Things that go boom in the night...and possibly the day.

[Butters]

Using the setting with all it's Alchemy and Clockwork madness what are the craziest weapons/equipment have you or your players come up with and is there a point where you turned down some ideas due to them being too powerful? 

Clockwork powered alchemical flamethrowers, Alchemist versions of Dragons breath shells for those Donderbus guns or maybe Clockwork powered chain blades betwixt wheellock pistols?

[Darius West]

Having run out of rocks for a trebuchet, reverse it, put a hook on the end of the launching line, then use it for hooking and launching siege ladders.

Clockwork repeating ballistae.  Box Kite arrays that drop incendiaries.  A clockwork riverboat that simply anchors itself and allows the current to rewind it when going upstream.  A clockwork factory that produces textiles by way of humanoid automata that run on tracks and are rewound by a waterwheel or a windmill.

[soltakss]

Not from Renaissance, unfortunately, but Players from our RQ2 game had a houserule that meant that Mobility worked better on creatures with more than 2 legs, using a formula, of course the PCs tried casting Mobility on giant Millipedes and found that they exceeded Mach 6, or something, so they launched them from little ramps.