Thanks for being open to questions. I always wanted to know this:
3 copies of a simple 50x50mm, 6 layer, board is 184€ and takes 13 days to make as per https://aisler.net/en/products/boards - for comparison, JLC makes five 100x100mm 6-layer PCBs in 11 days, for $2. (And no, it's not only because of the (always available) coupon. Pricing generally gets better at higher quantities.)
So my question is: why is 6 layers so expensive? Are you really truly economically unable to even get close to JLC, or do you just not care about prototyping orders (or the overlap between hobbyists and professionals), or are these smaller boards a too large part of your revenue that you can't compromise, or is it more a case of being stuck in an outdated legacy mindset where 6 layers is "a lot" and must be allocated to "serious business" only, or is it something else? Or am I just completely off about proper market segmentation? (Same for going to 2oz copper.)
Please don't take offense at the way I'm asking; I really really want to be your customer. I'm never going back to unnecessarily constrained shitty 2 or even 4 layer designs, when a simple part/sig, gnd, vcc, sig/gnd, gnd, part/sig stackup makes design soooo much easier even for simple circuits. But I really would love to know why nothing comes close to JLC one level up from novice PCBs.
Happy to answer that question! In the end it's a numbers game. Manufacturing gets cheaper with higher demand. For 6 layers the demand is rather low. We've figures from a US PCB comparison site and the share of 6 layers and more is below 5%, everything else is 2 and 4 layers.
JLC serves a huge domestic market, so even with niche products they can do order pooling. That's not possible for us, thus the difference between 4 layers (€28.29) and 6 layers (€184.83). If there would be more demand in general, we could offer much lower prices.
Thank you. I hadn't expected it to just be lack of demand/scale. All the best with Aisler; I really hope the EU's renewed interest in local production will lead to more business for you.
It has a fixed maximum number of concurrent sockets, and each socket has queues backed by per-socket fixed-size transmit and receive buffers (see `rxmem` and `txmem` in `struct tsocket`[1]). This is fine, because in TCP, each side advertises remaining buffer space via the window size header field [2] (possibly with its meaning modified by the window scale option during the initial handshake - see [3] & `struct PACKED tcp_opt_ws`), and possibly also how much it can maximally receive in one packet (via the MSS option on the initial handshake [4]; possibly modified by intermediary systems via MSS clamping). wolfip has unusually small buffer sizes, and hardcodes them via #define, and everything else (e.g. congestion control) is pretty rudimentary too, but otherwise it's pretty much the same as in a "normal" implementation.
Buffer size is the product of bandwidth and delay, so if communicating with something close, it can still go fast.
Had an illustration of this once when my then-employers IT dept set up the desktop IP phones to update from a TFTP server on the other continental land mass. Since TFTP only allows one outstanding packet, everyone outside head office had to wait a long time for their phone to update, while head office didn't see any issue.
If it's a memory-constrained embedded device you're sending a handful of bytes of telemetry every now and then, not aiming for gigabit speeds. In fact it couldn't get to megabit speeds even if it wanted to. For something like that this is perfect.
It's similar to FedRAMP systems like AWS GovCloud (US), which can only be accessed by someone who is a US person (US citizen or lawful permanent resident) and on US soil (physically in the US at the time of access).
LACK tables specifically are well proven to be quite sturdy actually. They happen to be just the right width for servers / network devices, and so people have used them for that purpose for ages. Search for "LACK rack", or see e.g. https://wiki.eth0.nl/index.php/LackRack. 20kg is nothing; I've personally put >100kg on top.
They're a bit less usable that way now. The legs are basically completely hollow these days so you're not actually able to bear much weight on the screws so the only option is stacking the items so the weight is born by whatever surface is below the "rack" at which point you could just as easily call stacking the equipment an air rack (or an iLackaRack maybe /s).
It really depends. The DMCA does have limited exemptions for reverse engineering for interoperability. The EFF has a good overview: https://www.eff.org/issues/coders/reverse-engineering-faq (search for DMCA). My personal takeaway is that this question cannot be definitely answered outside of court.
I have had a question for a long time, and this may be my one chance to ask someone who actually knows how these things work.
When you were working on this, have you considered playing music that (and please don't take this the wrong way; this may be exaggerated but maybe you will understand what I mean) pre-retirement non-musicians would listen to, where the composer is still alive, and that hasn't been played in the same venue a hundred times? Looking at the Gewandhauses schedule right now, there's absolutely nothing for me.
The San Francisco Symphony plays a top-tier movie (Top Gun, Titanic, Lord of the Rings, etc.) with the film music performed live by the orchestra every few months, and I go to many of these. I got tickets for the Game of Thrones series finale concert (different venue). I absolutely loved Video Games Live, which actually has been in Leipzig too, but in the Arena, and well over a decade ago. I went to a Lindsey Stirling concert, who I knew from YouTube.
So my question is: Why can't the Gewandhaus do something like that regularly? Why can these events only be available in large cities like San Francisco? It's actually frustratingly difficult to find such events in smaller cities. Is it licensing/artist fees? Not interesting for the local musicians? Events like this reliably book out large venues several times in a row, so can it really be lack of demand? Maybe only from the wrong customers?
Thank you! I always wonder this as well. Maybe part of it is "what is the difference between classical music and music played by a symphony/orchestra?"
I suspect it boils down to such things being done far more for social status and such than actual enjoyment.
Windows 11 recently pushed an update to discontinue Windows Mixed Reality (WMR), bricking my <5 years old, $500 Reverb G2 VR headset, which I bought after Meta bought out Oculus and started requiring a Meta account, essentially bricking my Rift S. No thanks.
3 copies of a simple 50x50mm, 6 layer, board is 184€ and takes 13 days to make as per https://aisler.net/en/products/boards - for comparison, JLC makes five 100x100mm 6-layer PCBs in 11 days, for $2. (And no, it's not only because of the (always available) coupon. Pricing generally gets better at higher quantities.)
So my question is: why is 6 layers so expensive? Are you really truly economically unable to even get close to JLC, or do you just not care about prototyping orders (or the overlap between hobbyists and professionals), or are these smaller boards a too large part of your revenue that you can't compromise, or is it more a case of being stuck in an outdated legacy mindset where 6 layers is "a lot" and must be allocated to "serious business" only, or is it something else? Or am I just completely off about proper market segmentation? (Same for going to 2oz copper.)
Please don't take offense at the way I'm asking; I really really want to be your customer. I'm never going back to unnecessarily constrained shitty 2 or even 4 layer designs, when a simple part/sig, gnd, vcc, sig/gnd, gnd, part/sig stackup makes design soooo much easier even for simple circuits. But I really would love to know why nothing comes close to JLC one level up from novice PCBs.