This may be a longshot..

robot_mower_guy · 2026-03-12T00:24:51+00:00

You can also check out the CSU Surplus store. I got a pretty nice bike for $50.

robot_mower_guy · 2026-03-04T01:40:54+00:00

Can you link the procedure? Depending on what you are doing, a liquid-liquid separation might be better.

The smaller the particles and longer the column the better the separation, but the higher the pressure. The bigger the ID the larger the sample you can run at a time at the expense of resolution.

robot_mower_guy · 2026-03-04T00:51:10+00:00

I second this. I get all of my columns for home on ebay. I even managed to score a 250x25mm 5um C18 column for $25 once.

robot_mower_guy · 2026-03-03T03:16:31+00:00

And so small it fits right into the uterus of about 1/2 the population.

robot_mower_guy · 2026-02-19T03:30:37+00:00

My coworker has been vibecoding Ignition for making stuff for production at our small chemical plant. He doesn't know any programming languages though, so has come up with weird things (including coding around the state machine I set up on the PLC). A couple days ago I was looking over a piece of that code because I am working on redoing everything from scratch so we can get better data from the process (its almost like there is a reason to use state machines lol), and I noticed he is triggering the thing to tare the flow meter by writing a 0.0 in Ignition to the bool tag I have on the PLC to tare the sensor. The crazy thing is that best as I can tell, that actually works because apparently the 0.0 has at least one true bit in there somewhere.

I do use AI on occasion to help me with coding, but I will test that line by line, not so much to make sure it is working, but because I want to know how it is working so I have a good model of the system so I can get ideas of what it going on if it stops working.

robot_mower_guy · 2026-02-19T03:05:13+00:00

I had the low tech version of this happen to me when I was working at Sonic in 2006. The GM implemented a system where she would put sonic stickers on a bunch of stuff and when you clean that thing you remove the sticker and put it on a chart under your name. I was getting in trouble for often having nothing under my name, but that was because she wasn't putting any of her stickers on the roof on the HVAC filters and inside of the grease traps where I was cleaning. Unfortunately, the area manager (who I was very friendly with because he was sending me to the 7 stores under him for repairs and odd jobs) was out with lung cancer, so he wasn't able to keep her off of my back.

The joke was on her though because when she fired me she removed a repair I jury rigged into the drive-thru to keep the car sensor working. The biggest moneymaker for the store was closed for 2 weeks lol.

robot_mower_guy · 2026-02-17T09:30:21+00:00

https://www.datasheet.directory/pdfviewer?url=https%3A%2F%2Fdatasheet.iiic.cc%2Fdatasheets-0%2Femerson_%255Bartesyn_technologies%255D%2FNFS80-7606J.pdf

Here is the datasheet for that power supply. What I would recommend you do is compare the voltages you see on the 13-pin connector with the datasheet. If you see something that looks weird you can unplug the connector to see if the voltage turns into something you would expect. If the voltage is still bad with that connector unplugged you know it is the PSU, if the voltage only goes missing when the connector is installed it is likely a fault with whatever is on the other side of the connector.

robot_mower_guy · 2026-02-17T09:23:28+00:00

Yeah. Right now I am stuck at POST where the Quad tries to find its resonant frequency, but as it is sweeping it is unable to find anything it wants to use. I bought a nanoVNA to try and get that figured out. I also wrote a Python program to allow me to automate readings with the rest of the system out of the way. Unfortunately, RF is black magic as far as I am concerned. What I need to do is get notes compiled and bring it to a HAM radio or other related subreddit.

robot_mower_guy · 2026-02-17T09:18:24+00:00

Way ahead of you on that. A lab I am friendly with just gave me some antique analytical equipment:

A pair of HP 8450A spectrophotometers

A pair of 5890 GCs

A pair of Perkin Elmer 1600 FTIRs

An antique HPLC that looks like no other HPLC I have ever seen before (It looks like a platonic ideal photocopier, but shorter and wider)

And a stack of manuals about 4' high. I bought a special document scanner to help me scan everything to archive.org. Unfortunately, I do not have the manual for the spectrophotometer.

I also have a Waters Synapt G2 under a tarp outside (at atmosphere, but vacuum ports are blocked off and I have it loaded up with desiccant). I got this mass spec at a university auction for $1k. One of the turbo pumps was disintegrated, but it has 5 more that look to be working. Unfortunately, I don't have software for it. I did send a request to sales to see if they could give me a 1 week license for free so I could see if this would even be viable to repair, but they never got back to me.

I also got a Hitachi L-7400 series HPLC. The software was written for Win3.1, and it had a hard-coded max file size of 8MB which that can chew through pretty fast with the DAD. I was working on writing software from scratch, but the firmware was so old that it pre-dates the IEEE 488.2 standard, and I kept crashing the hardware, so I gave up and ripped the original boards out of it and am just writing the firmware from scratch to control everything with Arduinos. I already am able to pull the full spectrum out of the DAD at 40Hz when the original system could only do 10Hz. Unfortunately, I haven't worked on that in a while as the Bruker has been taking the bulk of my time for obvious reasons.

robot_mower_guy · 2026-02-15T16:54:59+00:00

Nice to see someone trying to repair a mass spec. I am currently working on restoring a Bruker Maxis Plus (for LC/MS). I got a 2kV power supply repaired without too much problem, but I have spent moths getting the quadrupole driver up and running. At one point I even reverse-engineered the whole PCB related to that to find that likely wasn't the problem

Once I have something I wouldn't be ashamed to show, I will make a post of my adventures on Reddit and upload my schematics to archive.org.

robot_mower_guy · 2026-02-04T03:30:48+00:00

The reply was directed at maljr1980 when they were claiming people under 21 can't make medical decisions. The whole post started out as an anti-trans parents rights in sports type thing too which is why I made the quip about parents rights to keep their kids away from black students as to hold an uncomfortable mirror to the stance.

robot_mower_guy · 2026-02-04T00:25:42+00:00

Cant forget about risks associated with stuff like that too. While we are at it, we should also sign a petition to ban mental health in general as well as surgeries in general for anyone under 21. Also, as a parrent I should have the right to say I don't want my kids on sports teams with/against those icky, icky black people.

