Question about the bumpers.

[Brad Voracek]

According to R37, we must design our bumpers to be exactly like those shown in the pictures, however, do we have to fasten them as they show? I know that teams last year used the pool-noodle bumpers, although fastened with zip-ties, were able to not have those considered "custom" bumpers, but was that legal?

Last year we designed our bumpers exactly as the picture shows, and they were a hassle to get on and off for weighing them separately. So the question is, is it legal to have them fastened in some other way, as long as it is secure?

[sciencenerd]

Originally Posted by FRC manual 2007

<R37>
STANDARD BUMPERS must be designed as shown in figures 8-1 and 8-2. This is the only acceptable design for STANDARD BUMPERS.

STANDARD BUMPERS must be removable so that they can be weighed separately from the ROBOT. STANDARD BUMPERS must be attached to the ROBOT with a bolt-and-fastener system to form a rigid, robust connection to the ROBOT structure (i.e. not attached with Velcro!).

The zip-tie system is obviously not allowed ("STANDARD BUMPERS must be attached to the ROBOT with a bolt-and-fastener system") As for using other setups involving different configurations of the bolts, I would assume that's not allowed, but ask the Q&A.

[Justin M.]

My guess is that zip-ties is not considered as a solid, easily removable attachment method of the standard bumpers. It's probably going to result in a judgement call of the inspector, but be prepared to have to use a bolt or otherwise enter them as custom bumpers.

[Al Skierkiewicz]

Brad,
The bumpers last year were one of the most discussed and complained about system. I would ask yourself this question. 'If I use the bumper and the mounting hardware I use fails on one side, what will happen?' I think you will see that a failure of this type will severely limit the function of your robot and it may be disabled if there is a threat of carpet damage. At most you will be asked only twice at each event to remove the bumpers for weigh in so make them secure.

[T3_1565]

my big question about bumpers is.. Do you have to have them on your bot? It says "Strongly Encouraged" but it doesn't say its mandatory. And What if you made a bumper that only covered part of your bot?

[BillP]

Originally Posted by T3_1565

my big question about bumpers is.. Do you have to have them on your bot? It says "Strongly Encouraged" but it doesn't say its mandatory. And What if you made a bumper that only covered part of your bot?

No, the bumpers are not mandatory, and yes, it is OK if they only cover part of your robot. However, if you don't have the bumpers, the referee's may interpret "contact" with other robots differently (this varied a little from regional to regional last year).

Having said that, I'm pretty sure you can put a different bumper design on your robot, but if you do, they must be weighed as part of the robot and fit inside the sizing cube. (Only the "Standard" bumpers must be removed for weighing and sizing). This is just my interpretation. You might want to confirm this with the Q/A system.

[robostangs548]

I think that it would be in your best interest to just use the bolt and fastener system, and if you find out anything new to change it later. "Better to be safe then drilling new holes in your frame to fit screws and bolts" I always like to say! But seriously though... I think that with the hundreds of complaints and other problems that FIRST had last year with the bumper system, They are most likely assuming that you remember the rules last year, and will lay down the law on your team when the inspection time comes for your robot. I would make sure that you always build a robot that will not draw any negative attention toward your team. Doing so, will usually result in further problems and negative tension toward your robot. So it’s better to be safe then sorry, just go with your gut instinct.

[T3_1565]

Originally Posted by BillP

No, the bumpers are not mandatory, and yes, it is OK if they only cover part of your robot. However, if you don't have the bumpers, the referee's may interpret "contact" with other robots differently (this varied a little from regional to regional last year).

Having said that, I'm pretty sure you can put a different bumper design on your robot, but if you do, they must be weighed as part of the robot and fit inside the sizing cube. (Only the "Standard" bumpers must be removed for weighing and sizing). This is just my interpretation. You might want to confirm this with the Q/A system.

Thanks. I wanted to clarify that. And for the record I understand ref will look at bumping in a different light without bumpers, thats why it will be partly covered, so far our design cannot have a bumper on the back of it. So we will probably put one on the front for bumping purposes.

EDIT: Is it still considered to be a "standard bumper" if it doesn't completely cover the robot?

[Al Skierkiewicz]

Bumpers do not need to be on all sides of the robot. If your design requires you be able to scoop tubes from the floor, then a bumper would not allow that. The object with bumpers is that field refs will be watching for contact within the bumper zone as well as other rules relating to the competition. If you use bumpers, then they must be built using the construction guide in the robot manual. (i.e. two unmodified pool noodles on a plywood backing covered in the specified fabric, etc.) If they are not detachable then their weight and size will be included in the robot max dimensions and weight during inspection. By using the bumper design, you can legally pick up another 15 lbs and provide some protection for your robot. I predict this year will be a very defensive year, plan on pushing and bumping.

[Brad Voracek]

Hm, thanks guys. The zipties were obviously an exaggeration, I didn't mean we actually plan to use them. We were just trying to think of an easier way to secure the bumpers, but we probably will end up using the bolts still. They were just a real hassle last year, because we planned them last minute. I'll tell our build team that they should try to use the bolt system, and just try to make it easier to reach. Anyways, thanks again.

[Justin M.]

I feel you on the bolt system. Our chassis will have big milled channels for weight on the sides, so we have nothing to bolt them to. Looks like I'll have to custom engineer something when we actually have a robot to look at.

[EricH]

Easy use of bolts: use a t-nut (blind-nut) on the inside of the bumpers (well secured--you don't want to have to take the bumper apart to find it) and put a hole through the frame and bumper backing (and cloth as well) for the bolt. When you take the bumpers off, attach the bolts to them so you don't lose 'em. If you have something on the outside of your robot, like an axle end, try shaping a small hole/cavity for it. (Then mark which side that bumper goes on and which side is up.)