Last Minute Changes
 

Anybody else have any last minute changes? Our robot ended up being 10 pounds overweight (we never weighed it with the electronics board) so we had to ditch our only way of getting over the beam, leaving us only with the harder option of the balance bridges. Did anyone else have any last minute changes to their bot that resulted in a major change of strategy?

Re: Last Minute Changes
 

We make gametime decisions all season long. From yanking out our bridge tipper to adding a second shooter motor to adding some barbells to the front of our robot to make it less likely to tip, iteration is a part of life. Teams that do well in Week 1 have to keep their eyes open, as it could make all the difference at later regionals or Championship.

Re: Last Minute Changes
 

A few days before the end of build season our build/design crew decided to add an arm to bring down the bridge with. It was a simple design that helped us balance well. We had to change our placement of electronics, but it all worked out well and was an excellent decision.

Our design/build crew decided to replace the mecanum wheels we had with plaction (like traction) wheels during our first build window before our Detroit competition after watching the Week 1 competitions. This made a huge difference in our ability to balance and it was totally worth sacrificing some maneuverability (we also lost five pounds of weight).

During our build window before Livonia we decided to add a pneumatic arm to help us triple balance since we had five pounds of weight to play with. We tested it out and it works decently, but not as well as we expected.

Overall, the changes we made greatly helped us balance. I wouldn't change anything else or disagree with what our design team did (except maybe add a flamethrower... if only it were legal :rolleyes: ).

Re: Last Minute Changes
 

When I was on Team 67, we often had incomplete robots at the end of build season.

In 2008, we completely redesigned our arm and added it to the robot on Thursday at Finger Lakes.

In 2009, we changed our robot from a turreted shooter to a spitter during the 6 hour robot access period by doubling the width of our ball elevator so that two balls could fit in it side by side.

In 2010, we went to our first competition weighing 90 pounds and worked hard on adding a hanging mechanism during that competition and the next. We finally got it working during the eliminations at our second competition. And it was sweet too, because it could lift our robot after the buzzer.

In 2011, the robot was done, but several controls issues resulted in the HOT Team underperforming at their first competition.

That's why I was surprised when I heard several days before Stop Build Day that 67 had completely finished their robot as well as a practice bot, and had pulled of a very impressive demonstration for the parents.

I had told my new team this joke: "They procrastinate so much, no wonder they're the Heroes of Tomorrow!", but I guess the joke doesn't have any truth in it anymore. They were really on their game this year!

Re: Last Minute Changes
 

I know that 1425 added their pneumatic triple-balance-helper-thing (a technical term if I ever saw one) for Seattle, and won the regional because of it.

Re: Last Minute Changes
 

We removed our (non-functioning) shooter and rewired our electronics board at Waterford this year... We were an overpowered transmission and we kept tipping with all of the weight from the shooter. The next week at Detroit, we were able to balance on the bridge with ease and ended up being selected by the #1 alliance. Together we triple balanced 4 times and double balanced twice during the elimination rounds. The changes were well worth the stress at Waterford.

Re: Last Minute Changes
 

I always thought that was cool.

Re: Last Minute Changes
 

At our First competition(San Diego), on the first day, we added our hopper and shooter onto the robot(we have a practice robot, so we new everything worked)

Then, in our first match, we completely destroyed our electronics board, by ramming into the bridge. This caused us to have to spend our whole first day of competition, not only rebuilding our electronics board, but also having to go through a redesign. In the end, we came up with the idea of an upside down electronics board, that used the back of the board to protect our electronics. Overall, we think it actually helped, as we cut a lot of weight off our previous, heavy electronics board, cleaned up the wiring, and made it worry free. The weight specifically helped because we were 10 lbs over. Furthermore we took our active bridge mechanism off. The funny part was that we used the front of our robot, which was accidentally designed with a wedge in the front, to push up the bridge for other teams, which ended up being helpful at speeding up getting on the bridge, in elims at LA.

