If, for example, I'm supposed to have both feet in front of a mark on the floor before I strike the ball and don't, I wouldn't want the counter to increment even if I hit the target.

That's actually a do-able one. How much cross-distance are we talking about? You modulate an IR beam and use a IR remote control detector and look for missing pulses. That's an interrupted beam.

 

In making a large 2 part sensor, the Velostat would not need to be cut around the target, just the Al target. With a pressing cloth over seam, ran a med. hot iron over seam with mixed results. Seam almost gone but was replaced by ripples of lower amplitude but larger aria.
If necessary, could use pieces butted together. Might tape them together for installation then remove tape. Putting film under about 3 oz. / lineal inch when assembling might be enough to take care of residual seams & wrinkles.
Might make top film 22" X 14" to keep sensor from getting too thick and to not put more strain on Velostat- Al seams. Adhesives not great on polyethylene.
A counter thought. A 1 to 10 bar graph for units advances a second counter which counts 10s and a third counts 100s. Maybe 25 LEDs and 3 4017's
Would not need to be bar graph.

 

On a 24" X 24" X .5" plywood backboard, mounted a piezo geophone which gives a 5V pulse when struck with .5 oz. plastic ball with a soft under hand pitch.

 

That's actually a do-able one. How much cross-distance are we talking about? You modulate an IR beam and use a IR remote control detector and look for missing pulses. That's an interrupted beam.

Right now, I play a total of 10 five-minute long games, counting the number of times I hit the 18" x 10" target in 9 of the 10 games. I suspect that if time and money were no object, it would be possible to automatically count the strikes on target in all of the games. A few of the games are almost identical, except I'm standing 7' or 10' away from the wall instead of 4' or 5' away from the wall. Given the ability to move the line further from the wall, these 7 games cover all the requirements for all the games:

1) Plain: Strike on target counts if I'm standing behind a line on the floor. Right now, that line is 5' from the target. As my skills improve, the line will move further from the wall in 1' increments. So if I'm behind the line and strike the target, the counter increments. If I'm in front of the line and strike the target, it does not.

2) Side: There's a "center line" on the floor, perpendicular to the playing surface. The first hit is from the right side of the line and the second is from the left side of the line. I alternate moving left and right over the center line, and a strike on the target would increment the counter only if I hit the ball with both feet on the correct side of the target. Down the road, as my skills improve, I'll have two lines about 6" apart and have to be completely to the right of both lines or to the left of both lines in order for a strike on the target to increment the counter.

3) Close volley: I stand behind a line 4' from the wall and hit volleys at the target. The counter would increment only if both feet are behind the line AND the ball doesn't touch the floor before or after being hit. The line will move further from the wall as my skills improve.

4) Hi-Lo: Standing behind a line 4' from the wall, the first hit on the ball is any kind of normal swing. On the second hit, I make contact with the ball below my knee level, and then alternate between normal hits and hits below knee level. A strike on target counts only if I'm behind the line when I hit the ball and I strike the ball from the correct height.

5) Be-Bop: Standing behind a line 4' from the wall, I alternate between hitting the ball on the fly and letting it bounce once before hitting it. As my skills improve, the line will move back and I'll switch from the volley-bounce-volley-bounce pattern to a volley-volley-bounce-volley-volley-bounce pattern. Strikes on target count only if I'm behind the line and hit the ball in the correct pattern.

6) Trick: On this one, I'm counting any shot that hits the wall after being hit from behind my back, between my legs, or while I'm facing away from the playing surface. Whenever possible, I switch the paddle from hand to hand instead of using a backhand, so I do both a right-handed and left-handed "trick" shots.

7) The Z: On this one, there are 2 lines - one parallel to the wall and one perpendicular. I end up with 4 quadrants:

[a]
[c] [d]

Down the road, as my skills and fitness improve, I'll have 4 lines - two parallel to the wall and two perpendicular, which will increase the space between the quadrants.

I stand in quadrant D for my first hit, then move completely into quadrant A for the second hit. From there, I move in a "Z" pattern - A to B, B to C, C to D before starting the "Z" all over again by moving into A.

A strike on the target counts only if I'm completely inside the correct quadrant at the time I hit the ball.

So, while I'm sure all those could be automatically counted if time and money were no object, I think putting together a system that sounds a chime whenever I hit the target will be enough automation for now. I'll use the circuitry between my ears as the counter... and let that 63 year-old circuitry also determine whether or not a chime sound should increment the counter.

Thanks for your input!

 

In making a large 2 part sensor, the Velostat would not need to be cut around the target, just the Al target. With a pressing cloth over seam, ran a med. hot iron over seam with mixed results. Seam almost gone but was replaced by ripples of lower amplitude but larger aria.
If necessary, could use pieces butted together. Might tape them together for installation then remove tape. Putting film under about 3 oz. / lineal inch when assembling might be enough to take care of residual seams & wrinkles.
Might make top film 22" X 14" to keep sensor from getting too thick and to not put more strain on Velostat- Al seams. Adhesives not great on polyethylene.
A counter thought. A 1 to 10 bar graph for units advances a second counter which counts 10s and a third counts 100s. Maybe 25 LEDs and 3 4017's
Would not need to be bar graph.

