Hello, I would just like to thank you for how helpful this video has been throughout what has been an up and down SciOly season for Air Trajectory. I was able to get 1st recently at the SEPA regionals and am looking forward to competing in states as well!
hi there! I’m using a pretty similar design to the second one in that i have a mass holder (I 3d printed) sliding down the main PVC tube acting as a piston. The issue is, it just doesn’t fire the ball near far enough (maybe a m or two?) I think it’s because there is friction, so I am going to grease everything up, but how different in size was the mass thing vs the inner diameter of the pvc? i think mine is getting caught on the wall and slowing down so the ball doesn’t really fire much at all! Thank you for all the help
@@abhishekgarg3945 Go to the local hardware store and see what they have. This video is meant to give you a basic idea .. hopefully you can improve the design and build a better one!
What would would happen if we didn’t use the vent holes on the side of the drop chamber? Would that be a reason for the ball not going as far as it should be going (2nd design)
Vent holes allow the weight to drop fully, if there were no vent holes, then the weight wouldn't be able to go all the way down the drop tower due to compressed air building up underneath it.
Could you explain for the second design (the one with the two connected pvcs and the elbow, the air pressure system in that pvc that distributes air to the second launching pvc that shoots the ball? I don’t get how after the mass gets dropped, what the air pressure system would be hit and how it would go into the second pvc. Also was it some sort of foot launcher or balloon? and also how was the ping pong ball stored, did it go all the way to the elbow or was it stored straight on the launching pvc and how.
Yes, the ping pong ball went all the way down to the elbow. There was no balloon or other air storage that was hit with the mass, the mass was tightly fit to the diameter of the pipe forming a piston that compressed the air. No need for anything else
Would you be able to describe how you might be able to get the most maximum distance with the piston? I have replicated ur design, however, it doesn’t reach 8m, in fact it only goes to a maximum of 4m from each angle.
Simply gravity... The falling weight is carefully sized to be exactly the same size as the pipe. (layers of tape were added so that it would be a snug fit. The falling weight just compressed the air in the pipe- as it is forced out the side pipe, the projectile is launched.
@@d6mallik Yes... find a food can that is the same diameter as the pipe... fill it with fishing weights... wrap with tape or plastic to ensure a good fit.
Hi, good video but I have a question. For your 2016 design how did you make you ball go a farther distance because i am using your same design but my ping pong ball is only ping about 1 meter. so what should i do to make my ping pong ball further. also did you use any lining on the bottom of your design to stop a loud noise from the weight?
This has been answered with other comments... Diameter of the barrel is important, as are vent holes on the side.... some cloth or rubber on the bottom can cushion the landing.
How did you make the 4-inch weight that perfectly fit into the tube? Also wouldn't the air just go up? How did you get it to go through the elbow tube?
@@ChandiGarg we looked through our recycle bin and found a steel can that was close to the right size. Then added duct tape until it was a perfect fit. Once the weight/ piston was falling down, the only place air could go was through the hole at the bottom
Hi, so the mass is airtight and all but it still doesn’t seem to shoot the ball out far? Did your mass hit all the way to the ground and hit the wood on the bottom? Or was there a technique in how you released it? I just don’t understand how it still is a mass that is basically airtight and not shooting the ball out at all from our pvc.
The mass did not fall the whole way to the bottom... I believe we put some material in to use up the airspace below the exit pipe.... If that makes sense. I believe we may have also used some material to lubricate the falling mass...
Alright, we made the exit space become airtight however it still doesn’t fully shoot the ball out, did you guys perhaps use max weight, is there any additional information I should take into account to maximize the speed of this mass and the output of it shooting far?
@@user-qs5fu1of2q there are hundreds of small variables to take into account... In order to make more suggestions, I would need to see what you have built and how you are operating it... Part of the wonderful thing about science Olympiad is the experimentation... It will take a lot of trial and error to optimize your device. The more you practice, the more you experiment, the more you will learn about the functionality... That's engineering!
Hi! Just wondering, for the 2015 design, did you have to do any sealant on the pipes and also where did you get the pipe that the ball shoots out? We have been looking at different hardware stores but many of the pipes are extremely long
Almost all of the joints were just pushed together, hand tight, no glue or sealant. Most of the supplies, came from our garage from various home projects. The barrel pipe is one and a half inch PVC... Some hardware stores sell this in short pieces
hey, so I built the second design you showed, but I’m having trouble with consistently getting the ping pong ball to stay in its place. Do you have any tips, or was there anything specific you did to mitigate this?
@@TMartScienceThank you for answering, I appreciate the quick reply. I had another question regarding how where you drop the weight from affects the kinematics of the system. Would releasing the weight from a lower height make the projectile go further?
Hi! For you 2015 ball design, could you tell me which kinds of weights you used? I’m struggling right now because we need 20 lbs right now to launch the projectile, but we can’t find anything that would fit inside the dropped container!
Hi, I am currently using a similar design to your 2016 design but my cannon can only send the ping pong ball about 5 meters maximum. Do you have any tips on how to maximize distance?