Re: Last Minute Changes
 

Continous improvement.

In 2008, we didn't figure out a good full-speed ball-knock down method until the day before our first competition.

In 2009, we kept our turret out of the bag because we weren't nearly done with it.

In 2010, our ball grabber didn't work until the day of bag, and our lift-mechanism was working at half speed until our second competition when we put a new gearbox and a second motor on it.

In 2011, our minibot deployment system was finished on our practice bot then mounted on our comp bot during a 2 hour open bag window. We had 4 major iterations of minibot that year, where we completely scrapped the old in favor of something drastically better.

In 2012, we changed from a wedge style bridge lowerer to an arm in our first bag window. Just today, we changed our camera positioning, changed our ball-presence sensors, and are rewriting our vision code to be more robust.

It never ends.

Re: Last Minute Changes
 

At Lake Superior, we had a separate control of our intake roller and our poly cord ball elevator to our shooter. When we rammed the gear box to the ball elevator into the bridge during elims, one of our students very quickly decided to use surgical tubing to drive the poly cord roller from the still working intake roller as a makeshift workaround.

Turns out the drivers liked the new configuration better! We continued without a change (other than removing the now useless motor, controller & wiring) at 10K Lakes, and were Finalists-- getting the regional high score at our final winning match.

Re: Last Minute Changes
 

senior year, lead mech, im thinking that i'll stay out of the pits and let the youngins do the heavy lifting we git to comp and the first inspector comes by and says that due to bumper regs we have to drop the entire frame of the bot 2in so they will be "firmly attached" (although arguably you could have hung the bot by its bumpers at the time.:rolleyes: ) second inspector comes by and says they're fine, sadly head inspector agreed with inspector A.

so in all six hours of hacking the bot to bits, moving the entire superstructure up 2in so that we could drop the frame and ripping the entire drivetrain off and reinstaling it above the frame. but it was fun:D

Re: Last Minute Changes
 

We went to the new hampshire regional and are going to the championship and we are making many changes from our bridge manipulator, to our game strategy, to our attempt at 3 balance, to our shooting speeds even autonomous mostly because there are so many ways to play this game we did well in new Hampshire being ranked third but we could always be better good luck to all the teams going to st Louis

Re: Last Minute Changes
 

Every year I have been on the team the robot changed over the course of competition season. This year we had more time compared to the last 2 years to debug issues, though we need to finish things even faster next year.

2010: Our hanging mechanism did not work so we redesigned a new one. The ball intake roller was changed so balls actually stuck properly.

2011: All jaguars were changed for victors after issues at Traverse City. Minibot and deployment probably was on most team's list of changes. We ended up using an alignment hook and a deployment arm released by a pneumatic cylinder and powered by stretched surgical tubing.

2012: We arrived at Gull Lake and our bridge arm back drove against the bridge so that was remedied in time for eliminations. Duct tape was added to the polycarbonate shooter hood to add back spin.

We still have some more changes to do to the robot when its unbagged at State Championship such as attempting a wedge and changing type of drive shaft to steel from aluminum because a major one broke at West Michigan (during a qualification match trying to get on the coopertition bridge & after quarter-finals.)

Re: Last Minute Changes
 

Particularly this year, though I dunno if this counts as last minute, but anyone who saw us at Greater Kansas City and then at Oklahoma this year would noticed the top half of our robot drastically changed from a 4 wheel pitching machine to a 2 wheel custom fab hood shooter. That we designed in about a week and a half (our spring break) and it worked beautifully. Now we're tackling changing our entire bridge manipulator to something completely different. Hope it all works out well for St. Louis.

Re: Last Minute Changes
 

A thing we're considering is changing up (read: removing the entire top half of the robot) and changing to a hood shooter/pitching machine shooter, because as of now we are the ONLY team at the NC regional that is using an air cylinder firing mechanism. It works like a charm, and scared the hell out of a veteran team with its speed and power (without the block on the end to punch the ball the piston will go THROUGH the ball without it moving at all), but its just not as reliable or fast reloading as a pitcher.

