Week 5 - Assembly (v1 Snow Problem!)

A flurry of parts!
As we disassemble an old prototype...

Week 5 should have been a whirlwind of parts, prints, bolts, and more - but instead the whirling wind cast snow down upon our region, and we lost half of our shop days for the week. Needless to say, we did not catch-up our Week 4 goals, nor did we meet our Week 5 goals. It's fortunately warm inside, but it's cold outside - so grab some heavy mittens and let's brush off Week 5.

For better or worse, a short week means a short post! (Editors note: Apparently not...)

Week 5 was supposed to be a bit of catch-up and getting our first major subsystem onto the robot. We had a goal for Friday of Week 5 to "load out" to the practice field - our first time simply packing up everything we have, running it through a few paces, and building a baseline of - 'how is this robot doing?'. 

Waiting for... CAD? Snow? Parts?
Definitely waiting...

The days we missed earlier in the week turned into ad hoc CAD days - a <lot> or progress was made, and it's making me rethink how we plan some of our meetings for the future. Once we got back into the shop later in the week, we did create a mini-storm of parts and pieces, culminating in further organization and list making - what parts are left to manufacture, and what high level steps remain before we can start to build our minutiae burn-down list.

Mentor Musing:

Technically we had some different musings earlier this week - but I'll save those for next week, and supply a mini-musing following some amusing conversation and an anecdote.

Our lead designer, now a senior, wants a lot of things - a solid robot, a blue banner, a plane ticket to Houston, and a pony (probably) - all good things. She also recognizes when she should push and when to take a break - but even she has shown a fascination with pulling an all-nighter. "It feels like a rite of passage."

Last year at a competition I ran into a former student of mine, now on another team. Beaming, they proclaimed "I pulled an all-nighter this year!" Less animatedly I replied "We left the shop on time every day."

As a student, I had pulled all-nighters. As a mentor I've stayed up until 2, 3, 4am, even slept in my car at a shop. Having done those things, let me tell you that leaving the shop at the expected meeting end time, every scheduled day, week 1 through week 8 and competition season - is amazing. What is a rite of passage against good time management, being focused and on task, and building healthy habits for growing bodies?

As I write this, it's almost CAD curfew, so I think I'll pause writing for the evening and finish up tomorrow, rested and refreshed.

We have a super secret side project of convincing everyone
on the team to want a Remarkable or similar writing tablet.

Mechanical:

Friday and Saturday we were able to get into the shop and continue assembling pieces. Our elevator hardware all came in a kit - but we had modified the elevator for some of our needs. As we got into the final pouches and bags, our deviation from the standard kit started to slow progress as we had to find our own hardware, and had once again caught up to the number of manufactured components we had.

While the hole patterns had been lining up beautifully through the build so far, we started finding other small issues during assembly that we wanted to iron out as quickly as possible. In an ideal world, (would that we could live in an ideal world - spherical in a vacuum of course -) elevator tubes and bearings are in the slightest of constant contact on all faces. After assembling a stage and spot checking the movement, we noticed about an 1/8" gap between one side and its bearing. While it is entirely possible this would not be a significant issue with the number of cycles and loads on our elevator, this is a skill-building program and we pursued a detail oriented approach. After remaking the part and re-assembling - we once again checked the bearing movement and contact. Smooth throughout with no compression spots, and the bearing gap reduced significantly.

Slow but steady progress.
Catching and fixing issues along the way.

Electrical:

Once again our Electrical minded folks were supporting the team across other endeavors - making updates to the safety binder and robot tech binder, and supporting Mechanical by preparing parts and helping assemble. Their day will come. Soon. I can feel it.

Software:

Quite soon (hopefully), Mechanical will take the new chassis away from Software so that we can start adding all these bits and bobs to it. To that end, Software spent some time trying to get our 2024 robot, Oppo, updated to all 2025 firmware, libraries, code, etc, so that we could continue to work on drive practice through the next week.

I meant to capture two robots, but accidentally
caught three robots in the same frame!

