I know my friend Joe @Manly_Innovations would love to get these to market for FRC applications. I personally think they could be used for much more than just bumpers, such as implement switch-outs for different mechanisms. Obviously too late for this year to get production of these for FRC, but for next year…
This is from a 2018 thread HERE.
If that does what I think you are describing, it sounds like this would result in bumpers that are not supposed to pass inspection per build rules. As an RI, I’ve asked teams to fix bumper for similar reasons, but haven’t seen that with the AM brackets, personally.
For fun, my favorite instance was telling a team they could not, in fact, mount their bumper to an articulating frame perimeter.
It looks like those AM brackets could reasonably be used with quick release pins mentioned a few times here to replace the wing nuts. All good solutions.
We used the KOP drivetrain for the first time in a while this season and decided to use the provided bumper mounting system. We used it as described in the picture with the correct side mounts. I’m glad AndyMark is providing a system for the KOP chassis teams, and it is better than the old system, but it was still a bit of a nightmare to install and get all of the bolts to lined up for each bumper segment. This year CHS has all 1 day events, so we never had breaks of more than 1 or 2 matches and it was definitely a longer process than you’d expect to get these on and off.
In the past we’ve used the Slide-Snap latches and generally liked them, but it can be really easy to bend the forks if you aren’t careful.
We found an alternate vender that’s half the price. We ordered a few from there this season and they are legit.
I think this a wrong link? I had to check 10 times because I was literally just looking at that thread as well.
And that’s the problem. All too often, trying to fix it at an event causes huge problems for teams.I pulled the CAD for the outside plate and the front bumper mount into onshape to show the problem - it leads to a gap of .405", well more than the 1/4" allowed in the rules. I wish Andymark would move those holes in the frame back a bit (at least .155") towards the bend, so when teams make this mistake they still end up with legal bumpers.
Fixed! Thanks for the heads-up.
Thanks Greg - I can’t say anything yet but there are some things in the discussion process with a key US company. If this comes to fruition, you will all know.
In my opinion the most available and easy way to mount bumpers on pretty much any FRC bot is just a captured bolt with a nut. It takes less than a min to swap. Almost everyone has nuts bolts and angle extrusion.
There are faster more elegant options, but for me this simple solution is hard to beat and I don’t see a need to improve it any further.
Care to elaborate?
I’m sure it could work, but you would have to drill a larger hole in the chassis. With a knurled nut, you can bolt right through the existing holes and move it around if you need to. (Which has been necessary for us on occasion)
The next thing I’m looking to improve is the angle bracket that attaches to the wood. Currently it’s a pain to get right, and we use t-nuts for strength.
Accuracy can be a problem with students that have very little experience using power tools at all, so I would like to design something that could maybe be attached, then minor adjustments could be made to get it just right.
Honestly, I think 3D printing something would work beautifully. The problem is most inspectors I talk to would never pass a 3D printed mounting system.
I’m confused by this because I know a lot of teams that print their hooks for climbing and other parts that are used in places where durability is needed. If printed correctly, I think durability would be fine. Certainly better than a lot of metal bumper mounts I’ve seen. And teams could easily share files between each other and make a durable mounting system much more accessible for teams.
We used these push pins with a ball end that help hold them in place. All it takes is to be able to mount the bumper mount straight and square.
One thing that I haven’t seen mentioned here (edit: looks like @awulfing posted about this method earlier in the thread - the method seems very popular in the PNW!) is the use of toggle clamps to hold down pieces of aluminum angle that are attached to the bumpers. Here is a short description from EricH about how to do this:
2930 has used this method in the past. I believe we may have gotten the idea from looking at some of 1983 and 5803’s robots from around the 2016ish time period. 3142 also started using this method this year, and we specifically use this clamp: https://www.mcmaster.com/5128A61/
Here are some images of the clamps used on 3142’s robot: 
Because our bumper has a gap for the intake, we have to use screws to attach the bumpers on that side. But I think having 2 screws to replace is better than 6…
Most (all) teams will have the drill bits needed to do this. Most teams also have hardware stores nearby where they can get the larger bolts and nuts so no specialty parts are needed. The few exceptions are teams like those in the small towns in the Rio Grande Valley where they are often 100 miles from the next small town.
A lot of the issues with bumpers come from how the bumpers are built including the order in which the steps are done. Often, there is no thought given to how to make different parts line up properly. One of the teams I was inspecting at Channelview took over half an hour to get their bumpers installed, probably for the first time. The last AM bracket (screwed to the bumper wood) just would not line up with the chassis. Taking a closer look, I noticed they had just screwed the brackets to the wood with no attempt to make the brackets line up with the chassis so one of the brackets was about 3/4" too high. The solution was to remove the bracket, clamp it to the top of the chassis rails then screw it to the bumper.
We do the same, but tap the hole and run a 1/4-20 bolt up from below. The holes in the AndyMark frame can be tapped directly without any drilling. A bit of Loctite holds the bolt in place. A knurled nut is used to secure the bracket. I wish the nut was captured somehow, but at a buck each we just keep a bunch on hand.
As you say, not elegant, but effective and everyone has the parts on hand.
I was probably the original proponent of these back when bumpers first came out but I’ve changed my tune and don’t think they are the right solution anymore.
We stopped using these several years ago because they became more of a pain than they were worth. They allowed too much vertical play and fitting them so they are snug and hold bumpers properly with year to yea variations on custom drivetrain made them to fiddley. In the end we went to knurled thumb nuts that go onto screws threaded into our drivetrain.
https://www.mcmaster.com/knurled-nuts/low-profile-thumb-nuts-7/
I have watched a lot of teams struggle with trying to attach their bumpers using wing nuts, especially if they have installed something large next to the bumper retaining studs/bolts, leaving little space to work.
We found it was much easier using coupling nuts, driven using a nutdriver or a socket on an extension bar and a battery drill/driver. They can get lost but are inexpensive so extras can be kept nearby.
Agreed on wing nuts. Knurled nuts can have a pretty small radius, and we prefer to avoid having to use a drill/driver.
This reminds of the other thing we found that makes a great wing nut replacement, and has a very small footprint- short lengths of churro. We had some that had been used on a previous bot as stand-offs and they work surprisingly well. With random lengths lying around we have a virtually infinite free supply.
If you have limited space, you are likely to have the same problem with knurled nuts as with wing nuts.
The coupler nuts basically are COTS versions of the short lengths of churro you are describing. They are inexpensive enough, it is difficult to justify making them unless one has many students with nothing to do. They are also much more difficult to strip out. I noticed I forgot to paste in the link in my previous post.
https://www.homedepot.com/p/Everbilt-1-4-in-20-TPI-Zinc-Rod-Coupling-Nuts-822251/204337387
