[DFTF] Budgeting for a Competitive Robot...

[Joe Johnson]

This is part of a series of posts called Drinking From The Firehose on getting Dr Joe back up to speed on All Things FIRST.

Today's topic:
Budgeting for a Competitive Robot...

Okay, we have finally come to the 500 lbs guerrilla in the room.

How much does a competitive FRC robot cost?

This is not an academic question. I have currently signed up for a 2nd Regional (thanks NASA!) but I only have $1,500 left in the account we've labeled “build a robot."

Can I build a competitive robot for $1,500 plus the KOPs?

Assets:

• I have some robot raw materials, probably not enough to build a robot but I guess ~80% of the way there (AL stock, some polycarb sheet, some wire, lots of zip ties, all the 10-24 screws & nuts you’d ever want, some #35 chain & master links, … ).
• I have a small shop (mini-mill, mini lathe, drill press, bandsaw, drop saw, belt/disk sander, marble block & height gauge, …).
• I have student labor (largely untrained at this point, but we will get there)

So… what I have to buy is

• sprockets
• bearings
• wheels
• motors
• gearboxes
• sensors/electronics
• pneumatic solenoid valves
• pneumatic cylinders
• Jaguars/Victors
• PWM Cables
• Bumpers
• 2CAN2?
• ??? 100's of other ticky tack things that add up

Here is what I would like folks to help me figure out:

Give me a base number:

• What does a competitive robot cost (all inclusive less KOP)?

Then break it down:

• Price for raw materials (AL, polycarb, screws, pop rivets, tie wraps, hold downs, pool noodles, nylon cloth, …)
• Price for the main drivetrain (assume use of 2 CIM + CIMpleBox + sensor from KOP to make a 6WD drop center chassis – add in special wheels, chain, sprockets, bearings, etc. that are not in the KOP)
• Price per Motor-driven Actuator (MA) include motor, gearbox, chain/sprockets, Jaguar/Victor, PWM/CAN cables, fuse, sensor? Also how many MAs should I plan on? WRT gearbox costs, assume that I am going to have to use stuff from Banebots and/or AndyMark because, while I design robot gearboxes for a living, I am pretty limited on the kind of stuff my kids can make with our shop.
• Price to “ante up” for pneumatics (assume KOP stuff pump, tanks, regs, switch,… include costs stuff needed to make the KOP stuff work).
• Price per Pnuematic-driver Actuator (PA) over and above ante price above include solenoid valve, cylinder, end fittings, plumbing, sensors …? Also how many PAs should I plan on? If there is a way to cheaply gain cost advantage by ganging valves (for example using a special N valve manifold that works well for FIRST and costs less per channel)
• Price for custom electronics (anything above and beyond the KOP stuff. I assume that the KOP angular rate sensor is acceptable, but what else do we need/want?)
• Other robot costs not included above (e.g. extra batteries)
• Finally, How many MAs and PAs total should I count on (assuming again 4 CIMs are used in the Chassis)?

So…

Don’t spare my feelings here. Tell it to me straight.



Do I need to cancel our plans to go to a second Regional? Maybe even THAT isn’t enough, if I need more, tell me now.



I’ll work to find the funds I need. But before I do that, I need to know what I need to raise...


Joe J.
Team Leader / Mentor
Team #3958
Schrodinger’s Cat
BC High, Boston MA

[EricLeifermann]

If assuming this years kit stays roughly the same as last years kit when it comes to the kit bot. 1114 kitbot on steroids is a great starting point and can get you a competitive bot. The extra parts needed for the kitbot will cost you ~$400 including shipping from Andymark and then that would leave you with ~$1100 to build the rest of the robot and if done properly $1100 can get you a competitive robot. You just have to remember to keep it simple and to build within your means.

[Peter Matteson]

With no old robots to rob for COTS I would say that you need $4000 dollars to build a single competitive robot.

$1500-2000
You need to buy transmissions and other power transmission hardware (gears, sprockets, chains) that can easily run this range with reasonable spares and failed concept fallout.

