Same here. I guess we're both unlucky.
Here is the minimum required materials for a guaranteed equipment production. From the quoted part, you need a total of 18000 which is equivalent to 4500 for each mats more or less.120-5999: his own (★ 1)
6000 or more: Tsuchinoe (★ 2)
12000 or more: Ding (★ 3)
18000 or more: hei (★ 4)
24000 or more: B (★ 5)
30000 or more: instep (★ 6)
My question is: if I follow the recipe (cheapest 4* bullet -> 3000 metal + 2000 gunpowder + 2500 chemicals + 2000 fiber = 9500) down to every detail, is there still a chance that it will change into a random 3* item?