Homemade static grass applicator

[nicolasgreenin]

Hi All,

 

Apologies for yet another static grass applicator thread but I didn't feel right hi-jacking another one.

 

As the title says I have hashed together a static grass applicator from a small sieve, tub and a £5 fly swat from eBay

 

 

The first test has been less than successful the grass is standing up in places but not very well.

 

Before application of the grass

 

 

After application of the grass

 

 

 

 

I am using a mix of peco 4 and 6 mm static grass with woodland scenics scenery cement. I may get better success with neat PVA

 

The other issue is that the static fly swat is powered by 2x AA battery's and although I do get a big spark this may not be enough power for the grass to stand up.

 

Any advice would be greatly appreciated

Edited July 15, 2017 by nicolasgreenin

[allan downes]

With all due respect, I just can't see the point in making your own grass applicator when for a reasonable sum you can buy one that's guaranteed to work and cuts out all the hassle of will it work, or won't it.

 

However, you're quite right about the adhesive where neat PVA is just as good as any manufacturer's  offerings and a hell of a lot cheaper too.

 

Cheers.

 

Allan

[nick_bastable]

there is a web site which tells how to add more zap with a  simple modification to the fly-swat did mine several years ago works pretty well you will need to google for it

 

also if after applying if you hold a static charged balloon  it will lift the fibers

 

Nick

[nicolasgreenin]

With all due respect, I just can't see the point in making your own grass applicator when for a reasonable sum you can buy one that's guaranteed to work and cuts out all the hassle of will it work, or won't it.

 

However, you're quite right about the adhesive where neat PVA is just as good as any manufacturer's  offerings and a hell of a lot cheaper too.

 

Cheers.

 

Allan

Hi Allan,

 

To be honest I fancied building my own applicator as that is part of the challenge/fun...

[nicolasgreenin]

there is a web site which tells how to add more zap with a  simple modification to the fly-swat did mine several years ago works pretty well you will need to google for it

 

also if after applying if you hold a static charged balloon  it will lift the fibers

 

Nick

Hi Nick,

 

Thanks I will have a search for that now this is what makes me think mines need more zap as when I hold the charged sieve over the grass it doesn't all stand up!

 

Thanks Nick

[Tony Davis]

Hi Nick,

 

Thanks I will have a search for that now this is what makes me think mines need more zap as when I hold the charged sieve over the grass it doesn't all stand up!

 

Thanks Nick

If you do find it, please post a link on here.

 

Thanks

 

Tony

[nick_bastable]

try this

 

http://www.rmweb.co.uk/community/index.php?/topic/55448-static-grass-electrified-sieve/

 

Nick

[nicolasgreenin]

Hi All,

 

I think I might have wired my sieve to the negitive and the ground pin to the positive I will switch the round and try again tomorrow

[nicolasgreenin]

Ok I have wired the sieve and the ground the right way round and it now works!

 

I still have to make the modifications by removing the resistor

 

But the results are much better when in use the fibres stand up.

 

[nicolasgreenin]

Thanks for all the help I have removed the resistor across the outputs and now I am getting great results I am very happy.

 

See my build thread for more updates.

[Theakerr]

Very interesting because my experiment using the fly swatter had the same end result as yours so i will go back and check polarity.  BTW, over here in the GWN a static grass applicator is not cheap.

[russ p]

Thanks for all the help I have removed the resistor across the outputs and now I am getting great results I am very happy.

See my build thread for more updates.

Any chance of posting a picture of the resistor which you have removed.

I've made several of the but haven't removed the resistor, if it improves performance I may do the same

Cheers

[bertiedog]

With all due respect, I just can't see the point in making your own grass applicator when for a reasonable sum you can buy one that's guaranteed to work and cuts out all the hassle of will it work, or won't it.

 

However, you're quite right about the adhesive where neat PVA is just as good as any manufacturer's  offerings and a hell of a lot cheaper too.

 

Cheers.

 

Allan

A reasonable sum in comparison to £1.00:?, the nearest is over £40 or thereabouts.

 

The flyswatter circuit works fine, just slow down a bit, it is not a process to rush. also it is best not to mix the lengths, but apply the short first and then long flock. The glue is vital, PVA is best, and when watered down a bit, can have a few grains of salt added to the water that makes it more conductive. If washing up liquid is added then that contains salt anyway. The only reason to use neat thick PVA is for pre made tufts or clumps.

 

The mesh should always be as close as possible to the surface of the glue, plus a bit for longer fibres, and never try for large field areas in one go!.

 

I use one of the tiny USB powered vac cleaners to pick up waste and help raise the surface. Plug into a USB power bank to make it portable.

 

Also do not forget you can mix and match methods to the situation, using a poly bottle, or the twist and pinch method for fine detailing, where a bunch of fibres are rolled between the fingers and are aligned by this. The resultant roll is dabbed at the glue and gives excellent long grass effects, if a little slow.. Very good for adding in yellowed dead grasses to static laid general green.

