Macrofab Engineering Podcast

MEP EP#284: Real Engineering for a Real Engineer When to Schedule Python for Engineers Intro Stream? This Saturday July 10 at 6PM central Twitch URL for the stream Overview of the Topics Setting up a python environment on Windows PC Python script talking to an embedded device over serial communication Not a how to write python/code stream Might get into Tkinter for GUI stuff Embedded Device will be Arduino SCPI to handle the coms List of items Arduino Windows PC PyCharm PinoTaur Production Update Production is going well, boards are slated to be completed soon The Future of the Supply Chain Finding part alts that work for you Finding different temperature ranges, packages, and even packaging Adventures in Plastic Injection Molding We have reached 1 Mega presses First analysis - Images below All “failures” were due to test bed Could probably go more than 1 million presses Will repeat 3 or 4 more times New batch of actuators due any day now Finally Real E

MEP EP#283: You Adapt. You Overcome. You Put in a Pull Request. Custom DIY Multimeter? Fun article about meter design Specs DC Voltage Range 1000V Accuracy Resolution Autorange? AC Voltage True RMS? DC/AC Current? Range 10A Resistance measurement 4 wire kelvin Communication USB 2x 16 Character Display for Status Powering the meter Isolated DC-DC converter Enclosure 19” rack 1U Isolated mounting holes Safety HY3131 Digilent has an arduino shield based on this Chip When to schedule python for engineers intro stream? Slack channel for poll and discussion

MEP EP#282: When Print(); Just Works SMT Connector Considerations Switching from Though Hole connectors to Surface Mount connectors Price difference How many insertions? Via Stitching pads Plastic actuator update 420,000 presses and going strong 300 PPM Damn arduino Serial.println() Do Not Use Print For Debugging In Python Anymore Automatic verbose print statements for python! Easy disable Bipolar load switch with multiple enables Would rather not do this in discrete but probably going to have to +/-12V in with a time delay on switching in the load Second time delay that enables regulators after Preferably one control signal (capacitors charging) Considering SSR solution Tasty Chips segment Keystone 9081 Plastic standoffs that have double sided sticky foam Keystone 7693 Screw Terminal PTH 6-32 Thread Banana Jack Install Tool? No one makes a socket driven one? ¼” drive? Question for the future. What would it take to design your own Multimeter?

MEP EP#281: Through Hole ManufacturingThrough Hole Manufacturing Processes Hand Soldering Soldering “robot” Wave soldering Design Criteria Pallets Selective soldering Design Criteria Keepouts Lead Forming Pre purchase? Forming with a die? Using hand tools? PCB design Holes Non circular? Annular rings IPC stuff IPC-2221 Generic Standard on Printed Board Design IPC-2222 Sectional Design Standard for Rigid Organic Printed Boards IPC-2223 Sectional Design Standard for Flexible/Rigid-Flexible Printed Boards IPC-7351 Generic Requirements for Surface Mount Design and Land Pattern Standard Performance Classification (1,2,3) Producibility Levels (A,B,C) Land Pattern Determination (Density level A,B,C)

MEP EP#280: Don't Worry About It Adventures in plastic injection molding Beating the bubble Finding a new method of shooting the material to adjust for issues Change ejector pin depth Change material Light bleed Texturing Right to Repair is going global NPR business National Farmers Union Nebraska Legislature Bill 543 Getting a pro right to repair guest on the podcast? Louis Rossmann update Uncle's Brewery Update Setup the boxes Boiled water and got all the hoses cut Next Steps Mock brew day with lye Brew a batch! PCBs for 30W Power Amp Stephen opens up fresh PCBs for his recent power amplifier project Resin Printer Update Liqcreate Strong-X Resin Strength is amazing Post processing is a bit more involved Going to try “chroming” next Electroless Copper Caswell kit This is the process PCB manufacturers use to plate the inside of PCB vias Copper plating Thicken up the thin electroless copper layer Nickel plating For corrosio

MEP EP#279: Avoiding The HR Pit of Doom, Resume and Interview Tricks for Engineers Engineering Resumes The main goal: To start a conversation The resume is intended to give a snapshot of you not to be your autobiography The person doing the interview probably has other tasks that they have to accomplish Your interview is important but it is likely not their main focus, keep this in mind Too much information is a bad thing - remember people hiring have to read lots of resumes The 1 page rule The HR pit of doom There is a high likelihood that your resume will not go to an engineer when you apply via any portal/service/online app Grammar/spelling/design/layout You may be the best engineer out there but if you can’t get that across to a non-engineer then you are in trouble Humble Bragging You are not Engineering Jesus Use tangible wording and describe cornerstones of your career Example - I did X task and productivity increased Y% Do not obfuscate your work with unclear

