When to make practice bots

Our team made a practice bot this year after bag and tag, but for next year, we want to do it at a different time, preferably in the build season.

So to all the teams who make practice bots, when do you make yours, and why?

Thanks a bunch!

For the past 2 years we have made our practice bot before our competition robot for 3 reasons.

  1. Design time is less due to the lack of lightening holes, lights, ect.
  2. Build time is less due to the same reasons above
    These allow the programers and electric team a robot earlier
  3. Build always makes parts better the second time, more experience with the parts means a better competition robot.

Both robots have been made simultaneously on the teams I’ve been a part of. Once a part has been designed, a machine has been set up, and a student shown how to make the part, it saves a lot of time to just make twice as many.

we create our practice bot so after bag and tag our drives can start practicing and our programmers can make our autonomous code as well as so we can learn from mistakes during build season and make a better flight bot.

Practice makes perfect.

For the last two years which were our first two years building practice robots we built our practice machines before our competition machines. We also made some parts for each machine at the same time which saves time.

This year we used our practice robot (drive train portion only) to make our practice robot for this year.

If needed (assuming you made the parts within the build season per the rules) you can always take the parts off your practice machine if needed and transfer them to your competition machine if some parts don’t get made in time or there are problems.

Building the practice machine first allows the programers more time. It also allows most of the bugs to be worked out (mechanical, electrical, etc.) by the time you get to the competition machine.

This year our entire competition machine was assembled in the last week of build season. It was not ideal for us, but building two machines during the build season is no easy feat with a small crew and small machine shop. It was definitely worth the effort to have a practice robot ready to use after bag and tag.

Although I voted before our competition bot it really is a mix of before/at the same time. Some parts are machined at the same time and the practice bot does get assembled first but for other parts we use the lessons learned to make the competition bot better, nicer looking and/or lighter.

We try to make it basically simultaneous with our competition bot, making each modification to the practice bot first and then the competition one. It’d be great to do the entire practice bot first, but we’re not fast enough for that yet. This year our welding this year delayed this even more, so we actually just just drove our practice bot yesterday. This was definitely a disadvantage at our Week 1. (Luckily it was our base driving that helped pull off the clean win, and that we managed to practice on last year’s bot.)

We went from never having built a practice bot to building two this year (sort of)

Our mecanum wheel modules in 2011 and 2012 were similar enough that we could take last years modules out of our production bot and put them in a plywood frame (last year was narrow bot, this year was wide). The plywood frame effectively matched our production frame (which by the way is made of plywood and won the Industrial Design award at Lake Superior). We added 75lbs of weights and our driver practiced with it.

We also built a non-mobile base to mount our withheld shooter assembly so we could practice targeting and shooting.

Unfortunately our 4 slot cRIO went south as did its replacement from NI, so we had to share cRIOs between the two practice bots, so we could only use one at time.

We design the prototype before the final bot so we can find out what works and what doesn’t and take everything we have learned from the process and design an even better robot for the final competition bot.

Prior to this year, we always made the practice bot first, then the comp bot last.

This year, however, we were very determined to shrink our build schedule to 5 weeks. One of the biggest time savers that we saw available was to build the two simultaneously. As someone else mentioned, once you’re all set up and making one part, making a duplicate at the same time is very quick.

This also allowed us to insure that the two robots were identical. In the past, making the robots at different times meant that the practice bot was very different from the final comp bot. That is bad for your drivers and your programmers.

We nearly made our 5 week build, though a machining hangup getting our turret completed lost us that week.

We use our practice robot as a way to get all the kinks worked out of our design. We don’t have the skillset and time to CAD the entire robot in the short build season so we just CAD the rough overall plan and CAD particular tricky parts. The rest we work out on the fly with the practice robot not worrying much about weight. We use 80/20 for the practice robot because it goes together so much quicker and we can change our minds. That’s usually turned over to software by week 4. We then switch to 80/20’s Quickframe and other lighter materials for the competition robot which usually get’s done half way through week 6.