$200-300
Wire, nough said

$600-800
Motor controllers, you only get 4 in the kit of late and this is always the painful number to see.

$250
Fasteners: nuts, bolts, rivets, zipties, master links etc to stock up.

$200
Additional motors, you only get 2 of the CIMS in the kit and you need to buy more if we get to use 4-5 again this year. Banebots motors have had many issues and we never go into battle without spares anymore.

$200
Bearings: we use a lot of bearings and bushings. But we also build lots of spares and failed concepts.

$300
Bumper, fabric wood and pool noodles.

$1000
Shipping: to get the parts to you...

$500
Additional raw materials

$200
Solenoid valves and other pnuematic parts.

$200
Cutters for machine tools.

This is all best guess from memory. I know when you add all this up we easily spend $4000-5000 every year on the supplies to build a single robot. We also have a lot of spares, fallout from concepts that don't make the robot, and shipping costs to bring our robot in under the typical $3500 limit. I have to say with the cost of electronics consuming so much budget when we account our cost I would like to see it go to $4000. We are close every year to that limit, because we are honest to a fault with our accounting, and the electronics is a big factor.

[Clark Pappas]

Originally Posted by Peter Matteson

$1500-2000
You need to buy transmissions and other power transmission hardware (gears, sprockets, chains) that can easily run this range with reasonable spares and failed concept fallout.

Unless I read the original post incorrectly, it appears he wants to run CIMple boxes, in which case he won't be spending this much money on the drive train, even if you buy spares for everything and buy an new set of wheels, say the 6" or 4" plaction.


As for battery costs, I'm going with a 6 battery total on my new team, so with 4 additional batteries it will costs $166 from AM, without shipping costs. However, you will also need additional battery chargers. I don't remember if the KOP includes chargers or not, so you may need to get 2 chargers in addition to the 4 you would get for your new batteries, and even if it came in previous kits, never count on something being in the kit.

[Chris is me]

Originally Posted by Clark Pappas

Unless I read the original post incorrectly, it appears he wants to run CIMple boxes, in which case he won't be spending this much money on the drive train, even if you buy spares for everything and buy an new set of wheels, say the 6" or 4" plaction.

I don't intend this to be a call out, but there is a little danger in thinking this way. We designed a gearbox preseason last year on the assumption that the KoP gearbox was a Toughbox, and then they switched it out on us.

I would definitely not budget assuming a particular KoP gearbox.

[EricH]

Dr. Joe, there is one thing that you will be very interested in. This started last year, and was pretty successful: the FIRST Choice program. Effectively, some items that maybe there aren't enough of for 2500 teams are put into a "store", first come first served, with all items in the "store" free. This can cut down costs on certain items, depending exactly what's in there. It's hosted at AndyMark's website, or was last year, which makes it fairly easy to place an AM order and have it arrive at about the same time.

IIRC, last year's included such items as some hand tools, an FTC starter kit, old but unused batteries, wire, and speed controllers.

[Clark Pappas]

Originally Posted by Chris is me

I don't intend this to be a call out, but there is a little danger in thinking this way. We designed a gearbox preseason last year on the assumption that the KoP gearbox was a Toughbox, and then they switched it out on us.

I would definitely not budget assuming a particular KoP gearbox.

True, I have been careful to not assume with my new team.

But the point I was trying to make (However badly I communicated it), he plans to use what's in the KOP for drive train, which I don't think would cost that much money to buy additional materials and spares for, even if it is a shifting gearbox (which I doubt will be the case).

[the man]

Our robots have cost between $1000 - $1500. so I would say your good. I don't have a breakdown list but, they were competitive robots.

[Madison]

Unfortunately, I don't have a detailed break down of our costs available to me at the moment, but last season, we spent ~$7000 to build two "competitive" robots.

A lot of that is shipping; we don't meet often and decisions sometimes come late as a result. We're trying to be better about planning in advance.

I prioritize convenience over price, so we probably buy things that we could make and could save some money there, but I think spending a few hundred dollars more for a few days of extra practice is worth the expense.

