freETarget

[dulcmr-man]

I have the electronics and I've downloaded all of the various files. I was particularly enthused about 3D printing the target face with sensor mounts because that seemed the best way to ensure their accurate location.

As part of my 3D research I contacted Andrew Berryhill whom you've probably read about on this site because of his 3D printing efforts for custom grips. Andrew's printers cannot handle the target face as it is too large for his printers. Nevertheless, Andrew has been VERY helpful in advising me regarding 3D printing capabilities and options. He has advised me to use plexiglass or plywood for the target face and I may go in that direction.

Being a stubborn guy, I am still looking for a printing service that can do this job at a reasonable price. I have found at least one, but the cost was more than I am willing to pay at this point.

If I find a service I will post it here. If anyone knows of one that's reasonable, I'd love to hear about it.

Dennis, aka Dulcmrman

[bdutton]

I created a mounting guide to properly mark the places where the sensors have to go. It accurately measures the 230mm and the 165mm square.

I printed mine onto card stock and carefully cut it out and used that.

Here it is in use (my mounting are actually slightly off... I created this guide before adding the mounts)



Here is a 100% sized image that can be downloaded and printed:

[thirdwheel]

This is a very interesting development for 10m pistol shooters, I have put my name on the list to build one.

One conundrum I have is that in competition most competitors use the whole of the target as reference when aiming and not the black - area aim over center hold. As the paper target is at the back of the target and some of it is shield by the way it is held and the protective front face of the box also shielding some of the outer card, training competitors will not be seeing the full target. You need to do the same in training as you do in competition to keep it real.

Ok could I do this - mount the target on the rear of front of the protection face so I could see it all Using a full target size aperture), and mount the sensors on the back of the front protection face. My guess that the pellet passing through the card would upset the sensor readings, so what if I used a readily available target card (all electronic target systems use them) with a whole as big as the black, and not worry about the shots in the white as I don't shoot out there normally, but if I did I would see it on the card anyway. My thoughts on this is how would I calibrate it without a real witness hole to work to. Perhaps have an accurately indexed rear target holder that is indexed to the front holder and use the rear one with a proper target to calibrate the target then use the front face target with a hole for live shooting. I know there will be some parallax error between the two targets I've not done the maths yet but it is not going to be much in that that target box is not deep and the targets are on the inside of the front face (with the aperture the full target size) and on the inside of the back face.

Do hope this makes some sense.

[bdutton]

You can setup a pellet trap on the back an put a card in the front with the black cut out just like the do on sius or Metalink targets. I tested with the sius target face cards attached to the back but I may switch that to the front (technically the back to the front ) side ot my target frame. The target is only for visual reference and is not a part of the actual shot sensing system.

[thirdwheel]

Very many thanks for the info I was worried if I put a normal card of the front it would banjax it as it would "hear" the pellet punching the card, I've put my name down for the boards and was getting as much info as I can before designing how I propose to set it up as I want to see the full card so I do not mess up my training. The intention was to use proper electronic target faces with a hole to the front of the sensors, a swinging plate pellet catcher to the rear, steel front plate with it indexing in the frame accurately as the front will come off to change a target template, especially if I mount the sensors on the rear wood part of the box. I use electronic targets in competition and and moving from one to the other you do need to readjust your sights as they are not all the same but they do read reliably shot on shot, so it does not matter.
This is going to be fun and I'm really looking forward to having a play with it, and as it appears so simple I am going to get most of the target box made ahead of getting the electronics eg get the front face plate cut laser cut from 2mm steel with the correct size aperture and get some Sius templates from Kruger and sort out the best way to mount and index them accurately.

[bdutton]

So after a lot of trial and error and learning from my mistakes and the help from Allan from Fre-E-Target to understand better how the system works...

I fine tuned my sensor locations using my 230mm guide:







I then reconfigured my target frame to have the impact area as close as possible to the sensors and used a flat sturdy floating metal plate.





I shifted my aiming bullseye to the front of the target frame similar to what is used for Sius and megalink targets and illuminated with a pair of battery powered task lights...





The resulting accuracy was what I was originally hoping for.



Things to fine tune further:

1. Pellet trap metal is still not quite sturdy enough. I can see after only 20-30 hits it started to bulge a bit. I may have to switch to proper hardened steel rather than thick sheet metal.
2. Pellet debris is bouncing forward a bit into the box/frame. A better pellet collection may need to be designed or just allow the debris to collect in the frame and dispose after each session. Messy but should not affect the sensors at all.

