Help on suction of sprocket

As you know recently , NewZealand , i was amazed by their incredible “sucker” i would suggest. So we built a robot quite similar to it for a run , however , our robot apparently seem weird. Our 6-bar linkage was moving at different speed and we had problems in connecting the “sucker” to a suitable height and length , and even if we did so , our “sucker” will tend to move in opposite direction , i believe due to weak structure , how do you guy suggest ? I would like to hear your opinion. How were they able to place their “sucker” that is able to move around yet be very stable during the match?

In New Zealand we currently have two types of “sucker” intake - side suckers and top suckers. Side suckers seem to be much more common, as shown in where most of the robots used this intake style.

What do you mean by “moving at different speed” - it seems like that might be a problem with your six-bar arm programming, and not the intake. Make sure you have potentiometers on each side of the arm and that you are using the information from these to keep your arm stable.

What do you mean by “opposite direction” - that would indicate another programming problem to me.

I think he meant that their side “suckers” would spread apart/expand too much when it was collecting the objects, thus rendering it ineffective. :stuck_out_tongue:

I would like help with this sucker also. My team is trying it, but can’t figure away for the conveyor to drop. Also we don’t know how to have our conveyor expand/ contract so we can pick up objects of any size.

Any ideas?

If I’m not wrong, there is a “stopper” holding the suckers up before the match starts. To release the suckers, you simply lift up the mechanism slightly over the stoppers. If you analyze the videos carefully, you can see that most of the robots with this type of design have their mechanism lifted up at the start of the match and then lowered. This type of release mechanism can also found in Green Egg’s Round Up robot in their descoring fork.

As for the expansion/contraction of the suckers, i believe that they are just simply attached onto a piece of metal which pivots at one point. Vex aluminium is quite flexible and this allows the suckers to expand when needed. However, there are rubber bands providing the tension to pull these suckers back to their contracted position.

These are the 2 clearest photos i could find:

What would you like to see better of? I have my robot at home, so can help if you want it

In the meantime, here’s a clue as to how most teams implemented the the suckers dropping down at the beginning of the match. This is the photo above, just cropped:
New Picture (2).jpg

Yes , i mean’t by that , thanks for explaining

Could you give more information ? Apparently my school have a regional competition in 2 weeks and we need the robot to be up asap however , we
are only having problems with the latching. If we latch , we are unable to make it turn down and if we do not latch , the force of the rubber band would slam it down , can you give us a clearly picture or a demonstration ?

Yes certainly , that would help a lot.

Yes , i have seen those picture , however my team is unable to get a clearer picture of it .

Jacko we would like pictures of your locking mechanism. Also how your robot has the coneyor fold out/ stay down there securley. Lastly close up pictures of your sucker that would help show us how teams expand/contract there conveyor for objects.

So one of my teams robots is just like AURA, interaction zone robot, Java i believe. Umm i was thinking of making our rollers a bit faster without adding more motors. We currently have a 12t sprocket being driven. Will it make it faster or make the rollers/chain move faster if we but a 30t sprocket?:confused:

My team has tried making our old conveyor fast by changing the ratio. We tried a 5:6 (18 tooth on motor) This gear ratio works quite well. It felt slightly faster and still had torque. What sprocket do you currently have on your motor?

Yes, it will increase the speed and decrease the force. However it might make the chain more likely to fall off (I don’t know this for sure, just teams I’ve seen that used large sprockets on tread intakes seemed to have more problems with treads falling off than ones with small sprockets).

ok so what would you recommend? 24t sprocket, or smaller? because the speed of the intake/outake was a bit slow. Also we dont want it to fall off. what do you think is the best size, and what size do you have on your robot right now?

I think Java used an 18T sprocket (driven) at the back and a 12T sprocket (idling) at the front.

ok thanks, i think were going to test the 24t and see if we have any issues, then we might lower it to a 18t depending on how it worked. :slight_smile:

Do you have any pictures we could look at of this?

So do any of you have any pics on how the sucker can be locked at the beginning of the match then unlocked once lifted bc my team desperatly needs this we are running out of time to complete this intake.:frowning:

Please and Thank You:)

Why don’t you try to build it on your own instead of copying it? It’s not that hard to build a release mechanism for something that can fall using the force of gravity. It just takes a little thinking.

It’s one thing to use another team’s idea for the overall design of the robot, but another thing to start making screw for screw copies.

Creating a latch system to keep your intake within the size constraints can be challenging, but I can assure you if you are using the intake design discussed in this thread, making the latch is simple.

All you need is two “hooks” with lock into each other. Use the intake motor/motors to power the latch. One latch will be mounted solid to the “basket” of the intake, and the other to the “wheel”. When the intake is latched, the intake will remain in size, once the intake is spun the latches will unhook and the wheel will be able to fall. You will need a set of latches for each intake wheel.

Hopefully this makes sense, if not, let me know and I’ll try and explain further. :slight_smile:


Couldn’t you just push your intake down by hand? I think it would be quicker because you would not need to lift arm to activate latch…I am going to have to check in the rules though to see if it is legal