Bernard, I have a small business where I do 3 things.

Until the virus hit, companies would hire me to visit their facilities and help their personnel reduce their company's hydraulic-related downtime with 1, 2, or 3 day basic hydraulics training that focuses on what you need to know in order to not only do a better and faster job of hydraulic troubleshooting, but also what it takes to prevent hydraulic issues and get the best possible life from hydraulic components and systems. I'm in the process of converting some of that training to a live, online, interactive "boot camp," which is why it sometimes takes me a while to respond to this thread.

In addition to providing basic hydraulic training, I make name badges and customized magnetic-backed dry-erase refrigerator calendars (years and years ago, my wife contracted multiple sclerosis, and when her condition reached the point she couldn't be left alone for long periods of time, I left my job as a sales engineer for a fluid power distributor and started a home based business so I could work from home and be my wife's care-giver. My wife passed away over a decade ago, but I still make name badges and calendars).

The calendars are a "sandwich" of 3 things. The bottom layer is a full-sized piece of adhesive, made in the USA, magnetic sheeting. The middle layer is the calendar artwork - customers email photos to me of their family, vacation spots, pets, and even favorite tractors. The top layer is a sheet of clear, self-adhesive, made in the USA, dry erase sheeting.

I buy that self-adhesive dry-erase sheeting in 15" wide by 150' long rolls, and am confident that adhesive sheeting will be an excellent top layer for the target. If you have a need for adhesive-backed plastic sheeting, you might want to check the dry erase sheeting at https://remingtonlaminations.com/products/clearance-dry-erase-laminating-film , where they often sell 12" to 18" wide rolls for ridiculously low prices (as I write this, a 16" wide by 150' long roll is just $8.99, plus shipping).

 

A bowling lane is like 3' wide. What is that dimension? A beam where your foot might block would be how wide? 15 feet or 5' or somewhere in between?

 

A bowling lane is like 3' wide. What is that dimension? A beam where your foot might block would be how wide? 15 feet or 5' or somewhere in between?

The "court area" for my practice is 12' wide and 15' to 20' deep (depending on whether or not I open the garage door).

If we're trying to see where my feet are, to make sure I didn't run into, or step on anything covering the 12' width, the units would probably need to be about 16' apart, and units perpendicular to the wall could be 22' apart.

 

In that case a laser and sensor might be your best option.

 

An optical curtain on steroids. At 6" spacing maybe 54 sensor pairs at 4"- 81. Not easy but could be done. I once detected a laser pointer @ 300' outside, no notes just fading memory.

 

Just for future ref. 9:45 AM, Tucson, AZ, USA, in car port , bright sun, sensor facing N, red LASER pointer 22'
N of sensor, 5mm CdS LDR, which has a red filter & recessed 1". No LASER = 7k, with LASER = 1.5k, detectable with a comparator. Adjustment extremely sensitive.

 

Just for future ref. 9:45 AM, Tucson, AZ, USA, in car port , bright sun, sensor facing N, red LASER pointer 22'
N of sensor, 5mm CdS LDR, which has a red filter & recessed 1". No LASER = 7k, with LASER = 1.5k, detectable with a comparator. Adjustment extremely sensitive.

Thanks!

My guess is that if:
- the ball bouncing off the Velostat "sandwich" plays about the same as the ball bouncing off the plain plywood, and
- I can get the Velostat "sandwich" to fairly accurately sound a chime each time the target is struck by the plastic ball, and
- the Velostat sandwich is still sounding the chime after about 200,000 hits on the target (which is more than a year's worth of hits on the target),
then I'll probably consider the project complete.

I've found several battery-operated countdown timers with fairly large displays for less than $15, so I'll probably not even worry about adding a timer to the circuit and just make a circuit that will sound a chime for a fixed length of time whenever the target is struck, and allow me to adjust the chime's volume and pitch.

The Velostat I ordered should reach me on Friday. I should know by the end of the weekend whether or not the play of the ball off the target is acceptable, and if it is, can start working on the rest of the circuit in the following weeks.

 

Suggestions for Electrical Connections?

The Velostat "sandwich" that will be my target will probably have:
- a 22" x 14" sheet of adhesive material on layer 1,
- a 16" x 8" sheet of aluminum foil on layer 2,
- an 18" x 10" piece Velostat on layer 3,
- an 18" x 10" sheet of aluminum foil on layer 4, and
- a 22" x 14" sheet of adhesive plastic on layer 5.

There's a good chance the first adhesive layer will be removable, kind of like a big post-it note, so I can easily replace the "sandwich" if it stops working or if I want a smaller target.

