Steel Etching and Marking From a DC Adapter
I have a very nice machine that can do this, but others have asked me questions about etching and marking so I came up with a fairly direct approach
A forwarding device that can make about $20.
But first there are some backgrounds.
Many people etching with DC power and batteries.
Current flows through electrolyte such as brine in the circuit.
The etching process removes the metal from the surface of the knife and forms a valley in the place of DC (DC)
If we apply a little AC (AC)
After we etched, We blacked out the etched area.
This is the mark.
Therefore, the secret of etching and marking the power supply is to have a DC at the same time (etching)and AC (marking)capabilities.
Before we start: a little bit of understanding-
How to complete this project.
You need some basic tools and soldering iron.
Please note that the information provided is for educational purposes only.
I am not responsible for the use or misuse, damage, injury or death of this information.
You also have to know that the modifications shown here will result in any product approvalg. UL/CSA invalid.
I originally published a long article on my Knight Blog: D.
Best wishes from Comeau custom Knight, let\'s see what we need to start.
Tool: Material: this is the type of adapter you would like to use.
Do not use the rectangular power supply of the modern computer, because these are \"switch mode power supply\" and there is no AC power supply inside.
We want the old one that feels like a lot of weight.
Try at least 5 volts DC and 1 amp or more.
I have a trash can full of these puppies in my local 2nd hand store for $2 each.
Let the fun begin!
I opened this adapter with a hacksaw.
Cut carefully around the seam.
Don\'t keep going because you might cut some components.
Instead, you want to really get close and then do the final cut with a tool knife.
Once inside, you should see something like a small circuit board and a heavy iron thing called a transformer.
Schematic and component ID images for your enjoyment.
Let\'s take a closer look at the schematic.
The transformer is powered from a 120 VAC power supply or may be 240 VAC depending on where you live.
It reduces this voltage to 5 to 15 volts.
Usually four diodes (
Called bridge rectifier)
Convert AC to DC, and filter capacitors smooth DC before DC enters the output jack.
The schematic diagram of the etching/marking power supply is shown in the figure.
As you can see, we need to access the output of the transformer and install a double throw (DPDT)toggle switch.
This will enable us to switch between DC \"etching\" and AC \"marking.
In this transformer, the output can be identified as two heavier copper wires coming out of the transformer into the circuit board.
Once you find the output leads, follow them to the back of the board.
Pay attention to where they come from.
You should be able to track these and make sure they reach the diodes.
Now 2 15 cm (6\")
20 or 18 ad hoc working groups connect the wires and weld them to where the transformer leads go through.
Make a clean connection with some solder.
Please make sure not to drop any solder on some traces on the board and create the bridge.
We are trying to connect only to the pads with transformer leads.
Do not connect to the primary side of the transformer connected to the power supply (120 V or 240 V).
This should be obvious, but it is worth clarifying.
Carve a half circle where the DC power leads out next to the lid.
Carefully wire the two new wires along the DC lead side and temporarily reconnect the adapter tape together.
Now that we have taken out the DC and AC leads from the adapter housing, Let\'s connect the switch.
The switch must be a two-knife double-throw type and always have 6 pins.
The part I got was a few bucks from Digi. P/N EG2398-key
Good for 5 amps and 120 volts.
The blue wires shown are AC and we don\'t care which way they go.
In other words, changing blue to another Blue has no effect on the operation.
Peel off about 1/8 of the insulation and push the wire into the hole.
Heat up from the soldering iron and then stream some solder to the joint to establish a good connection.
Cut about 15 cm (6\")
A 20-or 18-byte connection line in red and black.
As shown, peel these off and Weld to the center pin of the switch.
Now we have to get the DC polarity right. . .
The black and red wires in my picture are DC.
Your Wires may also be black and black stripes.
Pure black is usually DC-
Black with stripes is usually DC, but the manufacturer may or may not follow any convention.
Here, the wires on the adapter are marked---(positive).
We need to know the polarity of the DC power supply so we know what wire goes to the pad and what wire goes to the clip.
