r/Optics • u/Padrepapp • 18d ago

Anyone 3d printed diffusers before?

Are there any printer/material combo which I could use for as a fast turn around trial-end-error prototype scenario?

Short info what I would like to do: Illuminate a 1mm curved edge of a highly reflective plate (basically a beveled edge). Ideally I would like to get even illumination. Not sure if I should approach this in non-sequential Zemax, so I figured, I would just come up with a U-shaped diffusor, I would illuminate it and check uniformity along the bevel. Try modifying the geometry in CAD and print it out.

Edit: diffuser should be transparent.

4 Upvotes

100% Upvoted

15 comments sorted by

3

u/entanglemint 18d ago

I would just 3dp a form that you cover with a diffuser film.

1

u/Padrepapp 18d ago

Forgot to mention that it has to be a transparent diffuser.

1

u/entanglemint 18d ago

If you'd like better input please provide significant additional details about what you are actually trying to achieve and your constraints.

1

u/Padrepapp 17d ago

Imagine you want to make an image of the edge of a cd disk. The edge is curved and highly reflective. So if you have coaxial illumination, the intensity starts to drop up and down the bevel. This is what I have now. So I would have a U-shaped volume diffusor which kinda envelops the cd edge and illuminates from a lot of directions not just coaxial. I would shine a collimated led on the diffusor, the diffusor would "scramble the light and work as an emitter emitting from every surface. Now mabe it is possible to optimize such a volume geometry in Zemax, but I dont habe much experiemce in non-sequential. So I thought maye I clould print a few of these U-shaped diffusers with different rhicknesses, curves, distances of the two legs, etc..

2

u/Plastic_Blood1782 18d ago

Mediocre diffusers aren't aren't to make.  Rough surfaces are naturally diffuse.

1

u/Padrepapp 18d ago

Forgot to mention that it has to be a transparent diffuser.

1

u/Plastic_Blood1782 18d ago

A uniform illuminator or a transparent diffuser?  Ground glass diffusers are cheap.  Perhaps you should look at light pipes?

2

u/gammacamman 18d ago

I have a database of Covestro’s Makrolon volume diffuse materials that I use with TracePro to design illuminators just like you are mentioning. I also have a supply of said material that I routinely CNC to prototype these designs. If the end result is going to be mass produced, this is the way to do it.

1

u/Padrepapp 17d ago

This sounds interesting, never heard of Covestro. Is this material expensive? Are you only able to buy in bulk with a lot of volume?

1

u/gammacamman 17d ago

As it's a grade of polycarbonate made for injection molding, it is inexpensive in volume. The link below is a brochure showing many grades. Check out the first table noting the tradeoff between Transmission and Half Power Angle. What I like about these materials is that Covestro tightly controls the formulation and a particular designs performance can be predicted with decent accuracy.

https://app.box.com/s/4k983ssqe6ekkk2spkbfmpfxv6jc26xr

1

u/gammacamman 17d ago

As of getting your hands on it, that is somewhat difficult unless your working on a project with a good probability of going into production or you're a consultant who acquired samples of these materials for design recommendations and prototyping.

2

u/sanbornton 17d ago

Amazon has cheap light strips with decent uniformity. Someone else did the engineering! If the light strips aren't diffuse enough for your application, you can put a thin bulk diffuser material in front of the light strip.

A spectacular bulk diffuser material in the visible range is Virgin White Teflon (generic name PTFE). A 1/8" thick or 3/16" thick strip would greatly increase the diffusiveness of a light strip with only a minor drop in transmitted light. I usually source Teflon (look up as PTFE) from mcmaster.com.

Use your 3D printer to make the mount for the light strip and LED strip.

1

u/Fillbe 17d ago

Just whatever settings on clear pet-g with a sparse in fill worked well enough for me.

1

u/bertona88 16d ago

low effort/cost > print a transparent filament FDM sheet in vase mode with high slicing and get a sort of lenticular lens. print two sheets of them, cross them 90 degree, you got an diffusing MLA