Chemical Clocks

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Re: Chemical Clocks

Post by nicholasmaurer »

jinhusong wrote:My understanding of the sensor ending the timer is you cannot use sensor to end it, but you sure can use a sensor to detect the end of it. You should not adjust the threshold for the time. Of cause, you should not have an internal timer to cheat.

My son's team is using the iodine clock with photo sensor. No problem in Mira Loma and Golden Gate invitations.
I am not sure I understand the distinction you are making between having a “sensor ending the timer” and having a “sensor detect the end.” Can you cite examples of each?

Any electrical sensor that is actively sensing for more than 10 seconds would violate 3.i.
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Re: Chemical Clocks

Post by Nletts19 »

Its my understanding that the rule was added so that you couldn't use a sensor's processing unit to make a "wait" timer, where a program just waits 2:30 and then starts the next thing, only appearing like the chemical reaction was sensed. To avoid this they banned all sensors in conjunction with timers to clarify the intent behind the "no electrical timer rule" which I believe exists for the same reason.

So a sensor determining when a reaction is complete would still be illegal because it is still actively sensing for 10+ seconds and because there is still a risk of it actually being a "wait" timer, even if it isn't in reality. There would be no way for an ES to know.
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Re: Chemical Clocks

Post by nicholasmaurer »

Nletts19 wrote:Its my understanding that the rule was added so that you couldn't use a sensor's processing unit to make a "wait" timer, where a program just waits 2:30 and then starts the next thing, only appearing like the chemical reaction was sensed. To avoid this they banned all sensors in conjunction with timers to clarify the intent behind the "no electrical timer rule" which I believe exists for the same reason.

So a sensor determining when a reaction is complete would still be illegal because it is still actively sensing for 10+ seconds and because there is still a risk of it actually being a "wait" timer, even if it isn't in reality. There would be no way for an ES to know.
That is my understanding as well. I can't address how this event was scored at the two invitationals in California that were listed, but this is certainly how it has been enforced in Ohio and how I anticipate it will be enforced at the National Tournament.
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Re: Chemical Clocks

Post by jinhusong »

nicholasmaurer wrote:
Nletts19 wrote:Its my understanding that the rule was added so that you couldn't use a sensor's processing unit to make a "wait" timer, where a program just waits 2:30 and then starts the next thing, only appearing like the chemical reaction was sensed. To avoid this they banned all sensors in conjunction with timers to clarify the intent behind the "no electrical timer rule" which I believe exists for the same reason.

So a sensor determining when a reaction is complete would still be illegal because it is still actively sensing for 10+ seconds and because there is still a risk of it actually being a "wait" timer, even if it isn't in reality. There would be no way for an ES to know.
That is my understanding as well. I can't address how this event was scored at the two invitationals in California that were listed, but this is certainly how it has been enforced in Ohio and how I anticipate it will be enforced at the National Tournament.
I agree with the first part. If I am the ES, as long as I can see the chemical reaction and can predict when it should end, I am OK with it, because the goal is to prevent cheating with sensor.

Sensor ending: program adjust threshold to end in time.
Sensor detects ending: expand balloon push limit switch.

My son's team will not be able to go to national. I will report back what the North California State say after 4/14/18.
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Re: Chemical Clocks

Post by nicholasmaurer »

jinhusong wrote:
nicholasmaurer wrote:
Nletts19 wrote:Its my understanding that the rule was added so that you couldn't use a sensor's processing unit to make a "wait" timer, where a program just waits 2:30 and then starts the next thing, only appearing like the chemical reaction was sensed. To avoid this they banned all sensors in conjunction with timers to clarify the intent behind the "no electrical timer rule" which I believe exists for the same reason.

So a sensor determining when a reaction is complete would still be illegal because it is still actively sensing for 10+ seconds and because there is still a risk of it actually being a "wait" timer, even if it isn't in reality. There would be no way for an ES to know.
That is my understanding as well. I can't address how this event was scored at the two invitationals in California that were listed, but this is certainly how it has been enforced in Ohio and how I anticipate it will be enforced at the National Tournament.
I agree with the first part. If I am the ES, as long as I can see the chemical reaction and can predict when it should end, I am OK with it, because the goal is to prevent cheating with sensor.

Sensor ending: program adjust threshold to end in time.
Sensor detects ending: expand balloon push limit switch.