MEP EP#278: Design With Manufacturing - Altium and MacroFab Ted Pawela Altium's Chief Ecosystem Officer Head of Nexar, Altium's cloud business unit Holds a M.S. in Engineering Mechanics from Michigan State University, a B.S in. Oceanographic Technology from Florida Institute of Technology and an M.B.A. from IE Business School, Madrid, Spain Chris Church Is a founder and the Chief Product Officer at MacroFab Has been working in the software industry for over twenty years, with a focus on robotics and electronics over the last decade Prior to MacroFab, he founded Dynamic Perception and Alert Logic Recent fundraising press release Altium's goals around connecting design engineers to manufacturing data Perspective on the role and level of control engineers have in manufacturing? Will engineers take on a much bigger role with electronics production? What about engineers being equally important to the supply chain and procurement process? What are you hearing from the engineers themselv

MEP EP#277: Bunch of Nibbles Tasty Chips segment Harwin EZ-Cable Clips Mac-Eight CZ series Update - E-Z Hook Insulation Piercing Wire Clamp - 8507 Built a housing to isolate the wire clamps COM port snooper / sniffer? Ended up using 'Free Serial Analyzer' Automating Testing Clock Drift Using an oscilloscope? SCPI or some other method? 115 pages of commands What is inside a scope probe? 10X? Rotary switch pcb - interesting bug? Pcb is 99% done - currently reviewing MF platform experience https://github.com/analogeng 49 unique resistor values 92 total resistors List of most used resistors Potentially bad bug in Diptrace Causes lots of headaches Injection Molded Actuators They work great Shrinkage - Identifying and dealing with it Voids - problematic for light passage

MEP EP#276: Skippy Documentation Fake LM338 Voltage Regulators? X-RAY results Should we Xray legit LM137 and see if the XRAY matches? SCPI or Standard Commands for Programmable Instruments IEEE 488.2-1987 Send command strings over serial to configure and get results from test equipment Test equipment mostly adhere to this with some weird gotchas COM port snooper / sniffer? Is there good software out there that can sniff the buffers / communication string between Windows and a hardware device? Is bad documentation worse than no documentation? “With no documentation you know immediately you're fucked.” Bringing back the Tasty Chips segment - E-Z Hook Insulation Piercing Wire Clamp - 8507 Spring loaded clamp that has teeth When you insert a wire the teeth slice into the insulation making contact Datasheet specifications are interesting to say the least! Max Current 1 AMP Max Voltage 0 V ?!? Covering the Amplifier Update on Parker’s Amp “refinishing” project Adven

MEP EP#275: Log Stepping Revision Control Log stepper Exercise in madness 24 position stepped attenuator 1db steps with step 0 being -infinite and step 24 being 0db attenuation Requires lots of non standard resistor values Constant total resistance Excel sheet Make before break operation Revision workflow How do you document and handle revisions for schematics and pcbs? Process Get new rev Go to testing Find issues and document Make new revision Repeat Venturing into hobby level SLA printing Elegoo Mars 2 Quality is amazing Print speed is interesting Will have to experiment with different resins to find a high strength, high temperature Plating process to test Amplifier update Live next week on parts replacement? Recovering it

MEP EP#274: The Pinch Load Thermal Management Part two! Interesting thermal management designs and devices Copper “fingers” Thermal Jumpers Common DRC Problems Annular ring Copper to Board Edge Tolerances of the checks? Why? -0.1mil or -0.00254mm Record Player Deconstruction Tube Amp Schematic Possible Fake components? From the thermal discussion from last week's podcast LM338 or LM317... Opamp Stability Interesting issue with opamps and comparators with latest design Make sure to add extra component pads for analog design prototyping!

MEP EP#273: Beating the Heat Delta Pag Fan Controller Hack Override inverter mod was a success! PinoTaur is in PRODUCTION Gotta start putting together the website to host the documentation Pinotaur.com Supply chain issues! RGB Lighting connector Beating the Heat Talking about thermal management

MEP EP#272: The Digital Mattress Right To Repair Ease of opening for repairs This sounds great but I have some thoughts Reason why phones are hard to open now Security screws only keep out people that probably shouldn’t be opening the device anyways Ultrasonic welding and potting? Access to manuals What if repair manuals don't exist for a product? Small and medium volume products don’t have the revenue or volume to make this kind of documentation Schematics, Circuit Diagrams, and Firmware Accessible What if the schematic is the secret sauce? Schematics are easily reverse engineered from a PCB assembly. What mechanics will be put in place to prevent cloning? Hardware Vs Software Tesla Software unlock to increase motor output by 50HP August software update License Make all contracts clearly identify which elements of the machine are not included in the sale Do not allow companies to create contract language (End User License Agreements) that modify or limit support opti

