R01 Question: Please save me from welding

[Munchskull]

While designing our robot I came to some ambiguity in the rules that I would like some opinions on.

Originally Posted by STEAMworks game manual R01.

The ROBOT (excluding BUMPERS) must have a FRAME PERIMETER, contained within the
BUMPER ZONE, that is comprised of fixed, non-articulated structural elements of the ROBOT.
Minor protrusions no greater than ¼ in. (~6.3 mm) such as bolt heads, fastener ends, weld
beads, and rivets are not considered part of the FRAME PERIMETER.

Our robots super structure flush with the robots frame perimeter on the front and the back, my method of attaching it was going to be to rivet some gusset plates on the inside and the out side of the drive train. Then issue I is the wording of R01. and its blue box.

Originally Posted by STEAMworks game manual R01.

Minor protrusions no greater than ¼ in. (~6.3 mm) such as bolt heads, fastener ends, weld
beads, and rivets are not considered part of the FRAME PERIMETER.

The gussets I would use would be made from .09" 7075 aluminum sheet metal, be riveted in. Knowing how small rivet heads are I can easily say that it would be under .25". I just do not know how to interpret the part that I made bold. The words "such as" leaves room for interpretation that have left me uneasy, I would like to say that flat gussets are fine and as long as the assembly is under a .25" but I fear that it might not be. For this reason I am preparing to TIG weld the outer seams.

Did I interpret this rule correctly or can you set me straight saving my team for my some what less than decent TIG welding?

If you can't save me, any TIG welding tips for 6061-T6511 aluminum would be great! I need them, although learning I was welding backwards made a world of improvement.

[engunneer]

the rivet heads are not part of the frame perimeter. the face of the gusset plate is (likely) the frame perimeter.

can you share a sketch or cad of the arrangement?

[Jon Stratis]

Your best bet is to ask on the Q&A - anything you get on here is going to be opinion that may or may not be correct.

That said, I'll give you my opinion... a plate is not a minor protrusion, and doesn't fall in line with the examples provided. I would love to be overruled by the Q&A on this so I can be more lenient with teams at inspection. This is generally how I've looked at items like this in the past.

Also, the question arises... does it really matter this year? There's no requirement for the size of the frame perimeter, which makes things easier. The bumper will be backed within 1/4". The only real question, then, is if those plates would constitute a "corner" of the frame perimeter for R22 purposes.

Edit: The above question assumes the plates are within the bumper zone.

[PayneTrain]

R01 this year does not have the same teeth similar rules did in prior years with the introduction of R03 this year. Check to make sure your design can satisfy R03.

[mott]

Originally Posted by Munchskull

Our robots super structure flush with the robots frame perimeter on the front and the back, my method of attaching it was going to be to rivet some gusset plates on the inside and the out side of the drive train. Then issue I is the wording of R01. and its blue box.

The gussets I would use would be made from .09" 7075 aluminum sheet metal, be riveted in. Knowing how small rivet heads are I can easily say that it would be under .25". I just do not know how to interpret the part that I made bold. The words "such as" leaves room for interpretation that have left me uneasy, I would like to say that flat gussets are fine and as long as the assembly is under a .25" but I fear that it might not be. For this reason I am preparing to TIG weld the outer seams.

If your gusset plates are down in the bumper zone and would be covered by bumpers, then the gusset plates contribute to the shape of your frame perimeter and if suitably covered with a bumper, you'd be fine.

IF your gusset plates are above the bumpers, 1 quick solution would be to simply mount some of the same kind of material directly below your gussets where it WOULD BE behind your bumper (thus reshaping your frame perimeter to include the gusset material) and you should be fine again.

[Munchskull]

Originally Posted by engunneer

the rivet heads are not part of the frame perimeter. the face of the gusset plate is (likely) the frame perimeter.

can you share a sketch or cad of the arrangement?

That is the conclusion I came to.

http://i.imgur.com/DombdNs.png?1

There is a gusset plate on the other side BTW.

[frcguy]

If it comes down to welding, I'd try and find a local shop/a mentor with TIG experience to do it. Welding aluminum is hard and you can mess up in a lot of ways, so unless you have a lot of experience go the outsource route.

[BumblingBuilder]

I'm assuming your issue is that the gusset is exceeding your frame perimeter. If that's the case, the inspector will not let it slide. The gusset would be illegal as it is not included in R01.

When our team runs into this problem, we get around this with L brackets instead of gussets. Gussets attach two flush faces (the ideal method) while brackets connect two angled (usually and hopefully 90 degrees) faces.

[rich2202]

Originally Posted by PayneTrain

R01 this year does not have the same teeth similar rules did in prior years

R01 may be less important this year (in and of itself), but it is very important with respect to Bumper Rules, and Starting Configuration - Everything must be inside your Bumpers at the start of the match, and the Bumpers must be properly attached to R01 Frame Perimeter.

[JamesCH95]

Originally Posted by mott

If your gusset plates are down in the bumper zone and would be covered by bumpers, then the gusset plates contribute to the shape of your frame perimeter and if suitably covered with a bumper, you'd be fine.

IF your gusset plates are above the bumpers, 1 quick solution would be to simply mount some of the same kind of material directly below your gussets where it WOULD BE behind your bumper (thus reshaping your frame perimeter to include the gusset material) and you should be fine again.

This, provided that you do not violate any sizing rules.

This would be a trivial job for any welding shop though, so fret not!

[Munchskull]

Originally Posted by PayneTrain

R01 this year does not have the same teeth similar rules did in prior years with the introduction of R03 this year. Check to make sure your design can satisfy R03.

What do you mean by teeth?

[Bryce2471]

Hi Anthony,

I believe you are interpreting that rule correctly. The gusset would likely be considered part of the frame perimeter, depending on the inspector. However, I think it's important to note that there is no limit to the frame perimeter this year, so this should not cause you any trouble (assuming the gusset is in the bumper zone and the bumpers fit in the sizing box).

-Bryce

[Munchskull]

Originally Posted by Bryce2471

Hi Anthony,

I believe you are interpreting that rule correctly. The gusset would likely be considered part of the frame perimeter, depending on the inspector. However, I think it's important to note that there is no limit to the frame perimeter this year, so this should not cause you any trouble (assuming the gusset is in the bumper zone and the bumpers fit in the sizing box).

-Bryce

Thanks you all for the feed back and (unofficially) confirming my sneaking suspicion.

Originally Posted by frcguy

If it comes down to welding, I'd try and find a local shop/a mentor with TIG experience to do it. Welding aluminum is hard and you can mess up in a lot of ways, so unless you have a lot of experience go the outsource route.

Originally Posted by JamesCH95

This would be a trivial job for any welding shop though, so fret not!

Thanks for the suggestion, I am now in the process of contacting one of my old boy scout leaders who owns an auto body shop in the hopes that they might be able to help.

[Chris is me]

Before you break out the welder, there's an easy way to solve this problem. Just shim your robot out with some 1/8" thick spacer at the height of the bumpers! Almost any material will work for this since it will be fully supported by the robot frame behind it - plastic, foam, cardboard even. This will make your frame perimeter slightly larger allowing you to use gussets elsewhere.

[FrankJ]

If the gusset plate is in the bumper zone it really doesn't matter if it is frame perimeter or not. Just make sure your bumper gap to frame is less that 1/4". If necessary strategically placed shims can properly define things. If it is outside the bumper zone, it is a little more problematic. I would make the frame in that area a little smaller. One year ws had to shim out our frame perimeter because of a gusset outside the bumper zone.

I would avoid welding 6061 aluminum if at possible unless you have some one really good with the right gear. Welding completely kills the temper and age hardening.