Building Turning Targets

[blind bat]

I'd like to build a set of simultaneously turning targets for a par time standards type stages. Like what's done on the Barricade stage at the Cup. Preferably I'd have three targets that turn simultaneously and automatically. Has anyone built such a rig? Any suggestions on what to do or not to do?

I have a couple of ideas: I could set up the targets stands with arms all connected to a common rail and then use an electronic linear actuator to move the targets like slats on wood blinds / shutters. My other idea is to weld two gears to each target stand the connect the stands together with chains and connect the last stand to a garage door motor. I don't know how well the chain idea would work since the targets would probably need to be spread at least six feet apart.

[sperman]

The only time I've seen these used (Barry, IL for the SS Nationals) they are air operated. I know that's not much help, but it gives you another option. I assume each has it's own cylinder, but since they operate off the same supply pressure, they all turn at the same time (or close enough as makes no difference.)

[blind bat]

Hmmm. Interesting thought. I wonder where I can get some cheap air cylinders.

Two minutes on google...

Maybe these will work?

http://www.grainger.com/Grainger/SPEEDAIRE-Air-Cylinder-6W133?Pid=search

[caspian guy]

Try these guys www.mpja.com (http://www.mpja.com/prodinfo.asp?number=19183+HD)

[jmorris]

I have built turning targets and pop up targets with and adjustable delay for return. I went the cheap way, a friend gave me a few windsheld wiper setups off of wrecked cars and I built the timers using a 555 IC.

You will likely have to change a linkage or two and add a switch to stop for the delay time before returning.

Here is a video of them and other electric activated targets all wired together.

[blind bat]

jmorris - I forgot how bad ass you are. Do you happen to have any pictures of your linkage for the turners?

[jmorris]

I sure don't and they are in a container at our farm. I'll get some photos next time I'm down there.

Cars these days have a windshield wiper transmission so you can get the entire assembly. Mount angle iron with 1x2 box tube, target holders to the shafts that held the wipers. Pick the speed you want it to run and wire switches to stop them at 90 deg.

[jmorris]

This one is pretty simple and if you don't have a buddy in a autobody/parts business, is on ebay for $40.

[Griz]

I have built pneumatic turners for NRA Action Pistol, with one cylinder turning 3 targets through a linkage arm. This works, but the linkage is a problem if it gets very long. We have a ~8' linkage that gets very floppy... If we used stiffer steel it would start to get too heavy, and we didn't want to use alumimum because of possible damage from bullet fragments.

If I had to do it again I would use 1 cylinder per target.

I considered electric actuators or motors, but either it gets expensive, or the targets turn too slowly for my liking. If you can get big/fast enough motors cheap it might be less hassle than using air.

I used cylinders with a 3" stroke and 3/4" bore. I would use a 2" stroke, 5/16" bore per target if I did it again.

You don't need much air. Running turners is like running a nail gun, not a die grinder. Just get a $50 Harbor Freight compressor and consider it a consumable item that you'll replace every year or 2 (and keep a spare handy!).

The most important detail is the solenoid. If you want accurate par times, you need a direct acting solenoid. Don't get a "pilot operating" solenoid because they have a different delay for each direction... I am using Asco 8342G001 solenoids. Retail price is crazy, but they pop up on ebay for much cheaper (I think I paid $35 each).

To interface the solenoid to a timer, I use a latching relay (Magnecraft 711XBXCL-12D) and drive the relay with a transistor that is turned on by the Aux output on a CED 7000 timer. You can also use a garage door opener remote to trigger the impulse relay, but a wire is much more reliable.