My son's team will not be able to go to national. I will report back what the North California State say after 4/14/18.
A limit switch is not an electrical sensor, so I agree that would be legal.
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Re: Chemical Clocks

Post by PM2017 »

Since my season is over (with literally every part of my device breaking down on Friday night except three tasks, chemical clock and final action, and only chemical clock working at yesterday's competition. All those hours of designing, building, and testing, only for it to break down a few nights before the competition and get a 28th place out of 31...), I might as well share what I did for my chemical clock. (the only part that remained consistent ironically enough.)

My clock used MnO2 to catalyze the decomposition of H2O2. (2 H202 (aq) -----> 2 H2O (l) +O2 (g) ). The production of gas displaced water from a reservoir, into my water task, and adjustment was done by changing the height of the electrodes.

I used three test tubes for my chemical clock, (1. reaction chamber 2. water reservoir 3. water task), two rubber stoppers, 3 straws, and a 3d printed piece to contain the MnO2.

In the rubber stopper on the reaction chamber, I drilled a 3mm hole, and fit in one of those coffee stirrer straws, such that approximately 1 cm of the straw poked into the test tube. Then I cut the top of the star to approximately 5 cm above the top of the rubber stopper. I then applied hot glue to the area around the straw, to seal the hot, and while the hot glue was still a liquid, I placed a vinyl tube over the straw and stuck it into the hot glue.

Then, on the second rubber stopper, I drilled two 3mm holes and fit into two straws. One of the straws (which I will refer to as the gas straw because the oxygen gas travels through it) was again moved down to about 1 cm below the bottom of the rubber stopper. The other, (which I will refer to as the water straw because the water gets displaced through it), was placed as far down the rubber stopper as possible while still leaving 1-2 cm on the top. I then applied hot glue around the holes on this rubber stopper. On the gas straw, I cut the vinyl (approximately 4-6 in) attached to the first rubber stopper and attached it to the gas straw. For the water straw, I cut a piece of vinyl approximately 12 in (you will probably cut this shorter later if you use this method) and attached it. You have to do the attaching quickly, as the hot glue solidifies very quickly. Note: You might have to attach a 1 in piece of vinyl tubing to make the water straw longer, such that it reached the bottom of the test tube.

Next, I 3d printed a hollow cylinder with no top (make sure when you do this that it fits in the test tube and falls without friction), and hot glued 3 neodymium magnets to the bottom of it, (you could probably use just one, but I put three so that later, when it fell, the weight would overcome the buoyant force on the container.).

In the water task, I epoxied two straws directly into the test tube and placed in wires into each, I epoxied one of the wires in, and the other wire, I was able to move up and down, to adjust the duration.

To attach it to the device itself, I printed two 2x2 grids, with each square just slightly larger than the diameter of the test tube, and use outdoors double sticky tape to attach to the device. I put one of the grids attached to the floor of the device, and place the test tubes in, slid down the other grid and stuck the grid to the device about 3/4 up the test tube. Now, when I placed in a test tube into one of the grid, it would stay still.

Finally, we get to the setup. First, in the reaction chamber, I poured 10 mL of 3% H2O2. and placed it into the grid. I then filled the open cylinder with MnO2 and slid that down the reaction chamber and quickly put magnets on the other side. I then placed the first rubber stopper on the reaction chamber. Next, I filled the reservoir up as far as I could with water such that the gas straw was still over the water level. Next, I placed the second water stopper on the reservoir. and the 12in vinyl tub was slipped into the water task, which I had already filled with salt. I did some testing and marked on the test tube the water level and corresponding time. I was then able to pull or push the wire up and down based on the target time. (Really just to demonstrate that I can adjust the time, but set up the run for approx 2:55 seconds)

You can do whatever you want with the wires once the circuit is completed.

Hope this helps!

EDIT: I guess I should add that this method will probably need to be the start task, since activation invloves removing a magnet. You might be able to get away with having a motor pull off the magnet, or slide the magnet down below the H2O2 level.

EDIT #2: In case your state says that you are not allowed the clock must be adjusted by changing the rate of the reaction, you can make more of the open cylinders, of differing volumes.
Also, in case anyone is wondering, mine worked fairly accurately, with a plus/minus of about 3-4 seconds.
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Re: Chemical Clocks

Post by jinhusong »

jinhusong wrote:
nicholasmaurer wrote:
Nletts19 wrote:Its my understanding that the rule was added so that you couldn't use a sensor's processing unit to make a "wait" timer, where a program just waits 2:30 and then starts the next thing, only appearing like the chemical reaction was sensed. To avoid this they banned all sensors in conjunction with timers to clarify the intent behind the "no electrical timer rule" which I believe exists for the same reason.

