Of all the methods of making large pieces of metal into small pieces of metal, perhaps none is more interesting than EDM. EDM is also notoriously cumbersome and must control arc discharge while accurately positioning the tool relative to the workpiece. Nevertheless, some home gamers will give it a try, and we like to share their success, such as this EDM machine under development. (Video, embedded below.)

We linked [Andy]’s first video below the break, and we hope that there will be more videos before everything is said and done. But in fact, [Andy] made a lot of progress due to the early stages of the project. EDM basically uses an electric arc to remove material from a workpiece, but as anyone performing EDM inadvertently, for example, by shorting a screwdriver between the terminals of a live socket box, the process needs to be controlled to be useful.

Part 1 shows how to start building with an old faucet burner, a 60-volt power supply, and a simple pulse generator. This is enough to test the mechanical control of electrode positioning and obtain basic knowledge of the electrical aspects of continuous, useful discharge. Part 2 continued to improve, and these improvements soon produced the first useful parts, which were processed quickly and cleanly from thin materials using custom tools. We admit to being impressed—many EDM builds either never reached the point of making simple holes, or stopped when the initial success proved daunting progress. Of course, when [Andy] gave up the fact that he made control panel buttons on a self-made injection molding machine, people would think that anything is possible.

We look forward to more information about this release. We have seen some EDM versions before, but none of them have such great potential.

I really have nothing to say except "This is great!"

What are you talking about, but in spades! I need one of them. I'm trying to make a jaw crusher for prospecting. I plan to use a 20mm x 20mm x 20mm triangular jerk file as a chewing tooth. But drilling and cutting threads in it is harder than the really difficult things, it just becomes It’s harder so this seems like a good choice. I’m still not sure how to install the teeth to the board but at least EDM will let me cut mounting holes in the teeth. I can weld threaded rods into these holes.

During the final burning process, you should support the workpiece with something that is non-conductive and hard, such as wood or plastic. You burned deep enough, but the workpiece bends away from the electrode. You need to redesign the pin component (or separate it from another electrode and operation), but CNC makes this easy.

About 40 years ago, I made an EDM by myself. good time!

Don Lancaster published a simple circuit that uses 2 capacitors and an incandescent bulb as a ballast and does not require a switching circuit. If the electrode touches/welds to the workpiece, the light will illuminate without burning the circuit breaker.

Mine has a coil around the wire leading to the electrode, then connected to the signal conditioner (voltage limiter), and then connected to the 68HC11 mini (the way before arduino) to calculate the number of sparks per second. Then it controls the position of the old chart recorder to which the electrode is connected via the serial port.

The system will continue to lower the electrode until it generates 200 sparks per second, and then adjust the height as needed to maintain this rate. If the spark stops, it means that the electrode touches the workpiece to complete the circuit, so it will withdraw the electrode and start again.

This is a closed-loop control system that worked well, but I really didn't have any applications at the time. It's still somewhere in my basement...

You can do quite a bit of filtering by refluxing the fluid and putting it from the side into a large plastic flask (such as the orange juice container you got for the refrigerator). The returned fluid rotates inside the flask and spins down, and you return from the top middle. Most of the soot settles at the bottom, you only need to filter out the remaining bits.

I have (or used to have) that book by Lancaster. Although I recently considered it, I haven't found time to build it yet. The filtration process you are referring to sounds similar to the method of self-drilling using a mud pump. For those who usually push backflow into a huge vat, the backflow is located at the bottom, the output from the top on the other side drains to another larger tank, and the drain on the other side leads to your "source" water . This allows large and heavy things to accumulate in the first bucket, and then the mud is filtered out in the second bucket, because then it moves much slower.

If I understand these two articles correctly, they will be slightly different. I think you are describing a gravity pre-filter, in which heavy sediment cannot rise to the outlet, while PWalsh describes a centrifugal "spin-down" filter, in which the inlet is injected tangentially to set up a swirling vortex. The fluid and contaminants rotate around the tank as they move down, so that centrifugal force keeps the contaminants outside. Eventually at the bottom of the vortex, the contaminants fall off in the form of sediment, and the fluid returns to the center of the vortex.

The same principle is used in Dyson (and others now) vacuum cleaners and industrial and commercial dust collectors (such as Dust Vice), where air is a fluid. It is very effective because it prevents most contaminants from reaching the filter, so clogging is rare.

When used for fluid filtration, a ball valve or solenoid valve is usually installed at the bottom of the filter tank to easily flush the collected sediment.

"Commercial dust collectors (such as Dust Vice),"

When you describe the whirlpool, you remind me of dust collection. I don't like Dust Vice's price tag, so I made one using a Thien Baffle and a large garden bin from the garden store. An engineer friend was impressed by this efficiency. After the 200-liter trash can was emptied several times, the vacuum cleaner in the store was still almost empty.

