What to use for ballast

[dradel]

Originally Posted by cgmv123

Be careful when using sand per R8-J. I don't interpret that as a hard ban on sand, but it's definitely not legal if it can get all over the field.

We had discussed that, but weren't worried about making a mess. Plus we are right at 119lbs with out battery or adding weight so even more of a non issue.

[Jarren Harkema]

I suggest a cast iron bust of Mr. Kamen himself. Perhaps a second one of Mr. Flowers if need be.

[jee7s]

A nice length of 1018 steel is a good choice, but you need to drill holes which makes it non-cots.

Other ideas I've seen (but don't necessarily endorse):

Sand in sealed PVC pipe
Sand in black pipe
Cast scrap metal blocks
Concrete casting
Kitty litter (Dallas 2009)

[Mr V]

Originally Posted by pdx

Our team needs to add some ballast to our robot, and we're trying to decide if we can use some donated sash weights from old windows. Does that count as a COTS part? What about weights from old barbells? What does your team use for ballast?

Thanks!

It doesn't have to be COTS to be used as ballast. If it is not on the prohibited materials list it is fair game. Some of the things that are not allowed are lead unless it is fully encapsulated so there isn't any skin contact or a way for dust/chips to be generated. Things like pennies, washers, ball bearings or other loose items must be in a robust container so that they will not dump all over the field if the robot tips over.

So the question is what are the sash weights made of?

The rookie team I am helping out is using sash weights as they are at a very old school and there is a stack of them in the maintenance shop. They are cast iron, though that doesn't mean yours are.

[Chinske4296]

We had a steel bar, roughly 2x4 and we would cut off pieces as needed. We let a few teams take some pieces at various competitions, let's just say the machine shop wasn't very happy with us. Milwaukee couldn't cut it so we had to take it to the college across the street to cut.

[GeeTwo]

Originally Posted by pdx

Our team needs to add some ballast to our robot, and we're trying to decide if we can use some donated sash weights from old windows. Does that count as a COTS part? What about weights from old barbells? What does your team use for ballast?

Thanks!

As stated above, COTS vs FABRICATED doesn't really matter, unless you're adding it after the bagging this Tuesday.

I expect that we'll wind up using some steel "uni-strut" channel, possibly hammered (closer to) flat, simply because we already have it in-house and it's heavy.

I have used coins as weights before, but not for FRC - it was for a Boy Scouts "pinewood derby" competition. It turns out that a quarter equals exactly 1/5 of an ounce. Serendipitously, the third and last quarter installed on Gixxy's car was an Indiana quarter, reverse up, and the car placed high enough within the pack to go to our region. In case anyone doesn't know what an Indiana reverse looks like, there's the link.

[jagoldman]

My team is looking at lead bird shot ballast. Are there any issues to building a solid aluminum box to bold them in? I saw the earlier comment about in in a plastic bag.

[Christopher149]

Originally Posted by jagoldman

My team is looking at lead bird shot ballast. Are there any issues to building a solid aluminum box to bold them in? I saw the earlier comment about in in a plastic bag.

In 2009, we had two water bottles (500 mL?) filled with lead shot, their caps glued on, and the bottles zip tied to the frame. Never had any problem.

To be fair, nothing moved very fast in Lunacy.

[asid61]

In 2013 we used a few 5lb weights (like at the gym). Worked fine, and it tells you the weight on the side!

[ratdude747]

Originally Posted by jagoldman

My team is looking at lead bird shot ballast. Are there any issues to building a solid aluminum box to bold them in? I saw the earlier comment about in in a plastic bag.

I'd think welded PVC would be a better choice. How is the box being closed?

As long as it isn't a leak hazard... as that what the issue with the baggies were; they came loose and when hit by a robot spilled EVERYWHERE... My memory is no good but IIRC a red card was handed out for the incident, due to the downtime needed to clean up the mess on the floor (you can imagine the sound created by the vacuum, high speed pinging!) and also because the baggies were supposedly deliberately "hidden" from the robot inspectors who would have otherwise not passed the ballast as legal.

Same goes for sand and any other "granulated" ballast weights. Make sure it is sealed and well attached.

[IndySam]

The only really safe way to use lead shot as ballast is to encase it in epoxy.

[Calvin Hartley]

Corndogs.

[Al Skierkiewicz]

Wow!
Here a few things for you to consider when contemplating ballast from an inspector standpoint.
1. Sand, don't think you can encase sufficiently that it won't pose some hazard. The capped steel pipe might work but... I had a team try to demonstrate sand as a hammer weight last year. When asked to demonstrate their containment they promptly broke the container and dumped several pounds of sand into their robot in the pit.
2. Shot of any kind must also be suitably contained. Plastic bottles do not fit that definition.
3. Lead, if your sponsor/build space/school allows you to handle it, must be fully encased and untouchable at competition. We have allowed lead to be painted and sealed with the understanding that it cannot be machined in any way at a competition. Many local ordinances and venues prohibit it's use.
4. To reiterate sash weights, you need to know the material as it varies in the part of the country you live and the era in which they were made. (See lead above)
In all cases, ballast needs to be firmly attached to the robot with fasteners. Ty-wraps, duct tape, etc. are not considered fasteners for this application. Personally I like big hardware with locking nuts.
R8 is pretty specific, if your ballast has the ability to come out of your robot and damage another robot, a volunteer, or the field (shot or sand dumped on the field comes under this heading) it violates R8.

[Jimbo2032]

Yeah, we found out the hard way this year that exposed lead is a no-no. I really wish that it had been explicitly stated that it cannot be exposed In the manual under the hazardous material section. We used lead dive weights, which as a diver I don't consider them hazardous in that form. Long short one of the safety crew said he thought we needed to call a Hazmat crew out to perform cleanup!

Maybe FIRST could provide us with a standard from EPA, OSHA, UL, or some other organization so that we can be informed of proper rules.

Edit: not bellyaching, just trying to let others know so they don't put their students in an uncomfortable situation.

[cglrcng]

You mean my 50 lb glass vial of mercury as robot ballast won't fly during inspection? What if I just hide it really, really well? Guess I'll change that to a small steel cylinder of Hydrogen, Oxygen, or Acytelene then.

No.....lead and mercury are both "Hazardous Materials." (As are the others I listed). If added to your Robot that is.

Now, where did I attach that compact 20 lb. nuclear weapon I used as ballast the last time it was needed? (Use simple common sense please).

Edited for Addition;
Sure enough I missed reading Al's #3 fully above...(Wouldn't even attempt that personally, due to the multiple venues, schools, and commercial arena's, we compete at in multiple jurisdictions each season, not to mention that eventually someone may wish to resize the ballast for wt. reduction eventually). Sry Al.