struggling with project

"I would add a simple robotic arm to grab the bottle and place it in the bin. the robotic arm will have grippers. who cares if the bottle is crushed. bingo"

how would you react the loads if your arm is only placed on the surface ?

picking up the bottle would be an ask, particularly with that offset.
maybe lay the bottle on its side ?

could the bottle have a hole in it ? maybe no cap ??

have they run a similar problem before ?

Time for OP to answer some of the questions we posed.

rb1957 said:

"I would add a simple robotic arm to grab the bottle and place it in the bin. the robotic arm will have grippers. who cares if the bottle is crushed. bingo"

how would you react the loads if your arm is only placed on the surface ?

picking up the bottle would be an ask, particularly with that offset.
maybe lay the bottle on its side ?

could the bottle have a hole in it ? maybe no cap ??

have they run a similar problem before ?

Click to expand...

it would require a base that is bolted down.
since a bottle mass is lite. minimal FBD.
forces would be minimal. it have to be able to rotate and swing. requires an actuator for the Jaws. very light construction. will it work?

First, thank you to whoever helps. I’ll try to explain myself more clearly.

I need to build a device (asseble a product by using the components above) that will be able to pick up a full 750 ml bottle of water which approximately weighs 770 grams. That bottle need to be place onto a mini tower which is 20 cm height, 21 cm long and 19 cm width (mentioned in the attachment as “here is where the bottle will be placed").

Let's say I’m standing infront of the diagram I've attached, my device will be place to my right (as mentioned "the model place here") , the bottle will be to my left somewhere within the elliptical area whereever i want to (mistakly wirtten as “recycling bin” instead of "bottle of water") and the mini tower is on upper right.
Let me phrase it like this: pre-experiment - i can put, using my device parts only, something on top of the bottle or even grab it. Then experiment begin by me activating a trigger starts a chain reactions which eventually place the bottle onto the minitower.

So let's break it down into sub-goals:

1. Grabbing the bottle: a. How would you pick the bottle off the ground? b. How can i create enough friction and stability on one hand that keeps the bottle from slipping and on the other allows it later to drop onto the mini tower ?
2. Generating height of just over 20 cm – How would you create a potetional energy? So the second challenge, after i've managed to grab the bottle, is to create a potetional energy of a little bit above 20 cm height. So the only idea i've in mind is doing it by dropping small weight from tying it to my device.
3. How can I create a rotational energy of an approximately 90-110 angle degrees to the right (the mini tower is right to my device)?

I've added some illustration of the bottle and the rubber bands.
I appreciate your helping

Ron247 said:

Just trying to understand what you are doing.

1. You are not building the recycle bin.
2. You are building the piece of equipment that moves the full water bottle from the big ellipse to the smaller ellipse.
3. You are calling the equipment, the "model".
4. The model must set inside the rectangle.
5. You are allowed to "place parts of the model on top of the water bottle" before activating the trigger.

Assuming what I have said above it correct:

1. Are you allowed to use force to "place parts on the model" in the sense of stretching a rubber band or forcing something to rotate as you place it on top of the water bottle.
2. Is your model secured/fastened to the top of the bin?
3. Does it have to be lifted, or can it be tipped over or slid?
4. Can you baseball bat it into the opening?

For me, all problem solving starts with 2 things. 1) accurately define the problem (this definition should not include a proposed solution) 2) think of ALL ways you could accomplish this REGARDLESS of your specific project criteria.

With training, these 2 steps take about 5-30 minutes in many cases provided no one gets wrapped up in your project specific criteria.

Click to expand...

1. Correct i don't need to build a recycle bin . what i do need to build is a device that be able to pick up a full bottle of water.
2. So to be clear I've mistakly written “recycling bin” instead of "bottle of water area". Let's say i'm facing the diagram to my left is the bottle to my right and the device and on the top right is a mini tower 20 cm height where eventually and bottle is needed to be put onto
3. Not sure if equipment is the correct word but what i mean is i need to assemble a product/ device that be able creating physics energies
4. Yes the device is rectangle.
5. Correct so before activating the trigger i am allowed to put something on the bottle or maybe grab it. also if it matter i can put the bottle whereever i want within the elleptical area (mistakly written as recycling bin

1. Yes As long as the bottle stays on its place without moving before the activating the trigger. i can put something on or even grab it (of course only by using the device's parts)
2. The device is put on 2cm height platform so i can tie it to its legs with threads or rubber bands. Just to be clear the device will be place within area the rectangler area which is 16.5cm long and 28 cm width and the ceiling is the height limit .
3. It needs to be lift off the board
4. Not sure what you mean - but generally speaking i can place the bottle wherever i want on the other half of the left board.