Once I connected the switch, I connected the red and black test leads of the multimeter to the red and black wires from the switch.
Set the meter to read the DC voltage and plug in the adapter.
Switch in DC (etch)
Look at the photo of the switch and the meter will read some DC voltage.
I\'m reading 16. 32.
Check if not-
Or the minus number in front of the number.
Please note this if there is, as we have to flip the wire over to the pads and clips.
Now switch the multimeter to read the AC voltage.
Flip the toggle switch and you should read some AC voltage. Mine reads 12. 44. This is good.
We can unplug the adapter and continue with the terminals.
I have about 3mm for a switch board (1/8\")
Convenient polyester. Any non-
Conductive materials such as plastic or what-have-you will work.
Drill a hole for the switch, 1/4 \"drill 3/16 for my small toggle switch and electrical connection hole\" or install any machine screws you have. 8-
32x1/2 \"machine screws are OK.
Assemble the switch board by installing the switch.
At the end of the red and black wires from the switch peel off and curl two ring lugs.
Now that we know the circuit will work, it\'s time to reconnect the adapter case together.
Mix enough epoxy for 5 minutes, reassemble the adapter housing, add a few more ml to connect the switch board to the adapter housing.
Once the switch board is bonded in place with epoxy resin for 5 minutes, wait for the epoxy resin to solidify.
You may need this time to make some labels for your machine.
I did the following: PADCLIPETCHMARKand \"Etcher for the poor\" 12 VDC 1. 2A. . .
Although it\'s crocodile clips and Q.
Tips or cotton balls will help with etching and I found the proper felt covering pad to work best.
I start with a small piece of stainless steel like 12mm x 50mm (1/2\" x 2\")
And made a hole in the middle and accepted an 8-
32 machine screws.
Then I sink the holes so the screw head doesn\'t stretch out that much.
I found a small piece of wood and drilled a screw hole in it.
Connecting the nut to the surface and flush the screw head will allow you to see what it looks like next to the ruler.
Because I have a light rope.
First Press two ring lugs at one end of the wire.
At the other end, press a ring lugs and press them back about 3mm (1/8\")
And welded to the crocodile clip.
Before welding, remember to slide the insulator of the crocodile clip.
The last step is to attach the single ring to the screw on the liner.
Just a hex nut here.
For the mat, I cut some of the felt from the dollar store into rectangles and fold it up.
Here we can connect it to the block with some rubber bands or in my case I used a small cable tie belt.
There is electrolyte on the mat.
You may have no purpose-
An electrolyte solution that is not a problem.
Many people use simple salt water made of water and salt.
Add a teaspoon of salt in 1/2 cup water and stir well.
Wet the mat, but don\'t drop to the point where it drops.
If you get the mat wet, put it on a paper towel.
For your first etching and marking, you need some steel to mark.
I chose an adjustable wrench.
Apply a thin layer of nail polish.
This is the mask.
Make the mask much larger than the area you plan to etching.
When the nail polish is hardened, scrape your name in with a pin or scribe.
Connect the crocodile clip to the steel you are etching.
Insert etcher and set the switch to \"ETCH \".
Hold down the mat for 15 seconds and lift it up.
Wait 5 seconds and then apply the pad for another 15 seconds.
The etching goes deeper when you hold the pad.
Lifting can cool the surface and padding.
Cooling becomes more important when you use the template.
In my case, I used three etches for 15 seconds.
Now set the etching/marking switch to \"marking\" and repeat at least 2 times in 15 seconds.
Unplug the etcher.
Clean the steel with water and wipe to remove any salt water.
Sandpaper with fine sand or Scotch whisky
Brite pad for removing nail polish mask.
Acetone is also very effective in removing nail polish. (
You may already know that the agent is mainly acetone. )
If you want very cool etching like my logo, please consider making the template.
What is displayed is the etching/marking on my template and the old scrap cutter project.
I hope you can find this information.
As always, there are a lot of things on my blog about the knife holder. D.
Custom cutter for ComoD. I. Y.