Good results. My impression is that there is an insulating film on the side of the EDM electrode, so the discharge only starts from the end. I would like to know.

The Noperam edm electrode will generate any arc within its spark gap-this depends on the machine's settings.

If you imagine that the tube goes directly into the aluminum, the bottom will see the most spark action, so it wears the fastest-but it will also bend to the side. There is no insulating layer on the electrode. If he moves it sideways after it passes (or even before), it will also burn sideways. Usually on circular electrodes, the head of the EDM has a rotating mode-to make the spindle rotate at a low speed (50rpm for my Agie Charmilles SP300), basically like an electric end mill, it will remove the material in any case electric direction Move without cutting pressure.

This is why ram EDM is so cool-you can do many complicated things, otherwise it would be impossible to use one. If you cut the thread at the end of the graphite rod and burn a hole in the top of something, you can put the threaded electrode in that hole, or even go around the text and copy the thread pattern into the object, just like an electric faucet . I have done it, and the surprising thing is that the line you end up with is very smooth, just like glass without gaps. You can blow on the screw, and if you do it just right, it will spin under air pressure. To make a thread copy, you need an EDM that can orbit on 2 axes-a little more complicated is all. 3D isometric tracks are now very standard.

I remembered a long time ago. Maybe there is a similar system based on electrolysis? I think it makes very precise finished holes in the electrode shape.

"But none of them have so much potential"-puns, very puns!

I want to know if weak EDM is useful when making PCBs for DIYers. Paint your circuit board and blow up the "resistance" you don't want. Similar to using lasers, but using electrons and photons.

I can see that it is used for short thick copper plates, which you cannot get from the usual factories. And Resist only exists in your Gcode file. One thing you must pay attention to and deal with is dynamic tracking to isolate. When the trace is cut from the rest of the cladding, it is no longer a conductive path, so you must reposition the ground electrode. One solution I can see is the pogo pin on the mini SCARA arm, which moves to touch the other end of the relevant trace

Indeed, I can see how it is done, and on heavier copper I can see why it can be done...but it seems that DIY PCB is still much easier with acid etching and resist... .I really don’t see the important reason for EDM on acid, even thick copper can be etched well by acid, maybe you need to change the resist size slightly to solve the longer etching time and implicit undercut , But it’s not impossible...

Ignore the availability of high-quality PCBs that don't cost much in about a week...

By correctly ordering the location of the PCB, you can avoid wire isolation (not to isolate, by the way). Make the innermost gap first, then work along the outer edge. As long as your electrode/tool ​​is thinner than the minimum trace spacing, it will work. I think this led us to use wire-cut EDM.

By the way, you don't need to draw anything. Generate GCode to position the electrode on the part you want to "mill" off. This is exactly what the various PCB milling plug-ins of EDA tools do. You only need to add a sort to make it work with EDM.

I really want to know how FR4 can withstand arcs.

It is well known that Edm using chemicals will sink a half-inch hole within two-tenths of its diameter at a speed exceeding 22 inches per minute. This is as fast as a carbide drill with a tool through the coolant

EDM basically uses an electric arc to remove material from a workpiece, but as anyone performing EDM inadvertently, for example, by shorting a screwdriver between the terminals of a live socket box, the process needs to be controlled to be useful.

I heard that the EDM that occurs when an uninsulated wrench finds itself passing through the bus bar of a 48V telephone switch battery pack is quite noticeable. There was a loud noise, a bright light, and the voltmeter twitched for an instant, and then a dozen frightened engineers scratched their heads, one of them was looking for the now-disappeared wrench.

There is also the smell of ozone. Don't forget the smell of ozone.

My father is an electrician in the Navy. He told a story that he had to train a new man on an aircraft carrier to understand some maintenance procedures. The first step is to use a controlled load to discharge a large number of capacitor banks, but the new employee insists that he knows a better method, and reaches out to insert a wrench on the terminal.

My father can see the light through the outline of the flesh and bones on his hands. Before his vision recovered, his eyes were bandaged for several days. When the newcomer was sent home, he had one arm less than when he got on the boat.

People would think that any "newcomer" who achieves such a result in the process will know better, and that it is not good on the device.

OMG! This is scary and ridiculous.

...And the nickname "Bright Spark".

I think anyone who has his own injection molding machine will find a convenient EDM sooner or later.

Better results may be obtained by using copper electrodes. I think we have used anaerobic and poco graphite is also effective. If possible, wash through the electrodes.

I am here to learn about the new electronic dance music machine that is about to go into production.

