Team 95 Hard At Work - 2015

[Andy A.]

Work continues. Due to poor weather we were unable to attend the week zero event in Suffield CT. We did, however, manage to get a lot of work done and some drive practice in at our work space, so it wasn't a total loss.



Assembly of one of the lifting bars. Each 'finger' is spring loaded on a rubber band and has two degrees of freedom allowing them to conform to the underside of the tote lips.



http://youtu.be/r_sZlhgY5q0

Drive practice with the arm! The tote stacker hasn't been installed yet. Between the weight balance being off, a very uneven floor and some frame quirks the mechanum drive has been less then perfect. Frustrating but all getting worked out.

The end of build is nigh!

[Tammyo]

This looks awesome!

[JamesCH95]

Update!



The Totem (HA!) is nearly installed and functioning. We've had a very busy last few days.

[JamesCH95]

Well, I am quite pleased to report that our hard work has paid off!

1519 Mechanical Mayhem was seeded first at GSDE and selected us as their first pick and 1307 as their second pick. With a careful and somewhat conservative strategy our alliance ranked 1st through all of the elimination rounds! Both 1519 and 1307 were a pleasure to work with and we hope to do so again in the future.

Our alliance and drive teams, plus a bunch of 1519.



We also won the Delphi Engineering Excellence Award for the first time in our history, making 2015 GSDE the most successful event for The Grasshoppers ever.

We would like to thank all of our competitors at GSDE, especially the alliance of 138, 190, and 811 (IIRC) that gave us great competition in the final rounds. 138 - we are working on some improvements specifically to counter RC grabbers like yours! Very impressive.

I would also like to give a shout-out to Jim and Jon of 885, Jeff of 58, and Brendan of 3467, it's always nice to see familiar faces helping to run events and your positive words are much appreciated.

We have a number of improvements planned for our robot before Pine Tree, I hope to have some pictures and/or video of said improvements this weekend after we have a chance to implement them.

[BrendanB]

Fantastic work this weekend 95! It was mesmerizing watching your robot move seamlessly around the field scoring cans with that elegant arm. The Engineering Excellence award was well earned as that is a beautiful machine and performs well on the field.

[StevenB]

Originally Posted by JamesCH95

Bring your cards and pegs, we'll play cribbage on the robot while we wait for eliminations matches! I swear we'll be on the same alliance one of these years...

Hehe, this was the year!

Thanks for sharing. It's always cool to see another team's design and manufacturing process, especially on a machine as nicely built as yours.

[JamesCH95]

Originally Posted by BrendanB

Fantastic work this weekend 95! It was mesmerizing watching your robot move seamlessly around the field scoring cans with that elegant arm. The Engineering Excellence award was well earned as that is a beautiful machine and performs well on the field.

Thanks Brendan! Your comments are much appreciated.

Originally Posted by StevenB

Hehe, this was the year!

Thanks for sharing. It's always cool to see another team's design and manufacturing process, especially on a machine as nicely built as yours.

Indeed! 1519 and 1307 were both great teams to work with.

You are welcome, and thank you for the compliment. I hope to have even further updates to this thread in the next few days. Always something else to improve...

[JamesCH95]

Some CAD for two of the improvements we will be working on.

Dual RC grabbing from the barrier.


Adding a 'wrist' degree of freedom to aid in picking up tipped RCs. The current gripped can do it, but not that well. This modification should help immensely.

[Nathan Streeter]

Originally Posted by JamesCH95

Adding a 'wrist' degree of freedom to aid in picking up tipped RCs. The current gripped can do it, but not that well. This modification should help immensely.

Very sweet! Especially love that 'wrist' on the virtual-4-bar!

[JamesCH95]

As if this wasn't one of our busiest seasons already, we have registered for an additional district event - Week 5 at Hartford! We've always like the Hartford event for it's proximity, great teams, and good venues and look forward to returning and playing with all of the CT teams (it looks like we'll be one of 3 robots from out-of-state, and the only ones from NH).

We are looking at making further improvements to our tote harvesting mechanism in the form of a more robust lifting mechanism and sensor integration to help us align onto the totes.

Edit: almost forgot to update!

The wrist mechanism worked out really well at Pine Tree. The antennae... not so much. They added too much weight to our arm and significantly degraded our RC handling ability, plus they were not very effective at grabbier barrier cans!

[JamesCH95]

First thing we found when unbagging this weekend was that a lot of moisture had worked its way into the robot bag and rusted a number of bearings and pins. Here is some of the (cleaned up) aftermath. WD40, oil, and a wire brush worked pretty well.



We made some plastic spacers to replace stacks of washers on our 'totem' bars. Saved a little weight and they look a little better.



Finished some new 'wrist drive' plates and installed them. These ones are more concentric than our first set, which had lead to some funny arm behavior.



I welded some parts out of titanium wire/rod. These parts will be used in the 'totem' to connect to top bar to the lower three bars. In theory this will allow us to pick up a stack of totes 4 high and two wide.



Finally, we installed and tested a 'sensor array' on the lower-most totem bar that will help us align onto a pair of totes. In the little bit of testing that we did they worked most of the time. We have some fine-tuning to do at Hartford this weekend, but I am optimistic.



Here is some context on the whole robot: http://i.imgur.com/iIfnmXb.jpg

[dradel]

I would be willing to bet that the reason for the rust wasn't moisture working into the bag. More likely from being bagged in a warm environment then being put into a cooler environment causing the air in the bag to condense a bit. Doesn't take long for rust to start that is for sure.
Good luck to you guys today, and we will see you there!

[JamesCH95]

Originally Posted by dradel

I would be willing to bet that the reason for the rust wasn't moisture working into the bag. More likely from being bagged in a warm environment then being put into a cooler environment causing the air in the bag to condense a bit. Doesn't take long for rust to start that is for sure.
Good luck to you guys today, and we will see you there!

It was nice to meet you yesterday!

I've got a few reasons why I think moisture intrusion might have been the case:

First, it wasn't as if a few components just rusted, there was a concerning amount of condensed water inside the bag that did not evaporate when the bagged robot was warmed up again. This implies that extra moisture was inside the bag.

Second, we have bagged in warm environments numerous times, passed through a cooling cycle, and never saw any moisture condense inside the robot bags before, let alone seen rusted components.

Third, and most importantly, the bag had several small holes it in from being transported in the back of a truck. The robot was loaded into a truck while it was raining outside, and then driven for four hours (mostly covered in a tarp) while it was raining/snowing outside. This provided ample opportunity for moisture to get into the bag. It is possible, if not likely, that the cooling of the robot/bag drew moisture and cold air into the bag though.

Fortunately we now have a trailer to transport everything with, so hopefully this occurrence will be a one-time fluke.

[Nate Laverdure]

It would be fun to bag the robot with giant packets of silica gel. You could even weigh the packets before and after to see how much moisture is adsorbed-- for science!

[BrendanB]

From what I saw this weekend 95 had another solid showing at Hartford. I really liked the 6 tote grab out of the landfill!