I'm thinking my best bet would be to cut a couple of narrow slots all the way through my plywood playing surface that would allow me to connect a length of flat, conductive material to each sheet of aluminum foil to the chime circuitry mounted on the back side of the playing surface.

I see that rolls of conductive foil tape are less than $10 for over 100 feet, but is there any reason I couldn't fold a piece of aluminum foil into a multi-layer strip, attach one end to the back of an aluminum foil layer with a piece of packing tape, and then feed the strip of aluminum foil through the plywood to the circuit? I don't mind spending the $10 for a roll of foil tape, but I don't imagine I'll use more than a foot of the foil tape.

Thanks!

 

I see that the target has changed size. Might review post # 31.
Possible Al connection is to counter drill back board maybe near a corner of target for a # 8 flat head machine screw, drill hole with 5/32 bit then apply adhesive sheet & Al target. My sample came out with screw head flush with target & measures 0 ohms. Outer screw same except counter
drill thru both spacer strips & backboard.

 

I see that the target has changed size. Might review post # 31.
Possible Al connection is to counter drill back board maybe near a corner of target for a # 8 flat head machine screw, drill hole with 5/32 bit then apply adhesive sheet & Al target. My sample came out with screw head flush with target & measures 0 ohms. Outer screw same except counter
drill thru both spacer strips & backboard.

Yep - the target size has changed. I've been playing a small selection of the games each day, and it is getting easier and easier to hit the 18" wide by 10" high target, so I've decided to make the target area a bit smaller.

Are you suggesting I use the machine screw as the conductor between the aluminum foil on the front of the playing surface and electrical circuit on the back of the playing surface and that the physical contact between the aluminum foil and the machine screw is just the aluminum foil laying on top of the screw?

 

I would suggest looking at the circuit here: https://www.romanblack.com/SonicRanging/Sonic_Ranging.htm

 

Sorry for the confusion, after the AL target is laid, running a finger shows where indentation is & then AL is perforated to receive screw. Screw can be flush or slightly recessed. Would be best if
screw were not allowed to rotate when tightening a nut so as not to strip AL.

 

i

Thanks again!

One of my first thoughts when you suggested the Velostat is that I could cut an 18" x 10" piece out of a 4' x 3' sheet of Velostat and then mount both the large sheet and the cutout onto my 4' x 3' plywood playing surface. That would give me a consistent playing surface over the entire board, and I could do something very much like you suggested - I'd wire the 2 pieces as separate pressure sensors and hitting the smaller one would be counted as a hit and increment the counter, while hitting the larger one would be a miss and reset the counter.

My "it is 3 AM and I can't get back to sleep" musings on this setup had me solving the problem of the ball completely missing the 4' x 3' target by adding some sort of timer to the circuit so the counter would reset if there was too long of a delay between hits.

The problem I don't believe I can resolve within my budget is keeping the counter from incrementing when I hit the target area, but haven't met the criteria of the game. If, for example, I'm supposed to have both feet in front of a mark on the floor before I strike the ball and don't, I wouldn't want the counter to increment even if I hit the target.

As far as the folding/rolling - is there any reason I couldn't cut a folded piece of Velostat a hair to the left and then a hair to the right of the fold line, and then mount the two pieces in the target area instead of one larger one?

Thanks again!

instead of so many text, can you post a rough sketch of your problem,that will be easier and faster to read

 

Thanks for the reply, Sophie! I agree that a drawing is often easier to understand than text, and my very first post has a PDF file attached to it with a sketch of what I originally had in mind. I first did that document as a PNG file, but redid it after reading in the forum guidelines that PDF was the preferred format.

In response to my original post, I received some excellent suggestions that would help me with that approach, suggestions about using sound or vibration to detect when the plastic ball strikes the target, and a suggestion from Bernard to look into using a sheet of Velostat between two pieces of aluminum foil as the target.

As Bernard made suggestions and I worked on figuring out how to implement them, I attached PDF drawings to several of my posts to confirm I understood what Bernard had in mind. I believe the vast majority of the text in this thread consists of questions, comments, and suggestions about the information on those drawings.

If I'm wrong about attaching PDF files being the preferred method of sharing drawings in this forum, I'll be happy to switch to a different file format for any future drawings I upload.

Thanks again for your reply.

 

Here is a sample of one edge of Velostat target. DFA= double faced adhesive, AL = aluminum
sheet, spacer = 4 strips of heavy paper, not folded or over lapped .004 to .005". The spacers
keep the Velostat edges from being pinched between 2 layers of AL. Layer 3, spacer could be widened by a half inch to spread out seams. # 1 to # 2 = 3"

 

So the spacer on layer 3 doesn't overlap the aluminum foil on layer 2?

And am I correct in guessing that the thickness of the spacer in level 6 is the same thickness as the Velostat?

Thanks again for all your help!