Average Cost of a World-level Competition Robot

VEX V5 General Discussion General Forum
1

My high school’s robotics program director is planning to impose strict budget limits upon our teams for next year (similar to how FRC limits the overall cost of a robot). He says that encouraging fiscal responsibility can help the teams win awards (through showing how our teams can come up with solutions that fit the parameters of the given problem while staying within real-world constraints, which is what engineering is about). We have yet to discuss the details further, but I wanted to ask you guys how much your world-level robot would cost (I.e. if you had to sell it and break even, what would the robot’s price tag be?) so that when we discuss what limit we set for our teams, I can come to the director with an idea of a limit that our teams definitely can get to Worlds with, yet pose enough of a challenge to be award-worthy.

Feel free to exclude the Cortex, battery, joystick, and other associated electronics from your cost estimates, as that is universal. I’m trying to differentiate between “mandatory” costs (due to parts that are absolutely required for a robot to work) and “optional” costs (the parts that are used to build the robot’s mechanisms, and which earn you the big points in matches).

2

We keep track of every part on our robot and we have a cost for each part and then we put it into a spreadsheet. Our bot we won state with was $1456.34. This doesn’t account for the the C channels we cut and don’t use or the parts we used and took off. So a good number for a team to compete with that takes into account of parts you already have would be $1250 for each team you have.

3

Don’t forget money to register for tournaments and other fees that are associated with them. Also, keep in mind V5 releases next season too.

4

That’s not what I’m concerned about. I’m talking about the robot itself.

5

If you take away the approx. $400 for the Cortex, Joystick, and VEXnet keys along with Approx. $80 for two batteries and another approx. $70 for chargers, power expander, battery clips, battery extender, the remaining part of our robots range from $1200 to $1400.

6

Similar to what 536Mentor said, not counting the control package, the batteries, or the power expander, my teams robot is sitting at about $1,550 in parts. Now, that is not taking into account any revisions we made throughout the season. If you account for all of the cut c-channel, broken motors, stripped screws, modified sprockets and gears, cut lexan, and broken sensors, I would add another $300 to $600 for that.

7

i always say $1500-2000 for the robot but that is artificially low as you always need a reserve of other parts of an equal amount to complete any given project. Some years you make a bot that which sucks up 1x2x1 c-channels, other years it is 1x5x1. We have not used tread for several years but you still need it and nothing seems to be suited to be completed within the contents of a standard kit. I think a bill of materials is great but a limit is not suited for Vex competiton.

8

So I have 3 numbers to give in answer to the question.

(1500-2000) The cost to completely replicate an existing world championship robot, depending by year is around 1500-2000$. That is the cost of all the parts from nothing.
(350$) The cost of metal etc that you might need to buy every year for cutting. No robot has more than 350$ in metal on it.

Then we get to the FRC rules for robot costs which are a joke. All stock metal doesn’t count, all electronics including motors and motor controllers doesn’t count. Anything less than 5$ each doesn’t count so screws, nuts, zip ties, rubber bands and polycarb sheets don’t count.
This robot

would be 0$

This robot

would be around 100$.

The difference being 60x did their anodizing in house and Antichamber had to order out for anodization. And any machining in house (regardless what of what facilities it takes) don’t count.

9

So my point is that the game incentivizes not being stupidly heavy so its hard to get better with increased cost. Not sure what any of the arbitrary cost rules actually contribute. The FRC rules are exclusively a marketing line anyway.

10

So are sensors “other associated electronics”?

If I include them, but leave off cortex/joystick/batteries/radios it’s from a low of $1000 to something like $1500. @tabor473’s probably right about the cost of the large metal parts, but the standoffs, spacers, gussets, axles, shaft collars, and other small parts really add to the cost. Gears, sprockets, chain, intake flaps, tread strips (for intakes)–all that can be $200 or a bit more per robot. Not to mention that if you want certain parts like ratchets or nautilus gears you have to order the kits which contain them. Every time I think we’ve built a robot on the cheap, it comes in at $1300 to $1600 with cortex, batteries, joystick, and radios. When we go all out, it’s $1800 to $2200 (again, inclusive of cortex and control components.)

