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I found one of the harbor freight bandsaws used for less than $100, and it came with a fancy stand someone built for it. I would suggest finding a used bandsaw and then replacing the band - as long as its not been dropped or obviously broken, a new band will make it have nice cuts.
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Feb 12, 2024 18:40
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Oh the thing I forgot to mention earlier is horizontal bandsaws will have more band wander and cut less consistently than an abrasive saw in my experience, cold saw is the best but is the slowest.
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Feb 12, 2024 19:48
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also a portaband will function far better when you remember that you actually need to change the blade occasionally, whereas an abrasive chop saw just works until you've ground through so much of the wheel that it doesn't reach the bottom any more, and it's obvious that you have to change the wheel now.
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Feb 12, 2024 19:56
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I realize this is a very "how long is a piece of string" question but how many cuts do you get out of a band saw blade before it needs replacing? 100 cuts of 1" thin wall square tubing? 200? Just 10?
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Feb 12, 2024 21:36
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We use a "cheap" horizontal band saw. I can usually get an infinite number of cuts in aluminum up to 6" in diameter, many many hundreds of cuts in mild steel of all kinds, and like, 10 cuts in 316 stainless. Fewer if no cutting fluid was used. We're also using the cheapest Grainger bandsaw blades and not actually setting the speed of cut based on material. I'm sure you could do better if you paid attention to that kind of thing. I've wanted to try a metal-cutting circular saw blade but haven't pulled the trigger on it yet. I hate abrasive chop saws.
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Feb 12, 2024 22:22
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Hadlock posted:I realize this is a very "how long is a piece of string" question but how many cuts do you get out of a band saw blade before it needs replacing? 100 cuts of 1" thin wall square tubing? 200? Just 10? Also for a bandsaw you want to follow the 'three teeth rule', where at any point in the cut, there are three teeth in the material. If you try to cut thin tube with a 4 TPI blade used for sawing wood, you're gonna bind the blade, break off teeth, or just snap the blade. For thin wall steel tubing, you're probably going to want a 14/18 blade. The chart here is pretty solid. https://www.bandsawbladesdirect.com/media/tech-docs/Tooth-Selection.pdf babyeatingpsychopath posted:We use a "cheap" horizontal band saw. I can usually get an infinite number of cuts in aluminum up to 6" in diameter, many many hundreds of cuts in mild steel of all kinds, and like, 10 cuts in 316 stainless. Fewer if no cutting fluid was used. We're also using the cheapest Grainger bandsaw blades and not actually setting the speed of cut based on material. I'm sure you could do better if you paid attention to that kind of thing. I had the Dewalt chop saw with that style blade in it, and it was an absolute beast for cutting solid aluminum stock. Downside is it's loud as gently caress, and the chips end up literally everywhere in a 20 ft radius. Tubes were really iffy, if you didn't cut it right it would bind and exciting/expensive things happen. We ended up getting the slightly bigger Jet bandsaw, and we're happy with the results.
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Feb 13, 2024 02:00
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Not to hijack, but this saw conversation is very convenient as I'm also shopping for a way to do some proper cutting. Stainless exhaust pipe would be the first project with various future mild steel and aluminum projects to follow. Though I figure those two are a non-issue for anything that can manage stainless. Anywyas, should I be considering something like this (with the proper blade) over a horizontal / vertical bandsaw? I hear cold saws are the way to go, but then some people saying it doesn't count as cold unless it has a coolant system and end up having no idea. https://www.amazon.com/gp/product/B083Y5W9YS I figure top priority is nice straight cuts for solid fitup but also want flexibility to cut something like a prebent 180* down to something smaller. I am also all ears for an alternate third option that isn't on my radar.
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Feb 13, 2024 02:18
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I used my 12" miter saw to cut 4x4x.25 aluminum angle, light constant pressure and it made a really clean cut. It was extremely loud and chips were everywhere, a bandsaw would have been made less mess.
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Feb 13, 2024 02:20
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WTFBEES posted:Not to hijack, but this saw conversation is very convenient as I'm also shopping for a way to do some proper cutting. Stainless exhaust pipe would be the first project with various future mild steel and aluminum projects to follow. Though I figure those two are a non-issue for anything that can manage stainless. That saw is 1400 RPM, with a 14" blade. That's a cutting speed of about 5100 SFM. Carbide tooling milling aluminum has a generally accepted cutting speed of 1400 SFM. The big blade gets away with the higher speed mostly because the total cutter engagement is like 5% of the saw's circumference. Stainless wants...200 SFM. If you tried to cut SS304 or SS316 tubing with that saw, you'd just smoke the $100 blade in a cut or two. In comparison, a real cold saw like this one spins at a blistering 52 RPM, which comes out to ~190 SFM, which is right in the sweet spot for actually cutting alloy steels and stainless. It's also $4000 vs. the amazon item's $500. I'd suggest a craigslist bandsaw for $500 instead.
