Help with stacking

Hey everyone,

Over the past few days, my robotics team and I have been building a robot that’s based off the OSIZR reveal by ALBA (it has the same chain arm and mobile goal intake presented in the video. Our claw is horizontal and consists of two oneby’s that have tank chain attached with rubber flaps meant to grip the middle of the standard cone.). However, we have run into one glaring issue, which is that the bot is only able to stack 6 standard cones onto the mobile goal before it is unable to stack anymore.

Here are some basic numbers about our bot:
4 Speed motor drive
4 Speed motor arm tower
1:5 Gear ratio arm tower
1 Torque motor mobile goal intake
1:7 Gear ratio mobile goal intake
1 Torque motor standard cone intake
30-hole tall arm tower
35-hole arm

How should we go about making the robot be able to stack more cones on mobile goals that are already held in our robot?
(Here’s a link for the OSIZR reveal OSIZR by ALBA Reveal - YouTube)

Well the main disadvantage of the robot is the low height, and by creating this design you can’t really go any higher. You can’t extend the bar because of the chain bar. The best option would to put the chain bar on a lift.

Hey Floop! (Cool name by the way :stuck_out_tongue: ). ALBA can only stack 7 cones high, and it’s possible a slight difference in spacing or positioning has decreased the maximum stack height to 6 for you. For an early season competition, 6 cones just might be enough to win. But, if you want to go higher, you will need to mount your chain bar on a lift. A 4 bar, elevator lift, DR4B, or scissor lift would probably be your best option. Here’s a video of a really strong chain bar on a DR4B.

This video is a great starting point, but a different type of lift might be just as fast. Good luck!

iFT robot design requires you to put the mobile goal down before stacking.
(And maybe I am nitpicking… but always thought all these designs are not truly internal stackers - the mobile goal is “outside” the robot, and not totally inside the robot).

What I find most interesting about this video is that 5 cones can be stacked without altering the height of the lift. Would it be correct to say that you could have a lift with a low position that stacks up to five, and a high position that stacks to 10?

In my opinion, the best way for you to increase the number of cones able to be stacked is to put the chain bar on a lift. However, if this is not a option for you at the moment. The only thing that i can think of is by grabbing the cone at the base close to the ground. This way you may get an extra 2-3 in for maybe a final cone at the top. Hope it helped.

Another possible idea is that rather than putting your chain bar on a lift, try to come up with a different intake that will still allow you to place cones while the chain bar is vertical. This may not be possible for you with a claw, but it would allow you to get the maximum height out of the chain bar and should waste less time since you are only going to vertical, not past vertical.

Why not put another chain bar on your chain bar?

@pie_safety Hmmm, that sounds pretty neat! Just curious, is what is shown on with 8059Z’s chain arm on a RD4B what you had in mind?

@Anomaly That video is great! The chain lift is practically what we have right now. The only problem I can see with that design is that it might not be able to reach cones on the ground. Do you have any more information regarding the IFT robot?

@nbennett Yeah that’s what we were thinking… However, when we moved the claw down to reach the bottom part of the cone we found that the distance we moved the claw down would compensate for the lower grip on the standard cone. Do you think we’re doing anything wrong or have any advice on how to execute your idea better?

@9065_parker Huh… We never thought of that. If we were to design a “double chain bar” (?) are you thinking of having the first chain bar be some sort of extension to the second chain bar, similar to what Cameron S did in , but could swing back and forth?

Personally I would change your intake mechanism from a claw. A saying that is common in FRC about intake is “touch it, own it”. That means if you touch the game piece you should have almost instant control of it, and to me that means you have an active intake. Currently what I(not my team) has been working on is a dual roller conveyor(similar idea to 2015 FRC intakes) that grabs the cone and then moves it through the robot in a linear fashion where it drops onto the stack. This would allow you to have the bottom of the cone approach the stack from the base of the cone rather than the top of the cone. This idea has not been tested in the real world, but I am confident that it will see great success

I mostly said that as a joke, as for some reason that just sounds impractical, but now that i think about it, it’d be similar to a “double reverse chain bar” like a dr4b, but with chain bars instead of 4 bars. And if you end up making it, please show me, as i would gladly buy you a soda the next time i see you

Another reason to reconsider, is its very easy to grab more than 1 cone, we tested that very design to no avail because it was so easy to grab more than 1 cone, and therefore get dq’ed

@9065_parker since your team has decided to not use this idea, would you mind sharing the specs on your teams version? Also Would you happen to have any pictures or video of it? I’d love to see how you guys built it and it in action. I already have a version, but its good to see others variations of a similar design.

I cant, as we already took it apart

Glad it’s helpful! A very short clip was posted on that team’s instagram, which I’ve linked here

It looks like the IFT bot can reach the cones on the ground, but a chain bar does definitely have reaching limitations. It might be a good idea to see if you can extend the chain bar to 38 or 40 holes instead of just 35 to increase your reach if you don’t want to build a lift.

@Anomaly If we were to increase the size of the c-channel we’re not sure if the arm would still fit in size… Right?