Build Quality!

I’ve seen a lot of people talk about build quality like some mysterious concept. I think a discussion of build quality could really help some newer teams avoid some mistakes and give more experienced teams a quick reference and reminder.

What is good build quality to you? What makes a robot better built than the rest? Tips and tricks?

Compiled list of everything I’ve seen so far.

  • Accurate spacing on axles - tight to reduce slop, not to tight to avoid extra friction
  • Pieces of metal line up - keep everything square, avoid slightly bending metal
  • Bearings, Bearings, Bearings!
  • Using screws as axles wherever possible - drastically reduces slop and increases joint strength.
  • Nylock nuts. Especially on bearings and gear attachments - reduces impact of vibration
  • Loctite blue everywhere - prevents screws from backing out from vibration
  • Use two bearings on axles - reduce slop
  • get the nice setscrews and use Loctite in shaft collars - stronger hold, won’t loosen as easily.

Also using Nylock nuts on bearings and gear attachments really helps, as that is where the most vibration is. Also use blue locktite EVERYWHERE

Most places I get, but do you use it in Nylocks?

No

oof…

Also, make sure you use two bearings when using an axle for minimum slop.

I use the Nylocks mainly for the screw joints like @Rod mentioned above. I also bought the higher quality shaft (hehe) collar set screws, and those have made a pretty big impact in my opinion.

Yeah we just had a very large order come in, which included the clamping shaft collars. I must say they are much better, and I highly recommend buying some for anyone who doesn’t have any. The only disadvantage is their size, they can’t fit in compact spaces.

No no I mean. I bought new set screws for the regular shaft collars. Nothing wrong with them and they are pretty small.

Oh ok. Well I still like the plastic ones much better, they never come undone since they have nylocks, and they don’t damage the axles at all

I bought one set of those when they came out just to try. Every single one broke on the first use. Split right down the middle where the screw sits. Not sure if I did something wrong but it they just don’t tighten.
Oh well. I’m fine using upgraded metal shaft collars.

Keep your tools sharp…Stripped tools strip screws - stripped screws strip tools.

Cantilever towers and other structural metal that might bend.

What do you mean by cantilever? Add support?

Cantilevering is when you attach a beam (or c-channel) between two other c-channels to form a supportive triangle that will prevent the angle between the two beams from changing or bending. From my experience, a lift without cantilevers will almost always bend in the direction of the linkages, which is why you should place the cantilever on the side of the tower that the linkages are on. This is an image of my old robot from October. We have a standoff as a cantilever in front of the tower connecting the drive and the tower which prevented the tower from bending. In hindsight, it would’ve been more effective if we had cantilevered them at a 45 degree angle but it still provides a lot of support
download_20171019_170655.jpg

Based off of what I know cantilevering is where an object is supported by only on side, anchoring something isn’t called a cantilever.

My bad. I meant a braced cantilever where the towers are the cantilever, and the standoffs are what braces the towers to the drive.

Its all good.

Make sure something that isn’t supposed to move, doesn’t move, and something that is supposed to move, moves with little friction

For Reference
types-of-beam-support-mechanical-engineering-5-638.jpg

Lol I use red loctite, the one used for cars. I made a list:
Clean C-Channel Cuts
Perfect Wiring
Perfectly cut shafts
No loose Screws
Keps with red loctite on the bearings