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Ohhh dear, well spotted!! It was one of those "URL shortened" links and they go bad over time. I've changed to a direct link now, no funny stuff!

That's correct - I use a small brass insert which is pressed into the end of the body. This has a broached hex recess to fit the hexagonal end of the mechanism. If you're making your own, the easiest way to achieve this is to drill and machine down the head of an M6 socket-head cap screw, since it has a 4mm recess already.

@imajeenyus42 one more question if you don't mind, is your inside diameter the same from one end to the other?

@@mattbeegle6847 Mine are drilled 6mm from the front, and 6.5mm from the rear, going half-way through. The mechanism tapers slightly so you need a stepped hole. I suppose you could do 6.5mm all the way through but you'd need to redesign the insert in that case.

@imajeenyus42 I'm trying to keep it simple and just use the pentel guts, I've just been picking up diffrent things from your videos and had a few questions to try and get ahead of the learning curve a little. Thanks for your time.

Thanks. Maybe around 0.5mm deep and took about 30min.

@@imajeenyus42 thanks, have to try it

Anything's possible, it's just a matter of design.

Propane and oxygen. Please see link in description for full details

No, it's just a piece of steel. Please see my webpage for details imajeenyus.com/vacuum/20140114_magnetron_plasma/index.shtml

@@__xiaifei Antigravity? 😂😂😂😂😂😂😂😂😂😂😂

@@imajeenyus42 是的 我做的是非真空等离子，目前在搞反重力 你很明白朋友。。牛

Good to hear! Hope you can get them sorted. Don't forget the actual controller IC itself - I once managed to fry the IC in a power supply I was using near high voltage/sparky stuff, probably voltage spikes or noise introduced back into the supply. I took the chip out and put a socket in so I could easily replace it in future.

@@imajeenyus42 Thanks for the suggestion! On psu 1 I missed checking for resistors failing open instead of shorted. I found 4 without any discoloration, probably because base and collector shorted on the bridge transistors. On psu 2 it's dropping in voltage under load, likely short circuit protection kicking in too early or something keeping dtc pin higher than it should. Some resistors can get quite hot when checking with ir imaging camera, some even 80+ degrees C. And one blue cap too. It still gives 24V withou load. Psu 2 is a newer version with slightly different pcb and component values.

Not really - I play a bit of classical guitar as well, which also has a wide neck, so they feel about the same.

What it is with people? I post something which is clearly a cobbled-together personal project and then get comments from people with bad English asking to buy it? Sure, you can buy it - the price is £100,000.

There is already a link in the description. I can't help it if people can't read.

​@@imajeenyus42I came here from the website. What I meant was that it could be helpful for CEO purposes to put a direct link to the pdf and sch file here.

I haven't the slightest idea.

Can you explain why? I can't wait to hear.

Several hundred volts. The ouptut from the inverter is squarewave, but this is filtered by the series inductors to produce a more sinusoidal signal which is applied to the transducer.

As long as the transducer is well-coupled to the cup/tank (e.g. by gluing the entire face of the transducer), there shouldn't be any issue. The water in the tank presents a large load to the transducer, which broadens its resonance significantly, so the exact driving frequency isn't quite as critical.

@@imajeenyus42 yes the transducer Is fully glued with JBWeld under the container. Thanks a lot for your answer.

No shit, you don’t say? Thanks for pointing out the obvious…

I don't think so - the fiber always produces a wall taper angle of about 10-15 degrees, so that will limit the depth/width aspect ratio of any slots or grooves.

@@imajeenyus42 Thanks for the reply. Interesting, didn’t know that, good to know.

Yup, I've done exactly that.

Go search eBay.

Sure - but I've literally only needed to turn one tapered thread in the 20-odd years since I got the lathe, so it's not worth the time making a dedicated taper turning thing!

@@imajeenyus42 true that. really only need a straight edge clamped down at appropriate angle. worth it if you gotta do a bunch. i also have never felt the need to go full hog with one... mainly as it wont do what i mostly do... steep tapers, ie, expanding pulley type things.

No doubt you could, but I have no idea about the precise details. AutoIt is able to simulate any key/mouse interaction, so if you can do it in the original software, you'd be able to simulate it with a script.

@@imajeenyus42 hm thank you. i think i understand , so i can't write custom scripts for automation but if is something that i can press manually ,AutoIt will make this process itself ? But how will it know when the deep engraving is done and make z axis come back to starting position and move xy axis and press autofocus and start again ?

@@dansv3872 That's correct - whatever you can do yourself by clicking a button or using key presses, you can automate. As for checking when it's done, EzCad2 displays a "marking" window when marking is in progress, and I'm just checking every 100ms to see if the window is still present. If not, then I assume that marking is finished. Take a look at my other automator script here, it might give you some ideas: imajeenyus.com/temp/automator.au3

Hmm, it shouldn't do. Something to check is that you have a sufficiently high input voltage - the LM317 has a dropout voltage of 2-3V, then there's the voltage drop across the current sense resistor, then finally the voltage drop across the diode load. If the supply voltage is insufficient, then you could still get an adjustable current at the output, but it wouldn't be as high and would behave strangely.

@@imajeenyus42 Thanks for the reply. I'm using a 9V input. For the blue diode laser, using my calculated values I just got 1.2 V measured across the diode max. So then I just kept slowly reducing the resistors until I got the diode lasing ... but according to the calculations using the new R's, it should be sourcing 125 mA. I'm pretty sure it is not because the diode is rated for 50 mA max and I barely made it emit light, so I'm definitely missing something. Right now my circuit is working, but I don't know why :(

@@Danyel615 What's the value you're using for the main sense resistor (R1 in the video)?