[rmca]

1. Pellet trap metal is still not quite sturdy enough. I can see after only 20-30 hits it started to bulge a bit. I may have to switch to proper hardened steel rather than thick sheet metal.
2. Pellet debris is bouncing forward a bit into the box/frame. A better pellet collection may need to be designed or just allow the debris to collect in the frame and dispose after each session. Messy but should not affect the sensors at all.

1. Would a proper commercial trap work? The ones that are shaped like this >

2. Mount the main board on the top of the trap instead of the bottom.
Should help with managing debris in the long run. Only the bottom sensors would be affected...

Hope this helps!
Looking forward to see this develop into a more complete out of the box ready project!

[Dr.Don]

Why does the deflector plate need to be so close to the frame? Why wouldn't the "box of rags" trap work?

[bdutton]

Why does the deflector plate need to be so close to the frame? Why wouldn't the "box of rags" trap work?

I'm still playing around with the configuration. I was getting inconsistent results with paper and a box trap I have with cardboard and plumber putty. It would get the first couple of shots and then it would either be off call or not registering. Having the plate closer and flat provided my most consistent results to date.

[Dr.Don]

bdutton,

That's really interesting. I'm at a loss to explain how the pellet capture location would affect accuracy or reliability of the results. Could the sensors be "hearing" and calculating from the sound of the pellet strike rather than the passage of the pellet? That would be strange but I suppose not impossible.

Don

[thirdwheel]

Good feedback and this is what "open source" is all about.
I've put my name down for a set of boards but I've got things rolling by ordering a laser cut 2mm steel front plate as the target mask and electronic target blanks with a hole in the middle from Kruger. I'm excited that this system can pick up the flight sound of a pellet whizzing past rather than picking up the sound from the witness paper roll found on commercial systems. They have designed in an output to enable a witness system to be incorporated if so wished which is great.
When I build my enclosure I intend to put a shield all around the target area to "box in" the sound and not have an larger box where the sound can dissipate to, also enclose the board to protect it and also shield the sensors from the front as they are within the full card shooting area by 5mm, all simple stuff to do. Also may plan is to use my swinging plate target holder out back to catch pellets this can have a black card in it to stop "spatter" encroaching back into the electronic area. There will also be a target holder indexed to the front hole in the target box so that I can use a full real target to calibrate and check the system whenever I think it needs doing.
Keep feeding stuff back that you have found works and solutions you have found that seem to work, eg your printed template.

[Pfonseca]

Does anyone have the dimensions specification of any of the commercial electronic target paper/blanks (SIUS, MEYTON or DISAG)?
Diameter of the orifices, positions, eventual tolerances, etc.

(eventually, a good 600 DPI scan would be enough for a correct measurement)

I'm asking this because I'm thinking on how I could base my own freETarget construction on these targets standard, but I can't find any information online...

[rmca]

I would start here:

https://best-targets.com/overview/elect ... ls-hs-s-10

And order a few first. Or go to sius:

https://sius.com/wp-content/uploads/201 ... S10_en.pdf

There are some drawings with accurate measures that can be used to extrapolate the dimentions of the holes on target faces.

Hope this helps

[thirdwheel]

Don't add systematic error by making your own blank paper targets with a hole in, get some real ones it will save you pain and suffering as they have indexing holes in to mount them and can only go in one place every time.

[Pfonseca]

It is the specification of those indexing holes that I'm trying to find out, so to order a rod of the exact diameter. I guess that each brand might have different specifications, and hence, I'm thinking on following the one less "odd"...

[Azmodan]

just buy a pack of the paper masks that are available to you, measure them and build the target around those

[Dr.Don]

I have my system up and running now. Getting excellent results on 10m air pistol practice. My setup has the target 12mm in front of the sensor plane and the z-offset set to 12. Trigger level is 1.2.

[Azmodan]

completed my second freETarget. full feature unit (with internal LED lighting and paper roll)

[Azmodan]

first test on freetarget with paper roll. 30 shots.
i taped a normal paper target on the back of the rear mask to check accuracy. result...good.

[janxjanu]

Hi everyone,
Is it possible to get Main Board PCB file? In github there is everything except that.