# BoM Question

As ship date is getting ever closer, our team (or at least me) are starting to work on the BoM (Bill of Materials). I finally found my copy of the template provided, to note to my horror that weight had a column to be filled out.

Getting the weight on some of this stuff will require some disassembly. Is the weight required? I can’t imagine it would be, all that really matters is that the robot’s under 120. But I’d also not find out that it is in Milwaukee and have to be madly disassembling the robot there to get weights.

While we’re discussing this, regarding the pricing. If, for example, we use a 20"x14" piece of sheet aluminum, we’re allowed to use a smaller piece to get an average price for the other, right? For example find out the price per square inch of the piece, times the total square inches?

Ex. 1/2" plywood at 20 cents a square inch, and a 50 square inch section = \$10 on the BoM?

I know it’s in the rules, but I’m a little confused on the implementation.

1. Weight is not required for the BoM.

2. you only have to account for the section of a raw material that you used on the robot. if an Al sheet cost you \$80 and you used ~half of it, you can calculate the cost of materials at \$40.

This is mostly correct. You may list a reduced price for a smaller quantity provided that you can find a vendor that sells that reduced quantity at that reduced price.

So, from the example in the rules:
We buy a 4’x4’ aluminum sheet and use 10"x10".
We find a 1’x1’ sheet for sale elsewhere.
The price on the BoM is the 1’x1’?

So it’s not allowed to say, for example, the 1’x1’ costs \$5, and has 144 sq inches, which is .288 cents per sq inch. We used 100 of the 144 sq inches, which is an average cost of \$3.47. Which number is the lowest acceptable?

\$5.00 would be the lowest acceptable cost to place on the BoM unless you found 10" x 10" actually for sale for \$3.47. No extrapolating of price per square inch or similar metrics is allowed.

It is my understanding that you must indeed quote the 1’ x 1’ price, since that is the smallest bulk size available and would cover the 10" x 10" piece you actually used. Basically, what it boils down to is that to get a 10" x 10" piece of aluminum, you have to spend the money that a 1’ x 1’ piece costs…you cannot actually buy a 10" x 10" piece at the price-per-square-inch that you paid for the 4’ x 4’ piece.

Ok then, thanks for the clarification.
Just wanted to make sure we’re doing it right, the robot overall should be well under the \$3500.

Could someone please post a copy of the “Provided template for the BOM” I looked all over and can not find it. Thanks a million in advance and by the way, where is/was it located?
Mentor Jeff

look here:

http://www.usfirst.org/community/frc/content.aspx?id=452

Scroll down to Section 8, then look for Inspection BOM Template

Go here:

http://www.usfirst.org/community/frc/content.aspx?id=452

Now scroll down to section 8 and grab the document labeled “Inspection BOM Template”

Note that, as others have said, you do not need to fill in the “Weight” column; that’s for your own convenience only.

I have a question and do not want to start another thread… Can anyone tell me if you need to include all electrical compents specifically Connectors, length of wire ETC? Thanks in advance

Fasteners that individually cost under \$1 are not required per <R25>.

Wire’s going to need to be in there. You can do that by the foot (or by the spool if you bought in bulk – see section 8.3.3.1 - you don’t have to take the cost for the whole spool if it’s available per foot and you didn’t use it all, but if you bought by the foot, you shouldn’t use the spool price).

 The cost of items purchased in bulk or large quantities may be prorated on the basis of the smallest commonly available unit that satisfies the need for the item.
o Example: A team purchases a 4’ x 4’ sheet of aluminum, but only uses a piece 10” x 10” on their ROBOT. The team identifies a source that sells aluminum sheet in 1’ x1’ pieces. The team may cost their part on the basis of a 1’ x 1’ piece, even though they cut the piece from a larger bulk purchase. They do not have to account for the entire 4’ x 4’ bulk purchase item.