Re: pic: Week Three 2009
 

After they published that drawing, they changed the wording of the rules to make it illegal to have your trailer hitch and bumpers that way.

You might want to ask on the Q&A forum if your specific design is legal. It would be much easier to fix over the next 3 weeks than on the Thursday of your first competition.

Re: pic: Week Three 2009
 

I don't think anyone is "going after" this team regarding their bumpers. In fact, I think everyone who has posted concerning the bumpers has expressed appreciation for the overall design, but have spotted a potential concern that we want to bring to the attention of the team.

There is clearly the potential for confusion between the wording of the rules, and figure 8-2 in the rules. The figure suggests that this design should be fine, but the wording of the rules seems to contradict the figure.

One advantage of posting photos, CAD images and sketches to CD is that it exposes your design to a number of FIRST veterans, including several experienced tech inspectors, who can offer suggestions if they see a potential rule violation. While the GDC will not rule on a specific design in the Q&A forum so asking "is this robot legal" is not a valid Q&A question, something along the lines of "The robot corners adjacent to the the trailer hitch in figure 8-2 of the game manual appear to be inconsistant with the requirement that all corners of the robot be protected by bumpers. Is special consideration meant to be given to such corners?" If it is possible to make the argument that in this design the rear corners are incapable of being the first part of the robot to contact another robot or playing surface then it may be that this bumper configuration is consistant with the intent of the rule (albeit not the current wording) and that the wording will be modified.

I hope the GDC rules favourably on this for the team. I can see how they could honestly believe their design to be legal. It is clearly consistant with figure 8-2 and is likely consistant with the intent of the bumper rules that the first part of a robot to contact a wall or other robot shall be the bumper.

Jason

Re: pic: Week Three 2009
 

Those corners are clearly a part of your BUMPER PERIMETER. Accessible or not, by letter of the rule they should be protected by 6" bumpers on each side.

I never noticed this apparent contradiction in Figure 8 -2. They are using that figure to illustrate allowable methods of extending the noodles to protect the corners. Yet the corners adjacent to the trailer hitch are not protected with 6" on both sides.

Joe, I would ask the question as Jason has worded it, and quickly. It's especially important as you are registered for a Week 1 District event. You can't risk an unfavorable ruling once you get there. (For those outside Michigan, if ruled against by an inspector, 1322 would not have a Thursday practice day to fix it; they would only have a few hours of Friday morning practice time.) See you in TC.

Re: pic: Week Three 2009
 

To determine the bumper perimeter, ignore the trailer hitch and wrap a string around your robot. From the picture I see this forms 6 vertex's. Those are the corners and the rules say that the corners (vertex's) must be protected in both directions with bumpers that are a minimum of 6 ". The problem with this design is the 2 vertexes on either side of the trailer hitch. They only have bumpers on one side of the vertex ( corner). To modify your bumper area frame to be legal you might as well square it off and be done with it. From what I saw yesterday driving our robot, you probably will not gain any advantage with your frame trailer interactions. In fact your design can cause more problems trying to back up in a jack Knife situation.

Re: pic: Week Three 2009
 

You guys are referencing fig. 8-2. I don't have a problem with that, except that I have 2.

1) The GDC has repeatedly said that the pictures in the rules are there merely for reference.

2) The figure has the right corners, but it also has bumpers on both sides of the corners, except right at the trailer hitch.

I think the question should read something like, "During the design process, we came up with a solution that we believe meets the intent of the bumper rules, but we would like to clarify that it meets the letter of the rules. [picture if necessary] We have an angled end such that every angle is an exterior corner and meets the bumper perimeter requirements. However, with the mounting of the trailer hitch, we can no longer put a 6" section of bumper between the hitch and the nearest exterior corner of the robot. We have confirmed that the trailer impacts bumper to bumper before the tongue hits. We think we won't need bumpers, but would like to confirm. If this design is not legal, we will change our design as necessary."

I would imagine that the GDC would either say, "we cannot comment on specific designs" or "This design does not meet <R08-X> and will not be legal."

Re: pic: Week Three 2009
 

8.3 Robot Rules
When reading these Rules, please use technical common sense (engineering thinking) rather than “lawyering” the interpretation and splitting hairs over the precise wording in an attempt to find loopholes. Try to understand the reasoning behind a rule.

I thank everybody for the heads up on this issue. Although I have read the rules and intrepid them to the best of my ability I did miss the bumpers on the corners. I looked at the diagram and seen the angle near the hitch and thought we could do the same. There is no indication where an angle ends and a corner begins. It will be easy to install corners on our robot (or slight angles) and will probably will but in the mean time we will try different things. I have posted a photo of an idea and would like comments when it comes out.

Re: pic: Week Three 2009
 

My team (675) is using the orange urethane belting for out conveyor belts too.

It works really well, good luck

Re: pic: Week Three 2009
 

So what was your method for cutting and sealing your belts together? lighter, heat gun? I'm assuming it's the Orange Urethane belting, right? and do you have the belts under much tension, or are they just wrapped around enough to contact the rollers?

Looks like a good start though. Good luck.

Re: pic: Week Three 2009
 

We used a lighter to heat the belts untill they were glossy and almost on fire, and while they were still on the flame we stuck them to gether. You have to hold them for abut 5 minutes and let them stand for about 30 minutes before using. We were told to cut them 10 percent short of distance to get the right tension. When you have that many belts with that tension it is alot of pull on the shafts.

Re: pic: Week Three 2009
 

Come on, lets see vids