Elements of a Detailed Materials Cost Estimate
A materials list should give all the details needed to accurately estimate costs and to accurately determined budgets. It should be done with a spread sheet and contain the following columns:
Number: The number of units to be ordered
Quantity: The size of a unit. For example dozen, box, carton, 10-pack, each, etc.
Price: The cost of one unit of the item
Item: A detailed description of the item to be ordered including part or model numbers.
Vendor: where the item is to be purchased. It's not necessary to list all the details on each vendor for each item. A code can be listed with the details can be footnoted.
Total: Number x Price the amount to be paid. Shipping and taxes are usually listed as a separate item. If shipping is unknown estimate it at 8 to 10%.
See example below:
Major Purchases - These are typically any item which makes up 5% or more of the project's material cost.
Tax - should be added where appropriate.
Shipping - should be added when known except for local pick up and delivery items. If shipping is unknown, use 8%
Misc. - small items like fasteners, paint wire, etc. can be lumped together but should not be ignored
Contingency - for items like unforeseen price increases. Contingency should not be used to cover for a sloppy or hasty cost analysis.
Cost Estimate Example
|Num||Quantity||Item||Vendor||Price ($)||Total ($)|
|2||each||1/4 x 2 in bolts||Acme Hardware||0.13||0.26|
|4||each||1/4 in nuts||Bob's Hardware||0.05||0.20|
McMaster Carr - has a huge selection of industrial components.
ER-1 Robot - the basis for SAM jr.
Robot MarketPlace - a good source of parts and ideas for robotics applications