Box Bolt Standoffs- Worth it?

I have been using’s Shoulder Screws for a while, and they are awesome.
However, one of my biggest problems with them is box bolting. I have been using a lot of box-bolts on my team’s robot this year, and it’s pretty sturdy. However, that is kind of hard to do with shoulder screws.
For one thing, the shoulders fit in the holes of 0.5" OD spacers, but not the 0.375 OD ones. The 0.5 ones fit fine, and this isn’t a huge deal, but it does get a little annoying when I run into screwhead clearances and stuff like that.
Another problem when box bolting with shoulder screws is that when attaching 2 pieces of metal to another c-channel with a box bolt inbetween, is that only one piece of metal gets the shoulder. This isn’t really a huge deal, as the slop is already reduced by at least half, but is a smaller problem.
The big problem for me is that the only shoulder screws that Robosource has that are good for box-bolts are the 1.5" ones. This means that I have to thread a nylock over more threads than I’d like for this, and it adds extra weight and means that the end sticks out more, which can mess up clearances.
However, I ended up revisiting this post not too long ago:

After re-reading @Xenon27’s post, I realized that using 7/8 8/32 standoffs from McMaster Carr could potentially solve all of these problems. Instead of having to stack multiple spacers to do the job, like so:

I could use one standoff in between, with a screw on either side, like this:

This would maybe be slightly heavier than the typical box-bolt, but probably not enough to make a huge difference. I would also probably put loctite in these standoffs, as these would make up a decent portion of my attachments and I don’t want them coming loose.
Are there any downsides to these that I’m not thinking of, or does anyone have any alternatives?


This certainly works, and would be extremely rigid, but I don’t think you’d want to use them absolutely everywhere. It’s very overkill for most applications, and while one standoff doesn’t weigh much, if you use them absolutely everywhere the extra weight is not insignificant.

But box bolting with standoffs isn’t a bad idea, and could have good applications in places where you really need a lot of rigidity.


The main benefit of using standoffs over nylon spacers for boxxing structure is that standoffs are much harder to crush down compared to spacers. With spacers, you aren’t able to tighten down the screw as much as standoffs without having to deal with the flanges bending in slightly. This can be fixed by using a thin metal washer (or anything to add slightly more than the 7/8" length) to help counteract this.


Due to manufacturing tolerances, I frequently find myself forcing the flanges open to cram a 3/8 and 1/2 inch spacer in.

Thanks for the responses,
The main reason I am considering using these is for convenience, as these seem like they will work better than spacers with the shoulder screws, making it so that I don’t have to work as hard to get everything lined up well.

Honestly, weight isn’t a huge concern for me, as I am running a 6 motor drive, the extra weight only seems like it would help with COG and being able to push people.
A side note, does anyone have any other places to order them from where they may be a little cheaper? 44c per standoff costs a little more than I’d like, if I were to order them from McMaster Carr.


Are 0.875" standoffs VRC-legal?

cheapest and the the most definitively legal way to obtain would be to file down 1" standoffs, probably the most efficient way would be with a belt sander.

I’m not sure if buying them directly from mcmaster would be legal, the rule in question would be:

<R12> Certain non-VEX screws, nuts, and washers are allowed. Robots may use any commercially available #4, #6, #8, M3, M3.5, or M4 screw up to 2.5” (63.5mm) long (nominal), and any commercially available nut, washer, and / or non-threaded spacer (up to 2.5” (63.5mm) long) to fit these screws. The intent of the rule is to allow Teams to purchase their own commodity hardware without introducing additional functionality not found in standard VEX equipment. It is up to inspectors to determine whether the non-VEX hardware has introduced additional functionality or not.

So obviously standoffs do not count as screws, washers, or non-threaded spacers. But could they qualify as a nut? they’re kind of just long nuts.

And I don’t think an argument could be made that they’re introducing new functionality as a part, since you can easily sand down a 1" standoff to get a functionally identical part as a .875" standoff. So it’s not a clear legal/illegal situation. a Q&A might be in order (though it’s possible there is already a q&a that clarifies this, I just haven’t seen it.)

To be safe, and also for economic reasons, if I were to use .875" standoffs in my bot I would make them from 1" standoffs.


According to the GDC, they don’t:

Previously, I had thought that Robosource’s standoffs were legal because of R12. However, I think that they are legal through the rule that allows parts that are identical in ways other than color (can’t remember what rule it is), which their standoffs are.

I briefly considered using round standoffs, which could count as threaded spacers, but those aren’t legal- R12 specifically states "non-threaded spacer).

I think it’s worth a QnA, and a search for “Standoff” did not give any relevant results. I am not set up to do a QnA on this, would someone who is mind doing one?


this rule was removed this season, which I remember causing some issues with things like pneumatic components purchased from resellers, and things like zip ties and whatnot.

which would lead me to believe that robosource standoffs are actually illegal for competition use, as silly as that sounds. Unless of course robosource buys standoffs from vex and then colors them and sells them, but I find that very unlikely.


I believe rounded standoffs are just modified standoffs. That does make them legal? I am now confused on what is legal or not.

They would certainly be legal if hex standoffs were turned on a lathe (by students—take a picture for the notebook) to make them round.


Well I’m not sure that they’re specifically illegal, but they aren’t legal to buy from alternate sources.

In the past teams have used rounded standoffs that where not made by them. This q&a from Tower Take over talks about this idea but in relation to spacers:

“commercially available spacers that are functionally equivalent to spacers that could theoretically be made from legal VEX spacers are legal”

Now while old q&a’s are not legal. It allows us to question now if its still legal. This q&a about Commercially Available Hardware : Robot Events suggests that being able to replace a part with a vex legal part and the functionality doesn’t change then it would be legal. So as to Xenon’s comment about color of robosource’s standoffs it would up to the head referee/inspector to see if color adds additional function. Does it? I would hope we could argue it doesn’t.