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Feb 13, 2024 03:05
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I went by and looked at the $120 Bauer porta a band that'll probably do the trick. I'm sure it'll go on sale at some point for effectively $99. The Hercules is $60 more I don't think I'll use it enough to justify whatever improvements exist. I think also they come in their own quasi sealed plastic carry case which is nice for keeping it tidy and clean
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Feb 13, 2024 04:36
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Hadlock posted:I realize this is a very "how long is a piece of string" question but how many cuts do you get out of a band saw blade before it needs replacing? 100 cuts of 1" thin wall square tubing? 200? Just 10? if you're cutting mild steel and you don't abuse it I think you can get 100-200 cuts easily. If you overheat your blade or cut hardened stuff, a lot less. Overheating is really only an issue if you have some kind of unusual duty cycle, like you're just continuously cutting for multiple minutes, but also be aware that you lose tension a bit as the blade heats up, and you should remove tension from the blade after that rather than just cranking up the tension and then leaving it like that. In other words: don't stretch your blade, it'll break prematurely. I have a portaband and I've never needed to replace the blade yet after ~8 years or so, but it's also only made like an average of two cuts a year except that one time when we did about 20 cuts. Mostly mild steel. It's still sharp. I cut steel more often than that but most of the time it's way more convenient to grab a hacksaw than it is to get out the portaband, which is big and bulky and has to be plugged in etc. etc.
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Feb 13, 2024 06:51
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Pie cuts are cool and easy to make with a bandsaw. But I don't have a bandsaw, just an angle grinder. So I made a 1:1 template in fusion 360, I needed to print this on two A4s , it's a 22.5 degree template.  That feeling when the template matches the pipe perfectly and both edges line up...  Been making a few of them by now, need more before everything it set up.  In case someone wants to complain about a stovepipe doing a u-bend, it's fine. It's not a problem, the flue gas is made to do worse in my masonry heater. I should add an access hatch later though to facilitate sweeping. But this is the only way I could fit that heat exchanger in without making a new hole in the wall to the chimney. Besides look at these crazy things  I've had a flue gas thermometer on the stovepipe for a while now and it puts out way too hot flue gas into the chimney, so I am trying out one of these flue heat exchangers to reduce the temperature some and get back some heat before venting it outside. I got big enough margins I don't need to worry about dropping the temp anywhere near enough to have problems with creosote or condensation, and the flue gas thermometer will be reinstalled later to monitor it.
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Feb 13, 2024 18:09
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Yup it's not just "fine" it's "better" because you are basically building a heat exchanger with your room air that will extract more of the heat from the exhaust gas for heating your space. With the one caveat that you will tend to build up more creosote and deposits as the exhaust gas cools and that stuff liquifies into droplets and deposits on the surfaces on its way out.
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Feb 13, 2024 18:21
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It's the main risk, which is why I will reinstall the flue gas thermometer after the heat exchange to see what the temps are like. But right now the flue gas is so warm coming out of this stove that even if this heat exchanger managed to reduce the temperature of the flue gas by 150 C (they claim it might do a reduction of 80-90C) I'd still have a lot to go before reaching problem temperatures. It's around 300-450 celcius when burning at full tilt, and that's the air closed off as much as possible, if I open the air I can get up to 500C which is just crazy and possibly harmful to the chimney. It might reach into condensation temps when it's just a few embers left. But we'll see after using it some months what the insides look like. I'll install a sweep hatch on the diagonal too to clean it, though it's easy enough just to pull the whole stove out. I do sweep and clean this regularly.
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Feb 13, 2024 18:30
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Just a random thing I came across like, yesterday, but have you looked into catalytic converters? Apparently they're a thing for stoves now - they go on the exhaust, get super hot and radiate that heat, and output exhaust gas with a lot less emissions, much like for a car. e,. this sort of thing https://midwesthearth.com/pages/catalytic-combustor-faq Leperflesh fucked around with this message at 18:44 on Feb 13, 2024 |
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Feb 13, 2024 18:40
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I've heard of them but I don't think they are common here in Finland, if so they're usually an US imported stove. I did read something about the catalytics increasing dioxins instead while reducing particulates, so it wasn't clear if the overall gains were a wash or not? But they help keep the deposits down while doing the kind of low-slow burn that's otherwide inadvisable as I understood it, for people who want the stove to be warm all night and leave a fire to smolder. Or so I was told anyway. Most stoves here that are of a modern design have opted for a hot burn with ceramics and use of secondary or even tertiary air to get a clean burn. I experimented with homemade ceramics plates in the sauna stove a year ago. My stove is a powerfully primitive design and it raised flue gas temps beyond what the thermometer could show. I might reinstall them after evaluating how this works.
