Team 95 2017 Build Thread


#146

Battle damage from MABOS!

After some percussive maintenance and reinforcing bits we’re good to go for this weekend.

We also added some fancy rope guides that don’t get sucked into the climber every time and painted and reinforced our ground gear collector.


#147

Per request, here is a link to the Weidmuller terminal kit we used for nearly everything non-Anderson Power Pole. We have really liked it so far and have had no issues with loose connections all season.

It is critical to use good crimpers designed to work with the specific ferrules you’re using. Having everything in one kit solves that problem.


#148

Grasshopper Pit Setup

BOM:
Wire Shelves $250 x 2
LED Lights $30 x 2
Power Bars $40 x 2
Rolling Workbenches $200 x 2
Small organizing box $30 x 4
Big organizing box $30 x 4

Total: $1,280

At our second and third event we won awards for having a safe pit. We have actually spent very little money to make the best pit we’ve ever had, and other teams may be interested.


(Selfie from our pit/organizing guru, he might kill me)

Start at the back, we have two wire racks, 24in deep, to hold a majority of our piece-parts, provide work surfaces, and even have a spot for coats on top. We directly mounted a work-top, power bars, LED lights, our cordless tool chargers and holsters.

The wire shelves being 24in deep is key to enabling the cantilevered boxes to open completely on the shelves. Not taking large boxes out or having to stack things was a firm requirement for us. The organizing boxes are full of small removable bins. Need some screws? Grab the bin! Need pneumatic fittings? Grab the bin!

The LED strips illuminate work surfaces, which are made of white-board material for jotting down notes. One was usually kept clear for the driver’s station while the other got a lot of use for light assembly, notes/strategy discussion, and other misc tasks.

The bottom shelf of the wire racks was set just high enough to store 4x totes. We use these for bulky items like spools of air tubing and raw materials. Of the totes also stores our soldering station, which is a piece of sheet metal with a soldering iron and holder attached. This lets us solder anywhere without fear of burning/dropping anything.

The two rolling work benches go back-to-back in the middle of the pit. This configuration allows people to work on all sides of the robot at a comfortable height with easy access to tools. They are fixed together with a little velcro and two bungee cords plus locked casters.

We found this setup to be very easy to work with. We could quickly locate any part, tool, or material. There was plenty of room around the robot to work and to talk with judges and we even had a little spare work area under the robot for parts/tools to rest. Everything collapses down quickly to load into our trailer. Highly recommended for the amount of cost/effort we put into it.

Final shot to show how ‘open’ this setup makes a 10x10 or even 9x9 pit. We have 6-7 people all in the pit talking/working around the robot with elbow room.

Not shown is our battery cart and file holders, which tuck on the right-hand side of the wire shelves in the spare 1-2 feet of pit space.


#149

James, I’m really digging that pit update especially the back to back toolboxes.

Where do you guys put your robot cart while in the pits working?


#150

Thanks!

Usually the cart is between the rolling work benches and the aisle.

Our setup at gsde was really dumb because we had to leave a direct walkway through our pit to an electrical closet.


#151

We’re working on software changes for DCMP with our practice robot. Mostly sorting out some inconsistencies with our auto moves.

We are also pursuing an electrical upgrade. We’re changing all of our main power wire from 6awg to 2awg. We calculate that this will give us a 0.6-0.7v bump under our heaviest loading. Our datalogs indicate we’re drawing up to 80A per drive motor in transient situations, which is not surprising given our 17ft/s single speed drive.

We got a decent hydraulic crimper to make our terminations. It fits very nicely in our pit bench vise’s tubing holder, making crimps very easy to do.

We made several test crimps and sectioned them to verify that all of the conductors are getting cold welded. This is why crimping with the right tools rocks! The wire and terminal become one solid chunk of copper with very little resistance.

Everything is larger, including the connectors.

However, we got ultra-flexible 2awg wire, so it’s actually easier to route in the practice robot and make/break battery connections, especially with the connector handles.


#152

Do you have part numbers for the crimp tool, wire, and lugs your using by any chance? Looks really good!


#153

Absolutely! And thanks!

Wire from McMaster

Everything else we got from PowerWerx
Housings
Contacts
Handles
Crimper

The crimper is a knock-off of a reasonably nice commercial wire crimper. I think that it will do well for FRC levels of usage, but isn’t a ‘lifetime’ sort of tool.

My cube mate of the last ~2 years used to work for Burndy designing crimping dies and crimping tools. There is a lot to it that I didn’t appreciate until recently!

Compare the above crimp sections to a pre-terminated battery lead from AndyMark.

They use a 4-die one-size-fits-all type of tool that does NOT make a solid crimp. I think we’ll see some improvement by changing these out!


#154

How did you attach the HDPE to your aluminum?


#155

Double-flush rivets.


#156

Learned a lot from reading this thread this season. Just wanted to say thank you.

Do you happen to know how much your voltage would improve if you used a crimper capable of cold-welding the 6 awg wire, rather than changing everything out for larger diameter? i.e. is your voltage calculation assuming the improvement is coming from the increase in diam, or from the improved junctions?


#157

You’re welcome! That’s a big reason why we do it.

Our calculation only accounted for the wire diameter change and had nothing to do with improving terminations. I couldn’t hazard a guess as to the improvement made by a good crimp other than to cite our experience. We’ve helped a number of teams redo all of their main 6awg wiring with good crimps which helped bring them from hardly driving at all during a match to driving and competing effectively.


#158

I sent at least two teams to you after seeing dubious crimps at NE District Championship.


#159

Not sure how many made it over…

While chatting with other teams I did discover a number of robots with loose main power connections, poor VRM-related connections, etc. As all of our robots age these connections can come loose, it’s a good idea to re-torque them on a PM schedule!


#160

We are excited to compete in the Tesla division at St Louis! We will be bringing some new functionality to the field in the form of our tie breaker. Possibly the highest fps rate in all of FRC! :yikes:

Too bad it’s only worth 1 to 3kpa and can’t be reloaded…


#161

Mid event update.

Wee discovered damage from our crate getting forked after two matches. This part is normally well covered, so the damage was not immediately obvious. Our radio was also damaged and cost us our first match.

The fork pushed in the outside plate, which buckled the inside plate. We have gotten things pretty straight with a hammer and are back up and running. Also got a new radio to boot.


#162

We had to up our repair game.

Our students say send it bud.


#163

That’s some gnarly repair work! Should we expect to see flanges on your drivetrain sheet metal in the future? :slight_smile:

That fuel mechanism is awesome! I like that the potential ties this year provide incentive to build a mechanism that will only score <0.3% of your total score.


#164

Ya! We’ve sketched out some designs that will be way more beef cake for the future.


#165

After a solid semi-finals run in Tesla, Orville is officially retired from play.

We’re a little bummed out about the bad luck we had in qualifiers. A forked robot, bad radio, failed velcro strap, and broken VP transmission.

However, we’re proud of getting further at Worlds than 95 has in long time (if ever) and had a great time playing with a ton of good teams.

I had a great response to the build thread this year and am planning on doing another thread next year.