Target changer- Keeping it simple!

[Bing!]

Hi All,

As the title says, Target changer.
Here is what happens. I shoot an Olympic discipline called 3 positional shooting using a .22 rifle at 50 metres. I practice at 25 metres at an indoor range (warm and local to me) and use multi diagram targets, usually 5 aiming marks on each 'card', like the number 5 on a dice face. What I currently do is get my position set up on one aiming mark, zero, then I move my whole body position to line up with the next mark and zero again. Great for practicing my body zero point but there are other parts of my shooting I wish to practice where constant movement is a nuisance. I currently have a set up where I get some targets in a line taped together and feed them down a slot, I index them down (down or up a bit only) with a small geared dc motor turning a shaft with a rubber wheel on it. I can only shoot the targets on the left hand side of the card like this. I have a battery pack with me, a DPDT switch and 25m of wire.
What I would like to do is stay in one position and have the target move to the next aiming mark for me, up, down , left and right, all at the press of a button. Press the button once and it goes to target 1, press again and it goes to target 2, press again = target 3 and so on.
I would like to avoid steppers etc as they tend to be expensive, I was thinking along the lines of small dc motors positioning the target via an X Y verticle target 'table' and a photo electric cell type set up to tell the motor to stop??? Maybe use an Arduino?

What do you think? Can you help?

WARNING... I am completely lacking in electronic knowledge or skills, my own set up took months and months of nailing/gluing/taping/starting again to get it to work. You cannot patronize me, I am rubbish at this. Keep it very simple. Think pictures (crayons allowed, I use them) and links to help sites.

Thanks in advance to you all.

Bing!

 

[Diver300]

Stepper motors are not expensive, and have the huge advantage that they move a predictable amount if controlled correctly. DC motors need some type of position sensing to end up in the right position.

How about pulling the stepper motors out of an old printer? You could also buy a stepper motor for reasonable money. https://uk.farnell.com/4743209

 

[Bing!]

Thanks Diver,

I had cnc style steppers on my mind, hence the prohibitive price. Looking at it from the micro stepper point of view it's not bad.
I have the mechanical skills to make the target mount and move it around, I just don't have the skills when it comes to the electronics side, any help on that front would be greatly appreciated.

Am I barking up the wrong tree with Arduino?

Cheers,

Bing!

 

[Diver300]

CNC steppers are far more powerful, often have extremely accurate gearboxes attached, and probably have expensive encoders as well.

An Arduino would work, but would need a driver IC or some transistors because it can't supply enough current. You don't need high speed, so the simplest driver circuit would do.

I would use a PIC, because I have programmed them a lot and I have the programers. A PICkit programmer is about the same price as an Arduino, but you would still need to have a circuit board for the PIC. The PIC itself is far cheaper. However, you would also need something to mount the transistors or the IC on whatever you use.

Are you needing two direction of movement? Mechanically and electrically it is simpler if you had all the targets in a row so you only needed one direction.

 

[alec_t]

What is the distance (approx) between aiming marks that you need the target to move?

 

[Bing!]

I'll shall start looking into some PIC stuff.

Yes I do need two directions of movement, the target has 5 aiming marks set out like the face of a dice, I fire 5 shots at the aiming mark then move on to the next one. I have thought about just using an extra motor and moveing X and Y by small inputs into a pair of DPDT switches. Simplest way but not very 'techy', I feel the extra effort to get it working with a push of a switch would be worth it. Yes I am straying from my own 'keeping it simple' motto but the benefits to myself and the other club members would be great.

Thanks again for your input Diver.

Bing!

 

[Bing!]

Hi Alec,

Aiming mark centres: Left to right approx 200mm (8") and up and down approx 300mm (12"). The overall target size is very close to fulscap (?) size, bit bigger than A4.
The target would be mounted to a very light verticle XY set up, made mostly from corex and various plastics, I have learnt from past experience to keep it as light as possible.

Welcome aboard and thanks for any input.

Bing!

 

[Reloadron]

Please do me a favor and look at the targets on this page. Tell me which target you are shooting. Next, do you want the targets to move on a horizontal or vertical axis? I am missing something in all of this. Also, when I hear three positional shooting as it pertains to Olympic or competitive shooting I think of Standing, Prone and Kneeling or Sitting position. I am not getting this shooter positional thing?

Something maybe to consider would be to put an "eye spot" on the target(s). That could be used for positioning using a simple motor.

<Edit> I see you posted as I was posting. So an A4 target? </EDIT>

Ron

 

[alec_t]

So we have an 8" x 12" grid. Would it be possible to simply rotate the target about its centre? No aim point would be further than 1" away from a 5" radius circle. The mechanics would be simpler than 2-axis translation.

 

[Bing!]

Hi Reloadron,

I'm guessing from the name/avatar your a shooter? Bit bigger than .22 I presume?

**broken link removed** Target no.2505bm, close to your A7

What I mean by body zero point is when I set up in position I get settled, close eyes, breathe in-out-in then out, open my eyes looking through the sights. Where the rifle is pointing is where my body zero point is, if not on the target I make fine adjustments till I line up exactly with the aiming mark, and yes, I shoot prone, standing then Kneeling, 120 shots over 3 and a 1/2 hours. In competition we use electronic targets, one solitary single aiming mark to ISSF rules, no problem when set up. When practicing I use the 5 bull aiming mark at 25 metres. To simulate single aiming mark and not start cutting up the clubs supply of targets I would like to keep the card whole, move the aiming mark and I stay still. During the winter, short range competitions are also run using the 5 bull target. So yes, move the target both horizontal and vertical.
A4 size in the UK is a standard stationary paper size and does not relate to a target size.


