Posted by Samuel Lindhorst.
Engineer on team #240, Mach Vee, from Jefferson High School and Visteon.
Posted on 10/24/2000 12:25 PM MST
I don’t know Chief Delphi’s rules about this board, and what I am about to post comes close to a commercial message, but I believe it’s very useful for FIRST teams, so here goes…
Aluminum is our material of choice. Getting you hands on exactly the right stuff in the middle of a build can mean a couple of wasted precious days sometimes. Aluminum can be expensive, too.
Without getting into too much detail, there are really only two aluminum alloys we use - either 6061-T6 or 6063-T5. 6061-T6 is normally refered to as ‘engineering bar’ and is the most common raw material stock, giving great strength at a reasonable cost. 6063-T5 is the alloy used most of the time for extruded shape, like 80-20, and offers a similar strength to 6061-T6, up until the area where forces start to deform it. Although easier to bend, its ductility means it loses proportionally less strength when formed. Basically, I think 6063-T5 is great stuff, easily bendable and still strong afterwards. Able to take most of what the typical FIRST student with a large hammer can dish out… :O)
Which leads me to a source for 6063-T5 extrude shapes in the Detroit area (and they take orders and ship too…)
Our problem getting good prices is that most of the time the size of an order for a robot build is too small to get any discount, so we pay a premium unless you are sponsored by a plant willing to use their purchasing dept for materials (and sometimes that doesn’t help). Also for things like the CDI, which isn’t a FIRST event, the plant may take no official part.
I’ve been buying material at a place near I-96 and Southfield for a while now, Aluminum Supply Company. These people come under the heading of ‘really nice folks’.
After talking to Bob Compton, a customer service rep, he’s willing to offer small quanities of aluminum at larger (50 pc) pricing. For example, I bought a 21’ piece of 1’sq tube with .063’ wall today for $20.25. Just for comparison, here’s a couple of more prices:
4’X10’ sheet of .125’thick - $139
1’ schedule 40 (alum) 20’ $41.23
½’ sq. channel .09’ wall 16’ $8.51
1½’ sq tube .063’ wall 21’ $31.89
½’ angle .063’ wall 16’ $3.46
¾’ angle .125’ wall 16’ $12.15
The best thing about this: it’s sitting in stock. They have a warehouse full, and they keep it stocked. Walk in, and walk out in a couple of minutes. They cut it for free to get it in the truck, too.
Call Bob Compton at (313) 491-5040 and tell him you’re a FIRST team. Ask for the standard products catalog, and ask him to quote something you’re using now to build with, and see if he’s competitive.