pic: Robostangs 548's 2014 Robot

548 presents our 2014 robot, Sagittarius. Sorry for the quality, we only had a phone.

Looks like 548 has brought back their 2011/2012 robot! Any specs on the newest Carbon fiber arm bot?

Historically, the success rates of our carbon fiber bots are significantly higher then those without. Once we saw the game, we knew we needed to make another.
Some specs:
4 40lb constant force springs
1 second winch
Shoots from just inside the white zone to the goalie zone
2 sets of intake rollers angled in
~4 fps low and ~14 fps high gear from a 6wd
110 lbs

Looks brilliant. I’m hoping this is bot is just as successful and cool to watch as your awesome 2012 bot.

Looking good robostangs!!!

4 40-lb CF springs?! Now that is a tremendous amount of force! Do you know if you really need 4 of them (i.e. assuming that do actually improve range, how much does that range get help you?)? Seems like it’ll mostly just be adding wear/stress, given that most teams that I know that are using CF springs are using ~40-100lb of force.

Looks really slick! I can definitely see the inspiration from the 2011 and 2012 548 robots. Also pretty similar to our design (and many other teams’) from a somewhat top-level standpoint.

We originally had 2 of the springs, but we were not happy with the power and bumped it up to 4. I believe it about doubled our range.

We started with 2, but it wasn’t really cutting it for us. We mostly wanted the extra power to make truss shots cleaner and stationary shots more consistent, but we’ve seen a big jump on range as well. 2 springs forced us to shoot in the middle of the colored zone, 4 lets us shoot from just inside the white zone, and there’s still room for us to optimize the shot further.
Edit: And Tyler beat me to it.

Wow two members answering the same question faster than the blink of an eye.
Nice Job:)

I’m curious as to what you’re doing that four 40lb constant force springs are only getting you 17 feet. We’re using three and (when we have the angle right and aren’t battling electrical problems) shoot pretty easily from 17 feet. I know the key for us was making the drum on our winch larger.

Right now our drum is at a precarious balance between winch speed and shooting power. I know we can shoot from beyond 20 feet, but at that point we start to loose consistency, so we set our long shot at the line. Also, we are being limited by ball inflation because of our heated build area and unheated practice facility.

We aren’t sure ourselves either. There was quite a bit of difference in the range of our comp bot and practice bot, with the comp bot being better. Both bots were built to be identical. We haven’t been able to figure out exactly what is causing this to happen. We were able to improve the shot a little after stopping some of the binding in the winch gearbox for the practice bot, but it still isn’t the same as the comp bot. Our current design limits us from going too much bigger with the spool for the winch.
Edit: and Mike beat me this time.

That makes sense. We have issues much farther as well, though we’ve been working on tuning that.

We’ve been having issues with consistency in our practice area too, being in a warehouse with doors opening and closing and breezes all over the place, and found that our competition bot seemed to be significantly more accurate (when working) than our practice bot.

IMO the biggest befit of the extra power is passing over the truss. We can get it to the HP across most of the field with a nice catchable ark. It also flattens our trajectory so we have a larger margin of error in our shoot points. The ball inflation thing has really been annoying our programers and their auton, but we are hoping to be able to tune in our 2 ball for Howell

Our original plan was to shoot from the white zone in auto but we gave up on that at 2771’s practice field after we seen only 60% accuracy with our shooter but that seems to be our own design flaw as we seen 2767 consistently do it. We still throw it very hard and could throw over to the truss to the human well but the big arch shot with lower power would be better for a catching robot.