SL-C Nose Hinge Group Buy

Scott

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#1


The SL-C’s nose is designed to lift off as a single piece. This works great for a race car because there are always crew members around to help you lift it off and you’re not worried about chipping the paint. However, if your crew is composed of your wife and kids, they’re not always available nor happy to be dragged to the garage when watching a movie or sleeping – yeah, last time I woke someone up to help move the nose it didn’t go well. Even with willing familial assistance you have to disconnect the wiring harness, make room to store the nose and you need to be careful not to scratch the paint.

What’s needed is a nose hinge. The primary challenge with designing the hinge is that the splitter projects in front of the body work. Since the nose pivots forward its leading edge will bind on the splitter unless the pivot point is low and in front of the bottom edge of the nose. While noodling on the on the problem I discovered that Bob, another SL-C builder, had built a working prototype. The following video demonstrates how easy the nose is to open when gas struts are installed.


Bob shipped the prototypes to me and I tweaked and redrew them in SolidWorks. I then sent them to Allan and he installed them on a SL-C that he’s building (see pictures below). Based on Allan’s feedback, I relocated a few of the mounting holes.









The following video shows the updated CAD model. The plan is to do a group buy and we're targeting a minimum of twelve hinge sets. There are 14 billet pieces in each hinge set and the two largest pieces have left/right mirrors, so they take twice as long to achieve volume pricing. We're working on pricing, but we're expecting to be in the range of a nice hot rod compound billet hood hinge.

The hinges are very useful to have early in the build. As soon and you have your body fitted you can quickly install these and you no longer need help moving the nose or finding a place to store it. Here are the top-level features:
  • Very stable
  • Easy to open
  • Easy to remove the nose (two bolts that are outside of the body work)
  • Billet 6061 aluminum
  • Arms are 3/8” thick
  • Includes all hardware (depending on shipping costs, we may or may not include the gas springs)
  • Stainless Steel mounting hardware from McMaster
  • Steel ball bearings from McMaster
  • Steel drilling jig
  • Easy to install (including finished cars)
The following video should give you an idea how everything works.
 
#2
Very well thought out. Great presentation. Put me down for a set.

A couple of pucks/spacers (one for each side) will be needed for the race splitter users like me. My picture shows my pen pointing to the area for the spacer. The race splitter is deeper at that point.

IMG_2420.JPG
 
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Scott

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#5
Ken, we could probably laser cut a piece to match the profile of the foot. What thickness?

For everyone else who's interested, let me know which splitter you have.
 
#7
Ken, we could probably laser cut a piece to match the profile of the foot. What thickness?

For everyone else who's interested, let me know which splitter you have.
I have both splitters and unfortunately my car is apart again. Hopefully someone with a race splitter can chime in.
 
#8
Hawt. Very nice! I believe I used a washer stack under that portion of the body so it would be more difficult to install on a completed car if you don’t know/can’t remember what’s under there. If you could relocate or have an alternate design that uses the side of the radiator box as a pickup you could make this easier to retrofit for cars already complete.

Maybe some type of L strap/bracket that mounts to the box and locates the ball at the same location you’ve currently got it at, so two additional pieces for completed cars.
 

Scott

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#10
relocate or have an alternate design that uses the side of the radiator box as a pickup
Cam it mounts to the side of the radiator box with three screws.

can’t remember what’s under there
I would think that the only part of the hinge that isn't visible from a casual exterior inspection of a finished car would be the Capture Plate (see 1:03 in the video animation at the bottom of the first post). That piece sits in the vertical piece of fiberglass between the radiator opening and the brake duct opening. Superlite bolts a L-bracket to the diffuser so that the vertical part slides into this gap. A pull pin is usually used to lock the nose to that L-bracket. I think all you need to do is remove those pieces from the diffuser, but you'd need to pop the nose off to check.
 
#11
Scott - The body side pickup point for the gas strut ties to the fiberglass portion of the spider. I assumed you had a spacer between the footbox and glass? My memory is that I placed a stack of washers between the body and the footbox at this location but I may be misremembering. Or maybe it’s just my whack alignment :)
 

Scott

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Lifetime Supporter
#12
Ah, now I understand. My car also has a gap between the body and the top of the foot box at that location. I'm not sure if there's enough space for a nut so I'm thinking about bonding a piece of aluminum to the underside of the body and tapping it to act as a nut plate. Another option is to tap and drill the foot box or drill a clearance hole and use a nyloc from the inside.

Tapping the top of the foot box would work for a finished car because you're unlikely to have anything other than maybe washers in that area and you don't need access to the inside of the foot box. If the mounting holes are sitting on top of a washer stack you could make a larger mounting plate to locate the holes where you want them (it would also cover the hole that you drilled to discover the washer stack). The bracket is simply 1/4" aluminum tapped for the ball stud. The cylindrical spacer between the ball stud and plate is removable.

You could also find another place to mount the springs which may require you to use different springs.
 
#13
I’d be down to give it a shot. I’m anticipating some front end rework in my future and this would definitely be a nice feature to add, it sucks having to have a second hand to lift the nose off for troubleshooting (I’ve done that a lot in my first 1000 miles).

Put me down for a set with the street splitter.

Thanks for all the work Bob & Scott, this has always been a feature in search of a well engineerred solution!
 
#15
I’d be down to give it a shot. I’m anticipating some front end rework in my future and this would definitely be a nice feature to add, it sucks having to have a second hand to lift the nose off for troubleshooting (I’ve done that a lot in my first 1000 miles).

Put me down for a set with the street splitter.

Thanks for all the work Bob & Scott, this has always been a feature in search of a well engineerred solution![/QUO
 

Scott

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Lifetime Supporter
#19
I’ve had lots of questions on price. Each set requires 14 billet pieces. For QUANTITY ONE, EMachineShop quotes just under $1,500 for a single set of hinges (other online quotes are similar). Volume significantly drives the price down, but the two largest pieces (the arm and pivot arm) have left/right mirror images so their volume discount only grows half as fast. At the current level of interest, it looks like the cost for the billet pieces from EMachineShop will be around $500. We’re talking with smaller shops to see how much further we can push that number down. The cost of the McMaster hardware and gas springs is $137.79 (we’re still tweaking the parts list) and we’ll have some cost associated with the laser cut steel drilling jig and PayPal fees.

So right now it looks like about $700ish, but we’re working hard to reduce the CNC cost. If you look at prices for billet hot rod hinges with gas springs (see link below) they seem to range from $495 to $799. While they have a more complicated mechanism, ours has a lot more aluminum, larger gas springs, ball bearings and a drilling jig. Our volume is also a little smaller

Here’s some billet hot rod hinges.
https://www.speedwaymotors.com/Search?query=billet+hood+hinges
 
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