The Surge 2

There are a total of 18 drone modules if you include the ones that are consumable. I believe the consumable one's do not count towards the achievement as I have gotten it to unlock without having a SPARK Engineer Turret or Proximity Mine, but I will include the consumable ones as well just to be safe. I'm going off of my memory for these, but I wanted to try to make it more clear on how to get these. There are only a few that I'd consider story related that you get no matter what, a few that are no doubt missable, and then a few others that aren't really missable but you won't get it if you don't chop off certain limbs from an enemy. I'm going to try my best to list them in chronological order that you are able to obtain each module.

R-1 'Diode' Laspistol- Story related, you will get this after killing Warden Garcia at the end of the prison.

S&R Drone- Story related, same deal here you will get it after Warden Garcia.

W-102 Banner- Missable? Not sure if it is or not as it's a pickup off the ground, and the world changes after a point in the story. As you make your way to the Seaside Court, you'll see a man by a barrel that you can talk to. There's a gate you can open up for a shortcut back from where you came, there is also a walkway that leads to some walkways above this gate. The pickup for the module is on that walkway somewhere.

W-101 Spray Can- Missable? Again, not sure as it's a pickup in the world. However, starting from the man at the barrel for the previous one if you're heading towards Seaside Court somewhere to your right you should see an area you can drop down to where there is an enemy with a hammer. The module is down here somewhere, this is also the same area where the Stranger, Warren, has his hideout that you need another module first before you can access.

Klokonov R-47 Autorifle- Starting from the man at the barrel you may have noticed two enemies up ahead towards the Seaside Court. One of these enemies has a Klokonov, just cut off his right arm (left for us) and you should get it. If you continue from W-101 Spray Can you'll end up coming from behind this guy as you take the magnetic lift back up. These enemies are around in various locations throughout the game and of course respawn, I don't think it becomes missable at any point.

Molotov Cocktail- The same group of enemies as for the previous module, the other enemy with the single-rigged fire weapon can drop Molotov Cocktails. I'm unsure if you have to kill them in a certain way or not, but they do drop from them because I had plenty of these without ever buying them. Speaking of which, you can also buy these from Rex who is upstairs to the right at the Seaside Court. If you do his quest and tell him where April is later on he will disappear and be unaccessible until later in the game.

Grenade Drone- You can buy these from Rex as well. Later on in the game, you'll encounter these four-legged robots that the A.I.D. have. If you target their tail and cut it off you can loot grenades from them as well.

CREO Industrial Magnet- Missable...ish. I say missable, but not entirely. You have to buy this from Rex for 10,000 scrap. If you do his quest line though he will disappear until later in the game. I've also read that even if you don't do his quest, after you kill Ezra Shields he'll move on to where he is later in the game but be dead instead of alive. I'd get this ASAP, and also do his quest line. I say this because you can buy one SSM 'Vanguard' Missile from him later if you do his quests. There is another way to get it as well which is how I got it, but I've seen some people say that way isn't working so I'd advise to do Rex's quests just in case.

SPARK Engineer's Turret- Ok, so this is one of the one's I didn't have when the achievement popped and makes me think the consumables aren't needed. I didn't get one of these until I looted it from a chest at the end of The Kraken DLC. This is apparently where you can get it though coming up. You should be in Port Nixon. Just progress a little ways until you see some little blue robots. To your left hiding in a corner is a SPARK Engineer, cutting this enemy types torso is supposed to give you SPARK Engineer's Turret, Even at the end game these enemies can still be found in Port Nixon and at Cathedral of the Spark, so if you don't get it I'd just recommend playing through the game and trying later if the achievement doesn't pop.

Proximity Mine- This is the other one I didn't have when I got the achievement, didn't get one until somewhere in The Kraken DLC. This is the same enemy as the SPARK Engineer's Turret, but you need to cut off their leg. I'm not sure if it has to be a specific leg or not, but apparently that's how you get it. Again, if you don't get it i'd just worry about it later if you don't have the achievement.

EMP-44 'Starfish'- Story related, you will get this after killing Little Johnny at the end of Port Nixon.

A.I.D. 'Empire' Sniper Rifle- So your next goal is to head to Gideon's Rock. While on your way there you will now start encountering A.I.D enemies. Some of these guys will be carrying this weapon and you just need to cut off their right arm (left to us) to get it. However, there are some of them that will pull out a melee weapon when you get close. I'm unsure if they need to have the gun equipped or not when you cut their arm. You could always weaken their arm to the point of cutting, retreat until they pull the gun, then run back in and cut. I believe there are also some of them that only have the gun and no melee weapons. I'm pretty sure you can find these guys in a few spots even end game, but I know for sure there is two of them in the final area of the game so it isn't missable.