11

I’m going to go ahead and question the premise. Why limit yourself for the hopes of greater judged award considerations? To me, judged awards are secondary to having a good competition robot. And. If it’s so important, the extra time spent budgeting could be used to work on your notebook.

12

And if you already have a parts stock to begin with, I’ve found that budgeting about 20% per year for replacements and upgrades works pretty well. If your team works with a $2k box of parts, that’s $400 per year, per team.

13

Warning: This is a very opinionated post from a very specific perspective, so bear with me.

I think that this depends on what you mean by “award worthy.” Getting your division’s design/think/build/etc award is very different than getting world excellence, champion, or even division champion. If you have a concrete program goal, the requirements become more clear.

When we won VEXU worlds back in 2015 (Skyrise), we spent something like $8,000 on our two robots for the season (back when VEXU rules were that you built a 15" and 24" robot and competed with both at the same time). Average that out and you’re looking at $4,000 for an entire season’s worth of R&D for a team + bots capable of winning the entire championship. From my experience, this cost is going to vary significantly from year to year since the mechanical requirements of the robots changes. A nothing but net robot will be significantly cheaper than a skyrise robot since they couldn’t expand whereas our skyrise bots expanded to ~60" and ~90" tall.

If your team’s goals are more in line with things like the design award, then you really can go a long way with less resources, since you have to do real engineering involving budget constraints. Due to the rapid-prototype style and nature of the platform, teams usually miss out on learning some of these core engineering values.

If your team’s goals are more in line with things like winning world championship, understand that your priorities require a level of efficiency that’s really difficult to achieve with more of these constraints. Precise planning and extra compromises imposed by budget constraints generally aren’t going to beat teams that don’t have to deal with any compromises. Teams aiming to win World Championship usually try to qualify early with some design that offers an above-average level of performance with perfect repeatability/reliability, then redesign their robots to be able to beat the most efficient or effective designs, and win no matter who you’re against/with. If they think they got the build/strategy wrong, they do it again, and again until they’re confident they can win with what they have. That’s generally where the big costs come from.

TLDR: If my goal was to be highly competitive at World Championship and you told me I only had $2,000 to build a robot for the season, I’d wait until January or February before I even built anything in order to minimize risk of not having resources, while maximizing confidence that I could win, and that’s not ideal.

14

This is an important point for programs. At the end of the season we strip our robots down and reorganize the parts. We don’t need to throw out that many screws, nuts, etc. Most of the motors, sensors, etc. can still be used as well. Even many of the metal pieces that have been cut can be reused, sometimes just at a fraction of their original size. So you don’t want to think of it as $1500 per robot per year outside of brain/controller stuff. It should be more like $2400 across four years, or about $600 per year, as @Rick Tyler says (adjust $1500 and 20% of that as needed).

15

Well that robot is worth 0$ for sure right now. The chopped up pieces are in a box somewhere after we salvaged the screws, sprockets and spacers that weren’t bent up.

16

I should clarify:

You may leave out the following:
-Cortex*
-7.2V Battery for Cortex and 6 AAA Batteries for VEX Joystick
-Joystick
-Battery chargers for both 7.2V battery and joystick batteries
-VEXNet keys
-9V Backup battery, battery holder, and cable.

*V5 is coming out, so you might as well as replace the cortex with the V5 in your cost estimates.

I want to isolate the control system from the rest of the robot to get a better idea of what limit I should give my robotics program’s director as an idea. The control system’s a must and thus universal, which is why I am letting you leave it out in your cost estimates.

