[jgraber]

Since the robot is sitting on insulated wheels, there is no way to ground it without using a drag chain of some kind. (as has been mentioned previously, but not lately in this thread) I suggest a 1Megohm resistor between the chain and the frame as well.

Thought experiment: Static discharge you can feel is > 10,000V.
Now illegally connect the conductive frame to the battery negative.
Now the battery positive terminal is at > 10,012V. So what?
Your finger is still at earth ground (or any other voltage if wearing insulated shoes).

Other (in addition to drag chains) potential (!) ways to reduce static electricity discharge into your fingertips when touching the robot after it has been driving around...
- Use a 1Mohm resistor to connect the frame to an otherwise insulated knob, and touch the knob first to more slowly (2 seconds) equalize the charge between your body and the frame. (like putting your hand on the ESD mat before picking up an IC)
- Hold your carkeys in your hand and touch the frame with a pointy key first. The spark point pain is distributed over the whole area of your hand that is holding the (conductive) car key, so you dont feel it much.
- Use moisturizing hand cream (really! it is required in ESD labs) to keep the surface of your hands equally resistive/conductive.
- Rap the robot frame with your knuckles first. Knuckles have fewer nerve endings, and if you rap it hard enough, the pain covers up the pain of static discharge.
- put on an ESD wrist strap, and touch the frame with the plug before touching the robot. (MegOhm resistor thing again)
- connect a CIM to a reciprocating linkage to a mechanical piezo-electric static discharge squeeze gun originally used to equalize the surface static charge on vinyl LP records.
- Do not use an illegal radioactive ionizer, of the type that is used inside automatic IC handling equipment.

FYI: Regarding Human Body Model ESD standard testing for ICs: Chips that fail 1KV test break too easily. 1kV and 2kV are common standards. It is hard to make chips that pass 4kV standard. Any static spark you can see or feel is typically 10kV-300kV, so if that was on the pin of a chip, its going to be a damaged chip.