marcoreps posts
Posts: 464
Files: 717
Anyone ever purchase linear rails from BG?
I did, they were mediocre at best. Now they have replacement sleds which make the same linear rails feel twice as good at least. In the last batch at least ... https://www.banggood.com/Machifit-MGN12H-Linear-Rail-Block-for-MGN12-Linear-Rail-Guide-CNC-Tool-p-1186173.htmlIt might even be acceptable for them to not have grease ports, because they are so cheap. For the linear hardware video I have also bought some of the new black ones for comparison: https://www.banggood.com/Black-450mm500mm550mm-MGN12-Linear-Guide-Linear-Rail-Slide-with-MGN12H-Li...
Another candidate for 'Precision Motion Control Ep02'
Got a BLDC in a NEMA23 enclosure: https://www.ebay.com/itm/162789541036I've replaced the standard magnet encoder (green PCB ring) with a CUI AMT102 so that ODRIVE can try and operate it precisely. I couldn't get it to work just now because there are a lot of changes in ODRIVE firmware and software ... and my botched Python doesn't want to update without putting up a fight 😩
Spectrum analyzer story
This broken beauty was sent by a viewer who bought 2, repaired one and didn't need the other any more.It seems to have mostly computer problems for now (and a missing 400$ step attenuator later). It gets stuck in the loading screen, so the previous owner tried replacing all the RAM chips. That only made it worse, so I just reverted to original RAM chips and now at least it shows something again!Next I'll try and listen on the pin headers on the main board, to try and catch some debugging messages.Hope I don't have to take too much o...
Fiber coupled laser EP02
The switching CC driver started killing the output electrolytic capacitors for some reason. They get hot and end up in a fluffy explosion. Will have to investigate!
New laser driver attempt
My last laser driver consisted of a high efficiency switching DC-DC converter 'to get close' and classic precise linear regulation to get the current precisely right. That works well and is safe, but not very energy efficient.This bloody battlefield is the result of me trying to make the DC-DC converter behave like a stable constant current source to drive the laser much more efficiently. Happy to announce that the battle was won and the idea works!It only needs a shunt resistor and a dual op amp: 1 op amp acts as a high side shunt ampl...
'Quick intro' for the next soldering video
It seems like the whole world is waiting for the new PACE ADS200 station https://www.eevblog.com/forum/manufacture/newest-pace-ads200-production-station-(a-jbc-killer-at-$239)/So I am not sure when I can get my hands on one, but I wanted to be prepared, so I made a 'quick intro' for that video already :)
Fancy 130$ discrete op amp
https://www.digikey.com/product-detail/en/apex-microtechnology/MP108FD/598-1407-ND/1762080On an aluminium PCB ... I hope with pre-regulation I can make the OSMU efficient enough so that normal FR4 substrate can be used ...
New killer microscope: Andonstar ADSM302
Would you look at that working distance ... madness!Only thing it seems to lack is display + HDMI out at the same time. But maybe that could be patched with a little HDMI doubler?
Video candidates for June (+many more months)
There has been only one thing I managed to do in the heat wave of the past week: Taking dogs to the pond. But cool stuff keeps piling up:1. Fiber laser EP02: Andonstar ADSM302 microscope Super efficient constant current driver Improved fiber lapping Burning stuff :)2. Spectrum analyzer EP01: TS100, ES121, DS212 giveaway RAM Chip replacement Boot problem analysis DIY precision SMA torque wrench?3. Precision motion control EP2: 0.9° Stepper motors Hollow shaft stepper motors JMC integrated servo Mirror galvanometer4. OSMU Rev2: RE Apex 10A +/- 1...
Small linear actuators
Anyone remember my ferrofluid clock plans? https://youtu.be/fdWlvf4-izc?t=238 based on this piece of art https://www.youtube.com/watch?v=dOCGQAXV9FYI've tried electromagnets since, but they would need lots of current and active cooling to work. I am not sure how they managed to get that thing working, but I think permanent magnets attached to 4x7 of these tiny linear actuators might be a viable, somewhat economical way of recreating one?
Giving away the remains of the Chinese thermal camera
Meaning the camera board and and the display assembly. No good for component-level inspection, unless you find a suitable lens. But maybe someone can come up with another creative application? Let us know, the comment with the most 💖 by next Sunday wins!
Whitest legs in town gets a package
A few YouTube commenters didn't like my previous 8 minute advertisement, but this one guy decided to actually do something about it: He sent me a very sick Advantest Spectrum Analyzer and is hoping for a lengthy repair video like back in the good ol' days.In conclusion: I should make more boring ad videos :))I have read all your comments about that video btw, but didn't reply to any. Thank you for the feedback, it is super helpful and I'll take it to heart!
