I’ve noticed that are standoffs keep coming loose and need to be tightened after every minute or two of use. Some standoffs on our robot are necessary for the robot to function properly, and we really don’t want them to come loose during a match. I have searched for a similar thread but could not find one, so I made one. What do you do to make sure your standoffs stay tight?
loctite
We haven’t had a problem, but I’m pretty sure the rules allow you use threadlocker on the screws.
Always reference: https://content.vexrobotics.com/docs/vrc-turning-point/VRC-TurningPoint-GameManual-20180817.pdf
If you look through <R7> you don’t see anything about Loctite, but the old motor screws used to come with some thread locker on them.
I don’t see any posts on the Official Turning Point Q&A either.
Using thread locker is standard practice, and would be impossible to check in inspections if it wasn’t allowed. My experience tells me that it’s OK, but the only official reason I would think that it’s legal is that some of the screws come with thread locker on them. I think it’s worth posting to the official Q&A.
Try <R16>
Doesn’t Vex sell thread locking screws? I’ve never tried them, but they seem like a good idea. I’ve personally used longer than necessary screws and tightened them down probably a bit too tight.
Are thread locker screws simply the golden motor screws or do you have to buy them somewhere else?
Also, is all loctite allowed?(permanent vs temporary)
I posted the rule above:
There it is! Not sure how I missed it. I used ctrl-F and everything…
Not the motor screws but vex sells screws that come with blue thread locker pre applied. They work pretty nice but can be annoying to get on since with pre applied thread locker it dries on the screw versus using thread locker out of the bottle which is liquid and doesn’t affect anything until it tightens
The best way to secure standoffs is to use plastic spacers and/or bearings. The force of the tightened screw will compress them and this will protect your screws from getting undone under vibration.
Here is an example of the standoffs that have white nylon spacers and metal washers on one end and bearing and piece of aluminum flats on the other. This works very well to keep screws secure and improves stiffness of the connection.
In very rare cases you may use Blue Loctite (available online, local hardware stores, or Walmart). Apply it in very small amounts and do not use Red Loctite, otherwise you will not be able to unscrew it without heat gun.
The vex screws with threadlock will hold the standoffs in place. They come in 1/4 and 1/2 inch sizes. Here are the part numbers for the Torx heads: 276-5006, 276-5007. Keep in mind that as the screws are reused the threadlock will begin to wear off.
Keeping multiple standoffs together is more difficult. You can use thread lock but it’s messy. Here are couple sources if you got that route:
McMaster sell connectors with built in threadlock that make it easier: https://www.mcmaster.com/94495a225
The way I always did that which worked well was to first apply threadlock to half of a coupler and screw it halfway into one end of a standoff. Then, apply threadlock to the other exposed end of the coupler. However, if you just try to spin the second standoff onto it the coupler will go deeper into the first standoff instead, so I would use my finger nail to hold the coupler right at the edge of the standoff. You can then tighten the second standoff almost all the way, and then for the last tiny bit it really doesn’t matter where it spins anymore.