Re: Last Minute Changes
 

Wasn't too involved before 2010, so can't comment past "of course".

2010: Kicker did not work when robot went into crate. Partial redesign of it before week 1 SD regional. Intake still didn't work. Complete intake redesign before LA regional. Changed kicking element (angle + reinforcement) and increased kicker power between SD and LA, and then again between LA and Champs.

2011: Intake & minibot did not work at SD. Redesign minibot, adjust intake for LA. Intake still sketchy in LA. Redesign for Champs. Minibot too slow during elims at Champs. Remove and replace with 1114's prototype deployer between matches.

Re: Last Minute Changes
 

When we arrived at Bayou and ran a practice match we discovered we had made a calculation error in our drivetrain, and the thing wouldn't turn on carpet.

The only way we could fix what we had done, was a spontaneous co-axial drive system.

Using entirely borrowed and scrounged up parts from other teams we were able to assemble in just 2 hours, a whole new drive setup, geared completely different taking up no more room on the robot, and having a pretty cool engineering aspect displayed.

Re: Last Minute Changes
 

In each of these last two years we have put a lot of time into significant upgrades mid-season, and that has been really fun and rewarding. Like some people have said, the build season basically lasts until the end of your last competition if you want it to.

2011: Complete redesign of minibot and deployment for second competition. Minibot went 9 for 9 in qualifiers! Redesigned minibot again for champs and also brought a plastic piece to clamp onto our elevator spool to increase its diameter and speed it up.

2012: Switched a set of wheels before our first competition to improve turning. At the second competition, installed a new shooter and a new bridge manipulator.

Re: Last Minute Changes
 

This reminded me of something similar that Dave posted long ago about building the technology of tomorrow, sometime late tonight.

It probably should be an FRC build-season mantra: never put off until tomorrow what you can do tonight.

Re: Last Minute Changes
 

Changes are inevitable, reading the rules etc... doesn't always give you a good idea of how the strategy and game will effect your thoughts on design.

2011 We had a great deployment mechanism and a decent minibot (4 seconds using the gearboxes on the motors) ready after the build season. After scouting Kettering and seeing the 2 second direct drive units we went that direction and had the new ones ready for our first competition (W. MI district) and it worked for us well on to MSC and St Louis.

2012 Our original idea for balancing 3 robots was to be a robot "car hauler" and have a robot on top of ours. After the West Michigan District where we did not see many robots suitable to ride on us, We built a "stinger" to replace our ramp appendage for Niles district. If we had not had the ramp idea we would not have had the room or weight to have the stinger. We still have the ramp and could rapidly change it in the pit but I think the stinger is much more useful as we can rapidly co-op balance in the seeding matches and the ramp was only an end game piece.

Re: Last Minute Changes
 

One of my key FRC philosophies is: if you aren't improving, you're falling behind. What is successful in Week 1 may not cut it by Championship, so continuous improvement is an absolute necessity! After each event this year we had a full team meeting to discuss what went well and what we could improve for the next event.

Since we "finished" our robot, a couple days before Stop Build Day, we have changed pretty much every subsystem at least once, be it a subtle or drastic change. Among other things, we went through:

• 4 iterations of our shooter hood
• 2 shooter gearboxes
• 3 versions of the "stinger"
• changed our wheelie bar to a wedge
• changed the number and type of wheels

It's a very different Scorpion than we first put together 7 weeks ago. Iterative design has always been a big thing for 148, and this year was no different!

Re: Last Minute Changes
 

Do you have any information on what made you change the drive train and pictures to document the change?

Re: Last Minute Changes
 

Watch out for the module rule. Talk to the lead inspector if you're planning to switch one for the other.

