Homemade scissor style hood hinges

I am building a Pro Touring style Astro Van. One of the styling changes I am planning is extending the hood to cover the cowl all the way back to the windshield. There is also a full length cowl type scoop in the works. Stretching the edge of the hood back to the windshield will prevent it from opening in the original direction. These are some hood hinges I designed to let the hood open towards the front like a Corvette. :)
http://images47.fotki.com/v405/photo...MVC004F-vi.jpg
http://images57.fotki.com/v512/photo...MVC005F-vi.jpg
This is a mark-up I did so you can see the in car relationship. This is with the hood closed.
http://images52.fotki.com/v640/photo...markup1-vi.jpg
And this is with the hood open. Cutting and notching the radiator support will provide plenty of strength to carry the hinges.
http://images52.fotki.com/v1565/phot...markup2-vi.jpg
The hood will open a full 100 degrees and I plan to have quick release fasteners to allow quick removal. I will also work some gas cylinders in there to help control the hood while closing.
Mark

An amazing looking hinge to be sure. Might you have any drawings with measurements? I would love to scale one down for a friends go kart body.

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Originally Posted by blkadder

An amazing looking hinge to be sure. Might you have any drawings with measurements? I would love to scale one down for a friends go kart body.

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These were designed in CAD and then sent straight to a laser cutter. Let me see what I can do to get you a drawing.
As you look at the hinge the short pieces are the same piece and the pivot pieces are the same piece so all you need is two patterns.
Mark

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Originally Posted by astroracer

These were designed in CAD and then sent straight to a laser cutter. Let me see what I can do to get you a drawing.
As you look at the hinge the short pieces are the same piece and the pivot pieces are the same piece so all you need is two patterns.
Mark

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Hi, is there any way you could get me a cad file or drawing? I want to build these for my Chevelle. Thanks, Mark

Hmmm, let me see if I can find a file. A few years ago and a number of computer upgrades... I may have them on a B/U drive somewhere but I am not sure. I don't remember finding anything for blkadder. I may have to remodel them. Would a .DXF file work for you? Or an IGES?
Mark

I looked thru two B/U drives this evening and found nothing... I will have to remodel them. Sorry, I will get them done but it may take a bit. :(
Mark

Actually, if you could just give me some basic dimensions and hole centers, i'll be good to go. I am going to build them by hand.
I want to build some to use on a fiberglass "pin on" hood for my Chevelle. They will work perfect.
Much appreciated.

That'll work. I'll try to get something marked up this weekend. :)
Mark

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Originally Posted by astroracer

That'll work. I'll try to get something marked up this weekend. :)
Mark

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Interested as well, looking for this same style hood hinge for my 34 Ford. Rod shop wants $180. Figure i can make them for about $20 and a couple hours.

Astroracer did you experience any wind flutter getting under the hood trying to lift the leading edge I have seen some factory hinges that would do this without some catch lock under the hood to keep it down

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Originally Posted by Frank S

Astroracer did you experience any wind flutter getting under the hood trying to lift the leading edge I have seen some factory hinges that would do this without some catch lock under the hood to keep it down

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Hey Frank,
I have not used these yet. The van is still a long way off from road trials. :( I will be using a set of Aero latches at the back of the hood though so I will expect zero flutter. During installation I will probably be working in a set of gas cylinders to hold the hood open. I am thinking those MAY help to stabilize the hood when it is shut also but, with the hard latches at the rear, I doubt they will do much.
I didn't get to the sketches this weekend (obviously) utilizing the good weather to get a mower deck sand blasted and primed. I will get to them this week though, promise!
Mark

The reason I asked was because I've been there albeit a long time ago, which is probably the reason why most manufactures of front hinged hood vehicles add in a safety system that holds the hood down taking any strain off of the hinge system. even the tightest hinge points have some movement from hysteresis (slack or flex in the joints) It is a fairly straight forward fix if needed just a loop or possibly 2 mounted to the hood that slides under a hook as the hood closes can possibly even be incorporated into the hinge itself at the mounting plate on the hood.
The last thing you want is to allow high pressure wind to lift the front of the hood @ 100 MPH because even the strongest hinges rely on their mounting points
A side note though I do like the system design you have come up with not sure about using bolts as pivots though I might have used rivets. at the very least they should be shouldered bolts so no threads are involved in part of the pivoting.

