Ok, so I’m aware that this is a dumb question, but here goes nothing.
Our team is thinking of buying our own fasteners, partly because we can and mostly because the school is extremely reluctant to fund our fastener-buying attempt.
How many of each dimension of screws would you recommend that we buy? Is a hundred per each too much? How many of nylock and keps should we get ourselves?
100 to 200 1.5 inch screws. At least 300 0.5 Inch screws. And 100 to 200 2 inch screws. You can get some of every size, but those 3 sizes will be what you use most.
Get at least 300 if not more keps nuts and 100 to 200 nylocks. (Most parts will not need nylocks but you can use more nylocks if you want)
Also star drive is preferred. Hex strips easily if you arent careful
As far as I can remember, our team used 0.25 inch screws most frequently, for fastening two structural pieces together. 0.375 inch for tightening bearing blocks, and 0.5 inch for my crappy screw joints. I don’t remember using 2-inch screws as frequently, though.
Can I get the use cases for each of the screws?
2” screws are used for most screw joints, so building any lift. I used .5” screws for pillows, not .375”. With nylocks, I think .375” is too short. Any time you would attach two pieces of metal together with .25” screws, you can probably box that joint for much better structural integrity with a longer screw and some spacers, so this is another potential need for 2” screws.
Without a doubt you can use all the sizes of screws for different things just depends what you are screwing together. Personally my team uses 2 inch screws for wider screw joints and they work amazing.
From what I’ve heard on the form, star drive screws are a lot better and easier to use than hex. If you are buying most of the screws you will use this season right now, it would be best to get stardrive than have to ever worry about needing to phase out hex screws that you already have.
You should try to use nylocks everywhere. I would get 300 of the thin ones. My team mostly uses 0.375, 0.500, 1.250 for boxing c-channels, and a lot of screws over 1.000 for different width of screw joints. I would recommend at least 100 of each. We don’t really use 0.250 because it doesn’t have enough length to thread onto the nylocks.
I bought 2 of these sets:
https://www.robosource.net/color-coded-star-drive-screws/423-color-coded-star-drive-screws-1600pc-variety-pack.html
and they were more than enough to build an entire TT robot, so they should tide you over for a while. The color coding is really helpful, star head is great, the washers it comes with are nice too, and the thin nylocks are beautiful.
0.5 inch screws are the most versatile. They can be used to attach pieces of metal to each other, attach bearing blocks, attach multiple pieces of metal, and overall are more versatile than the 0.25 inch screws which cant be used for attaching bearing blocks. In other words, they double as 0.25 and 0.375 inch screws.
1 inch screws are good for attaching 2 pieces of metal with a gap between them.
Screw _ metal _ spacer _ metal _ screw.
They can also be used with spacers to create protrusions from the surface of the metal, which is good for attaching rubber bands or other things.
1.5 inch screws are good for short screw joints, or attaching things across even larger gaps. Also good for boxing, as they can go across a c channel’s width.
2 inch screws are good for larger screw joints. I used one for my tilter this season, and it held up pretty well. Also good for attaching things across even larger distances, such as the 2 sides of a tilter.
You can go with other sizes, but from my experience, the other sizes haven’t been as useful. Only get other sizes if you want to do less screwing in, as these 4 sizes will have everything covered.
In cases where you need a smaller screw to fit in a tight space, you can allways just cut them.
I think that
.25, .5, 1, 1.5, and 2" screws are the most commonly used, but it’s always good to have all the lengths for when you need them. You shouldn’t use longer screws then necessary, or you’re adding needless weight.
0.25" screws are good to use in collars. I have found that the tiny hex screws that they come with strip really easily and come loose occasionally
I find them to be rather large and dont always fit. Personally I would just buy replacement hex inserts from vex or buy new star drive inserts which strip less.
Obviously, they don’t fit everywhere, but I like to use them on drive shafts where there’s space because you can tighten them a lot more without fear of stripping the screws
yeah if I can fit a .25" screw in a shaft collar, I do that. it’s nice especially because I don’t have to switch screwdrivers when using shaft collars, and it’s a lot more secure.
For a new season I’d go with around 200 .25", 100 .375", 200 .5", 100 .675" and .75", 100 1", 100 1.5", and 100 2" screws. That seems to work for me. I’d also get around 500 thin nylocks from robosource.
If you have money left over, buying nylon screws and nuts for use on bearings is a good idea. I buy mine from robosource