[DFTF] Bumper Tips...

[EricH]

Originally Posted by Cal578

I just read thru that section again, and looked at figures 4-4 and 4-5, and I still don't see many limitations on what we can use.

I'm going to assume that the first line of [R28] references Figure 4-5, despite it saying 4-4 (which figure is referenced by [R28-B], and illustrates that rule).

"Bumpers must be constructed as follows (see Figure 4-X)" is what the rule says. So, if we scroll down to Figure 4-5, the cross-sectional view of the bumper is shown. It shows the 1" limit for hard parts, the aluminum angle (optional), an example attachment method (TBD by the team), and the plywood (required). It also shows the cover (fabric type TBD by team within tough/smooth and color) and the pool noodles (size spec'd by section C).

What I don't see is anything (other than possibly fasteners, which are mounting-method dependent, and of course pool noodles) inside the fabric/plywood area. Does that mean it's not allowed? Not necessarily. Does that mean it's allowed? Not necessarily. So I think we're in limbo here until someone either a) asks Q&A or b) tries to pass inspection.

[thefro526]

Sorry if this has been mentioned, but during assembly, we'll usually put a dab (technical measurement ) or two of hot glue on each pool noodle to hold them in place. Really makes wrapping them much easier.

As far as attachment, we've been using the same Quick Release Pins (Similar to McMaster P/N 92384A034) for two or three years. They're a bit expensive, but work really well for us. Depending on robot weight, we'll attach the pins to the frame with a piece of string to keep them from getting lost - unless we need those precious few ounces.

[RufflesRidge]

Originally Posted by thefro526

Sorry if this has been mentioned, but during assembly, we'll usually put a dab (technical measurement ) or two of hot glue on each pool noodle to hold them in place. Really makes wrapping them much easier.

This is a good idea, but I will add a word of warning. Depending on exactly what your noodle is made of and how zealous the student is, it can be very easy to melt sizable chunks out of the noodle.

[GaryVoshol]

On making a one-piece bumper which you will slip down over the frame: It depends on what the rest of your robot is like. It might not be that easy to slide it down past everything. Yes, the Frame Perimeter in the Bumper Zone must be the largest horizontal extent of your Robot, but that doesn't mean it will slip on easily. Maybe compromise, and have 2 parts?

Bumper skirts won't work as well this year if you intend to have less than 100% bumper coverage.

We too have used spots of hot glue to stabilize the noodles while we are stretching the fabric over them.

Past rules and/or interpretations have stated that bumpers can be made only of plywood, noodles, fabric, fasteners and optional angle aluminum. I haven't extensively studied the 2 pages of bumper Q&A to see if that applies this year.

[Al Skierkiewicz]

Gerri,
Those of us who are writing, are doing so from our shared experience as inspectors. We have seen teams modify the bumpers with things like 3/4 steel rod, tape to constrict pool noodles to 1" in diameter or less, every kind of fabric you can think of including a couple of pairs of Levi's cut up, and recently every shade of blue and red you can think of. Please remember that the bumper design, for what it is, is intended to minimize robot to robot damage. Those who instituted the rule(s) believe they are working very well when built as specified.