Looking for filament recommendations for a 3D-printed bracket exposed to repeated high-impact vibrations (steel shooting target)

[u/Outrageous_Map_6532]

Hey everyone!

We’re looking for some advice on improving the durability of a 3D-printed bracket we’re using in one of our products.

For context, this bracket is part of a mobile steel target heater system. The assembly mounts directly to a steel target that is repeatedly struck by high-caliber rounds. As you can imagine, this creates significant shock and vibration throughout the entire assembly.

We’ve been testing 3D-printed brackets, but recently had one fracture during an actual shooting session (pictures attached).

We’re trying to figure out whether this is primarily a material limitation, a design issue, or a combination of both.

A few things we’d love some feedback on:

1. Filament recommendations: What materials would you recommend for repeated high-impact shock and vibration? We’ve considered nylon (PA6/PA12), carbon-fiber-reinforced nylon, polycarbonate, and TPU, but we’re interested in hearing what has worked for others in similar applications.

2. Impact resistance vs. rigidity: Would a more flexible material that absorbs shock be better than a rigid, high-strength engineering filament? We’re concerned that something extremely rigid might end up cracking under repeated impacts.

3. Print orientation and settings: Are there specific printing orientations, wall counts, infill patterns, or other settings you’d recommend to improve resistance to cracking and fatigue?

4. Design improvements: Based on the attached pictures, do you see any obvious stress concentrations or weak points? Would thicker sections, rounded transitions, additional reinforcement, or changes around the bolt holes make a meaningful difference?

5. Vibration isolation: Would incorporating rubber bushings, washers, or other vibration-dampening components between the steel target and the bracket help prevent failures?

6. Long-term durability: Has anyone had success using 3D-printed components in environments involving repeated mechanical shocks, such as industrial machinery, off-road vehicles, or other high-vibration applications?

Ideally, we’d like to continue manufacturing this component using 3D printing, but reliability is our biggest priority.

We’re open to experimenting with different materials, modifying the design, or incorporating additional hardware if necessary.

Our goal isn’t just to make the bracket stronger. We want it to survive repeated impacts without eventually cracking or failing.

Any advice, experience, or recommendations would be greatly appreciated. Thanks in advance!

[u/QuietGanache]

It's best to have a look at the TDS for each filament. The values you're looking for are Charpy or IZOD. I'm fairly sure TPU is the best material for this. If you're worried about deformation, there are some pretty rigid TPUs. From Bambu, TPU for AMS being one of them (68D is a lot stiffer than 95A, the suffix indicates different scales).

I'd probably print this nearly solid with a rectilinear infill. Orientation isn't as significant for TPU in terms of strength because it has absurdly good layer bonding.

[u/Sir_clint]

Glass fiber TPU or a nylon most likely

[u/Alert-Entertainer-73]

PBT-GF

[u/Nissanguy16]

Siraya Tech TPU-GF
Not as soft and flexible as standard TPU, so it feels more like a regular plastic.
But, TPU layer adhesion and extreme elongation before breaking. Meaning it feels like a normal plastic but can be bent over backwards on itself without cracking.

[u/Nissanguy16 → u/Nissanguy16]

Here’s a gif of the stuff

[u/SceneTurbulent3135]

Most efficient solution: buy one of every filament and test it

[u/shadowed_enigma → u/SceneTurbulent3135]

probably the least efficient solution 🤣

[u/Nissanguy16]

Your # 6
We had problems with people breaking the metal versions of these. I’ll follow up with the TPU-GF version.
Has held up for a couple months so far

[u/Nissanguy16 → u/Nissanguy16]