Since a number of people enjoyed our thread last year, here it is again for 2015: Team 95, the Grashoppers, fabricating parts!
Thusfar we have a number of chassis side-plates blanked out on our CNC plasma cutter:
http://i.imgur.com/1OqgEx8.jpg
Hello little kitty!
A close-up of the various surface finishes we’ve tried out so far:
http://i.imgur.com/rGq0mNO.jpg
I think this is the biggest chunk of metal I’ve ordered for FRC:
http://i.imgur.com/XXnKH1W.jpg
With CAD nearly finalized on most of the robot we have started making chassis and drive parts in earnest. #10AWG aluminum sheet is our material of choice for these parts.
Keeping the plasma cutter busy.
And the Prototrak is kept busy with final machining operations on the plasma-cut blanks.
And the lathe. Here we are using the tail stock to help broach some delrin tubes.
Looking good! We’re looking forward to playing with you guys in Nashua.
Looks like a cribbage board had been made on the Prototrak?
Thanks! We are as well.
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… I still regret not picking you guys in 2012 when we had the chance.
The hole patterns are for the chassis style we’ve adopted - plates and standoffs, like last year’s robot. It plays well to our strengths, i.e. plasma cutter and Prototrak and has proved to be elegant and robust.
Grasshoppers are one of the weirder teams in FIRST.
I mean that as a compliment.
Your team inspired my team in 2004.
Winning with a wastebasket in Ultimate Ascent.
I see a whole lotta love in your fabrication pics.
What unique strategy do you have in store this year?
Hope to see you at the NEDCMP.
Thanks! We like getting called weird and unique. 
I must extend a belated Thank You for the creativity award you gave us a Hartford last season. Your award (more so than the official creativity award) made the event for one of our rookie students - he kept it on his lap for the whole drive back, and only begrudging put it on the shelf in our build space.
Our strategy this year prioritizes getting the recycling cans quickly, giving our alliance partners easy access to them, and scoring the cans on stacks up to 5-6 tall. With a dash of making 2-wide-by-3-tall stacks in there. We figure a typical Ri3D robot can quickly make a stack of 6 totes from two stacks of 3 totes, plus all the landfill totes are laid out in twos…
We hope to see you at NEDCMP as well! We were very close to making it last year, hopefully a little more success this year will get us in!
I’m all for teams picking a set of build methods based off their fabrication strengths… we certainly have picked the way we build based off our available resources! That said, I meant less the spiffy-looking robot parts and more the piece of sacrificial wood on the Prototrak in the first picture… 
That said, a few hands of cribbage between matches sounds like a good idea!
GSR 2012 was a bizarre event for us… though I’m in way complaining about the finalist showing. I certainly couldn’t criticize anyone above us for not picking us though, as we were anything but an offensive juggernaut at GSR! We were just glad to be able to be able to assemble an alliance that made it to the finals!
Parts are looking great guys.
Who’s Austin/Morris Mini is that there in the background?
Thanks!
The Mini is being completely rebuilt by the shop’s class (Industrial Mechanics and Welding) and is owned by the shop’s instructor. When I say ‘completely rebuilt’ I mean we have head to clear connecting rods off the work bench to get some space!
Obligatory plasma cutting video of some of our chassis plates.
-0.100/#10awg aluminum sheet
-45A w/ 45A fine-cut consumables on a Hypertherm Powermax 85A power supply
-100ipm travel (table is not stiff enough to go faster, unfortunately) on Norther Plasma table and controllers.
Progress!
We finished assembling, greasing, and burning-in most of our transmissions.
We also experimented with Pem Nuts in our continuing effort to use only blind fasteners without tapping any material. Most methods worked well at setting the Pem Nuts, aside from the hammer. Also pictured is one of the 12V Rigid impact drivers that we recently acquired. We really like them and their 12V drill companions.
We also assembled a drive module! 6in AM mecanum wheels direct-driven from a single-speed double-reduction Vex transmission. The shaft is not cantilevered, but supported by a bearing in the outer plate. Free speed is a little higher than I’d like at 14ft/s, but I felt this was a reasonable compromise to use virtually all OTS parts, especially with the ability to throw 4 mini-CIMs into the drive to up the drive’s performance. As-pictured it weighs around 18-19lbs.
The drive pod also fits the battery quite nicely, which will serve as a counter-balance for our arm. We will be relying on closed-loop control on the mecanum wheels to account for the inevitable CG variances.
Looks good 95! Glad to see you guys doing this thread again this year it was enjoyable to see your robot progress through the season and then iterated at events!
Thanks Brendan!
We had a very productive Saturday.
We kept the plasma cutter quite busy making all sorts of parts.
0.032 sheet metal can warp a bit when being cut, it’s amazing watching the automatic torch height controller track the material as it lifts and settles.
They lay reasonably flat after some sanding and deburring to remove dross.
We also blanked some parts out of 3/8in 6061T6 at 45ipm.
We also made a number of small steel parts and popped some steel rivnuts in them. These will be the bases for some magnetic latches.
Assembly progressed reasonably well with the robot’s chassis.
An inside view of one of the drive pods. I was pleased to learn that a 10-32 Riv-Nut flange does a good job of locating the 7/16 hex sockets in a Vex transmission.
You can almost see the outboard bearing in this picture.
Arm pivot posts and fixed sprockets were installed.
Again, liberal use of Riv-Nuts, though they are difficult to installed near their maximum rated material thickness.
And at least one of the arm shoulder motors was installed.
A number of other parts were made and/or futzed with.
Some of that aluminum looks really thick for a game with no defense. 
And what kind of arm are you running?
Looks great so far, guys. Keep up the good work!
The main chassis plates are #10awg sheet metal, 0.100in. It is probably a little overkill for this year, but on the other hand we get the material for free and we were able to remove a lot of it for lightening, “trussing it out” as we say. Other ‘major’ parts, like the belly-pan and deck, are being made noticeably lighter than last year.
We’ve designed a 4-bar linkage arm with a little more than 180deg of total travel. It will be counter-balanced by two air cylinders and drive by two CIMs + 50:1 Versa planetaries + 16:60 sprocket reduciton.
Also, some over-all chassis pictures finally got uploaded. Around 47lbs as she sits currently.
We’ve been keeping the mills busy:
And throwing our fair share of money at VexPro:
So many prototypes…