So a sensor determining when a reaction is complete would still be illegal because it is still actively sensing for 10+ seconds and because there is still a risk of it actually being a "wait" timer, even if it isn't in reality. There would be no way for an ES to know.
That is my understanding as well. I can't address how this event was scored at the two invitationals in California that were listed, but this is certainly how it has been enforced in Ohio and how I anticipate it will be enforced at the National Tournament.
I agree with the first part. If I am the ES, as long as I can see the chemical reaction and can predict when it should end, I am OK with it, because the goal is to prevent cheating with sensor.

Sensor ending: program adjust threshold to end in time.
Sensor detects ending: expand balloon push limit switch.

My son's team will not be able to go to national. I will report back what the North California State say after 4/14/18.
Northern California State was hold yesterday. Mission Possible, our team was first to go. About VC Iodine chemical clock, ES only asked how it works and whether he can see the color change when it ends. No question about the photo detector.

Our team got second place. Mira Loma got first place even though they had to take one task out from their original list (I guess, from the long talk between them and judges). Their build is tight and high quality.
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Re: Chemical Clocks

Post by ScottMaurer19 »

jinhusong wrote:
jinhusong wrote:
nicholasmaurer wrote:
That is my understanding as well. I can't address how this event was scored at the two invitationals in California that were listed, but this is certainly how it has been enforced in Ohio and how I anticipate it will be enforced at the National Tournament.
I agree with the first part. If I am the ES, as long as I can see the chemical reaction and can predict when it should end, I am OK with it, because the goal is to prevent cheating with sensor.

Sensor ending: program adjust threshold to end in time.
Sensor detects ending: expand balloon push limit switch.

My son's team will not be able to go to national. I will report back what the North California State say after 4/14/18.
Northern California State was hold yesterday. Mission Possible, our team was first to go. About VC Iodine chemical clock, ES only asked how it works and whether he can see the color change when it ends. No question about the photo detector.

Our team got second place. Mira Loma got first place even though they had to take one task out from their original list (I guess, from the long talk between them and judges). Their build is tight and high quality.
I think the FAQ online makes it very clear that a timer cannot get points if it is ended by an electrical timer... The NoCal ES is by no means Patrick Chalker who will be running nationals
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Re: Chemical Clocks

Post by Unome »

ScottMaurer19 wrote:
jinhusong wrote:
jinhusong wrote:
I agree with the first part. If I am the ES, as long as I can see the chemical reaction and can predict when it should end, I am OK with it, because the goal is to prevent cheating with sensor.

Sensor ending: program adjust threshold to end in time.
Sensor detects ending: expand balloon push limit switch.

My son's team will not be able to go to national. I will report back what the North California State say after 4/14/18.
Northern California State was hold yesterday. Mission Possible, our team was first to go. About VC Iodine chemical clock, ES only asked how it works and whether he can see the color change when it ends. No question about the photo detector.

Our team got second place. Mira Loma got first place even though they had to take one task out from their original list (I guess, from the long talk between them and judges). Their build is tight and high quality.
I think the FAQ online makes it very clear that a timer cannot get points if it is ended by an electrical timer... The NoCal ES is by no means Patrick Chalker who will be running nationals
So Patrick Chalker is in fact on Mission and not e.g. Roller Coaster?
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Re: Chemical Clocks

Post by nicholasmaurer »

Unome wrote:
ScottMaurer19 wrote:
jinhusong wrote:
Northern California State was hold yesterday. Mission Possible, our team was first to go. About VC Iodine chemical clock, ES only asked how it works and whether he can see the color change when it ends. No question about the photo detector.

Our team got second place. Mira Loma got first place even though they had to take one task out from their original list (I guess, from the long talk between them and judges). Their build is tight and high quality.
I think the FAQ online makes it very clear that a timer cannot get points if it is ended by an electrical timer... The NoCal ES is by no means Patrick Chalker who will be running nationals
So Patrick Chalker is in fact on Mission and not e.g. Roller Coaster?
That is what he said at the Centerville Invitational.
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