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Will the portmanteau name end up BearDar or RadBear?
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Oct 15, 2022 06:20
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| # ? May 25, 2024 02:40 |
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Test and Debug An excerpt from the Bear Radar peripheral board Test & Debug Manual. Components the contract manufacturer will NOT be soldering to the board: IR sensor, radar, and the entire microcontroller board. These are either expensive, or the assembly process is tricky (PIR needs a jig to position it), and they're easy for me to do myself. Components that will NOT be tested: temp sensor, eeprom, ambient light sensor, etc. It's hard to test these without a microcontroller and some software. So I won't! For 10 units, I can debug and rework and issues myself, if there are any. What will be tested: power connector, power filtering, and 4x LED sections each with a PAM2841 LED driver + 10 white LEDs. Normally a microcontroller drives the control lines to turn on the LED drivers and set the brightness. But if no microcontroller is present, some 100k pullup resistors put them into a constant low brightness mode. This gives about 90% test coverage. Full coverage would need a test jig with pogo pins. The manual has enough info narrow down most problems to 1 sq inch or so.
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Oct 16, 2022 00:58
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 Render of the (close to) final board, with only the contract manufacturer's parts soldered on. This is what they will be shipping to me.
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Oct 16, 2022 20:57
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Looks like you could easily get away with 0603 components if you want to improve home solderability / repairability. But 0402 is still fine, Good Enough if you don't want to continue tweaking forever
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Oct 16, 2022 22:08
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Repairability? I'm going to glue the acrylic window to the enclosure with UV adhesive for water resistance, like a complete rear end in a top hat.
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Oct 17, 2022 00:58
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Ballsy.
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Oct 17, 2022 05:25
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BOM Adventures The Bill Of Materials is your component shopping list. Here is where you specify what parts the contract manufacturer will use. Some parts, like chips, will be specified by exact part number. For most resistors and capacitors, I spec the only the value (and tolerance, temperature, etc) not a specific part number. I don't especially care where they buy their thick-film resistors, for example. Here's an example of the subtleties of chip part numbering. VEML7700 Ambient Light Sensor datasheet Digikey carries two variations: https://www.digikey.com/en/products/detail/vishay-semiconductor-opto-division/VEML7700-TT/6210690 https://www.digikey.com/en/products/detail/vishay-semiconductor-opto-division/VEML7700-TR/5820243 A careful reading of the datasheet reveals TT is top view, and TR is side view. But there aren't two versions of the device. The chip has leads that wrap around the bottom and back of the device, so you can solder it facing up, of facing sideways. But robotic pick and place machines can't rotate parts along that axis. So for TT reels, the chips are packed face-up. For TR reels, the chips are packed facing sideways. That's the difference, the orientation of the chip in the plastic carrier tape.  
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Oct 17, 2022 06:21
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OK, I sent off a bunch of files to get quoted. I should know how much this thing is going to cost by tomorrow. I'm sure it will be shockingly high.
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Oct 17, 2022 09:13
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Costs All prices are per unit, priced as a 10-unit manufacturing run. Contract manufacturer work $11 pcb 120x70mm 4-layer $28 floodlight components $25 assembly (just soldering) = $64/unit from contract mfg Additional Sensors $80 sensors Microcontroller board $20 pcb 60x40mm 6-layer $85 components Mechanical $30 3D printed enclosure $5 laser-cut acrylic window $5 hardware, glue, etc Total $289/unit As order size increases, some costs (pcb, assembly) go way down, as most of the cost here is setup. In a larger run, pcb and assembly are more like $1-2/unit. Component costs also go down with larger runs (like 500 units), maybe by half. Prices below are from Digikey, Mouser, and other authorized distributors. This design also includes a few mini dev boards, which increase cost. Some of the dev board components are hard to get as raw chips though, due to the chip shortage. If you wanted to make thousands of units, the big changes would be to engineer out the dev boards and other pricey modules, and make the enclosure with injection molding. But this prototype/beta hardware will keep your software devs, investors, and even early access customers happy while you work on scaling up manufacturing. e: Quoted manufacturing time is 28-30 days, a lot of it waiting for parts. ryanrs fucked around with this message at 20:40 on Oct 18, 2022 |
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Oct 18, 2022 17:09
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ryanrs posted:Costs Are you comfortable saying who you are working with on this?