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Feb 13, 2024 18:58
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The catalyst actually has to be above a threshold temp, so much so that the design on the page I linked has a bypass you use when the stove is running low (like on startup) and you only put it inline with the exhaust when the fire's hot enough.
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Feb 13, 2024 19:19
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Methylethylaldehyde posted:That saw is 1400 RPM, with a 14" blade. That's a cutting speed of about 5100 SFM. Carbide tooling milling aluminum has a generally accepted cutting speed of 1400 SFM. The big blade gets away with the higher speed mostly because the total cutter engagement is like 5% of the saw's circumference. Oh boy, those numbers are way off. Bandsaw it is then! I've wanted an excuse for one of those anyways so this works just fine by me. Thanks!
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Feb 13, 2024 20:15
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Leperflesh posted:The catalyst actually has to be above a threshold temp, so much so that the design on the page I linked has a bypass you use when the stove is running low (like on startup) and you only put it inline with the exhaust when the fire's hot enough. There's some guy using his completely wrong then 
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Feb 14, 2024 05:31
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Why was brass used so much historically (and maybe presently?) for complex mechanical watches/clocks/scientific instruments? Is it just because it is relatively easily worked but hard enough not to warp? It seems like mild steel wood generally be cheaper and isn’t that much more difficult to work? Is it particularly dimensionally stable? I have no idea if some metals expand/contract more with temperature changes than others. Is the big advantage of brass corrosion resistance or what?
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Feb 15, 2024 04:34
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Steel has been around for thousands of years but wasn't really available in a large way until the Bessemer process in the 1800s. That was the tipping point from wrought iron being a primary material to mild steel. Now things are switched, steel is cheap and wrought iron is a rare commodity these days! So historically, mild steel wasn't really that available, steel was expensive, and it was harder to work, so why use it? Someone can probably answer better on why certain metals are still used in movements today but id put money on tradition and machinability. Brass and bronze have gotten way more expensive lately though it sucks, we're working on a project now and the bar stock was eye watering. threelemmings fucked around with this message at 05:09 on Feb 15, 2024 |
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Feb 15, 2024 05:01
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Leaded brass is significantly easier to work than mild steel, especially if you're trying to achieve a high quality surface finish. Corrosion resistance is a huge deal when you're talking about, say, gears with teeth that are individually the size of a grain of sand. The cost premium of brass over steel is not remotely significant in the amounts that are used for a watch, or with the sort of money you spend on laboratory equipment. Brass has lower friction than steel, which is beneficial for delicate mechanical moving parts. People have known how to make reliable, good quality brass for a very long time, but good quality steel is a much more recent invention. Until the industrial revolution you didn't even really have different district grades of steel. You had wrought iron, cast iron, and whatever kind of mystery steel came from the local blacksmith's knife making technique. Brass just looks prettier than steel. Maybe some other reasons too idk
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Feb 15, 2024 05:09
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Yeah I think corrosion resistance was a big part of it. Particularly for trim pieces. It's called brightwork for a reason I don't know, but if you look at the brass era cars* I think it was simply because chrome plating didn't exist at scale yet. Commercial Chrome plating didn't start until almost 1925, and all the chrome companies consolidated by 1930 *This is a real thing, I know, I was surprised too
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Feb 15, 2024 06:01
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So a fellow goon has picked up and been storing an engine for me 500 miles away (and almost a year ago) and is going to drop it off Saturday  . This all kind of happened all of a sudden and trying to figure out what to do with itOption A is find an engine stand but the cast iron block is 36" long and YouTube verified as 1000 lbs flat not including the transmission (also cast iron, supposedly 400+ lbs and another 20+ inches long) so I'm hesitant to put that kind of leverage on a stand designed for a relatively compact, 24" compact 400# v8. Also I have a toddler and this top heavy thing looks like a wobbly toddler death trap Option B is design and fabricate a dedicated engine "display" stand? Any thoughts on this? I was thinking about doing like, a 20x36" box of 1.5 square tubing with holes drilled for casters as a base, and then 1" tubing for the 4 uprights? Like this? https://www.jalopyjournal.com/forum/attachments/100_0143-1-jpg.1178068/ If that doesn't work it's linked to in a post by "Choff" about half way down here https://www.jalopyjournal.com/forum/threads/49-chrysler-spitfire-straight-8.540311/ Looks like he's using 1/4x1.5" steel bar for most of it? That seems... Wildly excessive? Hadlock fucked around with this message at 06:56 on Feb 15, 2024 |
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Feb 15, 2024 06:53
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I bet it's faster to slap something together with 1/4" bar than mess around mitering square tube, finding longer bolts, etc. The flat bar is probably also lighter. e: 1/4 x 1.5 flat bar is 1.3 lbs/ft 1.5 x 1.5 x 16ga sq tube is also 1.3 lbs/ft sq tube lbs/ft chart Even though square tube is a stronger, more mass-efficient shape, at these small tube sizes it's hard to come out ahead unless you go to fairly thin walls. And do you really want your 1,000 lbs engine stand to be reliant on your thin-wall welding skills? For example, if you were stick welding this thing, the flat bar would be an easy choice, imo. But if you want to save metal, you will need to actually engineer that poo poo and probably tig it out of 16 ga. or thinner. ryanrs fucked around with this message at 08:11 on Feb 15, 2024 |
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Feb 15, 2024 07:29
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OK I've completed the welding and made my first fire. No smoke leaks! You've heard of MIG like TIG, I present MIG like Stick:  Still need to disassemble and paint it with proper paint, and maybe clean up behind the stove while I am at it. And fit the flue gas thermometer so I can see what the difference is.
