How often do team anodize aluminum and how much would that cost?
We get ours done for free here in town. Check around your area and see who does it.
You can also find do-it-at-home-kits for smaller stuff.
We’ve anodized every year from 2006 and on…we get it done for free as well
We’ve never had any aluminum anodized, possibly because we don’t get it done for free?
Even if we could get it done for free, we would never get it done because the robot and parts for the robot aren’t done in time to be back from anodizing before ship date…
Try to find a local anodizing company and see if they’ll sponsor your team with free parts. Anodizing can be done in your shop, but you’ll need a really powerful DC power supply, as in like 20A+ continuous at 12VDC, as well as an assortment of heated chemical baths, including one with sulfuric acid. It’s pretty nasty stuff to keep in your shop when you’re trying to build a robot.
The one key thing to either anodizing or powder coating parts is that you pretty much need to have everything designed in CAD and completely machined/fabricated ahead of time. When you anodize or powder coat parts, there really should never be a “oh no, these holes don’t line up!” or a “gahhh! the roller chain wants to go through this piece of aluminum!” moment. You should know everything ahead of time, and the anodized or powder coated parts should just bolt together.
Also, when anodizing, surface finish is important. Any blemishes or scratches or marks in the surface will show through.
Would this change the thickness on critical tolerance parts so that some things are too tight?
Anodizing parts won’t change the thickness, but powder coating will.
We bought a kit last year and tried it out in the off season. Kinda cool, we used a battery charger from the school’s auto shop and did some small pieces of aluminum. We got some unequal coloring, so it is important that the etching process is done correctly. We learned that is something we don’t want to be bothered with during the build season, a professional shop can do a much better job anyways.
Actually, anodizing does ever so slightly increase the dimension of the part. I couldn’t see the effect being anything more than negligible in a FIRST robot though. From what I recall, anodizing adds about 0.0002 inch, whereas powder coating can add up to 0.020" I’ve never actually measured it.
Thats what i meant by not adding thickness. Of course it ads some but it doesn’t add enough that it would critically affect a dimension.
So its essentially insignificant. I’m looking into this for swerve parts. I guessing that these pieces wouldn’t cost very much to anodize and an anodizing service could do this in a short amount of time.
We’ve had things anodized before and had them back well before ship day.
You just have to know what you will need when.
While this theoretically is true, there has been instances for us in the past where we have made parts to very tight tolerances (+/- .001") and then anodized them only to find they no longer fit together. We make sure to anodize parts and then remachine them if they require a tight tolerance (such as a press fit for a bearing)
I agree, this is sometimes an issue.
Another thing to note is there are different types of anodizing. Some hard anodizing processes can add a thickness which must certainly be accounted for.
Anodizing small things is easy, frames and such are kind of a pain. My team had our swerve module done in 2 days. Since they were small, we said “next time you do gold, throw this in,” and they did. It isn’t much of a cost to them if they’re doing the color anyway, and if it’s small, it’s usually pretty easy.
1675 has a local place that offers their services for free. We’ve done the main lift pieces on the robot one year and parts for awards last year. It all depends on if we have pieces made in time or not, and the year we got the lift done, we just happened to have a blizzard the day it was finished, so not only did we lose the 4 days for anodizing, we lost 2 days for snow! Horrible timing!!
What are the material benefits rather than aesthetics? Does anodizing help with structural strength or durability enough to make a difference for our robots?
Hard anodizing is quite useful for parts that are going to be taking a beating. We had our Geneva drive hard anodized and it held up quite well. Without doing it I’m sure it would have failed mid-season due to galling.