This is not my idea. It’s the director’s. His reasoning (not mine) is that by having teams work within these cost limits (and thus show fiscal responsibility in building their robot), they can show to the judges that they can come up with effective solutions that follow the limits and constraints of a problem that they’re given (which would be to build a robot that can be competitive, at least at the state level), which is a part of the engineering design process. We are planning to have it fully worked out before we begin our next season in August. I’m a mentor for my former high school’s teams and also a former participant, so I need to advocate for them when we set these limits so that next year, the limits won’t prevent the teams from building robots that can get to Worlds. I do agree that a good competition robot should come before judged awards, and this is why I’m working with the director to set a reasonable limit that won’t hamper our teams. Those reasons are why I’m writing this thread right now to get an idea of what a cost limit should be at.

Thank you for that perspective. That’s actually good information for us to think about. One of the ideas for the limits is that we just limit how many new parts teams can buy for their robot each year, and thus exempting parts already in inventory from these cost limits. Again, we are still in the early stages of working out these cost limits.

17

We have fours year of an established inventory and we supported 20 teams this season. 11 teams made it through the regional and competed at states. Most of our strong robots are around the $1500 value.

We implemented a constraint this year in the effort of fairness where we budgeted $100 per team to purchase additional parts. Our interest wasn’t to limit teams access to resources but to force them to establish a plan. We had some teams that didn’t use any funds and we had a few that spent several hundred dollars but they documented a plan that justified the additional cost (mostly batteries and aluminum).

In the past we had students hacking up pieces of c-channel the first few weeks of the program. This year we did not allow them to cut steel for the first month until they truly had a plan. I was actually surprised how many full length c-channel pieces were returned at the end of the season. We also had teams that didn’t trim down their c-channel (they let four-bars overhang past the fulcrum when possible) so they would have the long aluminum next year.

I guess trying this plan may help organizations reduce waste.

18

@AppleDavidJeans,

Before opening this thread, after just seeing the title, I wanted to answer: at least 400-500 man*hours. And I still do. As previous posters said, costs depend on how much time you have to prototype and test and think about the designs before cutting. My observations are that many good robots start bulky at the beginning of the season and get leaner as they improve.

First, if your program director wants to save costs on the new parts, he has to invest space and money into providing extra storage space and organizers to sort all the old parts and have them easily accessible.

Also, to save money on materials without compromising quality of the results, he needs to give students more meeting time and support in the form of mentor’s availability and good equipment that makes it easy to refurbish and reuse old parts.

If you already have parts from the previous seasons, I would say you could build a good robot with as little as $600-$800, replacing only what is wearing out and not usable anymore.

That would be 2 or 3 packs of aluminium c-channels, some gears, axles, bearings, washers, collars, spacers. Potentiometers and limit switches are sensors that keep breaking and need to be replaced regularly. That would also include at least one new/spare battery because they decay over time. Also, money invested into giving them more time to practice and go to and extra local competition is well spent and will save some dead-end design solutions, by letting them see other robots and exposing to new ideas.

Again, you can avoid buying new parts if you pay for it by additional student’s time.

My team spends first couple of meetings of the season by refurbishing old motors. We didn’t buy any new motors this season and were able to qualify for states with 2014-2015 motors, then went to states with 2015-2016 motors and did there very well.

Similarly, we didn’t use new potentiometers until end of December, reusing the old ones that still had at least some of the working range. Same goes for HS gears that have few bad teeth. This all takes time to test and repair when possible. Does your program provide students with enough meeting time for that?

The only way this will work, if your director understands that the goal is not to optimize number of trophies per every dollar spent on the program, but to maximize amount of good learning students get within reasonable costs.

It is well known that creativity increases when resources are limited, but if the resources are way too limited then you cannot do or learn anything and it is just a source of frustration and a waste of everybody’s time.

19

$1500 per bot should be plenty.

Limit your rebuilds to 3 or 4 over the course of a season and you should be able to stay in budget.

We won with a bot that cost less than $1200.