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Feb 15, 2024 14:38
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Hadlock posted:So a fellow goon has picked up and been storing an engine for me 500 miles away (and almost a year ago) and is going to drop it off Saturday
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Feb 15, 2024 18:00
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Pretty sure that angle is just two pieces of flat bar. Dude bought 1 piece of steel bar, and made an entire engine stand.
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Feb 15, 2024 18:24
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Cast/crucible steel from the Huntsman-process precedes the Bessemer-process by over a century, but that was neither cheap nor easy to work. Certainly not mild steel, something like low HRC 50s hard, going by the old saws I have. Worlds of difference from brass. Also, with how much labor went into watches & instruments anyway, the cost of the materials is relatively minor. Substitute capital expenses & running costs for modern CNC manufacturing and that'll still mostly hold true I guess.
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Feb 15, 2024 18:33
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Yeah, brass is so much nicer to machine. That's still worth $$$ today in production machining, since you can run insane speeds and cut down cycle time. For the machined pipe fittings in this video, an alternative material might be stainless steel. But switching from brass to stainless probably increases your machining costs by an order of magnitude. https://www.youtube.com/watch?v=AUS5SJ5XcWE
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Feb 15, 2024 18:55
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ryanrs posted:Dude bought 1 piece of steel bar, and made an entire engine stand. Yeah I don't know poo poo about poo poo when it comes to designing and working with steel, I just assume it's half as strong as I think it is so I'm over here asking questions. I'm like half way done building a rolling tool cart and it's probably grossly overbuilt because I'm just eyeballing it and still learning Any pics of your single steel bar engine stand?
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Feb 15, 2024 21:45
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Comedy option - carve a stand for it out of a block of granite.
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Feb 15, 2024 22:00
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You just described most cars from that era yeah
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Feb 15, 2024 22:06
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that's a cool machine but boy that guy is really irritating.
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Feb 16, 2024 07:31
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He tries to be a presenter, but seems like just some egghead.
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Feb 16, 2024 08:58
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Those videos are really baffling, who are they for? Machining centers aren't exactly impulse buys, so it doesn't work as an ad. They're very light on information, so it doesn't work as a learning resource. (Questionable as it is to be requiring some dude on youtube to explain it to you when you run this kind of machinery to begin with.) Even as entertainment it fails, who is going to put up with some insufferable dude?
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Feb 16, 2024 18:20
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Just Winging It posted:Those videos are really baffling, who are they for? Machining centers aren't exactly impulse buys, so it doesn't work as an ad. They're very light on information, so it doesn't work as a learning resource. (Questionable as it is to be requiring some dude on youtube to explain it to you when you run this kind of machinery to begin with.) Even as entertainment it fails, who is going to put up with some insufferable dude? They sell pretty lovely training packages, and companies give Titan machines and tools to use in his videos.
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Feb 16, 2024 18:51
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Who drops hundreds of thousands of dollars on equipment based on product placement in a lovely youtube ad though?
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Feb 16, 2024 18:57
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The people who think Titan is cool and good, guy is a massive tool.
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Feb 16, 2024 19:20
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Just Winging It posted:Who drops hundreds of thousands of dollars on equipment based on product placement in a lovely youtube ad though? Advertising is a fake discipline driven entirely by masturbatory self-aggrandizing horseshit
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Feb 16, 2024 20:08
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