[GeeTwo]

The rules on bagging and withholding are pretty clear, but they are spottily enforced and even assuming you follow them scrupulously, there are layers of strategy possible. For the most parts, these layers are based on strategy and how well you've managed to do during build season.

If you have a mechanism that is critical to your strategy and that really needs work as you're getting ready to bag, pull it and make it some or all of it part your Withholding Allowance (WA).

Try to bag as much stuff as you are reasonably sure is ready for competition. As noted above, spare parts are not really intended to be in the bag, but there does not seem to be a rule against them, so carry on!

If you do build an updated mechanism between bag and an event, try to consider the tradeoff between showing up with a bunch of COTS items that can be built in the pit to match your new mechanism (does not apply against WA at all) and showing up with a pre-built mechanism (applies fully against WA). In many cases, you may be able to pack about half of your mechanism's weight as manufactured parts (part of WA) and half as COTS parts (exempt from WA) and do a tiny bit of building in the pits. For example, this year we plan to bag mounting brackets, bars, springs, and structure of our launcher, but to pull the launch arm for tweaking on our practice robot. The pneumatic cylinders that we are still awaiting will be brought in as COTS parts if we do not get them in time to bag, but we may have custom mounting hardware or similar.

I also suspect that we shall include a good fraction of our ball pickup mechanism in our WA.

If we did not have so much WA weight already tied up in tweaking core functions, we would probably try to develop a scaling mechanism to include in the WA.

Edit: The pits are nominally only 10 feet high. At some events they may only be 8 feet square laterally. Unless you are intimately familiar with your specific events' venue, plan to be able to contract a bit.