How do your teams generally finish aluminum parts before assembly? We are considering either cleaning with acetone or sanding with 1000 grit paper and then using a buffing compound. I’ve read that removing the aluminum oxide layer when sanding or buffing does make the part less scratch resistant though. Thoughts?
To be honest, we mostly just debur the parts now a days, and touch up corners or extras with a file. We have access to a sandblaster, but I dunno if the team still uses it - we used to put parts we could fit (basically anything that wasn’t structural) and give it as even of a coating as we could.
Deburr the sharp edges. Brush anodizing off with a wire wheel. Send out for powder coat.
If only… maybe next year 
Wipe down, clean off dykem with acetone, deburr, scotchbrite, maybe a rinse in the sink if it’s really dirty, and then off to powdercoat.
I’m a real fan of the finish left by 150 grit sandpaper in an orbital sander. Looks nice and hides scratches.
Get up with Gilbert Spray Coat, they’re local to you (and us…). The price is great, and the turnaround is a matter of hours.
We used scotchbrite on everything in 2015, and it got dirty and scratched very quickly. That being said, it didn’t look half bad. 
Spray paint can work great if you plan for the added weight and thickness of things.
As far as taking off the aluminum oxide, unless your robot is going to live in an oxygen-free atmosphere, there’s no point - it will oxidize again very quickly once it hits the air. We just debur and/or file down corners. Every once in a while we’ll do the orbital sander bit on larger pieces, like our side panels for Stronghold.
The oxide layer will re-form in several minutes.Don’t concern yourself with it. It has very little effect upon scratch-resistance.
We use a Scotchbrite pad (similar to sandpaper) to just clean up the look a little. A solvent is not necessary unless you plan to coat the metal (paint, etc.).
Turn around time to anodize your parts are a couple of days. Here is a link to a local plating shop in your area.
http://www.santaclaraplating.com/service/anodizing
You can add a teflon coat to increase lubricity
There are different types of anodize I suggest a Type II for your application.
If your frame is small enough to fit in a plating tank then anodize. if it’s too large then go for a wet paint. It works just as good as a powder coated frame. Wet paint is used in most electronic parts that are painted.
For parts that get welded, we debur the part then brush it in the welded locations with a wire brush to minimize contamination. For non welded parts (very little) we essentially just debur it. It usually gets painted later, sometimes in pieces, sometimes assembled depending on the way the piece is.
Are you folks putting powder coating as a separate line item on your CAW, or breaking it out into individual part costs or what?
For most parts it probably counts under nonfunctional decoration?
Your old school is showing. (Mine trips me up as well.) NFD isn’t anywhere in the current rules. The budget section says all items on the robot must be accounted for, and the only exceptions are KOP and individual items that cost less than $5. Additionally, items have to be costed at fair market value for materials and labor, though labor can be excluded if provided by a team member, another team, or a sponsor employee that’s considered a team member.
So I think anyone getting powder coating or anodizing is actually required to cost it somehow, unless the company is a sponsor whose employees you consider team members. Similar to how you’d have to cost any machining labor that didn’t come from a sponsor, really.
So, has anyone actually gone through that trouble before, or have we all just been assuming it doesn’t really matter?
For us, it’s deburring, then assembly into a state that we can paint. (Krylon enamel in a back part of the shop. Turns out nice if you take your time and do it right!)
Practice robot just gets a deburring–we don’t bother painting it.
Protip about scotchbrite being dirty: If you’re planning on welding, scotchbrite after you weld. We did it before this year and it turned out to be a complete pain cleaning off all the metal because we couldn’t get decent welds cause of how dirty the metal was from it.
Spray paint is ok at first, but as the season goes on your robot ends up looking like scratched up mess.
We do the same. Taking time to do it right is key. In fact we have been asked where we get our powder coating done. LOL
I mean, it DOESN’T really matter. Let’s be honest, it’s paint. Outside of a few VERY edge cases I doubt the finish on parts of the robot things don’t slide over matters.
If someone REALLY wanted to account for it - 79 has always just bought the powder and sent it to the people that do our powder coating for us. One bag lasts us a while, but realistically would have to account for the cost of that bag yearly?
Gah, that’s stupid NFD should come back. Otherwise some teams are going to have a CAW full of LEDs.
Powdercoating is a nice way to make a robot look great if you have the time and weight for it. Barring that, if possible, I like the look of sandblasted aluminum. Otherwise a little scotchbrite and you’re good.
I’ve put the bags of powder on BOMs I’ve written before. It’s really not that much money just for the powder, like less than $50 for the whole robot.