Materials Needed to Rig Tennis Balls Dropping

[PositiveCharge]

Hi All,

I need some suggestions for how to construct a container to hold about 15 tennis balls that can be rigged to drop on a cue. A kabuki drop for the bottom of the container would make the most sense, does anyone have any hardware recommendations?

The operator would be on the fly rail at the same height as the pipe trim to pull tie line to activate the drop. The container will be mounted between two battens that can fly in so the balls can be loaded.

Thanks for your suggestions!

 

[JAC]

Seems like a job for a snow cradle.

 

[PositiveCharge]

Seems like a job for a snow cradle.

That’s a great idea. The only thing to consider is if the snow cradle will affect the trajectory of the balls dropping straight down. They need to land on a specific spot. I’m wondering if the snow cradle will give them a slight push upstage or downstage. Going to give it a shot though! Thanks for the suggestion.

 

[jtweigandt]

I made a plywood drop box with hinged bottom that has been in several productions.. simple hinge bottom box. Latch was a re purposed battery electric screwdriver with a bolt epoxied in with a right angle piece of metal in acting as a latch on the door. Wall wort transformer roughly matching the voltage wired to it, and plugged into a dimmer. Now I have a drop box I can actuate from the booth. No one aloft, No training the kid who showed up because the other kid had a school event... never miss the cue.

 

[microstar]

How about a piece of PVC pipe that the tennis balls will fit in, mounted horizontally, with a cap on one end and a hole the tennis ball will drop thru right before the cap.
Then have a electrical screw mechanism at the opposite end that pushes the balls out.

 

[Van]

I've made MANY Drop Boxes for all sorts of different items and to me, the easiest and most reliable, by far, is a plywood box with a hinged bottom with the latch actuated with a low voltage relay. Well, Honestly if you want to put it on a LX Relay you can run it from the board and use a 120v relay but then you really need to use different materials to isolate the connections on the relay and blah, blah, blah, Low voltage is just easier. I built an FX box that was design for running 24v tricks.
So if you do it with Ply, you can get away with rather thin materials but you cannot simply screw the hinges into place with wood screw you must install at least 1 10/24 screw/bolt and peen or loc-tite it into place. This ensures it won't back out and drop the door on someone's head. remember to safety the box

 

[JonCarter]

How many tennis balls are we dropping here? If "a lot" (couple dozen or so) I would suggest a square box with double doors, hinged at either the US & DS sides or the SR & SL sides of the box. Any trapdoor on one side only is likely to allow the balls to "roll" off of the opening door, going either to to one side , up, dn, etc., rater than straight down.

 

[Crisp image]

this is what I have used. It can be juts be a push of a button or I have used a DMX relay to trigger it. Make sure the load on the latch is not too high or it will not release. I have also been known to use a car door lock solenoid to release items to drop. I added a micro switch to break the circuit to prevent over operation of holding the solenoid after operation to prevent burn out.
Regards
Geoff

 

[egilson1]

Here’s my $27 dollar solution.
Take one of these bins, put 2 eyebolts on each lid section, and run a dowel through the eye bolts to lock the lids closed. Hang inverted on batten and use tieline to pull the dowl out to release the lids and drop the balls.

You could even use a pair of clamps through the bottom for mounting.

 

[kicknargel]

I wonder if a sliding door would reduce deflection on the trajectory.

 

[Malabaristo]

Here's an example of a box using a car door lock actuator (courtesy of American Science and Surplus) for remote control. Apply 12VDC and away it goes.

This design is open on top for easy loading.

 

[Crisp image]

Here's an example of a box using a car door lock actuator (courtesy of American Science and Surplus) for remote control. Apply 12VDC and away it goes.

View attachment 24886

This design is open on top for easy loading.

I added a microswitch to break the circuit after actuation to protect the solenoid but the concept was the same. I do like this sort of thing. Door locks come cheap when you do road accident rescues for a community based organisations. We get cars to train on so I get to strip a few bits out of it.