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Ebay is your friend. Simple programs I code on the machine, for more complex stuff I use Fusion with a slightly modificated Fanuc PP. If at some point I will buy another wire EDM I´m pretty sure it will be a late 1990s or early 2000s machine, so not that much newer.

The gear has 71 teeth. 71 is a prime number so the gear cant be milled with a standard dividing head.

I would say; the harder and "pure" material the better (the machining).

I use Brother COMS on an antique laptop that has a serial port. On practical machinist you find a lot of information about the machine.

The alignment tool for the machine works quiet well in my mind? For rough aligning I use a square on the table as a reference.

@@flo_5235 I figured it out, I had to wait for solid lights and ignore the flickers. I set steps to 5 or 10 (in inches mode) and walk it in until one light is solid, then reset x2 to clear my read out and see how far off I am. Can also adjust a little. Key is to jog away then come back to the reset x2 position with steps, adjusting until both lights are solid in 1 or 2 steps.

5 Minutes/tooth, so about 6 hours for the complete gear wheel

Its built in 1990. Unfortunatelly it don´t have a U/V axis. There are small brother machines which come with a U/V axis but they are pretty rare and you can not flood the workpiece on these machines. Thats the reason why I sometimes search for a small WEDM which can cut tapers with submerged workpiece.

@@flo_5235 cool machine. The college I attend just sold a brother at auction for about nothing. It had taper and submerged, but it was a little bit newer. I wish I would have realized that it was going to go so cheap, I would have gotten in on the auction. It went for like 2200 bucks.

For roughing I want the spark energy setting as high as possible so I have the highest possible material removal rate. If the spark energy is set to high the wire is breaking. With the spark cycle setting I can influence the spark energy a little bit. If I lower the spark cycle the spark energy tends to get a little more aggressive, If i raise the spark cycle the spark energy tends to gets lower. Then you increase or decrease the feed rate so the available power meter shows a good reading. Now the machine should rough the part as fast as possible without a wire breakage. For finishing the data sheets whitch came with the machine gives you the settings for surface finish xy. In this case the settings for spark energy and spark cycle are experience values for a medium good surface finish. The feed rate is again set by the reading of the available power meter.

@@flo_5235 Thank you for the details!

Well, writing code and setting up a part is quite similar to a cnc mill. The EDM part is a little bit different. Older machines came with a lot of data sheets where you get the settings for the material you want to cut. The settings also depends on the material thickness you want to cut, the surface roughness you want to get and the wire you use. On newer machines you say the control ´I want to cut material x with thickness y and the surface roughness should be quite good´ and the machine gives you a few options of cutting settings which should work. All the settings from the data sheets or the control are recommendations, you have to finde the best settings for your actual part by your self. And this is trial and error and/or a lot of experience. Not super hard to learn but sometimes very annoying if you have to thread the wire for the 10000 time because your EDM settings are still not good or your part has a weird shape with is harder to cut than flat stock or something. By the way, the manual for the Brother machine is excellent, it´s a full how to do things with this machine. On the other side there is the manual for my Charmilles die sinker. It´s more like ´So you got a die sinker, good luck´.

Thanks for your reply! So learning by doing. I have a few other projects to finish first, but an EDM is definitely on my wish list. @@flo_5235

I film with my old smartphone and it seems like it don´t like to be in the water for quite a time. In the last part of the video where I check the fit of the hex with a gage you can see the first weird stripes in the video footage. This get´s a lot more worse in the rest of the video footage. So yes, the camera experience water problems.

Better safe than sorry.

The largest wire guide I can get over here is for 0,3 mm wire, the smallest for 0,2 mm wire. I have guides for 0,2 and 0,25 mm wire but I only use 0,25 mm wire.

@@flo_5235 I think I will use .010/.25mm wire here. Machine shows up tomorrow :)

No, the wire has to be threaded by hand

No

I have a chart which gives you a code for the programm which calls the different EDM settings. They depend on electrode size, workpiece and electrode material and the surface finish you want to get with the last setting. The chart don´t give you accurate numbers for voltage and amperage, for roughing the amperage should be about 10 A in this case. The fluid is a dielectric oil, the machine came with oelheld Ionoplus IME-ET.

@@flo_5235 Amazing how it can gouge metal like that. Thanks for the answer and description of the details!

Would have been a great idea ;) Changed the video slightly and reupload it. I will delete this video in a few days.

Spark energy 5 (or even 4 on thin materials) spark cycle 35. Good surface finish but also super slow if there is too much finishing allowance. So an intermediate finishing cut with approximately your values maybe is faster. Speed depends on material thickness, about 90% on the availabile power meter seems ok for a good finishing cut. Wire speed also depends on material thickness. On thicker materials the cut gets a little bit tapered with wire speed 8, so maybe 9 oder 10 is the way to go.

I dont know, good enough for the purpose.

Well the raw material was round stock.

It´s shopmade.

@@flo_5235 i have the same machine from 2 weeks. I see in command mode 2 offset. In the program is possible to insert H1 (off1) and H2 for the second. Is possible to change the speed in the program with Fxxxxx, but for change the current o other? Example: cut 1: H1 Fxxxx (first cut) Cut 2: H2 Fxxxx but not change the current o other? For finish cut?

No, the workpiece has to be conductible

Cutting speed depends on the material thickness

About 15 mm

Yes! That's exactly what I was thinking as i had cut this big hole for probing in the electrode.

None of the electrodes orbits around the shaft. The finishing electrode drops down so far without eroding is because the oversize between semi fininishing and finishing isn´t enough. The same for roughing and semi finishing but not that much. Some flushing around the electrode should prevent the marking on the bottom face and maybe save some wear on the roughing electrode. I have to play arround with that kind of setup a little bit but thats why I tried this out.

@@flo_5235 So you mean the semi finishing electrode only left a bit of tapper from wear towards the bottom? So the errosion starts only at the closest part of a tappered wall even if it is going to end up cutting further than it (the top of the finishing electrode didn't seem to be sparking in the beginning of the cycle)? PS: Amazing work nonetheless. Thank you for taking the time to make videos of it!

Thanks a lot! Yes, exactly. The plan was that the finishing electrode would burn all the way down too but there wasn´t enough stock left (except the corners where the semi finishing electrode wears). As the spark gap changes with different EDM settings (roughing, semi finishing, finishing) its not that easy to find the right oversizes between the electrodes. To much oversize and the erosion takes far to long and the semi finsihing and finsihing electrode wear more than necessary, to little oversize and the semi finsihing and finishing electrode don´t have material to work with and the surface finish on the part is bad (as in my case). Just my thougts, I´m not 100% sure if this is correct.