O̶S̶M̶U̶ ̶R̶e̶v̶.̶0̶
I've tried various ways of extending the voltage range of the LT1970 which I wanted to build the OSMU around: The NI way based on this http://www.ni.com/white-paper/4297/en/ It looked like I could just add equivalent circuitry for negative output voltages, but what I came up with had huge transverse current. Photoelectric gate drivers like this https://imgur.com/a/jTHDeaf sort of work, but the only ones I've been able to test have a fast-discharge feature which makes them super unstable I am trying current mirrors now https://imgur.com/...
Achievement unlocked: Unisolder revived
Pretty difficult, but worth the effort I think, very cool controller!Clicking is the current limit of my PSU
Giving away the Stereo Microscope
AS WELL AS the surveillance python! (But not the eye piece adapter, can't find it :(Comment with the most hearts in 7 days wins! Free international shipping, but I think this will not go past customs without an obolus.Have a nice weekend. Go!
Todays PCB order
^ Low voltage differential probes for USB, HDMI or LVDS^ TekVPI adapter for Tektronix Scopes^ Fiber Laser Driver Rev. 2^ And a prototyping laser driver. I want to try and use the DC-DC converters Voltage adjust pins or the Voltage sense pins for constant current operation. If that's possible it'd be much more energy efficient, smaller and faster modulation would be possible easily ...
How did you like the Tinkerforge video?
I am getting more negative feedback than usually and my first reaction was 'well, screw them'. But there are a few of 'them', so they might have a point ... what do you think?What went wrong and how can I improve? If you have any suggestions, I'd love to hear them! No need for sweet talk, I can take criticism.What most complain about:1. High price - Yes, but I've shown more expensive stuff before2. You'll learn more from DIY - It's not meant to replace electronic design3. It's a commercial - It is, I make tho...
Got a t̶h̶e̶r̶m̶o̶n̶u̶c̶l̶e̶a̶r̶ turbomolecular pump
The upper rotor seems seized, maybe because it uses air bearings and needs to be operated correctly? Or is it dead and eligible for a destructive teardown?
Professional building blocks by Tinkerforge
Gotta be careful, these might be addicting ...
4 months free Elektor membership
https://www.elektormagazine.com/pages/get-to-know-elektor-magazine-marco-repsAutomatically ends after 4 months, includes unlimited access to their archive of DIY projects. Code: YOUTUBE-MARCOI used to be a paid subscriber for a while and I actually kept all the PCB designs in this folder for later use. I don't know how it is these days, but they used to publish very good quality projects.
Feeling another 'Precision motion control' episode coming
Featuring a 0.9° stepper, a hollow shaft stepper and this thing: https://www.welectron.com/JMC-iHSV57-Integrated-Servo-Motor
Thermal macro videography?
Someone in the YouTube comments suggested that I should use an IR laser lens in front of a thermal camera. This one is perfectly transparent, which is a good start but I think I need a 3d printed holder for more consistent results. Would be interesting to see how heat propagates through a component, wouldn't it?
Unisolder repair attempts
I used to redirect everyone who wanted to build my JBC controller to the Unisolder project, which is much more sophisticated. MUCH more sophisticated, holy molyThese 3 are non-functional and I offered to try and get them going.
Giving away the Elektor Nixie Clock
It's cool and all, but I really don't need a device telling me how quickly time passes 😱The comment with the most hearts in 7 days wins!
Elektor GPS Nixie Clock?
Just trying to make them send me their Tesla coil next ...
Plans for May
We've grown a lot in the last month and I have a feeling that the OSMU announcement has something to do with that ...Well, as you can see in earlier posts, I have been working on that idea for a while now and even made some progress. Some of you have even helped with the circuit design, so I think we'll see some output voltages this month :)But 2 product videos have to be done first:1. Nixie Clock for Elektor, all filmed today. Nixie clocks are boring, but I hope they'll finally send that big Tesla coil then ...2. A few German-made ...
What are you here for?
Many new 5$ (and more) supporters have joined last month, thank you very much guys 🤑 I've been feeling bad for not making a lot of special 5$ content and now I am feeling worse about it, so time to set it straight.Does anyone care about special content? Do you just want the OSMU asap? Or do you have any suggestions in general? I'd love to hear all about it!At the moment I really like the idea of using this thing as a private Twitter and just sharing everything I got to all patrons.
Active differential probe using the TekVPI interface
I've been using the HP differential probe more frequently lately for stepper motor phase current measurements and power supply noise. Since isolation and current shunts are important points in the OSMU as well, I want to try and make a minimalist version based on an AD830 IC.It'll only be good up to 15 MHz but that's alright :) http://uk.farnell.com/tektronix/p7520a/differential-probe-5-1-12-5-1/dp/2855080
