PVC Swinger target stand

I've never shoot swingers well, so some practice is in order, but since I don't want to speed nearly $200 to buy one nor do I have any welding skills to make one, I went the PVC route. After some searching on the Internet I found this site FreeIdaho and directions to make a PVC Rocking Target as they call it.

Here is the link to the Steel version

Here is my PVC one after about 20 minutes of cutting and dry fitting:



Going to give it a try on the range this Friday afternoon.

Edit: now it works. I will be making one

I had somes idea on a cool one made from steel, but I couldn't weld if my life depended on it.

That is a cool and simple setup. Adding sand to the swinging part will change the swing rate.

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nice gonna have to make me one

SubGunFan wrote:That is a cool and simple setup. Adding sand to the swinging part will change the swing rate.
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No it won't. Mass does not affect the period of a pendulum.

If you want to change the speed of the swinger, use different lengths of pipe for that piece that hangs off the central axis.

You're a geek and nobody likes you.

Will_M wrote:

SubGunFan wrote:That is a cool and simple setup. Adding sand to the swinging part will change the swing rate.
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No it won't. Mass does not affect the period of a pendulum.

If you want to change the speed of the swinger, use different lengths of pipe for that piece that hangs off the central axis.

Would a shorter piece increase or decrease the speed? I want to say it would increase the speed.

I've thought about changing the actual swinging portion from 2" pipe and couplings to 1.5" so the slats fit more snuggly.

I like some of the target designs of that site, specifically the Reed Rattle Target

jdphotoguy wrote:Would a shorter piece increased or decrease the speed? I want to say it would increase the speed.

I've thought about changing the actual swinging portion from 2" pipe and couplings to 1.5" so the slats fit more snuggly.

The shorter the length "L" of the pendulum arm, the faster the period.

Protip: When you go to a major match, if you get there the day before to walk the stages, you can't activate the swingers but you CAN go see how long the arm is.

Increasing the mass at the end of the swinging unit WILL increase the swing velocity. It makes the unit more unbalanced. The increased mass should also allow the unit to cycle more times.

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A simple mod to change swing speed easily:

I don't think a "cross" fitting will side completely over the pipe.....

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duplicate post.....oops

SubGunFan wrote:I don't think a "cross" fitting will side completely over the pipe......

True, I was planning to use a 2" cross fitting and 1.5" PVC pipe that hangs from the axle, that way it should slide up and down freely. Then use a pin to hold the slat pipes at the correct height. I should have mentioned that earlier.

SubGunFan wrote:Increasing the mass at the end of the swinging unit WILL increase the swing velocity. It makes the unit more unbalanced. The increased mass should also allow the unit to cycle more times.

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No disrespect intended, but I'm gonna need to see the math/hear some reasoning on that. Here's mine:

First of all, since gravity is what is causing the swinging, increasing mass will not change the period (time for one oscillation) due to the formula:

v=g*t
where v is the velocity, g is the acceleration of gravity (9.81 m/s^2), and t is the time elapsed. As you can see, mass is not present.

If we want to take it a step further, it becomes a basic conservation of energy equation. The sums of kinetic and potential energies must always be equal. In the following formula, potential energy is on the left, kinetic is on the right.
m*g*h= (1/2)m*v^2
where m is mass, g is acceleration of gravity, h is the height from the weight to the ground, and v is velocity.

As you can see, mass is present on both sides of the equation. Meaning it cancels out. No matter what mass I use, it will always cancel out. Whether I use 1 pound or 1000 pounds, it won't change anything.

The only reason the mass is there is to counterweight the mass of the target and target sticks so that it doesn't simply fall to one side.

Science.

Will_M wrote:

SubGunFan wrote:Increasing the mass at the end of the swinging unit WILL increase the swing velocity. It makes the unit more unbalanced. The increased mass should also allow the unit to cycle more times.

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No disrespect intended, but I'm gonna need to see the math/hear some reasoning on that. Here's mine:

First of all, since gravity is what is causing the swinging, increasing mass will not change the period (time for one oscillation) due to the formula:

v=g*t
where v is the velocity, g is the acceleration of gravity (9.81 m/s^2), and t is the time elapsed. As you can see, mass is not present.

If we want to take it a step further, it becomes a basic conservation of energy equation. The sums of kinetic and potential energies must always be equal. In the following formula, potential energy is on the left, kinetic is on the right.
m*g*h= (1/2)m*v^2
where m is mass, g is acceleration of gravity, h is the height from the weight to the ground, and v is velocity.

As you can see, mass is present on both sides of the equation. Meaning it cancels out. No matter what mass I use, it will always cancel out. Whether I use 1 pound or 1000 pounds, it won't change anything.

The only reason the mass is there is to counterweight the mass of the target and target sticks so that it doesn't simply fall to one side.

Science.

You now have a new nickname: Beakman from Beakman's World and I guess that means Brandon's new nickname is Lester.

"No disrespect intended" None taken. One (or both) of us will learn something from this thread......

Your formulas are mainly meant for linear movement. We are talking angular (circular) movement. I am not comparing periods, just speeds the swinger moves when released.

Example #1: The arm (portion below pivot) and the target (portion above pivot) are almost equal weight with the arm weighing slighty more. The swinger should move fairly slow when released.

Example #2: Extra mass is added at the BOTTOM of the arm. Now the swinger should move faster when released due to being more unbalanced.

Hey, when this system is built....... we will see........

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Way to think outside the box JD. Pretty impressive.

In my experience with the swingers we have, adding weight to the counterbalance side does cause the target to present faster when the swinger is released. Does it actually cycle back and forth faster with more weight? That I don't know. I know that moving the weight further out from the pivot point (or lengthening the slats the target is on) causes the back and forth cycles to be slower and less jerky. I don't have math or science to back that up, just my personal observations. Could it have something to do with the fact that we're not really talking about a pendulum here? If there were no target above the point of rotation it would be a pendulum but that's not really what we have?

Anyway JD, cool idea. If you're interested I think Matt and I are going to be doing some welding this weekend after the match. I finally found a source for the steel I needed to fix a bunch of our busted poppers. I can't claim to be an instructor but you're welcome to join in and maybe get a feel for it. Steel targets are a great thing to learn on because it really doesn't matter how ugly your welds are and the steel is thick enough that it's hard to really damage.