Advice on refining prints for later cassting as well as precomplience testing

[yentzee]

Hi,
I developed a product I am very happy with and which I would like to take the next steps for.
The hardware as well as the code are working nicely.
I designed two pcb's within Kicad and had them manufactured and assembled (Version 4 so far)
In Fusion I designed a case consisting of three parts which fits nicely and holds the pcb's (1 fr4 1 MCPCB) in place and gives acces to the connections for audio, usb etc.
Now as this product is intended for a niche market and it is questionable if there is any money to be made I would liike to print shells, I can place the parts inside and pour a mould with silicone for later casting. I watched a lot of you tube tutorials on how to refine the prints for that but as I am dealing with plae surface I suppose that sanding by hand will endup with irregular depth of the surface (I might mode the part lying flat over sandpaper?) etc so I wanted to ask whether anyone has some infos on how to refine prints especially for enclosures and not for Star Wars helmets as  the majority of the you tube videos show.
The second thing is precomplience tests. I am running 16 5W LED's each with their own driver on 20 kHz and switch those on and off in periods between 1 - 70 Hz. While I think my mainboarddesign / buck converter is verylikely to be solid I suspect the LED board to be a problem (not sure whether to switch to fr4 with holes for the COB's instead and sandwhich a mcpcb just for cooling purposes underneath). So I will have to do some testing before approaching a lab for a report.
As I am a dentist and everything is self taught I am looking for resources to read myself into regarding the use of a frequency analyzer etc. If you had some good links I would be very grateful.
Thanks for helping,
Jens

[Renate]

Casting sounds like a lot of work.
How many of these things do you anticipate making?
Why wouldn't you just print a dozen cases to start?
You can always order higher quality than what you can print yourself too.

You could always show the case, there's little chance that somebody will steal the idea.

80 Watts of LED? Are they all running the same modulation? Why separate drivers?

[negativ3]

Look up Eric Strebel on YT. He does exactly what you want and shows the tools needed and steps in great detail.

Multi-parts which need to fit together sounds next-level complex, but without knowing the geometry, its tough to comment further.

[yentzee]

Thanks a lot for your answer.
Here are some photos of the product.
I did some prints which are ok for checking if everything is fitting but they do feel really cheap / plastic.
I just saw that printing alu isn't that expensive so I am thinking of printing the frontplate as well as the body with aluminium (that might also be beneficial for emi) ad do the backplate in some sznthetic material to allow wifi / bluetooth connection.
To be honest I have no clue how many I can or will sell of those. featurewise I went a bit too far and think have to offer way more than any potential competitor but then I have absolutely no clue in terms of marketing (and way less motivation than developing the device).
The device is intended to be used as a hypnagogic light  for audiovisual stimulation. the led's need to be able to be controlled individually to allow complex modulation pattern for the deired effect on the brainwaves. I probably could have gone for less drivers but then I wans't sure how to split them as there are 8 leds with 2800 kelvin and 8 with 4000. Heat doesnt seem to be an issue so far. I have a tempo sensor on the led board as well as a fan, a mcpcb and as the leds are not constantly on and very unlikely to be used in full brightness I think that should be ok, also attached some heatsinks tothe back of the mcpcb.

[Benta]

If you go to SLS instead of filament printing and use very fine slicing, the result should be much better and might be used as end product.

[Renate]

The printing looks pretty nice, much better than mine.
Still, you can see the vertical seams.
For your jack panel, I sometimes print just a small piece of a print to fine-tune the design.
It goes much quicker.
I think that a hex based speaker grill looks better than a semi-random one.

If you're still with plastic and concerned about shielding you might look into spray-on or brush-on conductive chemicals.

[cunningfellow]

Look here.

https://lcamtuf.coredump.cx/gcnc/

You can make parts way nicer than resin prints that way.  My prototypes look and feel just like the ABS part that that you will injection mold when you go to production.