if wood wasn't very sturdy, they wouldn't make trees out of it, right? in all seriousness, there are parts of the press that would just require strength. at these points i would think a good press with a wooden foundation would have additional hardware to provide more structural stability and muscle. i would think a well-built wooden press would last for years, wouldn't you? of course, you can fix chinese welds if you had to with a couple of bolts and some metal (which would be easier to fix than chinese dog food and chinese drywall and chinese....). i really don't know how long it would last if built right.
as far as machined precision goes, not so much judging by my old workhorse. if you have the means to cut a slot in metal, the rest can be bought at the hardware store as far as i can tell. repeatability is a potential issue, but the moving parts you need is likely something you'd have to buy, so i'm not sure that's *that* big of an issue. this is the part where someone with imagination steps in, to be able to look at how something is made from the vendor and put their own spin on it. i mean, my press is rigged in spots, and i'm sure that after time most other people's set-up is 'home engineered' here and there, too, and even customized to do other things. i could be wrong, but i doubt the parts that required repeatability needs to meet NASA specifications, no?
my wife had taken a class where the teacher showed her how to achieve perfect registration every time, apparently eliminating the need for micro-registration (but had i built a press, registration would be based on gears), so that's something i wouldn't have to worry about. supposedly. i would have to buy new screens, though, and right now that's not my priority.
like you said, why someone would build platen arms out of wood is beyond me. maybe if they built it as a desktop press it wouldn't be an issue? actually, that might work ~ i've always been unhappy with how my platen is adjusted... seems to me that if the arm had sliders on the sides ala a drawer and a good lock-down mechanism then i could eliminated half of my micro registration located on top right there? if that's something that would work, then why wouldn't the manufacturers build that in? simple: cost. having been in manufacturing nearly my entire working life, i can tell you there are better processes out there, but better usually means more money. anyway, someone should be able to find some tubular steel frame or something suitable. wood is just the easier and cheapest to work with, and the idea here also is that you're not going to be hitting your press 1,000 a day, either, so all that repeatability and theoretical high precision machining isn't necessarily needed. your point is well taken, though: twenty years down the line and you are probably going to have a store bought rig by then just because it seems to make sense in most people's minds.
it's impressive that you've built a conveyor dryer. given the cost of a new one, and you rather prove the point of this topic. what about it makes you think it wouldn't stand up with one you bought? that is, the fact of the matter is that no one builds 100% of their own parts in-house. they have a supplier for the motor, a supplier for the chain, the blower, any electronics (which is likely to be the biggest gap between us and them), probably the belt... the 'manufacturer' probably only bends their own metal and puts the rest of the shipped in pieces together. so, for example, if your motor is the same or comparable to what they use, why wouldn't it last just as long (assuming it's wired correctly)? i admit we're not talking about building spice racks, but there's this notion that store bought stuff is always the best and it's just not true. store bought stuff is completely built on the cheap, almost invariably using the cheapest suppliers and 'cost effective' processes. their advantages include engineering (which you can copy and a person with half a brain calls common sense in a lot of it. besides, when was the last time an engineer sat down and tried to re-imagine a manual press, i wonder, lol), machinery that allows them to make a thousand of something in a day, but you only need to build one, and the ability to do some precision work which, as far as i can tell in this case, can be done at home.
i would think the wood would warp eventually, too. the aluminum framing used in manufacturing is probably strong enough and requires no welding. i'd just have to track down some suppliers. but, a basic jamb and header (maybe web stiffener is applicable here, dunno, not a skilled trades guy, lol) might work, too. is that connection strong as a weld? stronger? ??? for the DIYer, it's probably at least good enough.
what about exposure units? or dip tanks? or washout areas? (heh, my washout area is an old three-basin sink with a trophy column for one of the legs, the thing surrounded by cheap paneling i tore off the basement walls.)
still, i'm interested in creative ways people have used to get the job done that you won't find in any 'how-to' article/book/video.
