I remember some user talking about some kind of clips that make attaching and taking off bumpers a complete BREEZE.
As my team and many others have gone frustrated bolting and unbolting bumpers through holes that barely line up, I wanted to bring up this topic to ask how your team (if it has) has coped with this challenge and made bumpers easy to take off and attach.
In the past our bumpers have had brackets attached to them that slide over a frame rail then we use these quick release pins to hold them in place. Just make sure the usable length is the thickness of your rail and brackets.
Edit: We use the shoulder style pins, don’t know why it won’t let me change the url to that page specifically.
For the past two years 1610 has used the nylon slides that are used with
20x20 and 30x30 extruded aluminium. In 2011 we made end bolted on bumpers
as normal, but for the sides we mounted four slides on the back of the bumpers
so they could just be slid to the side
off the frame. When the end bumpers were in place they kept the side bumpers
from sliding out. We had to counter sink the slides for the screws and slightly
route out the plywood so the bumper was flush with the frame.
This past season (2012) we modified that design. In stead of sliding them
horizontally we modified our frame for 30x30 vertical uprights with
horizontal 30x30 between them (this was mounted on one horizontal 30x30 piece
on the bottom.)so they could be slid vertically. We mounted
a nylon slide on each end and one in the center. It takes a little trial and
error to get them placed right so the bumper comes out the height you want.
We tapped the top end of the vertical 30x30s of the frame to accept a 5/16x 1" bolt.
We’d slide the bumper on,place
a washer on the 30x30 and bolt them down. We could change a complete set
off and on in two mins. Using this design made it a little harder to make the frame
but it saved a ton of time changing the bumpers.
To you folks, since the connection isn’t necessarily rigid/bolted, what’s preventing “play” in the bumpers? I’d image that if you have have a 1/4" pin into a 1/4" + some set of holes, you’re going to get some play?
Sorry for not explaining well enough. Yes we did drill a 1/4 hole for a secure connection. We did a quick release pin every eight inches for all sides. It was also tested against other robots at a off-season event as well as at home against other robots. It held up with the problems and had no play what so ever. It went though a 1x1" square tubing and c-base channel on the chassis.
Our team makes one set of bumpers. We staple one colour of fabric on the bumpers and atttach to bot. We then take the other colour and sew bumper covers that we can attach using velcro. This makes changing the bumper colour super easy.
-This is the method that our team used this year, and it turned out to be a huge success. My only word of advice is to make sure that your velcro mounts are secured firmly on (we ended up stapling the velcro to the fabric.
Quick Release Pins
-This has also worked very well for some teams, and something that our team is going to prototype within the next few weeks.
-This seems like a very innovative idea. I was talking to a mentor of Team 254, however, and he said that this tended to get annoying for the team to use. However, this is a great idea nonetheless to get your ideas flowing. You can find a picture of it here: http://2013.team254.com/wp-content/uploads/2012/08/skyfire-small.jpg
Also, check out their team’s website for other ideas.
We too used 1/4in pins with our reversible bumpers. 10 secs to flip colors and another 30 seconds to remove the bumpers with two people.
We also had reusable zip ties to hold the pins into our frame so we would lose them and kept a tighter fit. While their was a little play they never came off and after two very strict bumper inspections they never said their movement was unacceptable.
I did a quick sketch of what our brackets have looked like in the past. Angle stock attaches to the bumper itself while the square stock is mounted on the robot, we use this stock to build most of our frame. A drop pin then goes through all three pieces holding it in place. Usually a long section of bumper has two to three of these while a shorter bumper has two.
Since I can’t get the image to upload here is the dropbox public link:
A second set of bumper covers seems really simple and much quicker than removing and attaching a red and blue set.
Is there a problem with R28 - BUMPERS (the entire BUMPER, not just the cover) must be designed for quick and easy installation and removal?