FRC Robot Size

[988clark]

Hi,

So I was reading through the rules a while ago and I thought I read somewhere that as long as your robot was inside the 28 inch X 38 inch rectangle it would be alright to have a screw or bolt out past that rectangle. So like your major parts could be in spec, but a screw would be allowed to stick out a little.

Has anyone else read this?

Thanks!

[kromero18]

Originally Posted by 988clark

Hi,

So I was reading through the rules a while ago and I thought I read somewhere that as long as your robot was inside the 28 inch X 38 inch rectangle it would be alright to have a screw or bolt out past that rectangle. So like your major parts could be in spec, but a screw would be allowed to stick out a little.

Has anyone else read this?

Thanks!

i have.

[KrazyCarl92]

This is true, however, I would STRONGLY advise that you do not make your frame perimeter exactly 28 x 38, as you may be very unhappy when you get to competition and its 28.1 x 38 according to the inspector.

[Alan Anderson]

Originally Posted by 988clark

...I thought I read somewhere that as long as your robot was inside the 28 inch X 38 inch rectangle it would be alright to have a screw or bolt out past that rectangle.

Nope. The robot size is non-negotiable.

The FRAME PERIMETER does have provisions for a bolt head or similar to protrude beyond it, but that only helps you if your frame is smaller than the starting configuration size to begin with.

[Zoughtbaj]

This was in Team Update 5:

<R14> When a ROBOT is in its STARTING CONFIGURATION, no part of the ROBOT shall extend outside the vertical projection of the FRAME PERIMETER (with the exception of minor protrusions such as bolt heads, fastener ends, rivets, etc).

However, I would agree with the poster before me that it would be best if you tried to not have minor protrusions, as the inspectors can get pretty picky.

[EricH]

We're talking two separate things, FRAME PERIMETER (Yes, it is a definition in Section 1.6) and the robot size as defined in <R11>.

The robot size is non-negotiable. Either you're in the box, or you're trying to fit in the box so you can pass inspection. It's that simple. 28" by 38" by 60" is the maximum starting size. No screw heads, bolt heads, or rivet heads excepted. See <R11>.

The Frame Perimeter, as defined in Section 1.6, is "FRAME PERIMETER – the polygon defined by the outer-most set of exterior vertices on the HOSTBOT (without the BUMPERS attached) that are within the BUMPER ZONE." Bolts and screws and other similar items are not counted--this is to facilitate tight bumper-frame connections.

If your frame perimeter is 28" by 38", and has bolt heads, welds, rivet heads, and similar items sticking out such that it will not go into the box, then you are not in compliance with <R11>. If your frame perimeter is less than 28" by 38" (many teams design 1" undersize in all dimensions), then your bolt heads, welds, and rivet heads can stick out up to that 28" by 38" rectangle on the floor.

[sam_who]

Our team consistently undersizes our bot by one inch (37x27x59). We've been to the Bayou regional more than once to find that the measuring box is not square (the corners of the box did not meet at 90 degree angles).

A 38x28x60 inch bot would not have made it in the measuring box.

[IndySam]

As stated, experienced teams will not push the maximum size of the robot and will design to be slightly undersized.

Robots have a tendency to "magically" grow slightly during construction and pushing the limits of size can cause huge headaches during inspection. Also playing the game can be rough and things can get bent and out of square. If you push the size limits, re-inspection before the elimination matches can be problematic.

[Steve W]

As an LRI I can tell you that if it doesn't fit in the box it doesn't go on the field. Maximum is maximum. As was stated previous, frame perimeter is NOT maximum size but defines where the bumpers are attached.

[Wayne Doenges]

We always TRY to build our robots one inch less than maximum width and length.

[DonRotolo]

An inch or two smaller in each dimension won't really affect the performance of the robot. So make it smaller.

The inspectors measure the robot by trying to slide it (on a platform) into a rigid metal frame that is 28 inches wide and 38 inches deep. There is a bar at the 60" height mark. IF the robot fits into the frame without sticking out, it passes. ONLY If. The robot will fail inspection if it doesn't fit.

[Chris is me]

Originally Posted by 988clark

Hi,

So I was reading through the rules a while ago and I thought I read somewhere that as long as your robot was inside the 28 inch X 38 inch rectangle it would be alright to have a screw or bolt out past that rectangle. So like your major parts could be in spec, but a screw would be allowed to stick out a little.

No - all of your physical robot must be within the sizing box, including bolts.

Bolts may stick out past the plane of your frame perimeter (the area that your bumpers mount to) but no parts except bumpers may stick out past the 28x38 box.

Build to 27x37 and you will be dramatically happier.

[thefro526]

Originally Posted by Chris is me

Build to 27x37 and you will be dramatically happier.

Then when you have a bolt head sticking out of your frame you don't have to worry!

(We had a bolt head that made us about 1/4" over-sized in 2007 - it was not fun.)