We also burned A LOT of money on minibot development last season. Here's hoping that's an idea that never comes around again.

[AllenGregoryIV]

I think this could be a bit easier if people just posted their BOM. We all had to make one.

Here is the BOM from the Discobots 2587 from last year. I think this version is from before our FIRST Regional so it changed a bit by the end of the season but for the most part everything is there.

Discobots BOM 2011

This only includes the parts that made it to the robot so you probably need to add as much as 50% to this for shipping and parts that weren't used, broken and backups.

[Madison]

Originally Posted by AllenGregoryIV

I think this could be a bit easier if people just posted their BOM. We all had to make one.

While true, we spent far more money that our BoM would indicate. The BoM shows that we met the rules, but it doesn't show the cost we incur in research, development and breaking stuff.

[theprgramerdude]

We rarely spend more than $1000 a year on the robot. The main reasons being, A. we can salvage a lot of extra electronics and drivetrain items off of past robots or old KoPs that we never used, and, a big one,
B. We get a ton of items donated. Usually, each year we get around $500 + worth of Polycarbonate and aluminum donated from a local manufacturing company. This is mainly what we used to then build the rest of chassis on top of the KoP chassis, as our coach preferred to save money wherever possible.

If you don't think starting off with the KoP chassis is the best idea (I didn't my senior year, but we didn't have the means to not use it), but do have the means (manufacturing technology) to not use it, then I'd certainly try to go out and get a bunch of raw material donated like we did, and use that to make your robot with, rather than purchasing much more expensive COTS items like the pre-made KoP chassis.

[Billfred]

I don't have the breakdown, but I recall 2815 spending around $1,000 on last year's robot. (Despite our success on the field, the robot was average at best; you being you, you would be able to take chicken soup and make it fine dining.)

If you've got a few materials already, you'll be okay. While more is always better, these days a team can have a good season from the kit, the Lowe's hardware aisle, and a couple things from AndyMark or McMaster-Carr.

[Jon Stratis]

Pulled straight from our budget sheet:
2011 - $1900 spent "for the robot" (includes spare parts and some new tooling, but not a lot).

Is it possible to build a robot for less? Yes, absolutely. If you have a firm budget, however, I suggest you start with some significant planning the first week or two of build season.

Figure out what you want to build, then figure out how much it will cost to build that. Start taking out capabilities until you're within your budget.

Alternatively, come up with an "incremental" design - you can add on assemblies/capabilities in stages, and stop when the money runs out. We did this with Overdrive to alleviate worry that we wouldn't have time to do everything we wanted. First, focused on getting something that could drive around the track and score points that way (only two balls per alliance = 1 team won't be interacting much with a ball). Next, build our mechanism for handling a ball - essentially sucking it onto the top of the robot, and spitting it out. If needed, that can be bolted right onto the drive base and we're done. Finally, build the elevator that's going to let us hurdle the ball. This way we gradually increased capabilities without requiring that everything is finished to have a functioning robot.

[Peter Matteson]

Originally Posted by Clark Pappas

Unless I read the original post incorrectly, it appears he wants to run CIMple boxes, in which case he won't be spending this much money on the drive train, even if you buy spares for everything and buy an new set of wheels, say the 6" or 4" plaction.


As for battery costs, I'm going with a 6 battery total on my new team, so with 4 additional batteries it will costs $166 from AM, without shipping costs. However, you will also need additional battery chargers. I don't remember if the KOP includes chargers or not, so you may need to get 2 chargers in addition to the 4 you would get for your new batteries, and even if it came in previous kits, never count on something being in the kit.

I checked my numbers I actually had a 2nd robot in there for drive base.
My assumption was based on 6wd with spares for wheel breakage and no ability to make custom gearboxes for mechanisms:
2 AM Planeteries ~$200
8x 6" performance wheels ~$300
8 drive sprockets ~$100
4 Mechanism sprockets ~$100
10 Hubs ~$150
4 P60 planeteries ~$260
Chain ~$50

For a Total of about $1150.