Stephen

[bertiedog]

Glad to note that the circuit was the wrong way round!!! this is vital, and I wonder if this is behind other failures?

The circuits are pretty generic and the so called output resistor is there for a reason, it discharges the capacitors in the Cockcroft ladder circuit, so you do not get a shock from the charge. so at  your own risk remove, but it is usually several mega ohms and does not reduce the voltage whilst the circuit is running.

Of greater concern is the power rating of the transistor, not meant to be run continuously. It can be replaced by any more powerful version, or another one can be paralleled with the original. Most versions use discrete components not ICs, but I have seen one with a 555 timer used as the oscillator feeding the ladder.

To get extra voltage out, you can add diodes and extra caps to the ladder circuit, but do not get carried away, the voltage can get very high indeed !

Edited July 17, 2017 by bertiedog

[bertiedog]

 

If it does not run press the youtube button to go direct.

Edited July 17, 2017 by bertiedog

[bertiedog]

There's a lot more on Youtube about the zappers circuits and increasing output, but beware there are wild claims of 440KV, which are patent nonsense of course. The output on a normal one is about 2 kv up to 4 kv at most. I checked the output resistors and some are 90 mega ohms, which is so high it does not affect output, but will discharge the capacitors after use.

Even small capacitors pack quite a punch when discharged suddenly. With the transistor changed to a higher power rating, the whole circuit can be run at 9 volts, and would output at about 10 to 12 kv, or a bit more.

It seems Poundland no longer do them at a £1, but they go from £2.50 upwards on ebay, still a fraction of the dedicated devices.

Stephen

[nicolasgreenin]

Hi, I will take some photos of the circuit board where I removed the resistor and my finding is subjective as my volt meter only goes up to 500v so I didn't want to chance trying to measure the outputs before or after any modifications.

 

I tested it by holding the charged sieve over an area of static grass before and then I removed the resistor and went over the same area again and the grass seems to stand up more after.

 

It was the earlier link from nick_bastable that described removing resistors etc.

 

Thanks

 

Nick

[bertiedog]

It may be some have lower resistance to do the discharge, and it is certain the caps values are random, floor sweepings the trade calls them, the Chinese just use what's to hand. I have measured the voltage, using a multimeter, but across resistors to reduce proportionately. They make only a tiny difference, and the outputs are so high they make differences in nano volts!  Without them, the grid or cup will remain at full voltage and give a nasty kick on contact.

 

It seems that for the swatter use the polarity does not really matter, so always test the units making a tuft to see which way works to get the flock to stand.

 

If you are into electronics, change the transistor and up the battery voltage, or power from a power supply at 9 volts.

 

I take no responsibility for caps exploding!.....He Hee!!....... but if they do it s only pennies to repair.

 

Stephen.

[bertiedog]

 

If it does not run then press the youtube button.

Full explanation of voltage doublers, build a big one and feed with a zapper oscillator..........not recommended!!!!! .....but great fun.

It explains why the caps and diodes are lower rated relative to output. and why loading the output with several megs does not affect output.

Edited July 17, 2017 by bertiedog

[nicolasgreenin]

Hi, I will take some photos of the circuit board where I removed the resistor and my finding is subjective as my volt meter only goes up to 500v so I didn't want to chance trying to measure the outputs before or after any modifications.

 

I tested it by holding the charged sieve over an area of static grass before and then I removed the resistor and went over the same area again and the grass seems to stand up more after.

 

It was the earlier link from nick_bastable that described removing resistors etc.

 

Thanks

 

Nick

Ok so the resistor I remove is the discharge resistor which discharges the big capacitor when switched off this does not give it more zap but it does mean it will hold its charge more when not on which may be why it seems to be more effective as it is not discharging as soon as you let go of the button.

 

Hope this helps 

[bertiedog]

The one pound Zappers are back at Poundland at preset, not sure whether they are single cap output or the Cockcroft type, but should work for static grass.

[mwrosebury2000]

I tried to build my own applicator, it worked but I wasn't realy happy with the result so took the hit of buying a premade one... boy it wasn't cheap but it works a treat.

Hope you all have more joy than I did.

 

Mark

[bertiedog]

On the newer Poundland stock, I tried the new one converted and it works the same despite a simpler circuit. Output tests at about 3KV.

 

Of the home made versions I have tried making, the most successful is a type with the metal disc inside the static grass container, without a metal mesh, but a disc of plastic drilled with holes on the front The internal metal disc is amongst the flock, and gives a much better charge to it.

Also absolutely no chance of any shocks from the device. Using standard PVC pipe parts, I made several discs for the front to suit the various flock lengths, all drilled in plasticard, from .75mm to 4mm, which covers 2mm flock to 20mm flock.

 

Even if you have bought a Peco or other make, spare heads can be made to suit exactly the various lengths and simply connect by leads to the commercial unit. The old adage that one size suits all, is not true with these devices, the best comes from tailoring the head to the exact job in hand.

 

Stephen