While Software still had access to the new robot with all the test fixings however, they pulled everything into the main school building for some further testing, tuning, and drive practice.

Now, I wasn't there, and actually nobody said this, but they said everything works perfectly, and if Mechanical and Electrical gave them a completed robot, it would perform every expected operation - including autonomous! - perfectly. With zero mistakes. Our Drive Captain has challenged them on this, and declared a 5 push-up penalty for all missed autonomi. (Definitely the correct plural of autonomous.)

Design:

As OnShape lives in a cloud - On a cloud? - Next to a cloud? - somewhere above Seattle (there's always clouds here) on the internet, our days out of the shop were still working days for the Design team. And we used them well - the CAD is pretty much like, done. We spent time Saturday cleaning up unused sketches, renaming parts to make more sense, etc.

Some of the finishing touches were lightning patterns - we have used Altair's Inspire software in the past to produce lightweight and structurally sound parts. It's almost painful to say that we had an issue getting access to our account that we couldn't resolve before sending some parts out to a sponsor for cutting. Fortunately however, we asked around and got connected with the Part Lighten Onshape scripts and a tutorial! We very unscientifically created triangles everywhere, lightening the part while using a nice strong shape to retain strength. We do still plan to see what the Altair optimization would have derived, so I expect to show that in our tech binder.

I love learning new things, and I personally spent some time making some sketches. (Yeah, my skill level is currently 2D. I'll get there. 5 more pushups.) That's my week 5 CAD update.

Week 5 Wisdom - Assembly (v1 Snow Problem)

Well, I was going to talk all about how to assemble things, when to think about bolts and rivets, and some fun conversations we Bearcats had while looking at our chassis. But the snow has changed this section too, so instead we'll talk about which color shovel works best (black), proper form and technique for plowing a sidewalk, and how to reach those hard to reach spots when clearing off your vehicle.

Kidding - but seriously folks, please clean the snow off your vehicles, including the roof! You need to be able to see out your windows, and the driver behind you does not want a 40-pound sheet of frozen water flipping off your car and onto theirs. Thank you!

We did get a little bit of assembly done this week, so I suppose we can pretend to be wise on one or two items.

My diatribe on assembly and organization will have to wait until next week...

FRC is a harsh environment. In the automotive world, there's a test called the NVH test (noise, vibration, and harshness) which measures, well, how parts withstand (or exceed) their normal operation. The test measures how items oscillate, what sounds are produced due to oscillation, and how these tiny oscillations impact the greater system. (Dear actual automotive engineers - I apologize for butchering that description.) FRC robots experience <a lot> of vibration, and we have a few tools to help make sure things stay put.

• Threadlocker - This goop will harden and resist vibration between threads and captures. Make sure you're using small gloops, and applying it to threads that get captured.
• Nyloc Nuts - These look like nuts but have a thin strip of unblemished nylon behind the threads. When mounting, the bolt threads cut into the nylon which again resists vibrating loose. The nylon works very well the first time it engages on a bolt, and less so if it is removed and re-used. We prefer to use brand new nyloc's on competition robots, but will re-use nylocs when prototyping or demo-ing.
• Nylon Patch Bolts - Threadlocker and polycarbonate do not mix. When you need to bolt through or secure into polycarb, there's Nylon Patch Bolts. These look like normal bolts, with a colored patch of goop covering some of the end threads. As is a pattern here - that nylon is there to resist vibration, and hold the bolt in place.

While all of those solutions are there to resist the vibrations, oscillations, and harshness of the FRC environment - they are also all consumables, and add a step to each fastening step. Because of this, whenever we begin assembly, we prefer starting with a dry fit - put the pieces together, insert the hardware (or cleco) - but don't aggressively tighten anything down, and just ensure the parts actually fit together as intended. Once the dry fit is complete and checked, then we can methodically apply the specific method of anti-vibration - hoping we won't need to take it apart again afterwards.

Quote of the week:

Design Student: "Life is good when I remember that I'm in 3D space."

-B