That project is made by six parts and could be assembly without glue.

1. To assemble it I welded to the LED strips of small cables that I put through the holes.
2. Then I inserted the LEDs in the letters and then inserted the letters in the support.
3. I soldered all the positives and negatives on PCBs connected to the circuit breaker.
4. I also installed a 600 Ohm resistor to lower the voltage from 18V to 12V (to generate a voltage of 18V I used two 9V batteries in series).
5. Finally I placed the back cover to close the whole thing.

Here some links

• https://www.amazon.it/Senven-Interruttore-interruttore-bilanciere-elettrodomestici/dp/B07X169PBN?pd_rd_w=9z4f9&content-id=amzn1.sym.02a03cf1-c9ab-49f1-beb8-8a58f9c6f8ad&pf_rd_p=02a03cf1-c9ab-49f1-beb8-8a58f9c6f8ad&pf_rd_r=Y3D1AEMXD8KPP0Z4VZKE&pd_rd_wg=Sk5C9&pd_rd_r=2663eb7c-661c-4fef-a4b9-2f735562ef9f&psc=1&ref_=pd_bap_d_csi_prsubs_0_t
• https://www.amazon.it/Flessibile-Accorciabile-Collegabile-connessione-alimentatore/dp/B00HSF65MC?pd_rd_w=rc5XC&content-id=amzn1.sym.02a03cf1-c9ab-49f1-beb8-8a58f9c6f8ad&pf_rd_p=02a03cf1-c9ab-49f1-beb8-8a58f9c6f8ad&pf_rd_r=Y9XBBSV7JAADAXNMWR4D&pd_rd_wg=WyqzU&pd_rd_r=cf4a5e00-e7c3-4cd0-a758-5844dfbd8a1a&psc=1&ref_=pd_bap_d_csi_prsubs_0_nped_t
• https://www.amazon.it/Warriors-batteria-batterie-rilevatori-irrigatori/dp/B0BYD6PXZH/ref=sr_1_2?keywords=9v+batterie&qid=1707849130&sr=8-2-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1
• https://www.amazon.it/ZITFRI-Arduino-Nastro-Arcobaleno-Cavetti/dp/B07PN8GD6G/ref=sr_1_3?__mk_it_IT=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=1X4K0Y1X27TO3&keywords=Cavetti+piccoli+arduino&qid=1707849501&sprefix=cavetti+piccoli+arduino%2Caps%2C105&sr=8-3

I used the “Pink PLA Matte ” of Bambu Lab for the external case, “Lavander Purple PLA” of PolyTerra for letter L and for the heart and “Fucsia PLA” of SUNLU for letter V and E.