Thursday, February 27, 2014

2/14/2014 Day 41: Magic Smoke, Fun Smells, and Catching Fire

Today was a bit of a fun day.  After playing around with the robot and noticing the winch was not working very well, smoke started coming out of the robot, so that halted/severely slowed most robot stuff for most of the day.

Shooter

Today was a good yet bad day to find out something was not properly connected to a motor controller. While it was much better to find out today rather than tomorrow, since it would be Duel in the Desert, we were very shocked to see the smoke today and get a whiff of the result, and had to take it apart and get a backup for Duel in the Desert.  Pretty much, one of the mini-CIMs was disconnected from one port on the motor controller, meaning there was no current going through it, meaning the other mini-CIM was doing all of the work the entire time.  As it was doing much more work than the motor was meant to do, the motor soon overheated, and smoke could be seen rising from the robot, and the strong smell of burnt plastic (to me it smelled oddly like old mashed potatoes and gravy) was smelled when approached.  Since we knew something was overheated, one of the mentors came over to check, and, after checking both motors with the back of his hand, it was pretty obvious one of them was basically gone (since he jumped back, said ow, and told us not to touch the robot for a while).  This pretty much halted any testing today with the shooter, intake, and everything in general.
After taking the gearbox apart, we got to see what the inside of a motor looked like. (badly taken photos below, and yes, it is not supposed to be that color)






Intake

Today we had more struggles with the intake while the robot was still running.  Pretty much, the robot has to be driving at a decent speed now in order for the ball to be sucked up.  I am beginning to now think it is a mix of the tennis balls and the height of the gussets on the front that cause the ball to not go in, as it was much worse today than it was in past days, and today we just installed slightly taller gussets, but, we didn't really get to really test it.

Drive Base

Today not much happened in terms of drive base stuff, as there was the big distraction of the burnt out motor, but the frame did get mounted to the rest of the drive base, and the only thing needed on the bellypan was the pneumatic stuff.

2/13/2014 Day 40: 5 Days Left

Today was a big day in terms of the creation of a robot as a whole.  While it was a short day today (since it's a Thursday), we were able to hit a big mark or two, and were beginning to be ready to mount stuff on top.

Shooter

Today we continued to play with the shooter and the angle, of everything, but found something pretty big with the way it all shot.  Most of the time, the shot would be consistent, but it would shoot somewhat of a dud about one-third of the time.  When we looked back, one of our first guesses seemed to be correct. While sometimes the winch would unwind a teeny bit after it shifted to neutral, there were a couple other times where the winch wouldn't unwind at all.  This meant most of the time there was no resistance until a tad bit after the shot was fired, but, when the winch wouldn't unwind, the catapult would experience a small amount of resistance immediately, which changes the acceleration, changing the force and the energy put into the ball, making it travel a much shorter distance.  This ended up being fixed at the end by the programmers, who added an extra command for the winch to unwind a bit more after latching the catapult back.
Also, in terms of angle changing, we played around with adding something to raise the back of the catapult, so, as the ball rolls to the back of the catapult, it is pushed slightly downward, changing the angle and making it a little more even, since the goal is to have the highest point of the ball be just a tad above the top of the goal.

Intake

Today the intake was starting to die a little on us again today, and just would not pick up the ball at all sometimes, which was a bit on the disconcerting side, but it was mostly due to the size of the ball, as the diameter of the ball is 2" above the diameter it is supposed to be.

Drive Base

Today we finished all of the bellypan stuff, and went ahead and mounted the bellypan onto the drivetrain, completing most of the drive base, as all we have left to do is mount the robot frame on top.  The drive base was not heavily worked on today.

Approximate times of working: 3:30 PM - 7:00 PM

2/12/2014 Day 39: Putting Together the Frame

Today was another day of putting things together.  As we finally got our black rivets, we began doing the riveting work needed (no pun intended).  Also, we continued to play with the practice robot, and started trying to do some stuff to play with shooter angle.

