designed a simple attack timer for mini siren enthusiasts to make! it costs less than $20 to build and the parts needed cost next to nothing

threaded inserts: https://www.aliexpress.us/item/3256803396040989.html?spm=a2g0o.productlist.main.2.1c3044311ZfRkd&algo_pvid=383a94e8-9758-4df7-aa6d-649c80dd00c0&algo_exp_id=383a94e8-9758-4df7-aa6d-649c80dd00c0-1&pdp_ext_f=%7B%22order%22%3A%2215272%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&pdp_npi=6%40dis%21USD%211.77%210.99%21%21%211.77%210.99%21%4021030a4b17679809363745722ef75d%2112000026370649723%21sea%21US%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ab2c5a2ba%3Bm03_new_user%3A-29895%3BpisId%3A5000000197847478&curPageLogUid=fKHZApmHeIdB&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005003582355741%7C_p_origin_prod%3A

microwave motor:

https://www.aliexpress.us/item/3256806443089989.html?spm=a2g0o.productlist.main.4.459916c4VBtHUY&algo_pvid=303d0854-44b1-436d-976a-d6a6f9668fb3&algo_exp_id=303d0854-44b1-436d-976a-d6a6f9668fb3-3&pdp_ext_f=%7B%22order%22%3A%221%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&pdp_npi=6%40dis%21USD%214.54%214.54%21%21%2131.48%2131.48%21%402103110517679808976624586eca03%2112000037870015515%21sea%21US%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ab2c5a2ba%3Bm03_new_user%3A-29895&curPageLogUid=kXtrVWszWXJ9&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005006629404741%7C_p_origin_prod%3A

m3 screws: https://www.aliexpress.us/item/3256807448357932.html?spm=a2g0o.productlist.main.16.4c0b6bbaJG71aL&aem_p4p_detail=2026010909515310079163343250400005048295&algo_pvid=4b264636-f835-4aaf-a607-cf527e531ad7&algo_exp_id=4b264636-f835-4aaf-a607-cf527e531ad7-15&pdp_ext_f=%7B%22order%22%3A%22313%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&pdp_npi=6%40dis%21USD%213.41%211.88%21%21%2123.64%2113.00%21%4021033d1217679811136218091ed11d%2112000041586588349%21sea%21US%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ab2c5a2ba%3Bm03_new_user%3A-29895&curPageLogUid=KSuX5Zie0sDu&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005007634672684%7C_p_origin_prod%3A&search_p4p_id=2026010909515310079163343250400005048295_4

switch:

https://www.aliexpress.us/item/3256808766353854.html?spm=a2g0o.productlist.main.1.bd9516aevvkQWJ&algo_pvid=4b184feb-970c-4862-9d54-21e9f194f2b8&algo_exp_id=4b184feb-970c-4862-9d54-21e9f194f2b8-0&pdp_ext_f=%7B%22order%22%3A%228%22%2C%22eval%22%3A%221%22%2C%22fromPage%22%3A%22search%22%7D&pdp_npi=6%40dis%21USD%211.20%210.99%21%21%211.20%210.99%21%402103122117679811750382967ea711%2112000047342208914%21sea%21US%210%21ABX%211%210%21n_tag%3A-29910%3Bd%3Ab2c5a2ba%3Bm03_new_user%3A-29895%3BpisId%3A5000000197847418&curPageLogUid=nlHZ42ITsEEx&utparam-url=scene%3Asearch%7Cquery_from%3A%7Cx_object_id%3A1005008952668606%7C_p_origin_prod%3A

the switch clips into place, the motor is then screwed into the base with 4x m3 screws, after installing the threaded inserts. theres a hole in each corner so you can choose to mount it if you like. enjoy!

designed to print on a printer as small as the a1 mini