I figured out how to kill Mechaniods! It's easy once you know how!

[Barley]

So the big problem when facing mechaniods are that they often have many "organs" that all have high health. So your shots seem to do nothing while they spray bullets and fire everywhere. But don't give up! You need only two pieces of equipment to stop the robots in their tracks!

Ingredients for Win:
First, buy, steal, and capture as many shield units as possible. Give them to your pacifists, your melee infantry, and crappy shots in general. And I do mean ALL the shields. Even the crappy ones.
Next, buy, steal, and/or capture every fragmentation grenade you can find. Give these to your best marksmen.

The Strategy

Your shielded colonists will henceforth be known as "Rodeo Clowns". Thier job is to run around between your grenadiers and the mechs, drawing their fire. Mechaniods ALWAYS go for shooting over melee, so as long as your colonists remember to fall back when the shields get low, they'll be fine!

Now, remember when I said that mechaniods have many very strong organs? The key with the grenades is that they damage multiple organs at once. This means every two shots are likely to damage at least one of the same organs. If you have two or more grenadiers hitting the mechs this damage builds up, fast! With bullets, you'll probably hit, say, the 2nd body ring for 20% damage, then the foot, then the 5th ring, then the 2nd, then the eye, then maybe the 2nd again for another fifth of its health, and so on. With frags, you'll hit 3 body rings and an eye, then 2 body rings and the brain, then 5 body rings, then 2 body rings and-up, wait, its dead!

Target down each mech one at a time. Micro the clowns so that they never lose shields but always have the mechaniod's attention. Stay near cover if possible to let guys recharge and further reduce mechaniod damage output. Aim for inferno-cannon enemies first whenever possible.

Try it! It works! Then if nobody finds any flaws someone stick it on the wiki!

[SSS]

I've been using this method in the early game, when my colonists can't take on mechanoids through traditional means. Basically, you have one or two colonists with shields that are the bait- they don't even need to move. As long as they are the closest colonist to the respective mech, the mech will always fire at them. This is where the small numbers helps- the shield is never damaged enough to burst completely, and the mechs never wise up enough to attempt to melee. Your other colonists can take their sweet time chipping away at the mechs until they drop.

I had never tried to adapt it to larger numbers, though. I imagine the micromanagement needed would be insane.

[Gonumen]

You could also give one EMP to one colonist so mechanoids won't be able to do anything.

[b0rsuk]

You could also give one EMP to one colonist so mechanoids won't be able to do anything.

I need to try that ! Killing mechanoids in melee sounds fun. I don't think EMP grenades disable shields, do they ?

[Kegereneku]

The EMP effect power changed ? Because the only time I used them I couldn't even incapacitate one Mech with to grenade-thrower, it resisted and immediately turned them into nutriment paste.

[TLHeart]

nope, they still adapt after the first emp.

[Gonumen]

I always send one colonist with EMP and make him spam it, so even tough they adpat it, they don't have time to aim so it works just fine.