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Oct 18, 2022 20:02
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https://www.pcbway.com
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Oct 18, 2022 20:08
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Is the Paint Dry Yet? Not really, the paint is still kinda soft after one week.   I was having issues getting consistent coverage with my roller. And the paint was thick enough that it pulled a lot of fibers out of the roller. Guess I should have bought a better roller. Oh well, they're skid plates. Leaking A/C Goes to the shop to be fixed on Thursday. I have enough projects going on without doing this one myself.
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Oct 18, 2022 22:34
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25 bucks a board for assembly is honestly a lot less than I was expecting. I'm going to have to consider that for my own projects in the future.
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Oct 18, 2022 23:40
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Mind you, it's more like $200 + 5/ea. This is for single side assembly, 100% SMD, no difficult packages (BGA, etc). 138 components, of 26 types. Simple functional test (apply power, check that all LEDs light up). For hobby projects, check out https://jlcpcb.com. They will be cheaper. Like, taking a big loss to get customers kinda pricing, it's great. They have a reputation for turning out very high quality prototypes, but cutting corners on larger orders (100s to 1000s). I think they do the same sort of loss-leader pricing for prototype assembly, with the HUGE CAVEAT that you can only use components from their stock (which is basically LCSC, I think?). They have a list of 350,000 components, so they have a lot of stuff, but maybe not a specific western chip you saw on Digikey. So take advantage of their super cheap pricing and have them populate all the passives and other bullshit, which will save you 80% of the soldering work. I definitely wouldn't 100% lock my designs into their ecosystem, though.
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Oct 18, 2022 23:59
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Custom Ordered, Gold-Plated Parts Since I am both lazy and impatient, I use microcontroller dev boards like Adafruit nRF82540 or Teensy LC in most of my projects. This lets me design the main pcb quickly, without fighting hard-to-solder micro packages and chip shortages. Most people use straight pin headers to mount a microcontroller dev board to the main pcb. But through-hole headers mess up all the layers of the board, drilling holes through the otherwise pristine inner layers. So I prefer SMT headers. They sit on the surface of the pcb and require no holes. But the pins on most SMT headers are huge, over 5mm tall. This is horrible and causes all kind of grief in the mechanical design, so you have to cut off the excess pin length with pliers. The mini dev board is only 1.6mm thick, so I only need 2mm worth of header pin. Trimming pins by hand is annoying and stupid, though. And since I am the first person in the world to want to solder a dev board to a pcb without wasting a ton of height, I have to buy made-to-order headers from Samtec. Distributors don't stock them, and it takes Samtec 2 weeks to make them, but they don't cost a whole lot more than normal headers (...if you ordered them in small quantities direct from Samtec or Digikey). Yes, they are gold plated. e: the price breaks, for readers who don't want to log into their samtec accounts 
ryanrs fucked around with this message at 01:50 on Oct 20, 2022 |
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Oct 20, 2022 01:45
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ryanrs posted:So take advantage of JLC's super cheap pricing and have them populate all the passives and other bullshit, which will save you 80% of the soldering work. You know, I think I'm going to do this with the microcontroller 'brain' pcb. Have JLC assemble only the bypass caps and pullup resistors, no important chips. The most annoying part will be turning off the soldermask for all the Do Not Place (DNP) components. You have to go through some right-click menu poo poo FOR EVERY PAD, not even by component. It's horrible! Maybe there is a better way in recent versions of KiCad? I do not want the factory to put solder paste on components pads that I will solder myself.
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Oct 20, 2022 07:38
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In 6, you can use the selection filters window in the bottom right to set it so that you can only select pads. It's still not a one click solution, but it does make it quicker to click on pad, hit E, uncheck the layer, hit enter. Also make sure you turn off paste, not mask
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Oct 20, 2022 17:55
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Yes! Paste, not mask! Jesus, that's the kind of error that haunts me. Though I guess the board fab would catch it. Probably. KiCad's 3D render has been quite helpful for checking those little details. The board fab specifically says to send 3D renders if you have them, because it helps them in assembly.
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Oct 21, 2022 00:37
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A/C Leak Repair My mechanic determined that the welded A/C fitting is leaking from the weld, not the o-ring interface. I guess there was porosity or something. I took the fitting back to the welder and he welded it some more. The system is back together now and I have a piece of cardboard under the van waiting to collect evidence of failure. gently caress, I hope it doesn't leak.
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Oct 22, 2022 04:41
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gently caress! The A/C is still leaking, though less.
