Need help making my Peterbilt MOC's bonnet openable

[StudWorks]

I'm making a 10 studs wide Peterbilt Dump Truck for my Uncle and wanted the bonnet to open. However, I haven't been able to come up with a solution for how to make the hood open.

This is where I want the bonnet when it is open...

...and here is where I want it to be when closed.

Any building advice? Note that I want to be able to fit a detailed Cummins X15 engine under the hood so I don't want the bits and hinges that make the hood open to take up that much space. I can upload a Studio file of the entire truck's front end if you'd like.

Thank you.

Edited June 22, 2023 by StudWorks

[jus1973]

The problem you’re going to have is that the radiator grille is sitting flush with the bumper panel, so this doesn’t allow for a hinge to work.  IRL these things are often cranked to avoid this.  Also I think from your images, the bonnet piece is 5 studs wide, and the chassis is 10 studs, so you’re limiting the number of parts you could use as the studs don’t line up between the two built parts.  You’re best looking at something like this or this somehow coming from the chassis, with a bar held in something like this at each side of the bonnet construction.

Hope that helps.

Good Luck on the rest of the build.

[StudWorks]

4 hours ago, jus1973 said:

The problem you’re going to have is that the radiator grille is sitting flush with the bumper panel, so this doesn’t allow for a hinge to work.  IRL these things are often cranked to avoid this.  Also I think from your images, the bonnet piece is 5 studs wide, and the chassis is 10 studs, so you’re limiting the number of parts you could use as the studs don’t line up between the two built parts.  You’re best looking at something like this or this somehow coming from the chassis, with a bar held in something like this at each side of the bonnet construction.

Hope that helps.

Good Luck on the rest of the build.

The bonnet piece is actually six studs wide.

Any solution ideas using Technic pieces? I feel like they could be my best bet.

Edit: Moved the bonnet higher when opened so it is NOT flush with the bumper panel. Any advice for how to hinge?

Edited June 22, 2023 by StudWorks

[jus1973]

I see how he grille is made now, and I think this will limit your options.  You’d be hard pushed to get something to fit onto the bonnet (red) parts, without really hitting the space there for your engine.

It occurs to me that you could try something using these 2 parts, A & B, tucked away into the grille area and the bumper below.  The only challenge will be to get everything to line up, without showing too much of the hinge at the front, whilst still allowing the hinges to work.

I would suggest making a quick mockup of the bumper and grill area, on a short chassis to see what problems there will be.  Sometimes there is absolutely no replacement for actual fingers on bricks.  I’ve found digital building very limited and have given up on it as a method to fully design things.

[Henchmen4Hire]

If you really need the bonnet and bumper flush, maybe you can have the bonnet slide forward on rails a little, then hinge it open.

[ukbajadave]

Is there any mileage in using skeleton arms as links?

[jus1973]

On 6/24/2023 at 8:02 PM, ukbajadave said:

Is there any mileage in using skeleton arms as links?

I thought about this, but wondered if they would be strong enough for the weight of that bonnet.  Perhaps if you used 4, or even 6 across the whole front, it might just give enough of the ‘cranked’ hinge needed to get the bumper and bonnet flush at the front.