My three challenges :
1) creating a potential energy - how can i lift the bottle around 21cm off the board
2) I need to create a mechanism that as soon as one action ends, the next action will begin
3) Creating rotation - my device will face toward the bottle and i need to create 90-110 degrees to the right.
thank you for helping

rb1957 said:

"I would add a simple robotic arm to grab the bottle and place it in the bin. the robotic arm will have grippers. who cares if the bottle is crushed. bingo"

how would you react the loads if your arm is only placed on the surface ?

picking up the bottle would be an ask, particularly with that offset.
maybe lay the bottle on its side ?

could the bottle have a hole in it ? maybe no cap ??

have they run a similar problem before ?

Click to expand...

So just to be clear I need to build a device that will be able to pick up a full 750 ml bottle of water which approximately weighs 770 grams only using the specific components from the list above. Let's say I’m standing infront of the diagram I've attached (instead of "recycling bin" it should be written bottle of water), my device will be place to my right (as mentioned "the model place here") , the bottle will be to my left somewhere within the elliptical area wherever i want to (the whole half side approximatly half of the board) and the mini tower is on upper right which is 20 cm height .
I will just point out that the water in the bottle must not spill, otherwise it is disqualified. I have a total of three attempts.
initially i've thought about making a hole and maybe transferring the water to a sealed plastic container, but the tester is very rigid and as soon as a drop of water falls on the board, I will be disqualified. So I'd rather not take the risk by tilting the bottle or removing the cap.
no similar problem before which leads me to next question if you know a simulator, even with payment, that can simulate the course of the experiment with all the details?
thank you i apprecaite your helping

if you are allowed to bolt it down ... OP has said "placed", which open to interpretation

rb1957 said:

if you are allowed to bolt it down

Click to expand...

No bolts in the allowed materials list.

There's masking tape and glue.

yes, to assemble pieces together. OP, can you glue the device to the staging area ? (and leave it there to cure ...)

Seems simple enough, a 3 or 4-axis robot with path and acceleration control including a gripper that has a compliant mechanism that is just strong enough to hold the bottle and not strong enough to push liquid out the open top. 3-axis to put it onto a tower, 4-axis to turn and empty it.

With the main requirement now clearly stated, it's off to designing it from materials generally not known for use in doing any of those things and motive sources that aren't known for acceleration control.

Most robots used for this sort of task weight 10-100 times what the payload does and are still bolted in place to avoid tipping.

Step 1: Build a crane tower (use popsicle stick and skewer, with embroidery thread and glue to bind) tall enough to lift bottle about 2 cm above the finish point.
Step 2. Grab bottle with a non-stretch material (embroidery thread and popsicle sticks or skewers should work).
Step 3. Run some sort of rope over a pulley at the top of the crane tower to where the bucket (or cup) is located.
Step 4. Fill the bucket with enough material to outmass the water bottle and lifting arrangement. Mass can include the bucket/cup. This is your counterweight.
Step 5. Install locking mechanism to hold cup at top of tower - your trigger will release the bucket to allow it to drop vertically.
Step 6. Once the counterweight is near bottom (about 1 cm above floor level), use the mass of the counterweight to trip another action that pivots the beam holding the bottle toward the landing zone.
Step 7. Once bottle is over landing zone (remember, it's still about 1 cm above the landing level), figure out where the counterweight will be and install a small ramp to tip the mass out of the counterweight. This should allow the bottle to settle onto the landing zone.

The first trick is building the tower sturdy enough to support the bottle, the lifting arrangement, and the counterweight - AND allow the upper beam to pivot (relatively) freely. The second trick is to use just enough ramp (or whatever else you do) to upset the counterweight and lighten it.

Thinking all this through from the top again - lift higher, have counterweight start a swing action powered by the weight of the bottle (i.e. the transition from lifted toward the landing zone is not level, but slanted toward the zone). Then have a stop that prevents the counterweight from moving past a point where the bottle is in the zone.

I guess we don't know enough of the project description. Can you hold your structure down ? (that'll make it much easier) Can you direct/move the structure ? or can you only release a trigger ?

I think my best idea is to make an impressive looking structure, place it, place the bottle, laying down, then lift the table top (so the bottle rolls into the target).

Ron247 said:

Now back to the full bottle. Full bottle with or without a cap fastened to it?

Click to expand...

with cap

Robin, how about some of my questions ?

1) can you attach your structure to the base ? (or only place it there) ?

2) how much material is needed to create a counter weight for the bottle ? What's the densest material you have (and easily packageable) ? (popsicle sticks ?)