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Originally Posted by Frank S

The reason I asked was because I've been there albeit a long time ago, which is probably the reason why most manufactures of front hinged hood vehicles add in a safety system that holds the hood down taking any strain off of the hinge system. even the tightest hinge points have some movement from hysteresis (slack or flex in the joints) It is a fairly straight forward fix if needed just a loop or possibly 2 mounted to the hood that slides under a hook as the hood closes can possibly even be incorporated into the hinge itself at the mounting plate on the hood.
The last thing you want is to allow high pressure wind to lift the front of the hood @ 100 MPH because even the strongest hinges rely on their mounting points
A side note though I do like the system design you have come up with not sure about using bolts as pivots though I might have used rivets. at the very least they should be shouldered bolts so no threads are involved in part of the pivoting.

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The way the hinges close, if you look at the pics, they lock together when in the down position. The hood would have to pivot backwards to open the hinges from the front. It cannot do that with the double pivot design and it will not do that with gas cylinders and the latches on the back edge.
The plan is to use shoulder bolts when the hinges get assembled for the final time. The bolts you see in the pics are simply for mock-up and proof of concept. They were never intended to be the final product. I designed the hinges around 3/8th's dia. shoulder bolts. There will also be nylon washers between each "arm" to eliminate rubbing. The stack height of the arms over the washers and the shoulder bolts leaves enough space to let the arms move freely in their assembly.
I will get some better pics so you can see how I was thinking when I designed these.
Mark

I wasn't trying to be critical just pointing out some personal observations. Glad to here that shoulder bolts and nylon washers were the main consideration in design, others who see these designs then try to make them on their own may not understand their importance. A lot of things that I make I press in hardened bushings or sometimes use bronze flange bushings to isolate and reduce pivotal slack

Nope, no "criticalness" taken. I know it really helps when you understand the full design and that wasn't documented here. I don't think these hinges will need bushings, they aren't going to be used that extensively. I do know I want them to be a bit loose so they don't bind or fight one another while opening.
Mark

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Originally Posted by astroracer

Nope, no "criticalness" taken. I know it really helps when you understand the full design and that wasn't documented here. I don't think these hinges will need bushings, they aren't going to be used that extensively. I do know I want them to be a bit loose so they don't bind or fight one another while opening.
Mark

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Yep you don't want them causing the hood to wind up looking like a 76 chevy truck hood

Okay, I got some pics and made a quick sketch of both arms. When you make these make patterns out of thin cardstock first and try them out before committing to the hard stuff. If you guys have any questions just holler.
https://images60.fotki.com/v367/phot...MVC009F-vi.jpg

https://images41.fotki.com/v1634/pho...MVC008F-vi.jpg
The stacks of washers will be replaced with aluminum spacers when these are assembled to the vehicle.
https://images44.fotki.com/v1655/pho...MVC002F-vi.jpg

https://images45.fotki.com/v1649/pho...MVC001F-vi.jpg

Mark

I really appreciate it! This is perfect.
Thanks again, Mark

Nice work!

Studebaker used that style hinge on both their hoods, and trunk lids from the 1920's through the 1960's.
They put springs on theirs. Strong springs on the trunk lids to hold the trunk lid up.
Lighter springs on the hood, not to hold the hood up, but to hold the cowl end under tension so the hood would move foward as it went up.
The springs also take out any pin slop. Bad part is the springs also hide pin wear.
DEEPNHOCK

Thanks to Astroracer for posting these pics. I think this may be something I can use on an upcoming project.

I joined this forum to to say thank you for this design and making the pattern available for others to use. This will work perfect for my garden tractor I am building. The factory hood hinge set up is useless and this will allow me to tilt the hood up and out without hitting the grille. I am interested in how you would put the gas struts on it and what size. Thank you again, Richie

Is there any reason other than style/looks, that the bars are curved? couldn't this be done with straight bars? thanks

Mark
I found your scissor hinge on a google search. I'm attempting to duplicate it to lift the hatch on my sailboat, but I'm running into a problem. On a car hood there's very little or no overlap. On a boat hatch there's an overlap of probably an inch. I've been able pretty much duplicate your design, but I can't figure out how to get the lift before the swing. Was wondering if you can aid me with your CAD magic :-)
Thank you
Lowell ... Southern California

Check out this Linkage page for some simple explanations.
https://technologystudent.com/cams/link1.htm
Jeedub57

Hi Lowell,
I can try! I will need some dimensions from you though. Length of the hatch, the depth of the flange and how much clearance there is between the flange and the hatch opening. Once I have those I think I can reconfigure the pivot points to get what you need.
Mark

Mark
Thank you for your prompt response. I'll get measurements in the next couple days.
Lowell

Jeedub57 ... cool link to watch but can I build my own stuff on the site?