As a rookie team, we seem shocked that our simple design costs so much to make ($3500 in extra parts, most computing electrical components because our robot is 99% computer 
) I forgot the $3000-$3500 slot! UGH…
Are you sure you calculated your costs correctly?? I know my team averaged about $1000 USD per year, maybe $1500 if we splurged a lot. Anything that came included in the KOP does not count against you BOM total.
Yup. $600 in 5 super ultrasonic sensors.
$400 electrical compass
$1300 in 8 COTS servos
$200 special aluminum for arms
$275 slipring
and whatever else
Just out of curiosity, what kind of servos are you using? I don’t think I’ve ever seen a team in FRC use one that cost more than $30 or so…
To answer your original question, we’ve spent between $2000 and $3000 on robot construction in the past few years, it really depends on the game and robot design.
:eek:
What is wrong with normal aluminium? (of all the questions I could have asked, this is the first one that comes to mind:o). What is so special about it? What are you doing that would make using a $400 dollar compass any more reliable (in practice) than using 3 or 4less expensive sensors and average the values?
Secret
Less than I voted because of donated sprockets from the awesome folks at Gates. If we weren’t doing octocanum, I’d say about $500, plus possibly a laptop for on-board image processing. (We don’t know if that’s necessary yet!)
Here is a good post for a lot of this information.
http://www.chiefdelphi.com/forums/showthread.php?t=98775&highlight=[DFTF]
Could you post part numbers and/or data sheets for the “Super” ultrasonic sensors and the compass, I am curious what added value you are getting for the added cost.
I would also caution you about relying too heavily on an electronic compass, in my experience (with the blimps from RPI in Manchester and Atlanta) the magnetic fields in arenas can be less than predictable.
I don’t know how you could go less than at least $2000. This year there was hardly anything usable in the kit. So far we have spent almost 400 on wheels tires and chains, another 200 on shafting and misc. from McMaster Carr, $260 for aluminum for the frame, and $150 for the plexi. It would be more but a local company just donated about $150 in pillow blocks. I haven’t purchased bumper material yet and I’m sure we will have to order more sprockets etc. Hopefully we have enough misc. nuts and bolts this year. In years previous we spent about $500 just on nuts and bolts as a newer team. We have quite a stockpile now but getting here cost some money. If you aren’t building this in a decent shop it is amazing what all of the little stuff costs when you have to go out and buy every nut, bolt, key, tool, etc.
Can you clarify what servo’s you’re using? I can’t imagine a situation where a 4W servo for an FRC robot is going to cost $150+ when a cheaper servo couldn’t do the exact same job. Remember R48L…
I reccomend looking at this thread here:
http://www.chiefdelphi.com/forums/showthread.php?t=98775&highlight=dftf
I contend that anyone claiming their robot costs less than $2000 in extra parts is either incorrectly accounting, built a box on wheels that is no more than a kitbot, or flat out lying.
Additional speed controllers and other components that are supposed to be accounted for never quite seem to show up in bills of materials. Raw materials seems to be another area where teams take liberties with their costs.
This reminds me to mention that just because a you didn’t pay for something doesn’t mean that it didn’t add to the cost. (Some teams seem to forget this when totaling robot cost.)
If I remember correctly, we paid less than 1200 or so out of pocket to build our 2009 robot - but we had a good $500+ of donated belting on there.
We ordered about $1500 worth of pneumatics components this morning alone – but that was for two machines.
I can’t imagine how you could build a robot for anything less than, say, $2000, though.
Absolutely! Every year I’m an inspector I find teams who do this. I can count on one hand the number of times I have been able to accept the first version of a BOM handed to me because I just start picking out parts that aren’t listed. This is a huge pet peeve of mine.