Re: Last Minute Changes
 

In 2011, we didn't have a minibot or deployment until our second competition, and we were constantly tweaking it.
This year, we added pneumatic "Stingers" to our robot to aid balancing, and removed our shooter hood adjustment system in favor of a fixed hood, and added a second pneumatic tank.

Re: Last Minute Changes
 

As long as they don't change their minds after competing with the ramp, the change from stinger to ramp would be counted as a modification, not a second configuration. If they did want to be able to play their first match with a stinger, their second with the ramp, and the third with the stinger again, then they would have to comply with the multiple configurations rule.

Surprisingly, This is the only rule to mention this with the exception of this:

Which basically means that if you have a modular system with multiple configurations, the modules for that system are not exempt from the withholding allowance. However, this is redundant since the withholding rules this year are worded such that any fabricated item meant to be used on the robot, even replacement parts, count towards your withholding allowance.

Re: Last Minute Changes
 

I'd like to know how you made your robot modular enough to change that one. Usually for our team, our frame has a massive amount of welds that make it short of a miracle to change our wheels, lest they are fairly similar in dimension. Though, with it being 148, I'd bet money on your frame being amorphous metal controlled by thought alone.

Re: Last Minute Changes
 

Seeing teams like 166 at our regional this weekend, this isn't far from the truth.

Re: Last Minute Changes
 

That's one valid interpretation, however it's also plausible that [R03] applies as soon as the team forms the intent to bring a second mechanism.¹ This issue has been discussed among inspectors in the past (and possibly at the GDC level), but I don't know of any such discussion this year.

In that situation, I'd like to give the team the benefit of the doubt with the most lenient interpretation consistent with the rule, but I'm not entirely convinced that the modification vs. module dichotomy can be stretched that far. There's a continuum between a modification entirely conceived and built from raw materials at the event, and a prefabricated module; how do we decide where to draw the line? The rule doesn't really give any guidance.

I'm inclined to think that if the team intended the part to be used on the robot as a replaceable module, and prepared it in advance, it was their obligation to understand that [R03] might be applicable, and plan accordingly.

For modifications undertaken from materials gathered at the event (which were unlikely to have been originally intended as robot parts), I've previously ruled that they were legal, provided the modification wasn't going to be reversed at the event. (The status of the modifications/modules at subsequent events would depend on what the team did and intended to do with them.)

¹ I mention that because of course a strict reading of that rule makes no sense—just about anything could be added to a robot, but it's not practical to weigh it all.

Re: Last Minute Changes
 

148 builds out of riveted sheet metal. Though this makes it cleaner and easier to do, it is till a pretty large endeavor. I imagine they replaced the whole bottom of their robot.

Re: Last Minute Changes
 

At our second regional we had to lower the rod that we used to stop our drawbridge from lowering too soon when we raise our dumper mechanism. Because of that for one of the matches we couldnt shoot. We had to lower it because it couldnt fit into the box. After the next match we fixed it so that it could work and still fit in the box. At the first regional we had angled our front fender to help ead balls in, we fixed it, it didnt really change our game though

Re: Last Minute Changes
 

We had barely a hint of our current shooter on bag day. Since that time we have changed our firing mechanism, tried to put panels on the wheels and fill the space with foam--but only succeeded in splattering it all over the whole thing when it was turned on--then put stickers over the panels to hide the mess behind them, then took those same panels off and made some "other" changes to the wheels. We also took off the turret motor and chain--opting instead to bolt the shooter down on its lazy susan--moved both motors to the same belt and changed the gear ratio. In addition, we changed the compression factor on the ball and its points of contact within the shooter track, and the release point (anchoring it where it had been already).Finally, we got an encoder and PID loop working, entered preset speeds onto the controller, got vision tracking to work for auto-aiming (albeit for only one attempt before it went haywire--possibly for good) and a distance readout (though it is still in question whether or not we will use it due to the lag it causes on the camera).