Shooter

Today was our first day of playing with some shooter angle stuff.  To get us a slightly higher angle, but a lot more power, we went ahead and increased the height of the gussets that held the pivot point, or the gussets that hold the front part of the catapult.  This increases the time of contact the catapult has on the ball, allowing the catapult to add more energy to the ball, and also changes the "release angle" of the catapult, making the ball go a little higher.  This definitely did help the shooter with its range and power.
While this worked, we noticed a somewhat bigger problem with the surgical tubing.  While the shooter shot decently, we looked at the loops, and noticed they were beginning to shred, from the inside out, at the brass fittings.  While it would have been okay for another 50+ shots, we went ahead and took it all off as a safety precaution in the case of one of them snapping under tension (basically, would have same effect as a whip, and hurt close to as much).  We ended up replacing with the slightly cruddier tubing for now, but went ahead and ordered the same type of tubing, but much thicker.

Intake

Today the intake was a little inconsistent for the first time, and the motors would stall if the ball hit a certain area of the intake, which was highly disturbing for most of us.  This could be for a handful of reasons, whether it a slightly over-inflated ball, or a lack of bumper.  Pretty much, it should be just fine once we have the semi-compressible bumper, which can act like a ramp for the ball, rather than a large step that the ball currently has to go over without the bumper.

Drive Base

For most of today, we went ahead and worked on riveting the robot frame together, and all of the gussets that go on it, so we will be ready to mount it reasonably soon.  Also, we continued the wiring and mounting of electronics onto the bellypan, and got fairly far today with all of that (around 3/4 done with the bellypan stuff).

Approximate times of working: 3:30 PM - 7:30 PM

2/11/2014 Day 38: Last Build Season Day Off and 7 Days Remaining Alert

Today not much happened again, as it was our last day off (next Tuesday we will most likely be working, unless we are able to finish the competition bot).  Pretty much, everyone was in crunch time.  Some videos came out (pretty much just video from 842's working claw), but it won't be until closer to another 6 or 7 days that all of the release videos start coming out.

2/10/2014 Day 37: Anodized Parts!!

Today was a very exciting day, as we got our anodized parts in! (and we'll be the first team in Arizona to have an anodized robot).  Pretty much, since there is Duel in the Desert on the upcoming Saturday (and end of build season 3 days after), it was time to get down to business and try to build the competition robot as quickly as possible.

Shooter

Today not much happened with the shooter, as we wanted to start assembling the robot, starting with the drive base, so pretty much nothing happened.

Intake

Similar to the shooter, basically nothing happened with the intake since focus was on building the anodized drive base.

Drive Base

Today we went ahead and began assembling the drive base, as well as setting up components for the bellypan.  Pretty much, just back to putting things together, except for the bellypan, with the basic and essential components down, giving enough space to put the battery in the back left corner of the robot.


Above: A picture of the bellypan with digital sidecar, cRio, and talons (motorcontrollers)
Below: A picture of the beginning of the anodized drive base with gearboxes installed


Approximate times of working: 3:30 PM - 7:30 PM

2/9/2014 Day 36: Beginning to Make Stuff for Competition Bot

Today marked the first day of the creation of our competition bot.  Most of the day was taken by cutting out the same wood parts we hadn't cut out yet (mostly extra latches), but the day did consist of a few interesting design tweaks we wanted to implement to possibly better the bot as a whole/make it easier for drivers to drive the robot.

Shooter

Today not really anything happened with the shooter.  While we did mount tennis balls onto the shooter, it was for the intake rather than for the shooter.  Also, we had to replace the winch strap, since it broke/snapped, but that was just doubling the strap.
In addition to changing out the winch strap and redoing that, we went ahead and added a limit switch to the latch area.  This makes it so that winching back can just be pushing a button and letting go, rather than having to hold the button down until it latches.  Overall, this just lets the operator not have to pay as close attention on the shooter, and pay attention to the surroundings and timing the shots.
Below is a picture with a clear view at the catapult setup.