3) how much manual interaction can you have ? only action a trigger ? multiple triggers ? move the structure (pick up the bottle, hold the structure and move the arm, release the bottle) ?

If there is a cap how can it spill?

built a tower to lift it partially. Mahe ramp so it will roll intothe spot.

I would try doing it the following way although I have not worked out the details:

You need to lift up bottle about 8 inches (20 cm). The only thing that is strong enough to lift the bottle like a beam would be the skewers unless you could possibly make a complex truss with the popsicle sticks. A metal skewer should be able to lift the approx. 1.6 pound bottle without bending similar to a crane boom. I assume the skewer is 24 inches long minimum, if not you can request if you can use a specific length from the teacher.

To lift the bottle 8" you must have the beam (skewer) placed over the bottle at least 8" and pull up with a rope (embroidery thread or rope of twisted threads possibly) attached to the bottle. To do this you need a platform or crane pedestal to place the crane boom on (skewer). I would make a crane pedestal as follows:

Start with the core of the paper tower roll situated vertically and attached to a piece of square cardboard at the base. They are typically about 11 inches long but you can glue sections together to make as high as you want. Then install square rings of popsicle sticks around the roll at different elevations from very bottom to the top say vertical spacing about 4 inches. You can glue the flat side of the popsicle stick to the roll surface for all four pieces of the square then glue the ends of the sticks where it forms corners to each other. Then interconnect the popsicle sticks together by gluing four vertical sticks between each set of rings. In this way a continuous structure of popsicle sticks is formed that should be strong enough to lift the bottle. If you need to you could also install some diagonal members across the vertical members for additional strength forming a truss like shape.

Now you have a crane boom (skewer) that is on crane pedestal (popsicle sticks with paper roll core).

The skewer is to be placed such that it is centered over the pedestal. Half to one side and half to the other side. In other words if you have a 24" long skewer, 12" long will overhang the pedestal towards the bottle side and 12" length will overhang away from the bottle side. In this way it can be perfectly balanced on the pedestal at the pivot point.

Next you need a pivot point. This you can make out of piece of another skewer. If you have another skewer you can cut just enough to be able to install from one side of the pedestal to the other in the center. Extra popsicle sticks may be required where this horizontal piece of skewer rests on the pedestal for reinforcement support and attachment.

Now I think you can make some type of connection between the boom skewer and the horizontal skewer with popsicle sticks. You can attach two short pieces of vertical orientated popsicle sticks to the horizontal skewer by attaching to the horizontal skewer using holes drilled into the sticks and slipping over the skewer. Holes should be just a little larger than the diameter of the skewer so that they fit loose and allow rotation.. Now you have two vertical short pieces of popsicle stick that can orientated vertically up spaced at about 1 to 2 inches apart. Next you need to build something similar on the boom skewer with popsicle sticks to make an attachment on the boom skewer to glue to the popsicle sticks on the horizontal skewer. The popsicle sticks on the boom skewer needs to be glued fixed so it cannot move or rotate.

Now you have a completed crane that can lift the bottle vertically.

To lift the bottle you need a force applied to the crane once the trigger is released. The only way you can get a force from any of the components you show in your list of parts is from the elastic potential energy of the stretched rubber bands. The way I see it is that the small thin rubber bands you show are easily stretched so cannot support a load without stretching too much and maybe even breaking. Therefore you need to make a assembly of rubber bands consisting of rings of multiple rubber bands connected in parallel together then each set of rings connected to each other using a loop connection to put the set of bands together in a series of loops like links in a chain. This will give the entire assembly of bands enough force to lift the bottle while not stretching too much. I think you will need two to three separate links of bands.

Let me try to explain a little better. Take say 4 or 5 rubber bands and put on your finger together not connected but just close together side by side. This is one link of rubber bands. Create another set of 4 or 5 rubber bands on another finger. This is a second link of bands. Take one set of band and connect to other set of bands by fitting one set through the other then around and through to form a knot. Do this for more links in the assembly as required as determined by testing to see how many link/length of assembly you need. The assembly of bands will be stretched manually by hand and attached to the back side of the boom and kept stretched by the trigger mechanism so that no load is put on the boom skewer until the trigger is released. When the trigger is released it will engage the bands on the boom. The bands will want to contract to a point that the force of lifting of the bottle equals the force of stretching of the bands pulling down one side of the boom and lifting the other side and the bottle. Note that when initially stretching the bands there is much more force than required to lift the bottle so the bands will necessarily contract.

to be continued

Snickster said:

. A metal skewer

Click to expand...

I assumed

Actual bamboo has a pretty fast growth rate; it might be possible to make use of that if enough light is available.

I wonder what school proposed this effort.

Shear leg or similar simple derrick on a turntable.