We also found that changing the mass did not change the distance that much. We only used one mass. The vent holes along the side of the tower were very useful too. Allow some air to escape so that the projectile did not fire too quickly
Found objects are typically a better route than ordering.... see comment above, we found a can that was similar diameter, then filled the can with fishing weights.
What did you use to connect the pvc pipe with the falling weight to the pvc pipe that shoots out the ball? If it is possible, do you think you could provide a materials list? Would be much appreciated, thanks!
The fitting used was just a T fitting... All of the parts were just pushed together by hand, no glue necessary. As far as material list, you can see all of the parts, the best thing you can do is go to a hardware store and try and figure out what they have and come up with your own improvements on the design.
Hi I was wondering if you could explain how you were able to use the fence post to be able to change angles with the protractor with still being a snug fit so air isnt lost through the holes?
Hi. I think that in order for the ball to be launched at all, there needs to be an enclosed air chamber in between the piston weight and the ball so that there is enough air pressure to push the ball out. How did you enclose that kind air chamber in your design, if there even was one? Are there other alternatives to create pressure for the ball to be launched? Thanks, this video is a big help!
No enclosed air chamber required. As you can see, additional holes were drilled in the drop tower to release some of the pressure so there was not too much.
@@savoryseaweed495 Yes... that is why you practice it first.... figure out where to point the laser for each desired distance. It takes a lot of trial to calibrate the set-up
So for your bucket design (2015) how’s you connect the launch pipe and the beach ball while reducing air loss, and what’d u do to keep the actual launch pipe upright.
The pipe was connected to the ball and the bottom of the bucket with a bathroom sink drain (purchased from a hardware store) The launch pipe was held largely with friction
what would you do different if you did this again - it seems like there should not be anything that makes it better. Perhaps the intervals the weight is dropped or the number of holes?
As explained in the video, a bathroom sink drain was used. This compression fitting went into a hole in the ball and can easily be attached to other PVC pipe
Hello! I made a similar design to the piston device that you made with some of my own modifications. The issue that I am finding is that as soon as the pressure behind the ping pong ball is enough to launch it, it will launch. This happens regardless of how much air has been compressed/how far the mass has fallen, leading to very little pressure to actually launch the ball any distance. Sorry to bother, I know that it’s been several years since you made this. But if you did run into this issue/have any pointers, it would be incredibly helpful. No pressure and thank you for making this video! I’ve watched it so many times because I love how the air volume is higher and is going to be more consistent than an air bladder. Thanks!! -Kitnarp
This is what the large holes are for on the side of the drop tower... they release a lot of the pressure until the mass gains enough speed for the final compression.
We made the weight by putting all the fishing weights we had in the garage into a metal can that was wrapped in tape until it fit the pipe. BE CREATIVE!
So we built almost the exact same thing, but we attached a plunger sort of seal at the base of the 4 inch pipe and for the weight, we took a pvc end cap, stuck it together with a 3 inch pvc pipe, and put a rubber gasket around it to create a seal so when the weight drops it would push all the air to the ping pong ball, but it’s not going anywhere, only around 2 m for some reason, do you have any advice to fix this?
So we built almost the exact same thing, but we attached a plunger sort of seal at the base of the 4 inch pipe and for the weight, we took a pvc end cap, stuck it together with a 3 inch pvc pipe, and put a rubber gasket around it to create a seal so when the weight drops it would push all the air to the ping pong ball, but it’s not going anywhere, only around 2 m for some reason, do you have any advice to fix this?
The bolt was pushed halfway in the tower, then slid through the hook, then out to the other side. Moving the bolt up and down through the holes was a key adjustment feature
Hi, I was a little confused on how you made the drop weight for the second build? I have already tried many many variations and none of them work. Thanks!
@@TMartScience If it's not too much to ask for, could you perhaps send the stl files for the laser pointer? I have no idea how to design one and I think your design is very very smart. Thanks!
Hey ..Really nice video. ..How did you inflate the beach ball, cant seem to figure that out..and How do you keep the beach ball from deflating once you fill it up? Did you have to use special valves?
Hey, thank you so much for your video but, i was just wondering is there any actual correlation between the labeled numbers you made? Or is it rather just an indication of each possible drop point in your 2016 piston design and through experimentation you can personally figure out the combinations for levels and angles for a desired target? Thanks in advanced
Hi, my group took inspiration from your ball design, and right now we are coming up with the calculations. Is there an equation to find the initial velocity of the projectile from the mass and drop height of the dropped weight? When we use Ug=KE to find the initial velocity of the projectile, it’s giving us an incorrect initial velocity
Trying to do any serious calculations with this device would be next to impossible. Calculating the fluid dynamics of the moving air that is compressed from the following weight, frictional forces, turbulent flow, and so forth.... If you want to calculate and make some predictions, your best bet will be to graph experimental data and then see if you can find a relationship that approximates what you are achieving.