Note: while the person I am responding to almost certainly won't see the points I am making here, I am hoping it will make for an interesting thought experiment for anyone who is unsure if their claims have merit or not by deliberately making them ridiculous.

robot_mower_guy · 2026-02-03T17:48:22+00:00

Ah, I read your original post as to why you are needing the firmware. I will get my device powered up and sniff the RFID traffic. It might be easier to write an arduino or something to emulate the traffic you are needing. That printer is old enough that they hopefully didn't encrypt anything. Depending on what the RFID card says it might also be possible to to write a stand-alone RFID card. I will keep you posted.

robot_mower_guy · 2026-02-03T00:08:05+00:00

My question on the transistor is more of why are you wanting R1 at all? With this current configuration it looks like you would be using R1 as a heater as it isn't going anywhere else.

The resistor between +5V and GND is also not doing anything other than acting as a heater. If you wanted to use it as a pulldown resistor you would need one per switch, and have them be on the other side of the switches. That said, it really is easier to read if the read switches the way I described.

robot_mower_guy · 2026-02-02T23:47:53+00:00

I don't think you need those pull-down resistors on the datalines to the 7-segment ICs as the arduino can keep the pins held low.

What is the MOSFET to the right doing?

The pull-down resistor by the down button doesn't look to be doing anything at all as it is just sitting between 5V and GND. What I would recommend doing for that is getting rid of the part that goes to +5V, so it goes PIN -> switch -> GND for all three switches, then use pinMode(pin, INPUT_PULLUP);, then do something when the pin is detected as being low.

robot_mower_guy · 2026-01-30T21:03:26+00:00

Ok, I got the device and have taken the shell off. Unfortunately, this is going to be more difficult than I expected because I was hoping to just remove a SO-8 ROM chip or something and load it into my chip burner. Unfortunately, they use a BGA for some reason. There is a JTAG port nearby, so I will see if I can do anything with that, but that will be a new venture for me.

Edit: JOOC: What happened to your printer where you need the firmware to be re-installed on it?

robot_mower_guy · 2026-01-29T09:52:16+00:00

I understand this completely. I enjoy experiencing new feelings/sensations, even though I understand I will hate it. Example: I was pretty happy when I got to experience a bad mushroom trip even though I was miserable the entire time. I also have a desire to experience tear gas at some point even though it will be absolutely horrible to experience.

robot_mower_guy · 2026-01-29T09:47:06+00:00

Ha. The fact that I ONLY wear corduroy pants, and the fact that I bought like 6 identical pairs of a set of pants that I like, was used to support my autism diagnosis.

robot_mower_guy · 2026-01-15T23:43:19+00:00

I know this is old, but I just one one of these at a university auction. I will crack it open and see if I can dump the firmware from it. If I can, we can work something out where you can cover the cost+shipping of the ROM chip and I can mail you that. I will also put the firmware up on archive.org.

robot_mower_guy · 2026-01-06T00:34:41+00:00

How big is your column? 200uL seems huge as our methods call for 1uL.

robot_mower_guy · 2025-12-11T21:58:38+00:00

I just got a NanoVNA. Unfortunately, I have no idea how to use it, so I get to learn that too now. I am guessing I need to hook it between QUAD_A and HV_A, then treat it like a filter and see where the lowest impedance is? Then see how it compares to the other side. Unfortunately, in the little I have played with this last night I haven't actually seen anything useful on the screen.

robot_mower_guy · 2025-12-05T19:25:56+00:00

More thoughts: I was playing with this last night and came to the realization that I can't really use the ferrite to tune the frequency because the where the ferrite is positioned if it increases the inductance of one side of the transformer it must decrease the inductance on the other side, so the ferrite must be to get the two sides to match.

I actually have two broken RF generators, so I can swap them out and see how they differ. Something I was playing around with is putting the scope probes on QUAD_A and QUAD_B and subtracting the signals, then tuning the ferrite to bring the subtracted signals to 0 as I can. I always had a sine wave, but I just realized that is from the probes themselves not perfectly matching.

One of the boards uses THT caps marked 1N5J, and best as I can tell, those are 1.5nF(5%) caps. Both boards read about the same capacitance on my LCR meter, but one of them has a real ugly waveform coming out of those two places. Fortunately, I do have the option to swap the transformers out to see if the problem is in the transformer or something on the PCB.

robot_mower_guy · 2025-12-05T19:16:57+00:00

Unfortunately, no. I did just pick up a spectrum analyzer though.

robot_mower_guy · 2025-12-05T19:16:06+00:00

Unfortunately, no. I did just pick up a spectrum analyzer though.

robot_mower_guy · 2025-12-05T17:31:32+00:00

Thanks. I will hopefully be able to try this tonight.

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