New Electro-Etcher design

[Atlas Knife Company]

I hated building these until I had a bunch of PCBs built. It's about as much of a schematic as I have.

 

[Diez Knives]

What happens when you tap on the arcade button???

 

[AVigil]

The arcade button is where the magic happens. I tap mine to a count of 10 quickly and then move the Qtip to the next section repeat and do the entire logo about 3 times this way.

It leaves a nice etch in the steel

 

[Diez Knives]

So it won't work unless you tap button? Then the toggle switch when up or down is just the current? Tapping button is the control

 

[Atlas Knife Company]

Yes, the toggle switch determines AC/DC. Center position, if your switch has one, is an extra OFF position. If you want it on without tapping the button, just put a rubber band around it.

 

[Diez Knives]

had a question, so I found most of the parts at radio shack by my place but some of the voltage is more.. can i use the them or do they have to be the same as posted on 1st page?

also what about the power supply, radio shack carries a 13.8 vdc 3-amp power supply. would it be as easy to just open it up and connect a toggle switch and reroute the car side to run thru the gator clip side or just plug in car adapter to toggle switch along with the gator prongs side connected to toggle switch then running everything from there? i'm not to savvy on electric stuff..


http://www.radioshack.com/product/index.jsp?productId=2103959&znt_campaign=Category_CMS&znt_campaign=CMS&znt_source=CAT&znt_source=SrchAssist&znt_medium=RSCOM&znt_medium=RSCOM&znt_content=CT2818121&znt_content=PowerSupply

 

[Diez Knives]

So before I tried to make anything electrical I tried 4 nine volt batteries connected and etching worked and darkening worked just had to alternate positive and negative clip on steel.. I got lucky and won this one for 20.00 and bought a car plug from radio shack for 14.99 works great with q-tips or a make shift etching brass pad. All I have to do is pull plugs and alternate for dark or deep marks.

 

[TonyRV2]

So before I tried to make anything electrical I tried 4 nine volt batteries connected and etching worked and darkening worked just had to alternate positive and negative clip on steel.. I got lucky and won this one for 20.00 and bought a car plug from radio shack for 14.99 works great with q-tips or a make shift etching brass pad. All I have to do is pull plugs and alternate for dark or deep marks.

With a double pole-double throw toggle switch you could connect it so you wouldn't have to change the wires manually. There are 6 terminals, 3 per side. Wire your probe to the two middle terminals and wire your battery to a pair of end terminals on one end. Criss cross the battery connection to the pair on the opposite end. As you flip the toggle switch you'll change the polarity at the pair of center terminals that your probe is connected to. This would work whether you used a battery or a D.C. supply.

 

[Atlas Knife Company]

Well, you need AC current as well for darkening, which that unit does not provide. At 60 cycles, you would need to switch back and forth 600 times to simulate the AC current for 10 seconds. I do like your etching pad, though.

 

[Stacy E. Apelt - Bladesmith]

SIGH....
Tony, the post you are giving suggestions to made his etcher three years ago.


This is the info needed for anyone building an etcher:
An etcher needs at least 12VDC at sufficient amperage to etch, and at least 12VAC to mark. 24 Volts works better for some tasks. The best setup uses a 3 amp, center tapped, 24VAC output transformer, a 5 amp bridge rectifier, a SPST switch, and a DPDT switch. These four components ( plus the wires and connectors) are all that is needed for a good etcher. Add a variac to the AC line to the transformer and the unit becomes variable output. If you make it variable, a 0-30 volt AC voltmeter between the transformer and the bridge rectifier will tell you the approximate output voltage.

The simplest etcher can be built with just a 1 amp 12volt output transformer, a cheap bridge rectifier, and a DPDT switch. These can be bought through ebay for about $10 total. A dual voltage unit can be made for $30.

 

[TonyRV2]

SIGH....
Tony, the post you are giving suggestions to made his etcher three years ago.

Sorry Stacy....I'll try to pay more attention to dates in the future. My only defense is that I'm an electronics professor and when I saw the question, naturally I got excited that I could help.

 

[Stacy E. Apelt - Bladesmith]

Not a problem. I figured you found it in a search and didn't look at the dates. I appreciate your expert info.

I did Electronic Engineering back in the 70's. I was paid as a Electronics Mechanic, because I didn't have a degree.

 

[TonyRV2]

We may have had the same professor back in the day....short fellow with long white hair and round spectacles. We use to fly kites in lightening storms for lab.