Machining Car Door Hinge (Dihedral Synchro-Helix Hinge)

Im wanting to attempt to build a Dihedral synchro-helix door hinges for my car. Has anyone attempted this before or have any advise on how i might be able to tackle this project? Is it possible to machine the parts or should I look into a different approach? This is a project im very passionate about and willing to learn what it needs to complete it.

I do have access to large amounts of discarded steel car parts and hoping to use

Show up to a Tool Time with Tim, or any of the other times people are in the 'shop and talk about it in person. You’ll get 9 different ideas from 5 people and one or two of them will be sane lol.

We’ve got the tools, you could do it, but you need to know what it is first. I’d start by trying to find some drawings/prints/photos/examples of how they work and then showing those shapes to machine shop people. With a Manual and CNC of both a Lathe and Mill you could probably go to the moon with our shop, but how long it would take you is going to be the part related to skill and expertise.


I assume you mean a Koenigsegg style “out and up “ hinge ? The machining would be relatively simple if you have the engineered drawings . There is a very complex relationship of rods , cams and pivots , but nothing hard to machine . The big hurdle is having a good print to build from as every relationship of every part is super critical in tolerance and alignment . There is a youtube video of a guy who built a model in cardboard so you can see the level of complexity . First step is a drawing and several of us can help you learn to do the rest .

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Having the right piece of metal to machine it from. You are going to want a virgin piece of high ksi steel, not some scrap piece if steel.

This part will be under high torsional loads.

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Im currently looking for the right drawings. I appreciate the support! Will update when I find them asap

Ok i wouldn’t have known that, thank you!

Drawing should have material spec om it.




Can’t wait to see your fixturing plans!


I emailed the guy that has a video on youtube asking more about it. Im not sure what the next step would be since I havent done anything like this before.

You have definitely taken on an ambitious project. Will be interesting to see how you progress.

It would seem to me that the geometry of this hinge is designed for a very specific car/cars. Do you already have the vehicle for fit up checking as you proceed?

Yea and I know ill finish the project… how long will it take is the question. Ill be using it on my car (2014 Dodge Charger SXT) and i imagine id just have to modify my door to accepted it.

Now I know why you want to make them