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Oct 23, 2022 21:57
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Light Switch Logic I have mostly abandoned the idea of a pure hardware lighting controller. Instead I'm thinking of basing it on the same microcontroller board I am making for the Bear Radar. Its idle current is low enough that it can run full-time, even when the van is off. Next, I'm looking for a nice, small display, so I can show a couple minor stats like battery voltage and pitch/roll angles (for leveling the van). Azumo looks promising. It's a front-lit Sharp Memory LCD. I wonder if that will be distracting at night? e: ha ha, it's been just over 1 year since I got the offroad lights, and I still haven't wired them in. The project is so mismanaged, the Architectural Steering Committee is still having brainstorming workshops to determine the scope of the project (spoiler: it's growing). ryanrs fucked around with this message at 05:10 on Oct 25, 2022 |
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Oct 25, 2022 02:47
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The Sharp 144x168 memory LCDs are amazing. They're what they used in Pebble / Pebble 2. The contrast is absolutely phenomenal and you can easily read them by moonlight (and the quiescent current consumption is every bit as good as they say). I imagine their chonky boi LCDs are just as good, as long as they're the same transflective MIP pixel. (Pebble Time series used the color JDI memory LCDs, and they are substantially less impressive in terms of contrast.)
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Oct 25, 2022 10:06
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OH gently caress I had just installed the skid plates, and was torquing the last bolt, with a torque wrench, and it stripped. This is the huge M14 bolt that goes through the skid plate, the engine cradle, and into a big nut deep in the unibody structure. The bolt was new, but the threads in the nut were worn. The skid plate reduced the bolt engagement by 3/16", but the nut is super deep. Stock, there is like an inch of threading, because the bolt draws the engine cradle into alignment. I think the threads have just been worn / chewed up from removing and remounting the skid plates a lot. It's an M14 bolt that gets torqued to 134 ft-lbs, with huge thread engagement length. I am very surprised it stripped. Now what? e: this one, on the driver side 
ryanrs fucked around with this message at 23:55 on Oct 26, 2022 |
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Oct 26, 2022 23:49
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Helicoil. You'll need a helicoil tool and tap long enough to reach through all that stuff, or get stuff out of the way. Technically you're supposed to drill oversize then tap but I've had good luck just going in with the new tap very gently. Like 1/4 turn at a time.
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Oct 26, 2022 23:57
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Wait a second, this bolt was already stripped. A few weeks ago, I noticed a squeak/click noise every time I took off from a stop. It sounded exactly like it was one of those two engine cradle bolts, so I re-torqued them. I recall one was a little bit loose, which was weird. I always put those on with a torque wrench (and they take 134 ft-lbs which is a lot). Re-torquing the bolts fixed the squeak. When that squeak started, that must have been when the bolt jumped a thread. That would have been easy around-town driving, with no skid plate installed (I was building the new one). Huh.
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Oct 27, 2022 00:08
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honda whisperer posted:Helicoil. You'll need a helicoil tool and tap long enough to reach through all that stuff, or get stuff out of the way. What is the longevity of helicoil threads? I take these bolt out pretty frequently (any service more than an oil change). I wonder it it would make sense to go to a stud?
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Oct 27, 2022 00:10
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helicoil + stud. Or. Cut into the unibody. Remove the damaged captive nut with force. Replace with standard nut. Welding optional. Studding optional. Swearing mandatory. VVVV: shave the stud to sit shy of the skid and all is well.
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Oct 27, 2022 00:15
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You'll want to keep it a bolt as you'll end up crunching the end of the stud off roading. Helicoil and other thread insets are typically stronger than the base metal. I wouldn't expect any issues even with frequent use
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Oct 27, 2022 00:15
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Helicoil should actually improve that as you are going to be using the helicoil as the wear surface instead of the welded nut in the chassis. Once in a while the helicoil will get hosed up but you can pull it out with a pair of needle nose pliers and spin another in. The only real issue is making sure you get the tap perfectly straight when doing the thread cut. Since it's already stripped out, drilling the hole to size should go pretty easy, there's not much material left to remove. But since it's hardened steel (probably a class 10 nut), I would still do so. It's been semi optional every time I've done a stripped header bolt hole in an alloy head, but steel I take no chances.
