Electronic Targets - DIY?

[Synthasy2000]

I might have.

Well that link was clearly not AIMED at you

[eggplant]

Forgot about this one, was my first post and hadnt set automatic replies.

Glad you liked the pics, and thanks for the link, I'll reply there soon.
Heres a quicky of my 1st prototype to see if the idea worked, which it does.

http://www.youtube.com/watch?v=4DwD7QzN98I

[Garry]

Have you made any headway on this yet Synthasy2000?
I'm still scratchimg my head over it

[Home Guard]

I'd love to hear of progress too.

Had any luck?

[Synthasy2000]

I've identified the parts that would be suitable using phototransistors that are fast enough to detect a 800 m/s .177 pellet. I think I may be able to achieve 1.5mm resolution over a full target card of 17cm by 17cm.

I will need to design and get made a special PCB to accommodate the electronics. I have stopped at this point as time is short at them moment.

There will be a lot to do even after the PCB. Firmware for the programmable logic IC to collate all the phototransistor responses and software using a laptop to display the results and calibrate the unit still needs to be written.

It's still on the back burner though.

[1066]

I had a thought about this during the night.

What about mounting a round metal disc, say about the size of a CD onto the top of a joystick.

A shot smack in the centre, down the axis of the joystick will result in no deflection of the plate. A shot further away from the centre will deflect the plate so giving an X-Y position. The further from the centre the more deflection.

The output could be linked to servos or straight into a PC.

[1066]

Just had a thought about this.

How about having a steel plate, spring loaded toward the shooter some. Behind the steel plate are 4 pot resistors 2 on X and 2 on Y.

The plate needs to be mounted in such a way as it will move slightly when hit then return to its initial setting. Maybe on an old mainspring dead center of the plate.

As you shoot the plate in different areas, the plate would move and adjust each of the 4 pots differently. Use some electronics to keep track of the max setting each pot gets to then by knowing where the pots were, you could in theory work out where the pellet was.

You could possibly even strip a joystick or wireless PC gamepad controller and use the X-Y and Z-Thrust axis to do your measuring and use the PC to score. Gamepade have +-128 positions per axis normally.

Cheers
Stot

Sorry Stot - I should have read all the posts before I jumped in with both feet. Looks like I pinched your idea. Can't see any problems that could'nt be overcome. A few years ago I made an inertia meter out of an old joystick (basically an inverted joystick with a heavy weight hanging on the handle) for use in a car to try and plot the "quality" of the driving. This was a long time before you could get an app. on a phone.

[Stot]

its alright, its a good idea!

Cheers
Stot

[Dirty Andy]

Hiya

Not followed this thread too closely but wondered... A wheel balancer uses a series of pizo pickups on a spinning shaft to measure and pinpoint imbalance on a car wheel. Accurate to 1 gram on a 13 inch wheel? They are all electronic now with all sorts of displays

Andy

[keithatrochdale]

Hi

I know this is an old thread, but I am wondering if any progress has been made?

The use of infra-red beams seems it might be a good solution, any thoughts?

.

[imk1230]

Hello,
Was wondering if this thread is still alive as my background is electronics and have a Gamo Compact in the post and I was thinking about making an electronic target. (Save a tree)
Am based in the west midland UK if anybody wants to collaborate, as I have a idea that it based on some 199x technology.
So my questions is: is this for commercial use in top level air powered competitions or for home and club practice and what kind of resolution and build cost do people have in mind.

BTW are there any pistol match meets in this region that welcome newcomers?

IMK

[richardlce]

I wanted a system as you envisage, but ended up with a cctv camera £6-00 from china, fixed to the target holder, a 12v power supply at the target end and a TV with a duf tuner ,but OK AV input and wire, lots of wire and connectors.
It is good enough.

[harvey_s]

I think if what you're describing is a camera looking at a paper target -this doesn't quite qualify as an 'electronic' target

[RichardinDorset]

Wouldn't an electronic target have to have a very durable Bull area marked on it? It would also be subject to gradual marking by pellets...

I would guess that a heavy steel plate with maybe 3 or 4 piezo sensors on would be able to triangulate the impact point by comparing the vibration arrival times. Some deadening on the back would reduce ringing?

(edit) Speed of sound in aluminium is over 6000m/s so you'd need to measure the impact down to a resolution of under 100ns to get decent accuracy... makes it a bit harder!


The other thing I wondered is how long a pellet sits on a steel plate before falling off. Long enough for a camera to see it? The software required to detect the pellet i arriving and 'score' it is pretty simple. Capturing a pellet in flight is not so easy, but I would guess that a pellet takes a reasonable amount of time actually hitting and deforming on a solid steel plate target.

A pellet traveling at 700fps would cross the field of view of say 5 inches in about 600us, so you'd need to analyse the video from the camera at 2000 frames per second.

[1066]

Wouldn't an electronic target have to have a very durable Bull area marked on it? It would also be subject to gradual marking by pellets...

.

I would guess that in a system like this you would simply slip an official paper target into a holder just in front of the "sensor" back plate. Just replace it when it starts to get shot up.