Drivetrain: We went H-drive to be more maneuverable. Gearing didn’t change, so we’re 14-16 FPS when using the four main CIMs. Not that we’ll need it often, but it’s there. (The center strafe wheel runs only one CIM.)
The Stacker: Remember that 5-gallon tank John uploaded? Yeah, it was heavy. Turns out a 7-gallon aluminum tank is about four pounds lighter, so we’re running it instead. Still using that continuous-duty compressor though so that we can use our two (regulated) 1.5" bore, 8" stroke cylinders to lift. The lift is made out of Bosch FMS extruded aluminum, and is tested to carry a stack of five and a container. Six with a container is entirely possible. Our concern now is charge times, since it does take a small eternity (longer than a time-out) to pressurize from zero; to this end, we’ve been working on air conservation plans and we’re giving good hard thought to a motor-driven system we can swap out at Palmetto.
The hidden bits: We withheld our container arm. Two off the step in autonomous with a telescoping system envisioned in a Tractor Supply aisle. (John was shocked at how well it works. Business majors have game too!) And while the picture (taken at USC’s Engineering Week open house) doesn’t show it, don’t worry–there’s plenty of camo on this machine too.
4-H Garnet Squadron is supported by the University of South Carolina College of Engineering and Computing, Bosch, Bosch Rexroth Corporation, NASA, Fluor, and viewers like you.
See you at Palmetto, Orlando, hopefully Championship and IRI, and SCRIW V.
We are using a pneumatic lift and have smaller air capacity air tanks and have had no problem with refilling. I would expect that you would not have a problem either since you have more air. We have to run our compressor throughout the match though.
We also have a pneumatic lifter, and we ran into a lot of problems with air usage, but we have determined through testing that 7 black clippard air tanks (1.1 gallons) was enough to last a match. 7 gallons seem like overkill, but I guess too much is better than too little.
Looking good! That recycle container auto would be great for an alliance partner like us
We toyed with the idea of using pistons to lift the totes – first prototype had two big 18" stroke pistons – but in the end we went with a chain lift for simplicity. We had terrible problems with battery drain last year running a compressor all match, and wanted to avoid that this year.
Looking forward to getting out on the field with y’all in under a week now!
I think the size of our cylinders is what lead to our issue. They just use a lot of air per stroke. Our high CFM solenoids may also play into this issue.
We also have a pneumatic lifter, and we ran into a lot of problems with air usage, but we have determined through testing that 7 black clippard air tanks (1.1 gallons) was enough to last a match. 7 gallons seem like overkill, but I guess too much is better than too little.
Our initial in house tests were done with 7 black Clippard air tanks and we ran out of air really fast as per my observation. We thought we calculated a fair amount of wiggle room with a 5 gallon air tank. Which it would get us by. However the advertised 5 minute charge time of said air tank with the 250C compressor was not what we were seeing in practice. So we’ve had to consider what our options are.
The re-do of our lift movement system should be fairly simple. We’ll just have to see if we can get it done with enough time to spare to get some more practice time in.
Looking good! That recycle container auto would be great for an alliance partner like us
We made that function of our robot a top priority since day one. We hope to see it pan out well for us in playoffs/eliminations.
