Using a mechadendrite to fire a two handed weapon one handed. The Churgieon in my game wants to do this. Using his manipulator mechadendrite to steady a melta gun so he can have one hand free. He wanted to put it in a ballistic mecha first but I thought it could only use single hand weapons.

Unless there was something I missed in one of the expansions, Ballistic Mechadendrite can only be fitted with laspistols RAW (though I might allow a character to replace it with another Pistol-class weapon).

As to your question, the text on Manipulator Mechadendrite specifically says that they're not very nimble. I'd probably rule that gripping a heavy weapon with one would count as having it braced, but I'd probably also throw in a penalty of around the same magnitude to reflect the fact that it's being held by a very clunky arm.

I second that, and that's being generous. The manipulators are explicitly stated to be rather clunky and imprecise. I'd rule a negative 20 penalty and no aiming, at least.

I have seen people in real life fire rifles one handed, so maybe a smaller penalty. I think I may have told him that he had to have a good quality mecha to do it too. I wonder if a best quality ballistic mecha could handle a rifle?

Or, he could use his mechadendrites as the 'free hands' and just use a normal hand with a Recoil Glove to fire the meltagun. That or the Pistol Grip modification make it possible to use a Basic Weapon one-handed without penalty.

Oh, my bad. For some reason I thought melta-guns were Heavy, not Basic.

Still, my original assessment stands: I'd assign a penalty based on the fact that the manipulator mechadendrite is specifically stated to be kinda clumsy.

Just out of curiosity, what exactly does he want the empty hand for?

I don't remember exactly what he wants it for, possibly grenade chucking or a science or healing instrument. I could really go for a tech priest and nobles book to clean up a lot of details. I think I told him it was no penalty if he had a good quality mecha. Which makes sense.

I don't remember exactly what he wants it for, possibly grenade chucking or a science or healing instrument. I could really go for a tech priest and nobles book to clean up a lot of details. I think I told him it was no penalty if he had a good quality mecha. Which makes sense.

I think the quality requirement is a fine way to handle this request. Maybe -20 for Common, -10 for Good, and no penalty for Best?

I would probably allow it but have the weapon gain the inaccurate rule.

I don't remember exactly what he wants it for, possibly grenade chucking or a science or healing instrument. I could really go for a tech priest and nobles book to clean up a lot of details. I think I told him it was no penalty if he had a good quality mecha. Which makes sense.

Just an FYI on page 180 the book states "All mechadendrite cybernetics are considered to be of good craftsmanship unless otherwise stated". None of them state otherwise as of right now so all are good craftsmanship base.