Task: Door Hinges and Latches on a 3D Printed Vehicle
Description: We need to have ingress/egress points in the vehicle, but doors are some of the more complicated portions of a car. We need your help with a solution that handles the structural, functional and fitment elements required of any vehicle door.
Challenges to overcome:
1. Doors may have to house equipment and systems for controls, latching mechanisms (if latch is on the door side) and windows.
2. If conventional latching mechanisms are used, we need to understand how they can be securely mounted to 3D printed material so that they withstand high forces from impact, attempted theft and the impact of the occupants.
3. Door hinges, and latches are required to pass FMVSS 206, which states that each door must use a two-stage latch, and be able to resist the loads specified: 2500/1000lb longitudinally, 2000/1000lb transversely. Each door hinge should conform to SAE J934.
4. Doors and panels should be able to be adjusted for fit or the process should provide an extremely reliable accuracy of positioning to ensure proper aesthetic surface alignment.
Please provide your approaches to create the best system for ingress/egress on a 3D printed vehicle. We don’t need all the models and assets created; we simply need your best ideas. Please include the following:
o A general description of the system mechanism and approach
o A short description of hurdles addressed
o Links to any supporting info
o Links or leads to any specialized materials or equipment that are core to the solution
o Any diagrams that could assist in the understanding of the process solution
Will you help with this task?
1. Start with an already tooled production latch assy as it has undergone both component and system testing as well as real world crash testing and validation before being released for production. Sample vendors are GECOM from Greensburg, IN/Novi MI, Magna Closures, Novi, MI., Brose, Auburn Hills, MI and Inteva Products, Troy, MI. and Strattec, Auburn Hills, MI. They are major latch manufacturers for OEM's.
2. Using a conventional automotive door latch I am breaking no new ground here suggesting this but using the standard 3 fasteners, the door latch will be fastened on the inside (shut face) of the inner panel and between the latch plate and the 3D printed inner panel should be a metal reinforcement of 1.1 to 1.4mm thickness. For any basic vehicle theft deterrent, a plastic shield or cap should reside just above the latch and any release levers so that any thin tools cannot access or trip the levers. The cap also helps with water drainage keeping it away from the latch.
3. door hinges will have to be designed specifically for the car as cutlines will ultimately dictate door construction and more specifically your in and out swing unless you copy a door environment note from note from another car and even then there is a lot to overcome. Multimatic in Southfield, MI/Markham ON is probably the best hinge manufacturer on the planet. Consult with them.
4. As this will be a lower volume car, the cost of providing automated dimensional control devices would be extremely prohibitive. Doors inner and outer should be dimensionally checked via some fairly elaborate gauges. Many shops in the Metro Detroit area are experts in this specific field.
System mechanisms and approach: Two basic approaches as I am not ultimately sure how 3D printing will work out with this but door construction can be 1 or 2 pieces (1 pc - door outer and inner are the same part) or 2 pcs. (separately printed door outer and door inner). The design should follow basic automotive door construction in that you have a door (outer) panel or skin and then a door inner with the required apertures or holes for access to install hardware etc. I would suggest using an adhesive (bond) for the inner to outer.
Many car manufacturers now use a door module which is like a carrier plate (formed metal plate) with attached hardware such as the window regulator, speaker, latch and inside handle and cables etc. or a conventional door with each component or sub-assy installed individually. I would suggest a conventional door build approach (no module) as though the module is 'sexy' in some assembly corners if you are off dimensionally its a bugger to get everything to work right.
To get a successful door assy built use mock ups initially in clear lexan to simulate inner and outer panels and mechanical as well as electrical functions. Understand where you need to put everything (door beams, foam for crash conditions, keeping the windo reg spindle from intruding or piercing directly into the occupant if there is a side impact and how the trim panel (if you want one) will integrate to the door inner. As odd as it seems get a repair manual of a car similar in construction or size (Mini?) to the LM vehicle and look at all parts listed and create a BOM. Know all the parts you are dealing with. Weatherstrips and sealing a door alone is an art. Hope this helps.
Two words: sliding hinges. The
loop consists of a box, which is attached to the threshold of the car.
Inside - a hidden mechanism of the two moving parts. The first element
works like the swing door. I.e. it pushes the door from the outside of
the initial closed position, parallel to the vehicle at an angle of 90
degrees. By increasing the width of the car by not more than 30 cm. The
second element is a slide or guide rails. It pushes the door forwards or
backwards for easy entry into the vehicle. Loop - box is a reinforcing
element of the frame and threshold. Dimensions 600 x 150 x 100mm
. Existing details can be used or production established. Comment for more info. It is MAMI university's (Russia) project.
If these components by 3D printed and then assemble, how to avoid the sound insulation problems
Falcon wing doors similar to Tesla. You have to have a frame and you can us the frame as the shell you secure the hinges too. I know every model will vary and you could in theory never print the same car for years, but you need to have a small option of frames. Take 4 frame options, one convertible (no Falcon wing doors here), SUV/CUV, sedan, and couple. Three of the 4 can use falcon wing or even scissor wing that the frame supports the hinge and mecs. I would add the framing to handle the force, crash, and weight.
This may seem kinda stupid, but are doors necessary? I know it may seem crazy, but what if you don't have doors at all and sort of climb over or have an alternative way to enter the vehicle