2363 Triple Helix week one prototypes

[ToddF]

It was a good week of prototyping. We took a previous year's drivetrain and replicated the wheel spacing we planned to use this year. With AndyMark 7.65" diameter wheels we can handle both the defenses we've had time to build. The drivetrain shown has a crate of CIMs strapped on top to give a total robot weight of 121 lbs. Yes, it is top heavy, and yes a rookie driver tipped the bot, and yes, the tote shattered.

The shooter prototype was slapped together to let us know if a wheeled shooter showed any promise.

Here's video of some prototype testing this afternoon.

[PayneTrain]

Todd, have y'all played around with the drop or pressure on those at all?

[Nuttyman54]

Looks great! Mind sharing what wheel base and wheel track you're showing? We've been trying to figure out the best spacing but we haven't seen a traverse as clean as that.

[Kevin Sevcik]

It seems like your top heaviness is probably helping you over the rock wall. Keeps you wheels up longer so the front ones hit the wall at a better angle. I'd be interested how things work with a lower CoM closer to what you'd normally be running.

Also I probably don't have to remind you that shooting a single brand new ball consistently does not make a consistent shooter.

[ToddF]

Originally Posted by PayneTrain

Todd, have y'all played around with the drop or pressure on those at all?

This testing was primarily to see if our standard drop would work, or if we were in for a redesign. The tire pressures are whatever they ended up when pumping up with a hand bicycle pump. Next step is to use a compressor with a real pressure gauge. We'll play with the pressures in the center vs outside wheels to see how that effects the current draw when rotating in place. I can confirm that these wheels definitely scrub more than Colson wheels. We have Colsons on the way, too, and could switch to those, but we're liking the shock absorption of the pneumatic tires.

[ToddF]

Originally Posted by Kevin Sevcik

Also I probably don't have to remind you that shooting a single brand new ball consistently does not make a consistent shooter.

Nope. I'm still having PTSD flashbacks from the nightmare of trying to tune our foam basketball shooter in 2012.

[PayneTrain]

Originally Posted by ToddF

This testing was primarily to see if our standard drop would work, or if we were in for a redesign. The tire pressures are whatever they ended up when pumping up with a hand bicycle pump. Next step is to use a compressor with a real pressure gauge. We'll play with the pressures in the center vs outside wheels to see how that effects the current draw when rotating in place. I can confirm that these wheels definitely scrub more than Colson wheels. We have Colsons on the way, too, and could switch to those, but we're liking the shock absorption of the pneumatic tires.

Yeah, we tried the hard rubber first and I don't think many of us were fans. I have a couple reservations around us diving headfirst into the school of WCD design for this years drivetrain. The ability to absorb shock with those wheels and a couple other mechanical tricks we are looking at to assuage my fears should do the trick. We did some of this work too, but I'm pretty sure the only video anyone got today was me eating chili near the drill press.

Also our 2012 wheeled shooter is in a cold dark circle of hell along with our MK Is for 2013 shooter actuation, 2014 drive, and 2015... everything. We're kicking around some blue sky plans to solve the inevitable ball consistency problem; I can only imagine the damage some robots are going to inflict on them this year.

[asid61]

Looking good. I liked the use of a larger wheel for a flywheel on the shooter.
How much compression did you stick on the shooter?

[bEdhEd]

Have you tested that drive base on the moat? Our initial pre-built concept chassis had a similar wheel spacing and we just got caught up. We thought the rock wall would give use the biggest problem, but the spacing of the moat can cause the chassis to sit on the moat ends and have the wheels free spinning. The rock wall was no problem. The moat was deceptively challenging for us. Our new prototype robot will have the wheels closer. Hopefully, our new spacing will be perfect and we can use that spacing for building the next two robots (practice and competition).

Here's our video of this.

[dodar]

Originally Posted by bEdhEd

Have you tested that drive base on the moat? Our initial pre-built concept chassis had a similar wheel spacing and we just got caught up. We thought the rock wall would give use the biggest problem, but the spacing of the moat can cause the chassis to sit on the moat ends and have the wheels free spinning. The rock wall was no problem. The moat was deceptively challenging for us. Our new prototype robot will have the wheels closer. Hopefully, our new spacing will be perfect and we can use that spacing for building the next two robots (practice and competition).

Here's our video of this.

That is probably the best reaction ever. "That sucks."

[Kevin Sevcik]

Originally Posted by bEdhEd

Have you tested that drive base on the moat? Our initial pre-built concept chassis had a similar wheel spacing and we just got caught up. We thought the rock wall would give use the biggest problem, but the spacing of the moat can cause the chassis to sit on the moat ends and have the wheels free spinning. The rock wall was no problem. The moat was deceptively challenging for us. Our new prototype robot will have the wheels closer. Hopefully, our new spacing will be perfect and we can use that spacing for building the next two robots (practice and competition).

Here's our video of this.

That is hilariously and horrifyingly terrible. Can't wait to see how our prototype is handling the moat when I get back to houston. Also, I'm told using steel for the 1.5x2.5 bars makes things even harder. So you might want to try that.

[sanddrag]

This looks great! May I ask what amount of center drop you have on the drivetrain, , what diameter the Colson shooter wheel is, and how much you are gearing up the CIM?

[billbo911]

Originally Posted by bEdhEd

Have you tested that drive base on the moat? Our initial pre-built concept chassis had a similar wheel spacing and we just got caught up. We thought the rock wall would give use the biggest problem, but the spacing of the moat can cause the chassis to sit on the moat ends and have the wheels free spinning. The rock wall was no problem. The moat was deceptively challenging for us. Our new prototype robot will have the wheels closer. Hopefully, our new spacing will be perfect and we can use that spacing for building the next two robots (practice and competition).

Here's our video of this.

I believe one key to some of the defenses this year is to drive you bot like you stole it.
For instance, hit the mote with a bit more authority and you may just own it.

[dodar]

Originally Posted by billbo911

I believe one key to some of the defenses this year is to drive you bot like you stole it.
For instance, hit the mote with a bit more authority and you may just own it.

I tend to agree. This year, different from years past(specifically 2010), you need to launch yourself at a few of the defenses just to get over them.

[Nate Laverdure]

Originally Posted by asid61

How much compression did you stick on the shooter?

About 10%

Originally Posted by sanddrag

what amount of center drop you have on the drivetrain

.125"

Originally Posted by sanddrag

what diameter the Colson shooter wheel is

2.5"
VexPro p/n 217-4046

Originally Posted by sanddrag

how much you are gearing up the CIM?

1:1.21
AndyMark SpinBox