Favorite robot parts teams should know about

I posted a simple question to my Facebook page a couple days ago.

What are your favorite McMaster-Carr robot parts other teams should know about?

Other sources are cool too.

A lot of people contributed some awesome answers that I will share below. If you have some more great products teams should know about feel free to post.

I’ve tried to clean up the lists a bit and remove duplicates, but I’m sure there still are some. I added team numbers where I knew them off the top of my head for some people. I tried to keep as much of what the comments said but did some minor editing to make it readable as a single post. Part Numbers in bold are McMaster part numbers, just search for them on McMaster.com

T. Holtzman (2056)

J. Germita (5012)

  • 8307A355
  • 0.1950" Reamer - Use with a lathe to convert WCP BAG/RS550 aluminum pinions into 775 pinions - 8307A356
  • 0.1955" Reamer - same as above, but for steel! - 1004A12
  • Loctite gluestick! No more wasted spilled loctite! - 5099A34
  • 5/32" Dia cleco temporary fasteners. Great for installation of gussets and general sheet metal assembly - 5099A51
  • Cleco installation pliers - 2289T41
  • 1.9" omni wheels - kinda like the ones 118 use sometimes - 8585K108
  • 5/8" ID polycarbonate round tubing. Good for quick spacers on hex shaft if you don’t really care about the OD of the spacer being concentric with your shaft. - 3161T31
  • 1x1x1/8" Clear polycarbonate square tubing! Great for applications that call for 1x1 but not necessarily aluminum.

Picks from amazon and other sources:

118 Alumni - R. Stockton, C. Grat, E. Reed

  • 5236k529
  • Silicone Tubing We stretched this over 1.25" and 1.125" tubing for intake rollers - 18635A52, 18635A54
  • Turn Table Bearings, also from Amazon - 94290A571
  • Star Nuts - You can press these threaded inserts into the ends of tubes to get a 1/4-20 thread in the center of them. We used them on some non-FRC projects. - Pololu Step-Down Voltage Regulator D15V70F5S3
  • 7A 12v to 5v converter for powering lights, computing, etc. - 6208K484
  • Flexible couplers. They come in a ton of different sizes and they also allow for some misalignment. We turn down one of the drivetrain shafts to a 1/4" and then use these to couple it to the encoder. These are a good alternative if you don’t trust the surgical tubing method. (WCP also sales ¼” ones here - http://www.wcproducts.net/clamping-shaft-collars - A. Lawerance)

A. Gregory (3847)

  • 87145K32
  • Rubber Sheet used as the back wall of our shooter this year. - 1872A71
  • Slide-snap bumper latches but we buy them from here now https://www.pegasusautoracing.com/productdetails.asp?RecID=4660 Teams like Neutrino, 1296, & 971 have used them for bumper latches, Aren Hill is the first person I know to use them for this. Spectrum used them for our bumpers plus attaching our shooter and gear mechanisms this season.

Photos of them in use

E. Vendator

K. Ross

A. Heard (973)

B. Simons

A. Britt (3478)

R. Yarlagadda

B. Leverette

  • I am a fan of 6425K11
    for a solenoid. Not small, but it shoves the air through. (But then, I know AutomationDirect probably has a competitor for 2/3 of the price; we ordered those from McMaster in 2015.) - 6338K421
    was our weapon of choice in 2012 for the intake and elevator. We had a structure of 1" square tubing and wanted to use 1/2" hex shaft (because that was the best option of the day). So we turned the ends of each shaft

J. Killian

  • 18635A520
    lazy susan… there’s a lot of things I like from them but this one is really cool and fun to have.

** K. Buchanan (1296)**

  • “Deburring Wheel for grinder, 4628A21
    (saves a lot of deburring time)”


T. Miedzinski

  • 2282T35
    (and similar) - Aluminum Conveyor Roller

Flange-Mounted Linear Ball Bearing - 6483K63

For use with 1/2" steel* shaft to achieve linear motions.

*Aluminum shafts scratched too easily, causing binding issues with these bearings.