Thank the Lord, I am not the only one who is disappointed.

here you go. Well, from 2016...

https://youtu.be/Ov28C3QF6D0

Even if it works, it's crazy waste

The use case I saw is where you want to do some heavy processing. Traditional machines are large and heavy because they must be strong and durable to withstand tool forces. They are expensive and take up a lot of real estate. (Actually, you can buy a second-hand Bridgeport milling machine for a few thousand dollars, but I still don’t let one enter my basement.)

EDM and ECM machine tools have essentially zero tool force, so they may be relatively small, light, and inexpensive.

ECM is a different process-electrochemical milling. Its main advantage is that whether you make one part or one thousand, the time required to complete it is basically the same.

If you have never heard of ECM, it is very concise-if you want to learn more, check out the Precision Microcast by Josh Hacko and Adam Demuth.

I have run this ram EDM for several years-I really want a desktop EDM like the BaxEDM channel on YT.

This is also pretty cool. By the way, brass as an electrode was quickly eaten-it has almost never been used by a professional. Most stamped EDM electrodes are medium to high density pure graphite, copper or copper tungsten electrodes.

Even the very complicated electrodes were first made using wire-cut EDM tools, and then placed in the stamping EDM. Find a good example of Mike Sabotech on Instagram.

Thank you for pointing to the Hacko & Demuth podcast. Episode 5 gives several industry professionals' opinions on ECM.

Hacko & Demuth made the point that the electrolyte is actually a cutting tool. From this perspective, the control of the electrolyte makes the difference between single-digit micron accuracy and terrible chaos.

I found a way to cut the old wire 150% or better, the thicker the better, and use half of the wire. I combined two milling methods. Use a high-feed milling cutter for cutting at a 7 degree angle and a method called dynamic circular milling contour method. Basically, if the spark gap of the 0.01 line is 0.0015, I made a magnifying glass that can move backwards, and then move backwards 3 to 4 times, and move forwards 0.0003 for each pass. In the 6-inch material, I feed from 0.01 per minute, with an average of 0.017, and I can control my wire speed from 16 to 20. The reason why my welding wire can be slowed down is because the spark of the welding wire may now be 40 degrees on the side of the welding wire instead of the degrees around the 185 degree line. This also allows more water to flush into the wire channel because the wire channel is 0.013 wide and reaches 0.017 allowing more water to flush. I think Makino is doing this on their machine now

I think my opinion is that this method may only be used for wire EDM for 2 years, but these two methods of removing metal on CNC machine tools have been used for more than 3 years. I believe there are more metal removal methods for lathes and milling machines that can be used for EDM metal removal and increase faster metal removal time. I have not run edm of the receiver type. But it will consider whether it is possible to remake the mold for the sink or electrode to remove the metal, such as a high-feed mill. In order to continue, I must explain the role of high feed mills. If you know what an insert milling cutter is, then let us use a square insert. The old-school approach is that the blade is basically flush with the cutting surface. The speed is like cutting a depth of 0.1 at 600 RPM at a speed of 12 inches per minute. For high-feed milling cutters, you will now move the blade or rotate the blade 7 degrees. When you do this to make a 0.007 chip, you must move 0.059 between a chip. Therefore, this will reduce your rpm from 600 rpm to 250 300 rpm. Your feed rate increases from 12 inches per minute to 250 inches per minute, but you still need to cut 0.1 inches deep. So there is no sinking edm method that can make the small pyramid on the 4 sides rise by 7 degrees instead of sinking directly. We can place a small vibrating circular pattern while sinking. I think it can create more washing and faster The feed is sinking at the same time. I tried to use grade 7 wire, that is, the side tangent line with a depth of 0.0005 moves forward and backward, and the line 4 will change the cutting method of wire cutting in the future. I believe there are more cutting methods that can be added to edm to change the way we remove metal today

When I mentioned the line speed from 16 to 20, my first comment was wrong. 20 should be 10. So the line speed is changed from 16 to 10

When it comes to home-made EDM machines, BaxEDM is probably the highest quality. The mechanical design is open, but the arc generator is not, and it is quite expensive, 3000 Euros.

Yes-the arc generator unit is always the black box that makes EDM a usable device. This price is also what prevents me from making one. I still think that if you really want to get one, it’s fair. I hope he can open source it-but considering that it has to undergo a lot of engineering design, I can understand why he doesn’t. I just hope it’s cheap.

"Anyone who inadvertently performs EDM on a screwdriver, such as short-circuiting it between terminals in a live socket box"

B*gger, the text between my tags has disappeared...

Should be interspersed: looking at the screwdriver in front of you

I want to know why they don't publish the BAXEDM channel, it is definitely a crazy build.

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