Thanks for looking and posting.

Cheers,

Bing!

 

[Bing!]

Hi Alec,

I thought about rotation but the final centre aiming mark is the sticking point, how do I get it across. I keep coming up with needing two axis! I have attached a link to my previous post, take a look at the target. My thoughts were to start at bottom left, shoot. Press button, motor turns and the target holder moves down a known measured distance bringing top left mark into position where mark one was. Shoot. Button is pressed (or button 2 for aiming mark 2, 3 for 3 and so on), motor turns bringing target up known amount, second motor moves right known amount bringing centre aiming mark into position.... Etc. After 5 moves a reset button is pressed, the whole thing returns to position 1 ready for me to put in next target.
That is the mechanical side of it which I am confident I can do, various rods, bearings and steppers (abandoned dc motors now) etc. My electronics is practically non existent but in the last few days I have seen stuff such as arduino and now PIC, I'm confident that this is doable with a lot of help from the forum and the likes of yourself, Reload and Diver.

Again, thanks for the input, much appreciated.

Bing!

PS, An inch movement for a target shooter is quite alot, can mean the difference between a lovely group in the bull and a lovely group in the 8 !!! Also known as going from 1st to last!

 

[Bing!]

This looks like it could be used? Damn that looks complicated.

https://www.youtube.com/watch?NR=1&v=1e1ZwjcAkBk

 

[Diver300]

Obviously rotating the target would be easier, but it would only let you have 4 targets of the 5 put the the same place. With a rectangular not square bit of paper, you would not rotate by 90 degrees each time, but that hardly adds any complication.

The Youtube clip shows exactly what I was thinking about but you don't need a display.

Most stepper motors have two phases, both of which can be powered in plus and minus directions.

I have found that half-step drive works best in most conditions. It is smoother and quieter than running them in full-step mode.

https://en.wikipedia.org/wiki/Stepper_motor has a good diagram.

On the Wikepedia diagrams, A and C are the same phase in opposite directions, and B and D are the same phase in opposite directions.

 

[Reloadron]

Hi Ya Bling

Yes, over the years I have sent a few rounds downrange. Being older now I don't shoot as much high power competition but still enjoy getting out to the range for a day of shooting. I created that little avatar years ago.

What I had in mind when I mentioned an eye spot was maybe using a black magic marker to place dots on the target sheets at registration points. A small photo cell (or any opto detector) is mounted on an angle to pick up light bounced (reflected) off the target. That could allow for some sort of target registration. Similar in a way to the way people who build robots get them to travel a line using light.

Good Shooting
Ron

 

[Bing!]

Hi Ron,

I was a .308 target shooter for some time but time and cost (and a family) meant the cheaper .22 sport was more feasible. Turns out I was reasonably good at it and it ended up costing more! Hey, thats life (wife doesn't agree!).

I have seen a few line followers and I get the principle. Around the edge of our targets is a strip of card that can be cut away to allow them to fit in smaller envelopes for posting (smaller envelope = cheaper post), so a black mark could be made on this section. So your thinking that in the varticle axis I start already set up on aiming mark 1, press verticle axis button and the card feeds down till the black mark is registered and stops the motor. Would I then press the horizontal axis button to bring me across to the middle then press the verticle axis button to bring the card up to the centre mark? It would use dc motors or steppers? Would it still need some form of PIC programme?
I like the idea that I could get away with less tech requirements but I'm begining to realise that the more complicated PIC, steppers and programme may be the way to go, ok, more technical to start with but once done will be the simplest end product, user wise. As the end product user is quite simple aswell it could all work out just fine.

I'm enjoying this. Thanks again.

Bing!

 

[alec_t]

You can do what you want with no electronics at all: at the remote end just 2 geared DC motors (one for horizontal, one for vertical) driving respective indexing discs and levers, 2 roller-actuated microswitches, and a power supply. At the near end just 2 push-button switches. A 3-conductor cable links remote and near ends.
Each indexing disc has 4 notches at 90 degree points on its circumference. A microswitch roller runs on the disc circumference and the switch is 'on' (NO contacts closed) except when the roller is in a notch. Pressing and releasing a button temporarily shorts the NO contacts to start the motor, which runs until a notch is reached then stops. Each press of the H button moves the H disc 90 degrees, enabling the target to be moved cyclically to the left, centre, right, centre, left, ......positions. Similarly, the V button presses enable the target to be moved cyclically to the bottom, centre, top, centre, bottom, .....positions.

 

[Bing!]

Hi Alec,

This sounds simpler, only 2 switches at the users end and only micro switches at the target end. I shall have to start putting some ideas down on paper.

Thanks all,

Bing!

 

[Reloadron]

Hi Bing

Given the options right now I would think about applying what alec_t proposes. I wouldn't discount my thinking but alec has a good idea there. Well worth some pursuit anyway.

Happy Shooting
Ron

 

[Bing!]

Thanks Ron, Alec and Diver.

Bing!

 

[Bing!]

OK, I have some motors, switches etc.
I have wired up a few bits and pieces and have got the motors to turn then stop when the microswitch drops into the notch, in line with required place. I can flick the switch and the motor starts again, overiding the microswitch to start it of again.
Right, here is my problem.
I want to move in the opposite direction, How do I reverse the motor and it still rotate in that direction, the microswitch moves out of the notch, kicks in and the motor turns the original direction? I have a DPDT switch so I can reverse polarity but how do I get the microswitch to join the reverse polarity party??

Any help appreciated, again....

Thanks.

Bing!