Sack Attack 2012-2013 design The Black Sheeba II

So this is our first iteration for our 2012-2013 Sack Attack design. We just made a few changes on the intake from our gateway robot.

The intake mechanism is on a pivot so the zip ties make sure the mechanism does not hit the ground and the rubber bands help the mechanism stay down.

This looks really interesting. I’m assuming that since this was your gateway robot you are not capable of going under the troughs. Either way, if this intake works as well as 4886’s this could be the first fully functional sack attack robot. Congratulations!

The intake mechanism used here seems quite interesting in that I imagine sacks will never get stuck, as happens when using the legs. Have you tested this out with some amount of sacks? If so, around what number of sacks can be intaken/lifted?

So the velcro grabs the sacks well? Do you have a video of it intaking?

That’s pretty smart, I wouldn’t have thought of that. How do the sacks slide on the polycarbonate? I’m still waiting for mine. I can’t finish CADing my design until I know if they slide on say, a 30 degree angle.

Especially if you sand your polycarb, I think a 30 degree angle would work just fine. But it’s always good to do some testing (which I can’t because I don’t have any sacks).

I have some on the way that I hope to get very soon, I bought 20 at worlds and shipped them with the robot. Should’ve taken one with me… Yeah I can say though, I’m planning on a wide intake.

Well it’s certainly interesting that we seem to have all come up with the “efficient” design (or at least intake) this year already. Other designs will crop up, I’m sure, like scoops or tank treads (see 1103, Clean Sweep), but it should even out if they’re all pretty similar after tweaking. This leaves more time for creative designs…

Will the velcro work on the sacks, do you think? We were considering studs on the intake roller that hopefully won’t tear them with repeated use.

I was thinking about this design, however one reason we thought of the wheel legs for our intakes is because if the sacks are in stacks then the wheel legs will pull them down and in.

Tearing of the sacks is a concern here, too. I think the rubber tabs may work well this year, but I haven’t tested this yet. I’m excited to see many variants of designs this year, and less of very similar ones.

We have not tried using actual sack because we do not have any yet, but we have tried using duck canvas (which is the material the sacks are made from) and the velcro works nicely. There are still many changes to be made to the rest of the robot as we just changed the intake from our gateway robot.

Where did you get the duck canvas?

Looks good, is it still the same drive and lifting mechanism from last year?

Do you know how many sacs it can hold?

how did you stick the velcro onto the tank tread?

I found duck canvas on a blanket, you can find it on some common household materials. We still have not tried using actual sacks because they are sold out.

We have some sacks, and they slide pretty well over VEX metal plates at a 30-degree angle, so they should be fine on polycarbonate.

Thanks, that’s really good to know, that should make this that much easier for me