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Oct 27, 2022 00:16
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Not trying to discourage you, more like ask/point out some hows and what ifs and poo poo, hopefully you find it helpful and not annoying. Like what if you scrape over something and bend the stud vs the bolt that was in there originally? How would you replace it? How would you secure it in the first place? You could thread it in the captive nut and loctite it, but can you get a torch on that part to melt the loctite to remove it? What about tack welding the stud in there? Can you get the welder nozzle in there to tack it in place? Or a grinder to grind off the tack if you need to remove it? Take this with however many grains of salt you wish: If I had to do this I'd probably put a stud up through the captive nut, and (assuming it was accessible from above) then thread a jam nut on to it and red loctite that poo poo. Then I'd A: blue loctite the stud and tighten the stud/jam nut combo down to the captive nut. B: tighten the stud/jam combo down to the captive nut and tack weld if there is enough room to do so. Someone smarter than me is welcome to point out any reasons that those ideas suck if they feel so inclined to do so.
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Oct 27, 2022 00:22
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The end of the stud would be inside the tube spacer. The stud could stick out an inch beyond the nut and still be quite well protected. e: It might be possible to directly tap it for a M16 stud, which I could then loctite. The through hole in the engine cradle is this big plastic/rubber thing that may pass an M16 stud, I have to check. But the bolt is not the feature that centers the engine cradle to that mount point. The nut is on a steel snout that fits into the plastic bits.I will try to get a pic. e2: studs would also make it much less hassle to install the skid plates (similar to how wheel studs make putting the wheel back on easier). ryanrs fucked around with this message at 00:54 on Oct 27, 2022 |
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Oct 27, 2022 00:31
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M16 studs would mean I need to drill out a metal insert in the cradle bushing, so best stick with OEM M14. So it sounds like I should install an M14 helicoil.
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Oct 27, 2022 01:23
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I was expecting m14 helicoil kits to be eye wateringly expensive but honestly I just googled it and they're only a few bucks over what I paid for an m10 kit a decade ago. That's a pleasant surprise.
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Oct 27, 2022 01:31
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$111 at McMaster Am I asking for trouble buying a kit off Amazon? A broken M14 tap would be fun to remove.
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Oct 27, 2022 01:51
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Honestly the larger it is the easier it's going to be to remove because you can weld to it more easily without hitting the part it's in, and you can use a drill or die grinder to remove the middle without hitting the edges more easily as well. Not sure I'd go with Amazon, or what pitch you need, but I see them for 35 to 40 at AutoZone.
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Oct 27, 2022 02:13
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Moving the engine cradle aside is going to be an enormous pain in the rear end, yeah? Will I need an engine hoist? e: wait maybe I can pull the bushing, install the helicoil, and install a new bushing. Free subframe bushing replacement! e2: I'll post pics tomorrow. I have to pull the skid plates first. ryanrs fucked around with this message at 02:56 on Oct 27, 2022 |
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Oct 27, 2022 02:42
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Hoist would work. Option b is this https://www.harborfreight.com/1000-lb-capacity-engine-support-bar-96524.html Depends on how it's mounted but it's probably all off the subframe so will need some kind of support. I'd get a hoist if there's garage space for it. Useful for all kinds of stuff.
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Oct 27, 2022 02:52
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Get an engine hoist if you have the room to store one, it's also useful for removing tractor tires.
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Oct 27, 2022 02:54
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I'm having trouble finding the replacement bushing. It's probably called a "front subframe bushing" or "engine cradle bushing". It's one of the major structural elements that keeps the front from falling off. This is the part for the 2nd gen Sienna. https://www.dormanproducts.com/p-74148-924-269.aspx I need one for a 2000 Sienna, which is probably the exact same part as in the 2000 Camry, Solara, and similar Toyota/Lexus cars. It's hard to find repair info for these bushings because they generally don't fail. But I think the entire subframe is identical across the entire Camry platform, which widens my search. I suppose I can just walk into the Toyota dealer parts dept with a good photo and have them figure it out? e: got it. Engine Cradle Insulator  e: Bought the parts from the dealer. Once I get the new bushing, I'll fabricate a matching tool to press it in. I bet I have to make something stupid, like make a cup with four prongs to poke between those rubber blocks. ryanrs fucked around with this message at 05:53 on Oct 27, 2022 |
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Oct 27, 2022 04:20
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| # ? May 25, 2024 02:40 |
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Replacing those without pulling the subframe may not be a thing that you can do, they can take some pretty serious pressure to get in. I'd start by buying the helicoil kit and seeing if there's enough clearance to just run the tap in without pulling the bushing at all.
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Oct 27, 2022 13:58
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