Intake

Today we did the main thing we had to do with the intake, which was make it so we could still pick up the ball, but let it still sit in the shooter.  To do this, we just added tennis balls to the front of the catapult, so that when the ball is being sucked up, it bends the tennis balls back a little, until the ball pops over the tennis balls. Once it pops over the tennis balls, the balls go back to their original position, and keeps the big ball from rolling out.  We went ahead and tested it, and it seemed to work well, although sometimes the ball would not go back after intaking, but would stay back after moving the intake up.  While it did make picking up the ball slower, it did do just fine as a whole, and did everything we needed it to do.

Drive Base

Today we started up the whole bumper frame building process, since we plan on using slip on bumpers to make everything easier.  Pretty much, we just cut out the wood and put it together in the 23"x34" frame (since the pins add a little extra).  Pretty much, for now, the bumpers just look like a wood frame and scattered cut up pool noodles.  Also, we went ahead and cut out a new wood bellypan and spray painted it black, as it will go on the competition robot that we should be getting parts for soon.  The bellypan organization will be one of the big design changes on the robot, since we need to make space to stick the battery in the back.

Approximate times of working: 12:00 PM - 6:00 PM

End of Week 5: Comparison Update and EDP Evaluation

As it is the end of Week 5 and everything is wrapping up, I should be reaching my end of build season hypothesis for whether or not the engineering design process is worth it, and am.  Since I haven't seen the results yet (haven't gone through competitions/regionals yet), I can not yet make it my conclusion, but can base the hypothesis just on the general feeling of everything compared to past years.  As figured from past posts, we are way ahead of where we were in past years, with just barely beginning to test the intake and finishing the CAD of the shooter for 2013, and just getting the sheet metal parts for 2012 (did only get parts 2/8/2012), so we are ahead as said before, having a robot that could be bagged and play the game just fine.

For now, the question is pretty much "why?", and the main two parts of the answer are: "It was the engineering design process" and "It was having funds and experience/knowledge", and it's just a matter of what is the mix for the answer.  Another big part of what needs to be answered is how time affected the process as a whole, which means the identification of the other factors would also be needed.

Up to this point, I have found that the factors that may change the engineering design process are time, money, (non-financial tangible) resources (how well can you machine things how quickly?), and knowledge/experience.  Overall, I do think it was primarily the engineering design process for each of the mechanisms that helped speed us along, and, so far, has been worth going through it.  Also, I feel that, as I already have stated, time is not the only factor, and not bigger than the others, but time's effect on the process depends on the levels of the other factors.  As of now, it seems as though if one has high amounts of two of the four things that act as factors, and mediocre amounts of one other will allow for the last factor to not matter (in this case, plenty of non-financial tangible resources and knowledge/experience, so so funding, and not much time).  In past years, we had decent experience, mediocre machining capabilities and funding, and not much time, so we weren't able to do much.

I have come to this conclusion mostly because time has not had that much of an affect on the process as a whole.

Wednesday, February 26, 2014

2/8/2014 Day 35: End of Week 5 With a Working Bot!!!

Today was the beginning of testing in the duplicate bot, and it was (mostly) working how we wanted it to. The day started off a little slow, because it was our first time taking out the field, so we had to make our measurements so we knew where the distances/field indicators are/were.

Shooter

Today the shooter did work, but we had to add quite a bit of surgical tubing.  Although we did add all of the surgical tubing, and the winch was struggling a little with it all, the latch worked exactly how it was supposed to, and the ball fired, but a bit highly.  One of the other problems was keeping the ball on the shooter, but that should be solved fairly easily by just adding tennis balls or something of that sort to the front.

The biggest thing that needs work is probably the shooter angle.  Since it shoots on the high side, there is a band within the band of the hit range that is a miss range, meaning there are two ranges for the shooter to have to hit.  This we want to change, as it is best to have one continuous range rather than two separate ranges, and the next big design question is how to change the angle so the maximum height is at the top of the goal.

Intake

The intake pretty much did everything it was supposed to today, and worked effectively as expected, so we don't have to do much with the intake anymore.

