# My DIY Static Grass Applicator



## JeffHurl (Apr 22, 2021)

Greetings!

I watched a few YouTube videos about how to convert a cheap electric fly swatter into a decent static grass applicator.

I picked up the electric fly swatter at Harbor Freight for $5, and bought a cheap hand-held strainer at Kroger. I took apart the fly swatter and discarded the whole head of the tennis racquet shaped device. This left me with the handle and lose electrical cords. I figured out how to mount teh strainer to the handle, then simply soldered one wire to the wire mesh in the strainer, and the other to a longer lead with an alligator clip on the end.

Here are a few pics of the final product. I think it turned out nicely.

















In that second picture, you can see the results of using it to make small tufts of grass, and also a few long strips like you would see in the middle of a seldom driven gravel road. I start by putting down a sheet of parchment paper inside a metal baking dish. I used Elmers Glue and made a grid of small dots of glue. I also made a few long beads so I would end up with a strip of weeds.

This next picture is what it looks like after I applied a layer of 2mm medium green static grass followed by a layer of 4mm light green static grass. The one after that is after the glue has dried and I vacuumed the excess grass with a hobby vac. I have an old peanut butter jar that I store the recovered grass in.






























So far, I have made 3 batches that I am storing inside this plastic container until I', ready to start building this Fall. The white ones you see are upside down, or should I say, Glue side up?












It was surprisingly simple to make this applicator. It runs on 2 D cell batteries. I have considered trying to rig it with a 9v... But honestly, I'm "Stoked" about the results with it as-is!


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## Severn (May 13, 2016)

I ran into a vid by Luke Towan in which he makes a pretty fancy one.


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## Gramps (Feb 28, 2016)

Very clever, nice work.


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## Lemonhawk (Sep 24, 2013)

I think you've lost the warranty on that fly swatter! You did a superb job of making look like it came that way  How did you couple the strainer to the handle, looks like a perfect match!


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## Severn (May 13, 2016)

I have one. I thought about building one but got lazy and bought one. I know they are simple devices and I probably paid 25 times the cost of the parts. Oddly I haven't even used it yet & I've had it for months now. But i'm inching ever closer to using it and I can see the end of the tunnel now as far as that goes. The vids of folks using it and pics show excellent results and my expectations are pretty high...


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## JeffHurl (Apr 22, 2021)

I made a 4th batch last night, and will vacuum up the excess then add the 4th batch of tufts to the small plastic container.


Lemonhawk said:


> I think you've lost the warranty on that fly swatter! You did a superb job of making look like it came that way  How did you couple the strainer to the handle, looks like a perfect match!


I got lucky with the strainer. It had a plastic handle that fit almost perfectly in between the 2 halves of the swatter's handle. All I had to do was saw off all but about 3 inches of the handle, then drilled 3 small holes into the strainer's handle to make room for the three screws that held the original head onto the swatter. I only had to whittle away at the bottom edge of the strainer's plastic circumference. I could have avoided that if I had just made the thing an eighth of an inch longer.


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## JeffHurl (Apr 22, 2021)

Severn said:


> I have one. I thought about building one but got lazy and bought one. I know they are simple devices and I probably paid 25 times the cost of the parts. Oddly I haven't even used it yet & I've had it for months now. But i'm inching ever closer to using it and I can see the end of the tunnel now as far as that goes. The vids of folks using it and pics show excellent results and my expectations are pretty high...


I believe the ones you can buy put out a little more power than these homemade ones. I'm considering changing out the 2 D-cell batteries that the swatter was designed to use for a single 9v battery and see if it makes a difference without frying the cheap circuit board that came inside the swatter. I'm not much of an electrical engineer, but I believe 2 D cells combine to put out 3 volts? If that's correct, then one 9v battery should triple the power?


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## Severn (May 13, 2016)

honestly all i can offer up is this guys over the top home grown version... 




he's got the 9v battery or wall wart option. i mean surely that's all the power anyone would need!


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## Shdwdrgn (Dec 23, 2014)

Do NOT try connecting a 9V battery to the HF flyswatter. You're not the first person to think of this, and everything I found online stated that this would fry the electronics. I built one of these last year and had fun playing around with it for a little while, but my shelf layout is not ready for scenery yet. One of the things I read about this design is that they don't work well because the batteries lose power quickly. I found a small transformer which will connect directly to AC and outputs 3.3vdc at 1 amp, and fits inside the handle. Once I'm ready to start laying down some grass I'll do the conversion and see how that works out, but at the very least I should have a solid output that won't fade during use.

By the way, one of the techniques I've seen that really makes a difference in the realism is to mix in a little bit of another color. Yes most packages have varying shades mixed together, but if you mix a little straw colored grass into your green then you'll have some dried/dead bits. I'm thinking some shades of brown or tan would also work well for this.

I would also suggest your drops of glue are way too large, and possibly preventing the grass from standing up completely. For the small size of grass you are using, try putting down a tiny drop with a toothpick, or at least try to spread the glue thinner. Also keep in mind your electrical path. If you're doing this on parchment paper, try giving both sides of the paper a light mist of water before starting so the electricity can flow better. You should be able to get the grass to stand straight up when you pass the strainer basket over it.

And good luck! It's definitely a fun technique that can be very realistic. Can't wait to start doing my own layout.


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## JeffHurl (Apr 22, 2021)

Well, it turns out that using a 9v battery won't make the static charge greater, it would only recharge the capacitor more quickly.

The circuitry inside these things increase the voltage enough to work, but you can buy negative ion generators that are much more powerful, and give you a better result.

The circuitry includes a "discharge resistor" attached to the capacitor that slowly bleeds the charge out of the capacitor for safety reasons. Therefore, you need to press the "on" button frequently in order to maintain the capacitors at full capacity. This is what causes the batteries to lose charge faster than if the discharge resistor was not part of the design.

I can get the grass to stand straight up, but I have to get the strainer really close for it to work that well.

I just did my fifth batch last night. I'll post some pics later that show the tufts sitting next to a freight car for reference.

Edited to add pictures


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## JeffHurl (Apr 22, 2021)

It seems to work better with 2mm grass than 4mm. I imagine that's because it takes less static charge to keep the shorter strands to stand on end. If you zoom in on the pic, you can tell it's the longer strands that do not stand as erect.


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## JeffHurl (Apr 22, 2021)

Sorry for the thread drift, but all this talk about static electricity reminds me of the battle between Tesla and Edison. Tesla was a genius. Edison a shrewd businessman, credited for inventing a lot of things, but when you really dive into the history to find the truth, Edison stole many ideas and was quicker to market than his competition.


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