heavily. It's most common in vehicles with a beam axle layout. " I think they call it 'wheel hop' in the USA.

 

[François]

Thanks Alan!

 

[François]

Finaly got around to model the fenders. Of all the parts modeled so far on this car, these were the hardest to do. I'm not 100% satisfied and I might play around with them a bit but I think it a case of 'leave well enough alone'. I also started the under fender storage boxes. They will have two hinges so they can be opened. Not sure what will be stored in them yet. I made the gas pedal which will eventually be linked to the carburators via a cable.

Compared to the movie prop

The windscreen frame

And the gas pedal

 

[rshousha]

I did a bit more work on the drive train and aside from a few bolts, fittings and brackets, it's pretty much done. I should be able to drive all 4 wheels from the drive shaft. I inserted a top and side view of the complete car so I can better see if the parts I'll draw up have the right shape and proportions. Like I said yesterday, this car is a movie prop, it doesn't really exist so no dimensions to be found. All I have are 2 printed artist drawings that I can mesure off. Last thing I did today was to insert the Bentley in the Hydra assembly just to better see how big this model will be. Both car are the same scale !!

Hard to believe those are the same scale. I have seen the Bentley in real life and, yes, it is smaller than one expects, but your big boy is huge!

 

[François]

I reworked the fenders and I think they are better. So with this done, the body is pretty close to being finished. It is now composed of six parts so it can be printed. I also made a few cross members for the frame.

Here is the completed boby with revised fenders.

The 6 body parts

The frame with new cross members

And the car as of today

Next up, the front suspension and steering.

 

[François]

Made some good progress on the front suspension and steering mecanism. The front leafsprings are done, just need to add some dampeners. Not sure what type yet. As for the steering, it's been close to 40 years since I designed a steering mecanism. They are many rules to follow to get a proper steering geometrie but, this being a model, I'm keeping it simple. I did try to get the ackermann close ( that's when the inside wheel pivots more than the outside wheel since the 2 radii are different).

I also designed the steering column, I went with a worm gear setup a bit like the one on the Bentley. it's quite difficult to get the different pivot points in the righ places but l'm getting close to something that works. Hopefully, the steering box won't be too much in the way of the yet to be determined engine block.

View attachment 20240925_193953.mp4

 

[mondrasek]

I use Inventor. I'm pretty sure that I'll get it done using the lofting command. If I really can't fo it with Inventor, I'll try Rhino, it's perfect for this type of shape. And I can try it free for 3 mounths.

Can Inventor export to .fbx, .obj, or .gltf? If so it can be converted to a .usd and be an available asset (For visual purposes only. No dimensional data included) in the nVidia Omniverse. That is opensource and has a TON of assets already. It might be cool to add this. Oh, and the Bently if it has not already been!

 

[François]

Mondrasek, I can export to .obj
Not sure exactly what it would do.

 

[Daniel20]

I really love your work François; all I can do is follow along and shake my head in amazement.

 

[mondrasek]

Mondrasek, I can export to .obj
Not sure exactly what it would do.

If you would like to try you can send it to me, OR, just download nVidia omniverse (STEEEEEP learning curve) and do it yourself. I've never imported an .obj yet. But I am willing to give it a go and share the results.

FYI, USD (Universal Scene Description) was created by Pixar. Opensource. It is for visuals only AFAIK and contains none of the original CAD data. Just a photo realistic rendering engine with a LOT of front-end import tools.

Omniverse does require an nVidia RTX video card.

M.

 

[Dave @W]

Just catching up with this masterpiece after a summer hiatus. As usual, waaaay over the top!
One comment about the front suspension and my recollection building a pretty simple car about 30 years ago is that my research was that the drag link to work properly should pretty much parallel the frame rail instead of at that angle. That would put the pitman arm facing down. Although I no longer have this publication, it was used to design the suspension: Chassis Engineering by Herb Adams

 

[François]

Dave, we are all in the same boat (no ship of scale pun intended), too long ago and not enough memory. I did but the pitman arm the other way around at first but the worm i'm using has a right angle twist so the wheels turned the wrong way. I'd need to print a left handed worm gear. But the biggest problem is interference between the drag link and different components located in that area. I have to remind myself that's this is only a model, not a real car. But still, I'll see if there's something I could do.

 

[mondrasek]

For example, all of the digital assets from the online Steam game SQUADS are available. Here is one of those with "Debbi" dancing beside it.

It took about 2 minutes to make since the assets were already online.

M.

View attachment Demo.mp4

 

[Dave @W]

Francois - I absolutely understand about the same boat though mine has a major leak.
Steering boxes can be interesting to set up but to redesign the wheel so to speak to change that drag link - you have better things to do since this model is a fantasy build from your mud.
Of course you could design a recirculating ball steering box or go with a rack and pinion system and multiple U joints on the steering column shafting to clear obstuctions .... nahhh

 

[mondrasek]

Another quick USD scene (took 3 minutes) using a stock background and another asset from SQUADS. I was just playing around on a rainy afternoon.

View attachment Untitled Project.mp4

 

[François]

Dave, I fixed the drag link problem. It's now pretty much aligned with the frame and the pitman arm is now facing down. So everything's good with that.
The 3d model is slowly progressing. I started the v16 engine bloc. I'm basing the design on the Auto Union type C engine but like pretty much everything else on this project, documentation very limited. All I have are a few pictures of a totaly assembled engine so the dimensions and inner parts will all have to come from my imagination ( no problem there, that's even more). I inserted a few bentley pistons and conrod just to have a better feel. Should be ok.

Block in car

Block with bentley parts in just for fun

View attachment 20241002_220801.mp4


I also finished the radiator assembly which includes the radiator cowling, rad core and blower.

Speaking of the blower, there's a schene in the movie where you can see the blower being activated. And when activated, the blower's front dome starts to spin. I would like to reproduce this and have it spin while the engine runs. Now the easy way to do this is to simply have the dome in line and coupled with the crank. But that whould be boring. What I did instead is to slightly offset the dome from the crank and added a few gears to speed up the dome's rotation in relation to the crank. I was able to get a 2.5:1 speep up ratio.

Here's the dome on the prop car

And here is mine

With a few gears added

And the completed radiator

 

[Dave @W]

Hi Francois-
That drag link looks sooooo much better - and it's in proportion to the rest of the car.

That V16 is an interesting way to make an engine. As usual with your ideas and attention to minor details, I'll be watching closely.

Oh and that blower and just a curiosity question - is there any reason to have an exterior part like that rotate. I have minimal experience with a Roots type supercharger but the only moving exterior item was the drive pulley or in this case, the input shaft,. Is it a backfire relief device?

 

[François]

Dave, I don't believe there are any outfide moving parts on a bentley type blower. The only reason I'm doing this is because of this.

✂️ blower dome rotation

5 seconds · Clipped by atelierboisfranc · Original video "CAPTAIN AMERICA (2011) Movie Clip - Red Skull Chase [HD] Marvel" by JoBlo Superheroes

youtube.com

 

[Dave @W]

OK, Francois. It appears I'm to literal when it comes to automotive engineering/design. I watched the full 2.47 minutes of that movie trailer kinda dumb but entertaining. I guess that rotating gadget was just a Hollywood prop creators imagination running wild. I'll just go away quietly and wait fgor your next installment. Thanks