FRC pocketing
 

What is pocketing (gussets) in FRC?

Re: FRC pocketing
 

Generally, for gussets, (and pocketing in general) you're removing material from low stress points in order to save weight.

Re: FRC pocketing
 

An example of pocketing are the front and back plates of this gearox:

Instead of being a solid plates, numerous holes are cut into them to reduce weight, while being careful not to over-reduce strength.

Re: FRC pocketing
 

And hopefully ensuring you've accounted for manufacturability by adding radii in the corners of your pockets (like the above image does not have, not to call whoever made it out, its just a good example of whats missing).

-Brando

Re: FRC pocketing
 

Lasers. With a plasma or laser cutter this could be made exactly how it is shown.

Re: FRC pocketing
 

Or a CNC and a .125 end mill, which would leave you with at least .125 radii.

Re: FRC pocketing
 

It would still have a radius in the corner due to the laser/plasma diameter.

Also sharp corners represent infinite accell/decell to the machine (which has to ramp up/down). A curve allows the machine to be decelling in one axis while accelling in the other. Will actually reduce runtime appreciable in qty. This is a non-issue on an industrial sized laser, but for a smaller one it will be.

Re: FRC pocketing
 

There are different ways to look at pocketing... another way is to see it as a mostly unnecessary process, required only if you designed something with the wrong material, or wrong shape.

But I'm lazy and cheap, so take this with a grain of salt

Re: FRC pocketing
 

affectionately known to me as "swiss cheesing"
::safety::

Re: FRC pocketing
 

Gussets are completely different than pockets. Gussets (or more formally gusset plates) are pieces of plate metal which are used to join two or more beams or similar linear members and keep them at an appropriate angle to each other. Here's the page of VexPro gusset plates, probably the most common COTS gussets in FRC. They are typically riveted onto both sides of VersFrame stock with 5/32" aluminum rivets.

The first gussets I encountered in FRC were welded into place, in the 2013 game specific drawings The term is first found on page 37, but gussets were used to keep each layer of the pyramid square.

Re: FRC pocketing
 

Jim,
Please provide some guidance to inexperienced teams on how to always design with the right material and right shape. ;)
Otherwise, perhaps withhold advice like your previous post as it might send someone down a path they aren't prepared for. :)

"Mr Forbes says we don't need to do pocketing!" *140 lb robot*

148 loves pocketing / trussing. We do it on everything. Maybe we're just bad at designing with the right material & shape.

-John

Re: FRC pocketing
 

I don't entirely disagree... but keep in mind that pocketing is basically changing the shape - and getting it closer to the right one ;) You can of course take steps to be close to the right shape in the first place. Pocketing gets you closer.

Re: FRC pocketing
 

It's probably because 148 isn't cheap or lazy :rolleyes:

One simple alternative: use thinner material without pocketing. I've seen a lot of pocketed designs in FRC that could have been made simpler and cheaper with practically no effect on strength (although, oftentimes can be made stronger) by using thinner material.

Re: FRC pocketing
 

I'll let you all sleep on it, and see if you can figure out what I'm getting at.

Re: FRC pocketing
 

Or you could explain your reasoning? Wouldn't that be more helpful to inexperienced readers?