How far does the tote drop out of feeder station?

[mitchklong]

Due to design constraints our bot cant easily grab an object closer then 3" to the wall.

Can anyone who might have a mockup of the feeder station tell me how far the tote typically drops from the wall ?

[CalTran]

Originally Posted by mitchklong

Due to design constraints our bot cant easily grab an object closer then 3" to the wall.

Can anyone who might have a mockup of the feeder station tell me how far the tote typically drops from the wall ?

Given that a tote is 17" wide and 27" long, how does not grabbing something 3" from the wall constrain you from grabbing a tote?

[notmattlythgoe]

Originally Posted by CalTran

Given that a tote is 17" wide and 27" long, how does not grabbing something 3" from the wall constrain you from grabbing a tote?

My guess would be that they are grabbing from the long end and their gripper won't fit around the tote if it is closer than 3" to the wall.

[Kevin Leonard]

Originally Posted by mitchklong

Due to design constraints our bot cant easily grab an object closer then 3" to the wall.

Can anyone who might have a mockup of the feeder station tell me how far the tote typically drops from the wall ?

Totes seem to drop differently every time they come out of the feeder station, and often in different orientations.

The community here might be able to help more if you gave a few more specifics about your mechanism, maybe pictures or CAD renderings.

[earlybird]

Originally Posted by mitchklong

Due to design constraints our bot cant easily grab an object closer then 3" to the wall.

Can anyone who might have a mockup of the feeder station tell me how far the tote typically drops from the wall ?

It looks like you shouldn't have too much of a problem looking at one of the Robot in 3 days videos. I don't know what material they used for the chute though, it might make a difference because of the coefficient of friction difference between plywood and the HDPE.

https://www.youtube.com/watch?v=h928WDUTPSA

[mitchklong]

Originally Posted by CalTran

Given that a tote is 17" wide and 27" long, how does not grabbing something 3" from the wall constrain you from grabbing a tote?

If you looked down from about the bot is shaped like a U with totes going into the u.

The depth of the U is what we are considering. a 30" depth makes it quite stable but if we try to stack a tote touching the wall the stack is out of alignment.

If the totes fall 3" from the wall I dont think its an issue.

Do they ?

[Kevin Leonard]

Originally Posted by mitchklong

If you looked down from about the bot is shaped like a U with totes going into the u.

The depth of the U is what we are considering. a 30" depth makes it quite stable but if we try to stack a tote touching the wall the stack is out of alignment.

If the totes fall 3" from the wall I dont think its an issue.

Do they ?

I would encourage you to adapt your design to the unpredictability of totes falling from the tote chute, as they vary quite a bit.

If this does turn out to be a problem for you, there are some relatively simple solutions available.
The "Passive Hook" Mechanism from Build Blitz (found here: http://www.buildblitz.com/what-is-th...o-move-a-tote/) is an easy way to pull a tote along the ground away from the wall if this becomes a problem, or to pluck totes from the landfill to grab instead.

If you really want to get some data on how totes fall, or see how your robot interacts with the game elements, it's not difficult to build a feeder station out of plywood from resources provided by FIRST (here: https://rps01.usfirst.org/frc/manual..._Versions.pdf), and put down some carpet and test yourself.

[ehochstein]

Originally Posted by earlybird

It looks like you shouldn't have too much of a problem looking at one of the Robot in 3 days videos. I don't know what material they used for the chute though, it might make a difference because of the coefficient of friction difference between plywood and the HDPE.

Also consider what type of flooring the tote is dropping on. We've noticed a lot of difference in dropping the totes on a carpeted vs. shop (concrete) floor.

[Taylor]

Originally Posted by Kevin Leonard

Totes seem to drop differently every time they come out of the feeder station, and often in different orientations.

The community here might be able to help more if you gave a few more specifics about your mechanism, maybe pictures or CAD renderings.

Originally Posted by Kevin Leonard

I would encourage you to adapt your design to the unpredictability of totes falling from the tote chute, as they vary quite a bit.

These statements are interesting to me; in our tests, the totes come out exactly the same way every single time.
We are testing on carpet floor, with a slick chute surface similar to HDPE.
We have noticed that there is a tendency for the tote to do a nose-dive when exiting the chute and stand on end when on carpet. On a tile floor, the tote slides to a horizontal orientation.

[Bongle]

Every single one of our tote-drops through the wooden setup onto an official FRC carpet have ended nose-down. If you look at some of the field videos from kickoff, some people do a tote drop and it does the same thing.

[Hallry]

Originally Posted by Bongle

Every single one of our tote-drops through the wooden setup onto an official FRC carpet have ended nose-down. If you look at some of the field videos from kickoff, some people do a tote drop and it does the same thing.
.

Totes landing nose-down on official field: https://www.youtube.com/watch?v=Y1-3u9NEeO4#t=58

[Mark Sheridan]

Originally Posted by Taylor

These statements are interesting to me; in our tests, the totes come out exactly the same way every single time.
We are testing on carpet floor, with a slick chute surface similar to HDPE.
We have noticed that there is a tendency for the tote to do a nose-dive when exiting the chute and stand on end when on carpet. On a tile floor, the tote slides to a horizontal orientation.

Same thing here. It always lands nose down. We use HDPE in our chute with a polycarb door. I think our carpet is the same as the official ones this year (its from 2012 or 2013 vendor but I have to double check that)

3309 confirmed the same thing with their 2013 spec carpet.

[BrendanB]

Originally Posted by Hallry

Totes landing nose-down on official field: https://www.youtube.com/watch?v=Y1-3u9NEeO4#t=58

We played around with the official field and that was how they came out every time.

[Canon reeves]

Has anyone tried putting them in upside down? I haven't seen any videos of it, and I haven't been able to build a chute yet.

[Hallry]

Originally Posted by Canon reeves

Has anyone tried putting them in upside down? I haven't seen any videos of it, and I haven't been able to build a chute yet.

That's because they do not fit in the chute upside down.