Previously, I floated the idea that frames can/could/should be printed cheaply using an FDM/FFF printer with PLA0 and then strengthened using one or more of a variety of techniques- which would yield an inexpensive, fully compostable/disposable skate part, to be manufactured on demand anywhere by anyone with electricity and a basic printer.

process

I thought this was going to be difficult, would require strength-adding design compromises and might take a lot of trial and error to make work for more than just a session or two, despite PLA's rigidity and technically ideal mechanical properties ...

FDM/FFF (Fused Deposit Modeling/Fused Filament Fabrication)

This is the cheapest and most widely available 3D printing technique, wherein a spool of plastic is additively melted to create a form. Materials: PLA (polylactic acid), ABS (acrylonitrile butadiene styrene), Nylon (polyamide), Polycarbonate, etc.

Potential Applications

• Soul Plates
• Buckles
• Frames
• Boots

PRO

• Inexpensive printer hardware
• Widely available
• Easy to use/learn/get started with
• Cheap consumables

CON

• Not that strong without heat treatment/chemical post-processing. Still less durable than injection molded plastic.
• Slow: 10+ hours for a frame

SLS (Selective Laser Sintering)

Plastic (usually nylon/polyamide) powder is mechanically spread and ...

• Don't worry, pants are still important and divisive
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• Some still do big hammers, many do not. Every trick is not a nail.
• Living legend Jon Julio of Hoax II and unity grind fame ran a Roces aggressive sub-brand for several years called Valo that produced skinned and unskinned UFS Majestic 12s ("V13s") as well as a carbon skate: that company is no more and JJ currently sells THEM skates, which are based on the UltraWheels sabotage with modernizations.
  
  Yes, JJ has been pro the WHOLE time since 1995/6 ...

The main problem thus far (2020) with printable parts is a lack of durability. This isn't an issue for grind blocks or antirockers, which can be trivially reprinted- but an item like a complete plastic frame requires a more expensive printing technique like SLS than good 'ole FDM, or less environmentally friendly filaments (think fancy fiber-nylon) to last very long -- and SLS prints are probably going to be produced by a third party with deep pockets.

But it might be possible to overcome this hurdle by designing parts specifically for FDM, meanwhile leveraging the positive side effects of a ...

Lots of folks are making stuff, but few are sharing recipes.

STLs or it didn't exist?

Open Element 2.0

A model akin to the Kizer Element 2.
Direct Link
https://www.thingiverse.com/thing:3964175
Method(s) Frame: CNC aluminum alloy; Grind Block: CNC UHMW; FDM ABS/PLA/Nylon/etc or SLS Nylon, Alumide.
License CC-BY-NC-SA

Salomon Souls

By Starscream/Claudio A. Sizes for 265/75/85mm boots: scale up or down manually for other sizes. Protects the original boot surfaces with minimal added ride height.
Direct Link https://www.thingiverse.com/thing:4025289
Method(s) SLS Nylon ...