Are team has run out of fasteners and we are planning on refreshing them before build season. What sizes do you recommend getting?
I’m no expert, but I learned last year, try to have all fasteners work with the same screwdriver size/wrench size, etc. That way, you won’t have to keep getting a different wrench for different bolts. We have some special-colored tape on our main wrenches so it is easier to recognize them!
Small! We use a lot of #10 and 1/4" threaded fasteners, as well as 1/8 thru 3/16" pop rivets.
But no matter how many we buy ahead of time, we never have enough of the right length for whatever it is we’re building
Any recommendations on what riveter to buy? Are the cheap ones OK?
For bolts, we have standardized on 1/4-20, mostly socket head cap screws but also button head allens and hex heads. We also use #10-24 (same heads plus flat head allen) and very limited #4-40 (pan head philips only).
We get every size up to 1.25", then every 1/4" to 2", then every 1/2" to 3" (except the 4-40, we get 1" and 2" only). We stock between 100 and 500 of each size, larger amounts generally at smaller sizes.
Thousands of washers, lock washers, nuts, stop nuts. And several feet of all-thread, just in case.
For rivets, we buy the good ones from Bolt Depot in 1/4" and 1/8", some with steel mandrels, some with aluminum. We have a pneumatic rivet gun too. We have used the Harbor Freight ones in 1/8", they were fine, low-strength areas only though.
We use a small cheap rivet gun at school. I do have a cheap large rivet gun too, which I’ve loaned the team for pulling the 1/4" rivets we used to assemble our chassis last year.
Don has good suggestions…I guess his team takes materials more seriously than we do! 
Ace Hardware is just down the street from the school, I stop by almost every day on my way to build
Attention to detail with fasteners is a big deal for us. Every fastener we use is specific to the application. It would be grossly impractical for us to pre-order anything. We try to standardize on 10-32 thread size, button head for most things and countersunk flat head for bearing blocks, but there are plenty of areas where 10-32 thread is not a good choice. We spec our fasteners, and order from McMaster when needed, and they show up a day or two later.
We do keep a lot on-hand, but it’s all remnants from the above, and used primarily for prototyping and maintenance purposes.
Sorry rookie question what are fasteners and what do they do! ( I most likely know what they are but cant think of them right now)
I have what amounts to a small hardware store in our build room closet…
Our standard fastener size for mechanical elements is #10-24. I have every size in 0.25" increments from 1/2" to 2" and 0.5" increments to 3"
Electrical items tend to be #8-32. We have every size from 1/2" to 2" in 0.25" increments.
We have an assortment of 1/4-20, 5/16-18, 3/8-16, 1/2-13. of varying lengths from 3/4" to 6"
We have a few #6-32 and #10-32 screws that we purchased for COTS items that use them.
We have every size mentioned in regular and ny-lock nuts.
We also have #4-40 and #3-48 screws for a few tiny parts. (And most importantly, holding the cRIO breakout boards in…)
We will buy other hardware as needed by design during build season, but that’s a small list of what we keep on hand so we don’t have to worry about not having a fastener when needed.
Hardware that holds stuff together, like screws, bolts and rivets
Disagree with that, we prestock a good selection of #10-32 and it saves us a bunch of time (and $$$ on shipping).
If we need something odd we didn’t prestock, then we order. But you say stocking ANYTHING is grossly impractical is a huge hyperbole.
In general, our team decides on what fasteners we are going to use for that year, and then orders a large amount of them form McMaster. We always have left overs at the end of our season which are sorted and kept in containers in the shop closet. When prototyping, we use the leftovers, but when assembling the robot we use the new bolts/screws/rivets. In general, we use socket head cap screws (SHCS), but also use button heads, low clearance, or even counter sunk bolts/screws when clearance is an issue. For rivets, we pretty much only use 1/8" blind aluminum rivets.
Last year specifically, we used a standard size of 10-32, of varying lengths. Occasionally we used #6 and rarely used #4 bolts. From what I’ve seen #10 and 1/4-20 are pretty standard in FIRST.
Fasteners are generic names for things that fasten two or more things together. Bolts and rivets are the most obvious examples, but they include (by some definitions) rivenuts, nuts, washers, snap rings, split washers, wood screws, etc.
Like Adam, we use mainly 3/16" rivets (ordered in massive quantities off McMaster) and 10-32 screws where rivets don’t make sense. We have a small store of other sizes of fasteners (we used to standardize for 1/4"-20, so we have a fair bit of that), but generally have to order the weird stuff. We also keep 80-20 nuggets and other hardware around.
It’s important to note that keeping screws and stuff organizes is just as important has having the right ones. If you can’t find a fastener, the money you just spent on it isn’t really doing much good.
We just hate to run out of stuff like nuts and bolts. The hardware store is just down the street, and we have several options for large amounts of hardware…all of which are probably closed 9:30 tuesday nights…
These are two really good things for every team to do.
Regardless of what size hardware you use, it’s awesome when it’s all similarly sized and can be installed/removed with the same series of tools. If you color code the tools for each different hardware size, or each different use, it makes fixing stuff on the fly much, much easier.
What Pratik said. Our standard is 10-32, SHCS with a 5/32" Internal Hex Drive, so about 75% of our robot can be taken apart with a single pair of wrenches. Any exceptions to the 10-32 standard are dictated by a COTS part, specifically if a motor/transmission/etc requires a different screw, we’ll use it. Otherwise, for sheet metal metal connections that shouldn’t need to be undone, we’ll use 1/8" Pop-Rivets, usually Aluminum Body with a Steel Shank and for isolated electrical components we’ll use good velcro or 3M Dual Lock.
If you’re trying to define your own standard, or just get an idea of what hardware makes sense, here are some of the common sizes found on some of the more common COTS parts:
1/4-20: Pre-2014 Kit Bot (2014 Hardware size hasn’t been announced), VexPro Axle Stock, Some AndyMark gearboxes
10-32: CIM Motors, Mini-CIM Motors, Versaplanetary Gearboxes, Banebots P60s
10-24 Self Tapping: AM Wheels, Sprockets, etc
8-32: VexPro Sprockets, Wheels, VersaFraming, etc
6-32: Victor 884/888 Mounting Holes, DSC?, etc
Metric:
M3 - RS550 Motors, AM-9015 Motors, Fisher-Price Motors
M4 - BAG Motors, RS775 Motors, PG-Series AM Gearboxes
M6 - Power Distribution Block Main Studs
As far as lengths are concerned, most of them will be application specific, although you can probably guess pretty close based on previous year construction methods.
I also like the 2-56 x 1" screws for those pesky solenoid valves.