Help me 3D Print/Prototype These Rear Upper Spring Seats

So I received the 3D print of prototype number 1 and the results were overall, very positive!

Here she is.


It looks like the photogrammetry process did produce some pretty accurate results!

This is with the suspension at ride height. The lower spring seat on the shock is coplanar to the upper spring seating surface at ride height!



Very happy, although, there are a couple of issues I need to work out.

I had to clearance the the spring seat in one area because it was not clearing that chassis hole and preventing the two mounting holes to the chassis from lining up.



The problem is that this area is already pretty thin because it is bored out for the spring to seat in. I will likely need to move the spring seating surface downwards to below the bottom surface of the entire body like so. That way I can maintain the correct profile for the upper portion and it will clear the chassis hole and allow the two chassis mounting holes to line up. It would be much stronger this way as well. Blue circled area in the screenshot is the area that had clearance issues that would be good to go in this design.



The issue that this creates is that now the shock body will be inside of the upper spring seating surface at ride height, unlike my current design. There is not much clearance at all so as the angle of the shock changes, it could come in contact with the bore of this area just like in my initial design I made at work. I think I will have to make the spring locator around the outside of the spring rather the inside of the spring like it is now. It's too close. The dust boot on the shock would not fit through the bore either as it doesn't now.



There are a couple of other details that I'm going to change too. The 2 mounting hole slots don't have much material around them so I'm going to beef up that area a little. I'm also going to tighten up the bore at the top for the PDV upper shock mount so that there is more supporting surface area on rebound. Couple of other things too.

Going to get to work in Fusion 360.

Something like this:

Here's an update on my progress with this project:

Here's the 2nd prototype (blue) next to the 1st version (black.)



I made a bunch of small changes in the design but most notably, the spring is now located by its OD instead of its ID so that the bore for the shock body is larger which allows the shock dust boot to be used.

Huge thanks to Shiann (broinkrist) for 3D printing this for me. I had the design but he made the changes and recommendations necessary for it to be printable and quite possibly a functional prototype. His experience with this type of work has supercharged the quality and rate of progress. He's a really good dude.

Here it is assembled and then in the car.




I have only had time to do a quick assembly and test fit but it looks very promising. Everything lines up as intended at the desired ride height. My only concern is that as the suspension extends, the angle of the shock relative to my upper spring seat changes which means that the upper and lower spring seats are no longer coplanar as they are at ride height. I imagine the spring being slightly bent and loaded unevenly. I don't know that this is going to be an issue or not until I get everything assembled. If it is an issue, the backup plan would be to explore using some hydraulic spring perches to potentially alleviate the problem: Hyperco Universal Hydraulic Spring Perch (not threaded) - Pegasus Auto Racing Supplies
I will likely require a helper spring to keep the spring seated as well. Lots to play around with and waste money on lol.

So from here I think I probably need to mirror the design and print it to ensure that the passenger side is indeed a mirror image.

After that I'd like to look into doing some kind of stress simulation to see if I need to beef them up at all before moving forward with having the final ones made up.

I'll keep posting as I progress with this. It's a slow process but very exciting.

Sent from my iPhone using Tapatalk

Enraged said:

What IDs do you need? Could you use a bearing bushing/sleeve instead of two different bushings? Like this: SKF

Click to expand...

Wow... I really wish that I had known about those back when I made those custom shoulder nuts so that I could use the KWs with the PDV shock mounts... lol.

I don't know about the BCs but here are the KW measurements:
KW rear shock shaft threaded end diameter: couple hundredths of a mm shy of 12mm.
KW rear shock shaft polished section (shoulder) diameter: couple hundredths of a mm shy of 18mm.
KW rear shock threaded end total length ~30mm.
KW rear shock threaded end, shoulder to end of threads ~22mm. Remaining 6mm of lenth to end is the 9mm counterhold nut.

I found some spherical bearings that have the right dimensions that I want to try out. McMaster-Carr

Incorporated it into this design. Kind of an ugly top but positions of everything are accurate and there should be no clearance issues. I would like to taper the cylinder and the bore at the top in a way that would maybe add strength, reduce material, and still be easy to machine.



Here's a point of concern though:



Need to keep working on it.

Anyways, here's a little video of the prototype 2 showing the shock clearance in the bore as the suspension travels from fully extended to fully compressed to where the bump stop starts making contact. Goes to show how accurate this photogrammetry can be.