When things like the drive train are set in stone (usually around week 2-3) we’ll start doing that portion for the competition robot in parallel with higher level things happening on the prototype.

We have found that the greater the delay (in either direction) between the construction of the practice bot and the competition bot, the less the two bots look like identical twins and the more they look like fraternal twins.

My team makes the practice robot second. We found that it is best to hae the second iteration be the competition bot, which is almost always lighter, as well as higher preformance. Why make mistakes on the competition bot that you only end up correcting on the practice bot?

Our two robots are usually made in parallel. Ideally, we first make our practice bot and get a working prototype. Then, as parts on the practice bot are finalized, we duplicate them and start assembling the competition robot. Depending on the time constraints, we sometimes only have the time to build one complete robot in 6 weeks, but we always have our second robot finished and fully functional by the week after ship/bag.

You asked, “when DO you make…” so that’s what I answered. If you’d asked “When would you LIKE to make…” the answer would be different! Or even “When did you PLAN to make…”.

We would love to build our practice bot in parallel with the comp bot, or even before. Sadly, we barely had time to get one good bot done by B&T. The practice bot had been started (chassis and drive train), and we had a “drive mule” (just chassis and drive train, for new drivers to practice basics) all season, but we have just ironed all the kinks out of our practice bot and our drivers (and programmers) are now working with it for the next 1.5 weeks.

We did make a few improvements, which are part of the 30 lbs. that we will take to competition and sub for parts on the bot that we shipped (a different chute-mounting mechanism, for example). But it’s basically just a duplicate. We just didn’t have the person-power or time to get the practice bot done on schedule.

Still, every year we get closer to our goals.

We build our practice bot before the Comp bot. We do this for a couple of reasons,

  1. We want our programmers to have a solid test bed as soon as possible,

  2. If anything doesn’t quite ‘fit’ right we would much rather it be on the practice bot than on the comp bot. This way we have time to fix the issue before we assemble the comp bot,

  3. When be bag the robot we don’t want that to be the stop working point, we want the practice bot ready to go so we have time to practice and continue working on any improvements before competition.

Exactly my point. If it were up to me, I’d have both robots built by week one, giving us 5 weeks to perfect them both, and another 5 weeks with the practice bot.

But of course, it never does go the way we want it to. I want the actual answers, showing that you’ve done it, compared to what you want, showing what you could have done.

Thanks to everyone who has provided answers. I’ve looked into your answers, and the robots you make, and how your teams run, and after seeing what my goals for our team next year are, I’ve decided to build the practice bot along with the regular bot, however, we will have the practice bot always be one stage ahead of the competition bot, so we can correct for error if we need to (Like the comp bot would have a base, and the practice bot would have a base AND a shooter)

As Pat already said, we make both robots at the same time. Make twice the parts, assemble them side by side. Quick, easy, and interesting to watch.

This is our first year building a practice bot and we did it after are final robot was mostly finished for a few reasons. One if for some reason we couldn’t build two robots we had our competition robot complete. Two we knew that there would be certain parts that we would have to take off the competition robot to make the practice robot complete, that meant we would only need to do the parts swap twice once on bag day and once at the beginning of our first competition.

Our build schedule allowed us to build our first robot in under 4 weeks, this left plenty of time to build the practice robot and get it nearly ready by Bag Day.

We were also able to practice with the real robot for as long as possible which was nice since are practice robot isn’t identical because we don’t have any advanced machining processes.

Here’s our schedule for the last two seasons:

Weeks 1 and 2:
Hardcore design and CAD work, resulting in a full, functioning robot model and part prints. Mock up kit chassis for programmers to start tinkering.

Weeks 3 and 4:
Fabrication, assembly and testing of practice robot. Noting design changes as we go.

Weeks 5 and 6:
Fabrication and assembly of competition robot.

The definite (and as I feel most important) advantage to building a practice bot is drive practice. Confident drivers make less errors which results in better performance on the field.

You could also say that it gives programmers more time, but you could have a 12-week build season and the programmers would still want more time. :smiley: (sorry Tubby)