@@Rouge-h2h Read the previous comments, it was all the fishing weights that we had in the garage. Stuffed into a can that was the right size compared to the PVC pipe
There is a force called GRAVITY.... that is usually what makes things fall. I think maybe your question needs to be rephrased... I'd be happy to try and answer a more specific question.
I do not know if ping pong balls come in different sizes.... We used a standard 3 star ping pong ball and it fit fairly well in the one and a half inch PVC pipe
I'm not sure we ever figured out the best place to drill the holes. We realized there was too much air coming out too soon, so we added vent holes to allow the mass to accelerate more before compressing the air. This was all built through experimentation... I hope you figure out a way to do it better than we did
@@__buzz__ The vent holes are supposed to help so try that. But also remember that the diameters of the ping ball ball and the barrell should be the same.
A racquetball is heavier, so less influenced by air currents. A ping pong ball does not weigh as much so does not take as much air to get it moving.... This is why we used a ping pong ball
Do the holes on the PVC of 2016 model where the weight is dropped affect the actual performance? What if we had used a normal 4 inch by 2 feet pipe without any holes?
My logic behind this is if the weight drops down a tube with holes doesn't the collected air while the weight is falling down the pipe leave through the holes?
@@TMartScience An additional question I had was what the purpose of the toilet flange on the 2016 model is. It seems to not be attached to the PVCT but instead be a ring around it, does it serve some sort of purpose?
great video! i was just wondering how long each of these took to build, from the planning to finishing the actual build and doing testing? i am just looking for a rough estimate of things to make sure im not behind for the competitions.
The height was dictated by the competition rules. We used as tall as permitted. The vents were located to release air on the drop. If you cut too many holes, you can always patch them with something like packing tape. You have to experiment and see what works best
So we built almost the exact same thing, but we attached a plunger sort of seal at the base of the 4 inch pipe and for the weight, we took a pvc end cap, stuck it together with a 3 inch pvc pipe, and put a rubber gasket around it to create a seal so when the weight drops it would push all the air to the ping pong ball, but it’s not going anywhere, only around 2 m for some reason, do you have any advice to fix this?
I appreciate the request, but science is not and SHOULD not be a "cook-book" activity! While it would not take long to come up with a materials list, I have not provided this b/c This device was not built from "ideal parts" . It was built by looking for leftover bits and pieces in our garage... re-use and re-purposing materials is the way to go.
I’m not an expert but because the surface that makes the ball is light it shouldn’t collapse into itself without outside forces (correct me if I’m wrong)
@@TMartScience oh okay thank you! Also, what did you mean by “fittings” (1st design) and what did you use as an air chamber (ex. Beach ball, 2 liter bottle being pressed by a force) in your 2nd design
@@PegasusPlayzYT The ball was one of the big round balls that you can get at a store like Walmart... Regarding sink drain fittings, this can be acquired from a place like a home improvement store....
@@Franklin_Saint_ yes, clearly something is wrong and it must not have been built the same way... I would have to know more details... Did the ball deflate? Is the ball opening sealed to the drain pipe? Are there other leaks in the system?
The ball is fully inflated and sealed to the drain pipe. As far as I know there no leaks. The ping pong ball flys halfway up the barrel but then stops there. Is it an air issue?
@@Franklin_Saint_ what size of pipe are you using? Is the pipe similar in size to the projectile? If air can get around the projectile, it will. Just like in a gun or canon, the projectile must be basically the same size as the bore diameter.
We found a metal food can that was similar in size to the PVC diameter, then Filled the can with fishing weights. To ensure a snug fit, the outside of the can was wrapped with tape
Does diameter affect the airflow? We used a 3 inch pvc for the weight to go into with no holes drilled and it didn't go very far. How can we make it go farther?
@@cow1723 we used a 4 in PVC pipe for the drop tower, the combination of holes along the side allowed air to escape until a final compression burst. This along with carefully sized and fitted barrel was essential for getting the distance
@@cow1723 you may need to experiment with this... Like I have noted elsewhere, rules and requirements change from year to year. This was as built 9 years ago and I no longer have the device
Hi, besides using metals, what other recommendations would you give for the falling mass? we're trying to follow your second design with a 4 inch diameter cylinder.
@@TMartScience do you think if i made this i would need the mass? Also i took a trrip to my local hardware store but couldn't find anything to use for the falling mass what would you recommend?
@@vihaanj5560 You have lots of options... we used fishing weights... but you can use anything.... Part of this competition is experimentation.... maybe you can find a better configuration!
It was attached with clear packing tape. Align a protractor along the length of the barrel, put tape on one side, then fold it over and put tape on the other side
How much did the mass weigh for your second design and what substance did you use to glue them together? Will it damage the bottom when it strikes? How many holes should be drill to release pressure?
1 The mass was all of the fishing weights that we had in the garage... 2 No glue... Melted....3 we put some scrap foam at the bottom. 4 Experiment with your design!!!
@@John-u8p2y I understand... Like I said we just used what we had... Part of the point of science Olympiad is experimentation. Maybe you can improve on our design
