1726 progress - week 4

[Akash Rastogi]

What a crazy buncha NERDS and your robots....

Great looking bot guys. I'm loving the helical loader. Is the entire thing being painted blue and white?

[s_forbes]

The current plan is to make an improved drivebase, but painting it beforehand. The rest of the wooden parts will likely be painted blue and white as well.

Neat thing about the shooter though: since it's been operated so much, there's a nice little oil streak along the wood in line with the chain. There's also lots of oil marks on it from where we grabbed it with dirty hands... not sure how well paint will stick to it. We could always just build another one, we might actually have enough time this year to make the robot look good.

Woah. That's one impressive bot!

[adengler]

Impressive robot all around! Best of luck at the regionals!

[dtengineering]

That looks great, and if the tracking gets tuned in over the next couple weeks it should be deadly in competition.

Rather than painting it blue, however, might I suggest a nice bright aniline dye and some lacquer? Our drive modules a now a nice bright red baltic birch... and as soon as our second toughbox arrives (yes... we were short shipped one in the KoP and FedEx tracking says it will arrive tommorrow) we'll get it mounted and take some photos.

Thanks for the update, great to see that things are going well and that beautiful helix is working well.

Jason

[GaryVoshol]

Oh man! You make the scorer's job hard.

Since I won't see it in AZ or LA, I'll expect to be watching it in Atlanta. Preferably on Sat afternoon.

[Sean Raia]

WOW! i never thought of feeding the ball to the turret like that! I like how you mounted the electronics, make sure thats stable because if the gets bumped it looks like it might fall off.

Nice design though!

[pitzoid]

Nice job NERDS! Can't wait to see you guys on the field in AZ.....

[JesseK]

Innovation with wood, and a near 360 degree turret it looks like; great job guys!

Now, it's time for some color!

[XXShadowXX]

what do you use to turn the turret; servo, motor, or is connected right to the robot's frame

[Vikesrock]

Originally Posted by XXShadowXX

what do you use to turn the turret; servo, motor, or is connected right to the robot's frame

Their turret is powered by a Banebots RS545 through a 36mm 64:1 transmission. It has a V-belt pulley on the output that drives their "turret base" which is actually a very large V-belt pulley.

Pictures can be found here:
http://photos.project1726.org/thumbn...lbum=34&page=1

Specifically the turret motor and pulleys:
http://photos.project1726.org/displa...lbum=34&pos=15

[JoeArnold]

Nice.

[falconmaster]

As usual, Awesome! Just Awesome! I wish I were you! Way to go!

[TheOtherGuy]

Thanks for all the feedback!

I sure hope the programmers get the robot for the last week this year, that would be a first! Although we're mostly still waiting for the rest of the robot to be "adjusted" before continuing

So we basically did a small distance test today with PWM values and distance; we managed to get very consistent shots considering the variety of conditions our balls are in. Plugged into a jaguar, here are the basic results:

output(0to1)   Distance
.3-.4          0-1ft
.4-.5          2ft
.5-.6          3-4ft
.6-.7          6-7ft
.7-.8          8-9ft
.8-.9          9-10ft
.9-1           9-10ft

Not very exact (off the top of my head, I'm pretty sure it's right) but it is much more accurate than it sounds. We'll map this out and create some relationship between the motor speed and distance. We're planning on using the height or size of the target as the distance calculator. If we have time we'll add some form of revolution counter to the shooter for more a more determinate angular speed than PWM values (3500rpm is kinda fast for an encoder... I saw 111 used a reflection sensor on their 2006 robot in the "Behind the Design" book? perhaps that'll work...).

EDIT: I have been reminded to mention that the distance calculated was between the front of the robot and the back of the trailer (space between the robot and target trailer). Which may or may not be important

Originally Posted by TheOtherGuy

Not very exact (off the top of my head, I'm pretty sure it's right) but it is much more accurate than it sounds. We'll map this out and create some relationship between the motor speed and distance. We're planning on using the height or size of the target as the distance calculator. If we have time we'll add some form of revolution counter to the shooter for more a more determinate angular speed than PWM values (3500rpm is kinda fast for an encoder... I saw 111 used a reflection sensor on their 2006 robot in the "Behind the Design" book? perhaps that'll work...).

A good way to sense speed on a high velocity wheel like that would be to put a small magnet into the wheel (drill a small hole and put an iron nail in, slice the head off), and set up a hall effects sensor. Each rotation should be VERY noticeable, so you should be able to get some speeds out of that....