JAG Bio-Sensor- Missable, it's only missable if you complete the quest the wrong way. To the left of the first A.I.D. checkpoint you'll see on your way to Gideon's Rock you can find a building to the left that you can enter. You'll find the shady doctor who will give you a quest to retrieve something for him. If you just keep progressing along to Gideon's Rock through the A.I.D. checkpoint you'll eventually drop down into an area that has a Zebra painted on the wall, and I believe there is one of those Athena echo's there. This is where the item is that the shady doctor wants. Just bring it back to him, and end the quest where you side with him and ask for a reward and you will get this module. DO NOT kill him.

SIDE NOTE: When you encounter Hawke at Gideon's Rock, agree to split the reward with him. This is alternative way for the SSM 'Vanguard' Missile later on.

GAIA Laser- Missable? At Gideon's Rock you will come across enemies that are big statues that attack you. You get the GAIA Laser by cutting off their head. There are areas where the nano stuff is taking over and the statues will be stuck in one place rather than being able to move. I think these can still give you the module, but I am unsure. I believe after you kill Ezra Shields the entire place gets that nano stuff everywhere and most of the statues become stationary like that, I believe I was still able to find one that was normal, but I am unsure. I would get this before completing the area just in case.

Jag-1000 'Carnivore' Shotgun- Missable, in Gideon's Rock you will come across a boss named Captain Cervantes. To get this module you will need to kill him by cutting off his left leg (right to us).

VULC-88 'Panthera' Rotary Gun- Missable, at the end of A.I.D. Command you will fight Major General Ezra Shields. He will start out in a mech called Metal Armor. Do this part however you see fit, but when you kill it and enter the 2nd phase where Ezra comes out of the mech you will need to target the flamethrower on the mech and destroy it. After you destroy the flamethrower on the mech you just need to kill Ezra and you will get this module. The flamethrower can hurt him too, so be careful he doesn't accidentally get killed by it.

SSM 'Vanguard' Missile- Missable...ish. If you agree to take Hawke's deal, on your way to the Cathedral of the Spark you'll have to pass through the Seaside Court again. Hawke will be here downstairs to the right as you enter the area. Make sure to have 5,000 scrap on you before talking to him. You'll be able to pay him his half of the reward and he will also reward you with the module. However, as long as you did Rex's previous quest you can also find him at the Cathedral of the Spark now alive, but locked up. I'd look up a guide for the specifics of if, but if you complete this next quest by answering April correctly she'll give you the key to Rex's cell. After his release you can talk to him now and buy the SSM 'Vanguard' Missile from him. Or later on he will re-locate to Gateway Bravo with April. If you kill April I am unsure how this quest plays out. I assume you can still free Rex, but I'm not sure whether or not he will sell you things, if he re-locates, or what. Just in case, do it the way where April lives.

SPARK 'Enlightener' Electro-Beam- In the Cathedral of the Spark you will see a few enemies with a big gun that shoots electricity at you. Simply cut off their right arm (left to us) and this module is yours. There is also one located in the Underground somewhere, but I am unsure of exactly where. These enemies will always be here at end game and so it isn't missable. This was the last module I needed that got me the achievement without having the consumable modules SPARK Engineer's Turret, and Proximity Mine.

I hope this is helpful, and more clear on how to get some of these.

A.I.D. ‘Empire’ Sniper Rifle
CREO Industrial Magnet – Buy from the drone vender.
EMP-44 ‘Starfish’ – Reward for killing Little Johnny.
GAIA Laser – Story related
Grenade – Buy from the drone vender or obtain from a quest.
JAG Bio-Sensor – Help the fake Russian by finding the broken drone and turning it over to him. You can only obtain this if you choose to look the other way.
JAG-1000 ‘Carnivore’ Shotgun – Cut off Captain Cervantes’ left leg.
Klokonov R-47 AutoRifle – Story related
Molotov Cocktail – Buy from the drone vender or obtain from a quest.
R-1 ‘Diode’ Laspistol – Unlock through story progression.
S&R Drone – Unlocked through progression.
SPARK ‘Enlightener’ Electro-Beam – Finish Highball’s quest.
SPARK Engineer’s Turret – Simply cut off a Spark Engineer’s body. These are the enemies that deploy turrets in the bay area. Please note, they’ll almost, if not always, lack chest armor, so you get this as a reward instead.
SSM ‘Vanguard’ Missile – Split the reward with Hawke or buy it from the drone vender.VULC-88 ‘Panthera’ Rotary Gun – Destroy the flame turret during the second phase of the Major General Ezra Shields fight.
W-101 Spray Can – Story related.
W-102 Banner – Story Related
Proximity Mine - Obtained by cutting off the left leg of a SPARK Engineer.