558 Loves McMaster. I’ll try and post more later, but here’s a first batch:

6529K15 - Miter Gears we used for our intake on VP Planetary Gearboxes
96225K41 - Metal “High Temp” Velcro on our Climber
5973K2 - Floating Chain Tensioners for #35 Chain
60185K919 - Awesome Yellow Grippy Rollers we used on our gear intake
38105K51 - Miniature Air Gauge
48435K71 - Awesome Pressure Relief (Legal 2017)
8514K53 - Sorbothane (super grippy sheet material)
92235A111 - Bolts to mount 775pros
5779K685 - Push in 90 degrees for plastic air tanks

4450K91 Sintered brass muffler for quietly venting your pneumatics!

6341K94 Cold shrink tubing for making intake rollers without looking silly as you’re wrestling your latex tube onto your bigger mandrel!

I also want to point folks to Tapeswitch, who makes an absolutely bulletproof ribbon switch and other goodies. We used their 121-BP stuck to the back wall of our gear grabber to detect an intaked gear, which then rumbled the driver’s controller. The ribbon can be cut to length with scissors.

McMaster Carr
1a58h9b - Electricians’ Scissors my favorite scissors for everything.
**7292K66 **- Love these style of wire strippers.

This big crimper - Crimps battery cables like it’s nobody’s business. It doesn’t ratchet, but it has enough leverage that it barely matters. The only issue is that it’s not exact, since the measurements are in mm^2 and not AWG, but it does the job. (and it sure is better than the hammer crimper my team used to use)

XT60 connectors - I’m going to start a connector war in this thread by saying this, but these are probably the best high amperage connector for our robots since they’re cheap, only require soldering, and are widely available online.

Neither of these appear to be on McMaster, but they’re pretty useful.

you left out 4933T15

I hope to expand on this post, as I have sources for quite a few handy products.

These are 48mm/1.9" Omni-wheels, come in 3 durometers and are reliable. Available with a 1/2" round bore for simple broaching to 1/2" hex.


Banebots sells 1.625" and 2" Colson wheels with a 1/2" Round bore, you can broach these yourself to reduce cost.

Bearings, you can never have enough bearings especially small ones. Buy small flanged bearings from Aliexpress for cost reduction and better mechanism packaging, I like 688’s.

Flanged bushings such as 6338K481 are good for arms. ( thanks to Chris is me for this idea)

Ferrules!!! doesn’t matter where you buy them from but CTRE sells good quality ones.


82825T21 is another favorite

Definitely this one too: 4739T11

It’s time to 5940T89.

1 Like

Anyone care to create a language where all syntax and linguistics are created through McMaster part numbers? If you think being fluent in Klingon is nerdy…

7131T49 is pretty useful for build season

Maybe 3049K85

Or for those late nights 3586T4, 3586T16, 3586T2, 52665T53, 52665T3, and 3586T14

In all seriousness, the actual suggestions in this thread are great, and I’d love to hear more of them

Agreed. There are some amazing things in the original post that I will definitely be taking back to my own team.

But in all seriousness, who would buy creamer from McMaster?

The Throatless Shear from Harbor Freight has been very useful for cutting think aluminum and polycarbonate sheet up to about 1/8" thick. It is especially good for cuts longer than the blades on a pair of tin snips. I loaned mine to our neighbors at Team 624 and after a few weeks they bought their own. Wait until there is a 20% or 25% coupon.

XT30 XT60 and XT90s are the best connectors known to man if you have skills in soldering. Definite favorite for any of the wiring guys.

Someone who wants to REALLY only put in 1 order and slip something by on a purchasing request form. Nobody’s going to question a $3.87 item on an order from McMaster that costs $1000. It’s convenience I guess.

Maybe some kind of metal shop that also has a coffee maker, so they order all of it at once?

But actually, clip nuts are incredibly useful for bolting sheets of material onto other sheets of material without having to find a way to shove a wrench behind the part you’re bolting or unbolting.

Also I didn’t think of this at first, but coffee creamer needs to be refrigerated. How is McMaster shipping it without letting it spoil? How are they storing it in their warehouses?

Maybe they ship it inside 6333T55