MEP EP#271: The Right to Repair Right To Repair Dot Org The Right to Repair Electronics refers to government legislation that is intended to allow consumers the ability to repair and modify their own consumer electronic devices, where otherwise the manufacturer of such devices requires the consumer to use only their offered services. This already exists for Autos for the most part Motor Vehicle Owners' Right to Repair Act Ending the "unfair monopoly" of car manufacturers maintaining control over repair information that could result in independent shops turning away car owners due to lack of information. IFIXIT Manifesto Movement: Major Players Apple Do you really own your cell phone? Withholding repair information Requiring that all repairs happen at designated service centers ISL9240 charging chip from renesas John Deere Requiring repairs be done with approved contractors Louis Rossmann of Rossmann Repair Group Go Fund Me 1.55M subscribers $317,000 Direct Ballot Ini

MEP EP#270: Radio Frequency Eyeballs Cool XLR connector with a smart method of assembly NC3MD-H-BAG NC3FD-H-B XLR with two parts - one for mounting to the enclosure and the actual connector. Assemble separately - allows you to test the electronics on the board Insert and turn a small screw and lock the connector to the body Keysight scopes are now “dark mode” Jeff Keyzer comment on Twitter It is like the evolution of PC cases for test equipment Chipmakers are hustling to make auto chips--and say it’s not a hustle Some resellers have resorted to buying up used chipmaking gear by stalking old factories in the U.S., Japan and Europe and waiting for them to close in hopes of purchasing the gear inside. Chips used in braking and engine systems are typically made using older tech that is sufficient to meet automaker reliability requirements, while newer infotainment and assisted driving technologies require modern chips made in cutting-edge chip factories. New American Chip Fabs Int

MEP EP#269: Illuminati Moment Fan controller for Jeep MCU P/N: G80F960AP 8051 core Chinese Generic MCU Override signal passes through a diode then pulled up with a 10K to 5.0V Diode to prevent back feeding voltage if you slap 12V onto it Mosfet inverter as the fix! PinoTaur REV 4 has Arrived! Goes into final testing for production certification! RGB LED boards testing Mind the details - Cross talk Actually ran into this as a unique problem Those values in datasheets can creep up Beat head on table trying to figure it out How long is it reasonable for a project owner to support their open source design? 10 years? More Automotive Woes 2/3rds of the facility was dedicated to automotive parts Toyota and Tesla affected

MEP EP#268: Avoid The Extremes Fan controller for Jeep Brushless fan temperature controller Nothing fancy but the “override” signal is ground triggered! Will have to invert the A/C compressor signal with a relay Controlling PCB cost What are the knobs that can be turned to adjust the cost of the PCB itself? The easy ones Size (not necessarily rectangle) Panelization Base material TG ratings - The glass transition temperature FR4 Trace/Space Minimum hole size Mask Color Surface finish Copper weight Not as easy ones Vias Tented Plugged Blind Buried Digikey’s Latest Innovation Information printed on the backside of cut tape 8mm tape

MEP EP#267: Honey, I Shrunk The Parts Tradeoffs on component sizes "World's Smallest" Claims Can Come With Trade-Offs Design and Production considerations when going small Different PCB Design Rule Checks PCB pricing Via in Pad Escaping Components Silkscreen Part placements Assembly documents Tooling Paste Jetter Stencil coatings STICKERS/Labels for products Find out what label printers your CM is using Consumable items Label Material Location! Location! Location! Printing Instructions and Information Databases Low frequency Network analyzer Perhaps I am looking for the wrong thing but I can’t seem to find what I want 1hz to 100khz range Can always do it manually but damn is it slow Tsunami - this is *almost* what I want but not really good enough I want to design one but no…..

MEP EP#266: The Expert Design for Manufacturing – Beyond the Digital Domain Webinar that Chris Church (Co-Founder of MacroFab) will be co-hosting with Edwin Robledo of AutoDesk. Building a Program and Testing procedure for your first production run Take lots of pictures Keep it up to date and version controlled Hand off the procedure to a colleague and have them run through it Work with your CM MacroFab works closely to help flesh out procedures and fixture designs What is you acceptable fall out from production This is where scaling up production runs can help iron out QA procedures for your product Find tolerancing issues with components Keep in mind your target pricing Elements of a good test procedure - THINGS TO KEEP IN MIND It is almost impossible to have too much information in your test procedure - within reason. Remember - Your CM can always distill your information down to something less than what you provide Typically they have one “expert” who kn

MEP EP#265: NuFuel and Gas Classic Resealing 12oz cans? FAIL! Worked till can shaken a bunch Improvements Working on finding a softer sealing surface Currently using a Shore 55A neoprene rubber sheet Increase seal pressure on can Carmakers wake up to new pecking order as chip crunch intensifies Follow up from last week's discussion on Auto industry shutting down production due to lack of electrical components. Both automakers and chip manufactures are pointing fingers Chip makers point at the auto industry in that they are quick to cut production and cancel orders when car sales slump Auto industry where used to being the center of attention for chip and electrical component manufacturers The industry spends around $40 billion dollars a year on chips By Comparison, Apple spends more on chips just to make iPhones! Chips used in Auto tend to be more basic products and older micro controllers, Something that chip fabs do not really want to invest more production into Chip