In my mind, one of the most dangerous things we have the students do at the competition is lifting and carrying the robot onto and off of the field.
With a robot typically weighing in at 150 pounds (w/ battery and bumpers), and really only room for two people to carry through the gate, not only are we are having students carry a lot of weight, but to maneuver around others and onto the field… this is especially challenging for smaller students, in a lot of cases, the robot weighs more than the students.
I did a quick search and didn’t see it, but are there rules against pushing the robot over the ramp onto the field? and if so, does anyone have the history as to why that would be an issue? i know they’d still have to lift it, but if someone else pulls the cart out of the way, then at least it is a straight up and down and not a carry (backwards) over a ramp and onto the field.
OSHA lifting limits for a single individual is 50 lbs, and we are beyond that, just wondering if there is a better way to do this.
My team (1319) created a “no-lift” cart with a foldable ramp that allows us to roll the robot off the cart and onto the field. It usually went faster than teams who lift and then struggle to navigate the gate. We were also concerned at robots weighing 150 lbs being lifted by students, especially years when robots were tall and oddly shaped.
For more information about the cart: see this older post
Side note: I think lifting robots on and off the field is another thing that requires longer cycle times and more lenient time out rules. Because it is dangerous enough to move these machines without the added pressure of keeping up with a ticking clock.
I have seen robots completely lacking a drivetrain (years ago).
Those had to be carried.
And it was safer to lift a robot off the Hab at the end of a match than to push it off…
And a certain team at Tech Valley calibrated their gyro squared to the Alliance Station wall, before lifting it and rotating it to place it on the tarmac. I commented that it was sort of robot ballet.
We always roll our robot around. We avoid carrying it for student safety and robot safety. We take it off the cart at queue and roll it through the gate and into position. Taking it off the field, we roll it to the cart and then lift it onto the card.
Team 4153 built lifting bars for this purpose a few years back, basically two broomsticks with cords attached to carabiners which clip into big “screweyes” on the robot. I’ll try and find a photo and post it here later. Agreed, lifting the robot is a BIG deal and doing it safely is important.
Not that OSHA requirements apply to unpaid students… Do you have the section of the standard that applies?
I do agree that lifting robots by random bits of structure can be bad ergonomically. Since our swerve modules do not push very well. We use Husky lifting straps that clips into the swerve guards. The allow the robot to be lifted with legs and not backs.
I stand corrected, OSHA doesn’t have a lift limit. NIOSH has a 51 pound limit though. I’m used to the rule that anything over 50 lbs need to be designed for a two person lift.
I’ve thought for many years that FRC robots with battery and bumpers are far too heavy for 2 high school kids to lift. When you add in all the awkward maneuvering in cramped spaces and the height of pickup truck beds these days, it’s just not safe. I was surprised when they raised the limit by 5lbs a few years back. It doesn’t take much to throw out your back. I wouldn’t mind if we lost a few lbs on the weight limit.
I agree that this is a big safety issue, especially when teams have to rush to carry the robot through the narrow field gates.
If the robot is being carried by a team member on each side, the only way to carry the robot through the field gate is to i) have one team member walking backwards, or ii) have both team members walking sideways s.t. they take up more space and risk tripping over the gate. Neither of these options is very safe.
At Monterey this past weekend, a student going with approach (ii) tripped over the gate, causing the robot to fall on top of her, which obviously could’ve ended very badly (luckily she just got a bit scraped up).
There were several teams at the two events I volunteered at using straps like that. I think they all clipped them into eye-bolts set in the frame. They all had an easier time maneuvering the robot and clearly had a more secure hold on the robot.
I don’t have any pictures handy, but I am also a big proponent of using lift straps/ropes to carry the robot. It’s really easy to get a rope loop, feed it thru an appropriately sized/rated carabiner, and then clip that onto a for-lifting eyebolt that is securely mounted on the robot. That makes it far easier and far safer to lift up these robots, without having to struggle to find good handholds, worry about bumpers slipping, or use awkward hand positioning. These have the added advantage of being able to be tailored for folks of different heights (longer rope loops vs shorter rope loops) to make the process as fluid as possible (no longer do your height mismatched drivers have to struggle to find the appropriate height to carry the robot). Additionally, the same eyebolts on your frame can double up as attachment points for safety harnesses during initial climber/endgame testing to help avoid spills while you’re still working out your climbing motions.
The only downside I’ve found with these so far is that you do have to be mindful with your cart design that you won’t have 100% positive position control when setting the robot back down on the cart (so leave a couple inches of potential margin for error in your cart railing).
