# DIY "Hit It!" Board



## wildo

Well, since my a-frame project is nearing completion, I've decided to move to another project. I thought it would be interesting to try to make a "Hit It!" Board. The Hit It board is a noise making, contact sensitive board that marks with a tone when the dog runs over it. They cost $199, and I think I can make it for significantly less.

I decided to start with the circuitry since I haven't done any electronics in a while. I used a 555 timer (the single most common integrated circuit in existence) in its astable multivibrator mode. I tuned the output tone to 3084Hz, which sounds about right, and I used skeleton construction in order to keep the circuit as compact as possible (not to mention I didn't feel like making a custom printed circuit board for such a small circuit).




























A switch will cause the circuit to play a 3084Hz tone out of the buzzer:


----------



## wildo

Well, I just couldn't put myself to bed until I got this circuit redesigned and built. Finally, at 3am, I'm done. I've redesigned the circuit to include an adjustable one-shot timer where the trigger pulse time is irrelevant to the output pulse time. This means that even if Pimg stands on the board, it will only tone once for the adjustable time. This change pretty much necessitated a circuit board. As much as I *HATE* perf boards, I didn't feel like printing a custom circuit board. It's dirty, but it works.


----------



## Jelpy

I'm awed. I wouldn't dare try to make something like that. I usually put batteries in wrong. 

Jelpu


----------



## ponyfarm

Cool!


----------



## wildo

Some major progress tonight (I really didn't think this would be a super time consuming project). Got the majority of the work done.


I cut a piece of plywood as the base for the board, and then cut out areas for the electronics









I glued a piece of 26 gauge sheet steel to the base with spray adhesive and then put 3/8" wide weather stripping all the way around









I also adhered a second piece of sheet metal to a piece of plexiglass. This unit has a wire soldered to the metal. The plexi unit sits on top of the weatherstripping and the plexi will be flush with the top of the board.









The whole board assembly glued up. I cut 5/16" thick strips of oak with mitered corners to form a "box" for the plexi to ride float in.









Pimg getting in on the action. You can see in this pic the second wire soldered to the lower piece of sheet metal. It's these two pieces of sheet metal that will act like a giant switch. The buzzer is also mounted in the side (right where the strap clamp is)


----------



## wildo

Here's a demo of the hit it board. The electronics are just hanging (on the carpet, no less) and so I think a few of the tones are due to that (static electricity can easily cause the circuit to tone). This is just a little "Does this thing even work!??" test while on my lunch break:


----------



## wildo

Mounted the circuit board to a piece of hardboard with double-sided tape:









The hardboard screws to the bottom:









I had some blue wood stain, so I stained the oak. The plexiglass is been sand textured with yellow. I painted the plexi with an adhesion promoter prior to painting/texturing.


----------



## wildo

Got the Hit It board complete! Nice to have another project done!


----------



## HundenHaus

Great work! I tried googling instructions on how to build like one but no joy


----------



## wildo

HundenHaus said:


> Great work! I tried googling instructions on how to build like one but no joy


As did I...  You'll just have to use your head to come up with something on you're own! The electronics could easily be replaced with a basic circuit. Think about a lightbulb, switch, and battery- but replace the lightbulb with a buzzer. The only thing is that it will continue to tone while the dog is standing on it. But it would be an easy solution. Also- you can google "how to make a metal DDR pad" to see some examples of pressure switches like this. I found this one to be the most useful: Stoli's Chrome Dance Pad for PS2 DDR - Dance Dance Revolution


----------



## LuvourGSDs

Great job Willy! You are just too stinkin talented! Now you can build another to ship to us...............


----------



## wildo

A little update on the hit it board. It just wasn't as sensitive as I thought it should be, and it was too tall. I've decreased the height as much as possible; it is now just over an inch tall. I've also increased the sensitivity by removing all of that foam and putting thin cardboard in just the corners. You can see from the video- no false beeps, and every step properly beeped. This thing will be fun to use!


----------



## wildo

Here are some final pictures of how I settled on the sensitivity.

I used illustration board instead of the foam. The illustration board is a thin cardboard, about 4mm thick. I found it at a big box crafts shop.









I cut a small triangle for each corner, but kept cutting it away until I got the sensitivity I wanted:









Here you can see in order to reduce the overall height, I had to trim away some of the speaker's plastic casing. I also epoxied it in place. If you look close, you can also see the wire that makes contact with the upper piece of metal. I found it wasn't required to be soldered:









Oh, and I'm not sure if I mentioned it before, but I drilled holes in the plexi, and then put in small plastic tubes so that the the plexi can slide against the tubes easily:









...That's pretty much it. This project turned out really nice! I'm very pleased with it!


----------



## MaggieRoseLee

Good job, can't wait to see the video with you and you pup using it!


----------



## wildo

I suspect that will be about 1.5 months from now, just an FYI.


----------



## MaggieRoseLee

wildo said:


> I suspect that will be about 1.5 months from now, just an FYI.


Hmmm.................. you getting a new addition to your family? Anyone we'd know????


----------



## wildo

No- haha, I think you definitely misunderstood that comment! Nope- no new additions until Pimg has passed on; she hates puppies! As much as I think there are a few _superb_ breedings happening right now that I am interested in- no, I will not be taking the plunge!

Running contact training doesn't start until mid-June in the SG contacts course. I know she uses the hit it board for that, but am unsure if she uses it for anything prior.


----------



## Beau

Wow, I am totally impressed!

As an aside, I just watched some of your videos! Thanks for posting them! Pimg is gorgeous!


----------



## wildo

How nice of you to say, Beau! Clearly I'm a bit addicted to sharing. Hopefully some of this stuff is beneficial for others. If not, at least I can reference it as documentation in the future.


----------



## Beau

Lol! Then by all means....keep sharing!! It is very beneficial!


----------

