Target changer- Keeping it simple!

[alec_t]

I'm sure we could come up with a way of reversing, but do you really need to? I had in mind a driven disc with an eccentric pin riding in the slot of a slotted arm supporting the target, so that with each successive 90 degree disc rotation in the same direction the pin moves the arm successively to left, middle, right, middle, left, middle..... positions. They say a pic is worth a thousand words, so bear with me and I'll post a pic in due course.

 

[Bing!]

Hello again Alec,

I've just taken a look at your pic. I see what you are saying now. I will break out the paper and card and start a mock up but I fear the centre aiming mark will still be the problem, I can see the 4 marks in the corners being simple but the movement to get to the centre eludes me.

I shall have a crack at it this weekend.

Thanks,

Bing

 

[alec_t]

I should have explained: that pic relates to one degree of movement only (L/R). I envisaged mounting that set-up (A) on a lever (or sliding shaft) moved up/down by a similar set-up (B) providing a second degree of movement. So if we assume we start at the bottom left target position, then one step up using A and one step right using B takes us to the centre target. Etc.

 

[Bing!]

Now thats explained it becomes very obvious.
Thanks Alec. Again.

Bing.

 

[alec_t]

It occurs to me a single uni-directional geared motor can be used to give all 5 target positions. A driven shaft carries an indexing disc as before, but this time with 5 notches, and also carries two cams as per the attached; one for controlling vertical movement and the other for horizontal movement. Respective cam followers are coupled to linkage (pivoted arms, parallelogram linkage or whatever) for the V and H movement.

 

[Bing!]

OK, you're showboating now.

Very impressed with the cams.

Bing

 

[ghostman11]

i am not gonna but in here, all i wanted to say was... should you need or want to go down the PIC route. i can program the chip for uou as i am in the uk, that would save you having to buy a programmer. unfortunately i havnt got time to be of much help apart from the physical loading of a program onto a pic for you... having said that if you need a pcb making and can get the layout or schematic i can also do the board for you
regards jason

p.s i should also say that as a farmer that needs a gun for work and vermin control, i DO NOT agree in anyway shape or form the needless slaughter of paper targets for so called fun!!! i do not see it as any less cruel than the merciless killing of poor clay pigeons that goes on round here at weekends! due to the actions of a thoughtless few who slaughtered all that crossed there path, the lesser spoted clay pigeon is now on the brink of exstinction in theese parts!! when not long ago as a boy i saw them everywhere in the summer
you and your kind shoulod be ashamed

 

[Bing!]

Hi Jason,

Thanks for the offer of the PIC programming. I may be in touch at some point, as you may have spotted I'm not particulary knowledgable when it comes to electronics. I would have to learn how to 'join' the PIC chip with the driver boards to the steppers etc.... I'm a long way off that.
As for the wholesale slaughter of innocent paper targets... It's all for conservation. I only take those targets that are getting on a bit, maybe a bit dogeared at the edges, past there prime. Nothing is wasted as every part is used, mostly for toilet paper I think!
I was involved sometime ago with reintroducing Clay pigeons back into the wild, most weekends we would head off to some quiet piece of farmland and set the "clays", as we affectionatley called the wee tikes, free into the great outdoors. They were sent on there way with a springloaded pigeon helper, some made it, others didn't... Such is this cruel world.


Bing!

 

[alec_t]

Talking of toilet paper, couldn't you get a roll printed with aiming marks all at the same level and simply scroll through it using a single DC motor drive? Even simpler than all this vertical/horizontal shifting.

 

[Bing!]

Unfortunatley the target is an official, authorised design. No deviation allowed. I have another practice target changer which I knocked up some years ago that is exactly as you described.
It has been noted that there is a link between my targets and toilet roll in the past, they are good for one thing....! Hence the need to practice, with the aid of my trusty new (eventually) target changer.

Bing

 

[alec_t]

It has been noted that there is a link between my targets and toilet roll in the past, they are good for one thing....!

Perhaps not, if you've shot holes in the paper !

 

[Bing!]

I nearly choked on my tea.

Good point well made.