Re: [Ri3D] The GreenHorns 2016
 

From what I can make out from your videos, it looks like you guys are using direct drive mini CIMs w/ 2" wheels for your shooter, is this correct?

-Thanks

Re: [Ri3D] The GreenHorns 2016
 

Mini CIMs in a 1:1 versa planetary direct driving 4" high grip wheels from AndyMark. When in taking they're programed down to 90% speed and when shooting they're 100%.

Wednesday night/Thursday morning I will be writing a white paper as well as editing our reveal video. You can see a lot of our functionality from the vines that we have been putting out, but you'll need to watch our reveal video to get the full effect. I'll just say that the 1114 style articulating arm is going to be highly effective... as will tape measure climbers.

As a pre-teaser teaser here are some of our robot performance specs:

Height: ~14.5"
Low goal with 100% accuracy
High goal capable (a good driver and some sensors would make it deadly)
Touch-it-own-it intake
Winch with hook for climbing (just didn't have the resources to get the hook to the bar, tape measure climbers with detachable hooks!!!)
Capable drivetrain that can traverse: Low bar, Ramparts, and Rough terrain (if we had access to 2 more 8" pneumatic wheels it would've been a much better drivetrain)

And the best part... it's only 72 lbs. The only necessary addition is the device for getting the hook to the bar. There's so much weight for additional functionality. It's more volume limited than weight limited, so if you're creative you can have one heck of a robot.

Re: [Ri3D] The GreenHorns 2016
 

Thanks so much for replying, and to you guys in general for all your hard work the last few days! Also, can't wait to see that reveal video/ read that paper.

Re: [Ri3D] The GreenHorns 2016
 

Well after sleeping for a combined 6 hours the last 4 days, your sleep schedule gets shifted. Plus it's build season. Any chance to help a team be more successful is one I'd jump at! Good luck this year!

Re: [Ri3D] The GreenHorns 2016
 

I have one last question if you will indulge me; what is the center to center distance between your shooter wheels, It seems like you guys are getting the perfect amount of compression?

Re: [Ri3D] The GreenHorns 2016
 

Center to center would be 11". Given that they're 4" wheels, the critical dimension from tangent to tangent is 7" which gives ~3" of compression.

Are you going to release a CAD model. If so when? If not could you give me a few more details on the shooter.

For instance what is the depth of the shooter. How tall from the plastic tubes to the top of the shooter.

What are the versaplanetarys mounted to and how.

What motor is driving the pivot on the shooter and is it chain driven or belt driven.

How far back did you mount the shooter from the edge of the chassis.

Sorry for all the questions. We had a similar design sketched up so when we saw urs we pretty much decided we are just going to create a more optimized version of it. :)

Re: [Ri3D] The GreenHorns 2016
 

Whether or not we release a CAD will be directly determined by how hard my college schedule is this semester. It's a 50-50 thing. We tried CADing as we went, but it turned into "CAD the prototype and we'll just optimize the final design in person".

I will be happy to answer any questions about our robot ASAP! I'll also be writing a white paper after my classes today.

I'll answer these questions after Circuits 1 in a half hour :D

I am curious to know how you run the versa at 1:1 what gears are being left out to basically make it a shaft interface.
Our team is trying many new gear boxes and other types of hardware this year. But funds are tight so trying to gather as much info as possible.

Re: [Ri3D] The GreenHorns 2016
 

The shooter is 11" from the top of the polycarbonate tubes where the ball rests to the top of the upper arms.

The versa planetaries are face mounted to some angled aluminum which is riveted to our upper arms.

Moving the shooter up and down is one of my favorite functions. The things that are hard have the biggest payoff in the end. We used a Cim motor in a 100:1 versa planetary. On the hex output shaft of the versa we direct drive a 48 (or 50?) tooth gear. We support the output shaft on both sides of the gear with a bearing, and we have a plate in between the cim and the cim adapter. The gear is directly mated to an identical gear which is on another hex shaft. The arms of our shooter are directly mounted to that hex shaft with a versahub.

There are multiple ways to power the shooter including lead screws, but I like the gears because it allows the shooter to have a 180 degree range. We have it set up that articulating our shooter all the way back is the perfect angle to get it in the high goal from right beneath the tower.

The wheels are about 8" away from the front of our robot and we would have open bumpers. One would think we would have trouble intaking boulders along a wall, but the open frame allows for getting the ball away from the wall.

With the vp's all u so is leave out any stages and connect the little drive cap gear thingy to the motor shaft. Then all you do is slide It in. It's pretty simple actually just fits in the same way you would if there was a stage or 2 in there. We originally thought that you could only run them 3:1 but learned 1:1 works just fine and allows the motor to interface very well with other parts because of its full sized hex or keyed circular shafts.

Re: [Ri3D] The GreenHorns 2016
 

I wasn't the one who assembled them so I'm not 100% sure either! You just leave the gears out and you have to cut the shaft of a Cim or mini cim. I'm sure there are assembly instructions somewhere out there! I can say that we were very happy with the versa planetaries on our robot. We used 4 of them for 3 different functions with 3 different kinds of motors.

Edit: Sniped

Re: [Ri3D] The GreenHorns 2016
 

You can also buy or print an adapter that spaces the (mini)CIM off the mounting block slightly so you don't have to modify the motor shaft.

Re: [Ri3D] The GreenHorns 2016
 

Why did you guys not end up using the pneumatic catapult system you were prototyping earlier?

Was it not reliable enough? Were you running out of air too quickly?

Re: [Ri3D] The GreenHorns 2016
 

We never actually prototyped a catapult. You may be mistaking us for Snow Problem? Interestingly within 2 hours after kickoff all 18 members that we had agreed on a design. It's hard to get that many people to agree on anything, let alone that quickly. We are more than satisfied with the results.

Here are some of our vines to check out before we post our reveal video:
Vines!