This step requires x5.25 the QL in Mechanical Engineering and x5.5 the QL in Weapon Smithing
The Biomaterial Tubing set's the ql of weapon.
The Fused Biotech Material needs to be at least 80% of the QL of the Biomaterial Tubing
Still not enough? If you're willing to invest some effort inside APF 35, it can be upgraded further.