Drive Base

Today the drive base did its job, in terms of it was structurally stable, but the biggest problem that will need to be accounted for is the amount of weight on the front, as the front was much heavier than the back, since the battery and intake were both on the front (the two heaviest things on the robot other than the drive train itself).  This meant when the robot would suddenly stop or accelerate backwards, more so when the intake was out, the robot would rock forward first, rather than staying steady.  This should be an easy fix, and the only thing that will probably happen while still working is moving the battery to the back.  Also, though, this is one of the slight disadvantages to using a wide base over a square or narrow base.

Approximate times of working: 8:00 AM - 1:00 PM

2/7/2014 Day 34: Finishing the Bot

Today was finally the end of the whole process of building the practice/duplicate bot, and we went ahead and got the robot ready for testing for tomorrow.  Today consisted on primarily finishing wiring and pneumatics routing.

Shooter

Today we went ahead and attached a couple loops of the surgical tubing to the shooter, mostly to make sure it all worked.  Also, we went ahead and went through latch stuff, making sure the latch was just fine, and both cleared the bar and was able to return to hold the bar on the catapult.


Above is a picture of the current practice bot, and us attaching the surgical tubing loops.

Intake

As before, nothing happened with the intake, but it should finally be used and tested tomorrow morning.

Drive Base

Today we finished the rest of the wiring and pneumatics for the robot, as well as the routing, so we could have the robot ready to go tomorrow morning for testing.


Today we went ahead and finished painting the other sides of the gussets green, so now all we have to do is rivet everything together once the anodized metal gets here.

Approximate times of working: 3:30 PM - 7:30 PM

2/6/2014 Day 33: Dropping Off Parts and Finishing Bot

Today was just another day/continuation of the building aspect of things, pretty much other than the latch. Also, the parts, being tubing, gussets, and metal parts of the drive train, were delivered to be anodized, so those should be back between 3 and 5 days to work on.  Since the first robot was the preliminary design bot, and the mechanisms were the preliminary design mechanisms, and those concepts haven't really changed much, we will be entering the second part of the whole detailed design process when we get the nicer parts back from the people anodizing them.  For now though, as previously stated, we have to finish building this bot before any more design changes will be happening.

Shooter

We finally are finishing latch stuff for the shooter.  Today we went ahead and drilled out holes and mounted the angle, so we could mount the piston and latch, although the two pieces of angle for the latch were a bit off center.  Pretty much though, the shooter just needed to have the surgical tubing loops and wiring stuff finished.

Intake

As everything else is getting close to finished, and intake is already done, nothing happened with the intake today.

Drive Base

Today we went ahead and finished mounting everything needed, as pretty much all that was still needed was the battery area and finishing wiring.


Today we also went ahead and cut out the gussets for the robot, and spray painted each of them (just one of the sides, because it was too late to do the other side)

Approximate times of working: 3:30 PM - 7:00 PM

Tuesday, February 25, 2014

2/5/2014 Day 32: Confirming Designs

Today was another day of putting stuff together, but we did begin cutting everything to get anodized tomorrow, mostly the tubing, but also the gussets we got back a couple days ago.  Overall, not much happened, just continued building.

Shooter

Today was another day of playing around with latch geometry.  We found that if we attach the piston to the latch itself, things wouldn't work, since the piston shaft pushing open the latch travels linearly, while the latch rotates around an axle.  After thinking about just creating a slot so the piston could slide within the latch, we figured it would be easier not having the piston attached to the latch, but just pushing the bottom and using the latch like a lever to open the top.

Intake

As said in previous day, not much happened with the intake.

Drive Base

For the drive base, the general layout of components for the bellypan was beginning, as we now knew the shape of the bellypan and the general components need on top.

2/4/2014 Day 31: Week 5 Tuesday

Today was not a heavy day at all in terms of robots, and pretty much was used entirely as a break.

2/3/2014 Day 30: Beginning of Latch Design

Today things continued to come together, and some designing began again, as the latch needed designing.  Also, the drive base was worked on a little today, in terms of the organization of the bellypan electronics, tanks, compressor, and so on.