As for rounded standoffs being a part possible to create from vex legal parts, yet they do in my opinion add enough functionality to be running a risk. Because if you replace a rounded standoff with a standard vex standoff you lose functionality, but if you create one rounded standoff that is from a vex standoff you could prove that you could use that standoff to replace any rounded standoffs that you bought commercially.

But now we are back at if I can theoretically make a something from a vex part is the commercially available part that we want to use legal. Do we have to prove that it is possible to make said part? What does it mean to prove that one can make that part? A actually part that we made? Or rather a description on how to make it? A picture of you attempting to make one with a home made lathe. How many teams have lathes? I can make a lathe with a drill and some time and effort. But that isn’t really safe.

Talking a bit into fairness now and hypotheticals: It would be fair that team X has a lathe and can make rounded standoffs but decides to buy them commercially so they don’t have to go through the process of actually making them. Team Y doesn’t have a lathe so would they not be able to use/buy a rounded standoff. Is that fair? I feel this scrapes up next to the 3d printed parts discussion/augment.

What are your thoughts and should we ask a q&a regarding theoretically creating parts from vex legal parts that have new functionality, yet buying them commercially?

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nowhere in the manual does it say you can use non-vex parts even if they are functionally identical to vex parts.

in fact, the manual specifies that you can only use official vex parts, with these exceptions:

<R12> Certain non-VEX screws, nuts, and washers are allowed. Robots may use any commercially available #4, #6, #8, M3, M3.5, or M4 screw up to 2.5” (63.5mm) long (nominal), and any commercially available nut, washer, and / or non-threaded spacer (up to 2.5” (63.5mm) long) to fit these screws.

<R8> Certain non-VEX components are allowed. Robots are allowed the following additional “nonVEX” components:
a. Any material strictly used as a color filter or a color marker for a legal sensor, such as the VEX Light Sensor or the VEX V5 Vision Sensor.
b. Any non-aerosol based grease or lubricating compound, when used in extreme moderation on surfaces and locations that do NOT contact the playing field walls, foam field surface, Scoring Objects, or other Robots.
c. Anti-static compound, when used in extreme moderation (i.e. such that it does not leave residue on playing field walls, the foam field surface, Scoring Objects, or other Robots).
d. Hot glue when used to secure cable connections.
e. An unlimited amount of rope / string, no thicker than 1/4” (6.35mm).
f. Commercially available items used solely for bundling or wrapping of 2-wire, 3-wire, 4-wire, or V5 Smart Cables, and pneumatic tubing are allowed. These items must solely be used for the purposes of cable protection, organization, or management. This includes but is not limited to electrical tape, cable carrier, cable track, etc. It is up to inspectors to determine whether a component is serving a function beyond protecting and managing cables.
g. Non-functional 3D printed license plates, per and , are permitted. This includes any supporting structures whose sole purpose is to hold, mount, or display an official license plate.
h. Rubber bands that are identical in length and thickness to those included in the VEX V5 product line (#32 and #64)
i. Pneumatic components with identical SMC manufacturer part numbers to those listed on the VEX website

<R10> A limited amount of custom plastic is allowed. Robots may use non-shattering plastic from the following list; polycarbonate (Lexan), acetal monopolymer (Delrin), acetal copolymer (Acetron GP), POM (acetal), ABS, PEEK, PET, HDPE, LDPE, Nylon (all grades), Polypropylene, FEP; as cut from a single 12” x 24” sheet up to 0.070” thick.
a. Shattering plastic, such as PMMA (also called Plexiglass, Acrylic, or Perspex), is prohibited.
b. Plastic may be mechanically altered by cutting, drilling, bending etc. It cannot be chemically treated, melted, or cast. Heating polycarbonate to aid in bending is acceptable.

<R11> A limited amount of tape is allowed. Robots may use a small amount of tape when used for the following purposes:
a. For the sole purpose of securing any connection between the ends of two (2) VEX cables.
b. For labeling wires and motors.
c. For covering the back of License Plates (i.e. the “wrong color”).
d. For the purposes of preventing leaks on the threaded portions of pneumatic fittings. This is the only acceptable use of Teflon tape.
e. In any other application that would be considered a “non-functional decoration” per <R13>.

As you can see, any third party part not included in these exceptions is illegal, regardless of how identical they function. This means that any standoffs from robosource or mcmaster are illegal for competition use, even though they are functionally identical to (or could be easily made from) official vex standoffs.

That said, teams have been buying standoffs from robosource for many years now, mine included. And not only standoffs are affected here, things like antislip and other products commonly purchased from robosource, mcmaster, or other resellers would also be illegal.

However, I believe you could make the argument that <g3> could be used to excuse the use, and frankly the continued purchase of these parts. It’s unreasonable to make a bunch of functionally identical parts purchased from 3rd parties that were legal in past seasons, suddenly illegal, forcing teams to buy new parts from vex when they already have these perfectly good parts, and it makes no sense to force teams to buy parts from vex when they can purchase functionally identical parts from a reputable 3rd party such as robosource or mcmaster.


Looks like these are legal now!
VRC Tipping Point Game Manual Updates - #12 by VEX_GDC

  1. Updated R12 to include standoffs
    Certain non-VEX fasteners are allowed. Robots may use any commercially available #4, #6, #8, M3, M3.5, or M4 screw up to 2.5” (63.5mm) long (nominal), and any commercially available nut, washer, standoff, and / or non-threaded spacer (up to 2.5” (63.5mm) long) to fit these screws.


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These are now available from
Black Aluminum Standoffs, 7/8" Length, 10 pack for VEX Robotics -