@@imajeenyus42 I'm using R1 = 500 Ohms, so I min = 1.25/500 = 2.5 mA. R2 = 100 Ohm, R3 = 1.5 kOhms, so R3/R2 = 15 and Imax = 2.5 mA*16 = 40 mA, at least that's what I had at the start.

@@Danyel615Here's the reason it's not working with a 9V supply. Say you drop 3V across the LM317, and 1V across the load, 4V total. That leaves 5V maximum that can be dropped across R1, so the maximum current that can possibly flow is 5/500 = only 10mA. You won't be able to reach the 40mA maximum current, because that would require 20V to be dropped across R1. This is actually a point which I should have mentioned. The main resistor R1 is sized based on the lowest current output, but it still has to carry the maximum current as well. For large min/max ratios, this means that R1 is quite large, drops a large voltage at maximum output, and hence you'll need a higher input voltage. A better circuit for what you're trying to do might be this: imajeenyus.com/temp/current_source.jpg. That's a single-transistor current source. The 10k pot applies a 0-9V voltage to the base of the transistor. It ensures that its emitter is always about 0.6V below the base voltage, so a 0-8.4V voltage appears across the 200R resistor. This will give a current range of 0-40mA or so. Neat thing is it's adjustable right down to zero (note if the base voltage is below 0.6V then the transistor will be off totally). I've shown both NPN and PNP versions, in case the diode needs to be connected to the 0V rail. Any common small amplifier transistors should work fine. The linearity and stability probably won't be as great as with an LM317, but it's maybe enough.

oh wait nvm i saw that you said you made it

Thanks - about 0.5mm in this case, but I can do deeper.

@@imajeenyus42 Do you have a laser enrgaving business or do you just do this as a hobby? Do you have a website where I could contact you directly?

@@altar7885 My own website is eyejayinstruments.com/ and you can contact me via the email there.

lindsay@imajeenyus.com

@@imajeenyus42 Hi First thank u for your very useful explanation of the modification in CZcams. Im a technician from iran. I sent u comments on your video for a help on a subject. Please in case u got free time Think for my problem on smps s-360-12 30A Chinese made model

@@imajeenyus42 i will mail u the problem with pictures and diagram later Thank u very much

Thanks! It should be possible - AutoIt seems capable of using pretty much all of the Windows controls, so you could pick choices from a list and then set them. www.autoitscript.com/autoit3/docs/guiref/GUIRef.htm

Please direct all inquiries about the AxiDraw to Evil Mad Scientist Laboratories (www.evilmadscientist.com/), I can't help.

Yes, that should work - remember that the LM7812 has a dropout voltage of around 2V, so your fan will run at a slightly reduced voltage until the power supply reaches 14V.

​​​​@@imajeenyus42thanks How about the lowering the output voltage a little bit more to 4 volts,mine the lowest reach to the 5.9 volt Which resistors in the divider network i should change to get the 4 volts at the lowest

@@amirvafa7344 You would want to increase the value of R4 - this will decrease the lower voltage limit. However, you may then run in to problems with the short-circuit protection circuit kicking in, in which case you would have to remove D13 as described on my page.

Thank u bro As soon as l added a load to the output ,the lowest voltage came to 4.8.and every thing was perfect No need for any changes You were a great help for me Your description and analysis of the circuit was perfect. I learned very much ..im not professional in electronics Im just an aircraft electrical technician Which mostly our jobs is troubleshooting for wires and generators which rarely involved in electronics Take care and bye

Thanks! To be honest, I'm not entirely sure, but my feeling is that you should optimise the horn so that the entire system operates at the same frequency as the bare transducer. The transducer has presumably been optimised to operate at 40kHz - at that frequency, the piezo elements will experience a longitudinal node, so they are only vibrating radially, which is where they are happy. At any other frequency, they would experience other sorts of vibrations, which might damage them. So better be on the safe side and get everything working at 40kHz!

Thanks! I don't think so - if I have my figures right, a 5mm thick piezo disc made from PZT will change in thickness by only about 60 nanometers with 200V applied. Things are obviously different at resonance, where the amplitude is far greater - I measured about 20 microns peak-to-peak. Piezo actuators generally have many stacked elements, or additional mechanical amplification with a flexure.

Why? Just buy a higher voltage supply. It's not worth the trouble to modify this way. The transformer is designed to output a little over the nominal voltage maximum, so you're never going to get it to produce a significantly higher voltage than its designed to. Additionally, you would need to change the output smoothing capacitors to a higher voltage rating, change the current sense resistor to provide the same power limiting, besides the feedback divider itself.

@@imajeenyus42 thanks for the reply. I have modified an atx psu which is more complicated than this chineese psu ,and i got at least double voltage for every line of it But i had to ground the dtc pin so losing every protection. But in your job u did lowering the output voltage without losing under voltage protection,i like to do that for O/V protection and change the outputs caps. It's so fun have your psu made specially for yourself.

@@amirvafa7344 If you really must, then make sure that the output smoothing caps are rated at an appropriate voltage.

@@imajeenyus42 of course. Thank u .again u gave a very clear explanation of the modified circuit.but still i think that the fan of the s400 psu must run independent of the main circuit and as soon as the power supply gets on start spinning.