Shooter

Today was a big day for the shooter mechanism as a whole.  While the latch was the pressing happenings, as we needed that before we could get the robot fully functioning, we began figuring out the surgical tubing loops.  With the latch, we figured we needed something with a progressively increasing slope, so the bar could slowly open the latch, then let the latch close at the end from the surgical tubing getting it back to a closed position.  The only question was how sloped does it have to be, but, since we have the wood cutter available, it was easy to immediately start playing around with it and begin the iterations.  So far, the current iterations just haven't had a big enough slope, so it was a bit hard to open.

In terms of the surgical tubing loops, we went out and bought some brass barbed fittings, and went ahead and put them into one of the sides of the surgical tubing.  To keep the tubing on the brass fitting, we went ahead and used thick wire and wrapped it in the grooves of the barbs, squishing the surgical tubing between the fitting and wire.  This seems like it will work well, and looks really flashy.

Intake

Not much should be happening with the intake for a while, since it's all finished.

Drive Base

Today we went ahead and worked on the organization of components mounted on the practice bellypan, and mounted the compressor and rest of what needed to be on the bellypan.  Pretty much, it was just putting stuff on and seeing if the current positions of motor controllers and everything else was okay.

Approximate times of working: 3:30 PM - 7:00 PM

2/2/2014 Day 29: Beginning of Week 5 and Crunch Time

Today was the official alarm bell for most teams, as it signaled 2/3 of the season gone, and the fast approach of the final stretch.  Still, not much has been happening in terms of the design of any parts, but the latch should be beginning soon.

Shooter

Today we finished mounting all of the shooter stuff to the robot (bolting in the catapult and putting in the winch), and it was time to figure out how the latch stuff should be mounted, both the piston and the latch itself.  While the shape still needed to be further thought through, we just need to figure out what to use and where to put things.  As we had a single-action piston (a piston that is spring loaded, so it will go one way when air is pumped into it, but not return), and plenty of surgical tubing, we felt that was probably the best actuator to use, as the surgical tubing would allow for the latch to easily return to a closed position, and the piston would easily allow for hitting the latch to open it briefly.
While we easily decided on doing it this way, we did have reasonable amount of debate involving the positioning of the piston.  Originally, most wanted it to be placed vertically, but then it would be sticking out and made the thought of a designing a simple latch a little more difficult, since the latch would be oriented in the same way as the piston, but actuated in a different direction, perpendicular to the orientation of both the latch and the piston.  Also, a random piston sticking out would appear visually unappealing.  From this, we decided mounting the piston parallel and beneath the catapult would be the best idea.  This would allow for a simple latch shape, as well as easy mounting, as it would only require three pieces on angle.

Intake

Today we went ahead and added the pneumatics to the intake/robot frame, so we could actuate the intake and move it from inside the drive base to outside the drive base.  That was about it for the intake stuff.

Drive Base

Today just consisted of adding the pneumatics from the intake onto the robot frame, and, other than that, nothing much happened with the drive base.  Most likely, once the latch hinge and piston mount is confirmed upon, pieces of angle will be added to the frame.

Approximate times of working: 12 PM - 6 PM

Monday, February 24, 2014

End of Week 4: Comparison Post and Evaluation

While last week I said time has not had much of a limiting factor as of now on the process as a whole, that continues to stand true for right now.  As of now, we have been running fairly well and maybe a tad behind schedule, but way ahead of where we were in past years.  In 2013, we were only just beginning to prototype the intake mechanism, and had only just built the shooter out of wood and prototyped a firing mechanism, but did have a finished drivetrain. While we haven't yet made a concrete version of the latch for the firing portion of the catapult mechanism, we definitely have done everything else, and the bot could function and do what's needed in a competition.  In 2012, we were just finishing all of the CAD drawings by now and getting ready to send them in.

Overall, we are definitely at least 2 weeks ahead of past years, and have stayed fairly on schedule.  In terms of the process of evaluating the engineering design process, not much more has happened since the last week in terms of moving along the process, since most of what has been happening is the building, rather than designing or testing parts of everything.  Pretty much, we have just been going off of what has been already designed, and are continuing to do so, but should be done sometime soon.