Monday, August 10, 2020

Rule One of craftsmanship

 No matter how proud you are of that new thing you've made, some kid half your age on YouTube has made one that is ten times better.

wild hair

 I'm pondering how much it would cost me to convert my shop from inch to metric.

 It might not be as bad as I at first thought. For example, the mill switches over with the press of one button because I have a DRO on it and I never use the dials. The parallels I use for it have labels on them in inches, but it doesn't matter because I never look at those numbers.  The end mills I have are sized in inches, but that does matter a LOT, so long as I know what their dimensions are, and even that I don't usually need to know with any precision at all - just enough to calculate cutting speed.  Gradually I would probably convert them to mm just to make math easier... since that's kinda the whole point.

 Likewise my calipers switch with a press of a button, and feeler gauges and rulers are cheap...

The dials on the lathe would be a PITA however.

And worse, I have a lifetime of instincts and judgment built on measurement system which, while it may be stupid, is now thoroughly entrenched in my technical thinking and my visual and physical interactions with the world; I would have a lot of habits to un-learn, and until I re-adapted, I would not reap the benefits of being metric.

Hmmm... America... so advanced... >_<

whither video?

 I realized that all the video channels I watch - including the folks I called out in a previous post - are using nice cameras on tripods, and that shakycam BS taken with a phone is going to annoy ME, never mind be unacceptably amateur-hour for my tastes.

SO...

 I'm going to wait until I have the dough to spare for a tripod and a Go-Pro or similar (or I figure out the video recording issue with my SLR), before I attempt to make actual, long, lecture-y, talking sorts of videos.

IN THE MEAN TIME, sometimes a picture is worth a thousand words, and a video is worth, um, mumble frame rate times minutes of running time... well, you get the picture.*

So I'll occasionally use my phone to shoot shorts bits of video, like this one:

Oh crud, sorry about the background music, I forgot to mute the mic.

 That piece of steel which is floating across my surface plate is one of three pieces of scrap low-carbon steel I've been working on to make flat and parallel.  I'm trying to prove that I can make gauge blocks effectively out of junk, and without owning a surface grinder.

 With one proviso: I'm not planning to finish them to any particular dimension. So if they come out = .17278xx but reasonably flat and reasonably parallel, I'll be pretty darn content. (the xx's are values I care about, but won't be able to measure with any accuracy any time soon because my name ain't Tom Lipton)

 I do however, intend to make all three equal, otherwise they'd really be useless.  The point is to prove the process, but I need better measuring tools - some actual gauge blocks, say - before I'll be ready to try making any to a specific dimension.  Even so, with almost minimal effort, they are flat enough to float, which means they are trapping a layer of air - thinner than .001 in / .025 mm - between the block and the plate.

 To do that means that the microscopic features of both surfaces have to be very low in height - the surface has to be very flat and very smooth - for this to work. Realize there is no lubricant present but air - the surfaces must be very clean and free of finger prints, etc.

 This is actually already more flat and more smooth than I'm even ready for; the three blocks need more work on parallelism before they are ready for lapping; they are more like small angle blocks†... and they are not supposed to be...

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* sorry not sorry
† .0382º if you're curious, or 138 seconds of arc, or .00067 radians...

Sunday, August 9, 2020

Is that SpaceX's Starhopper in this music video?

 

 
 
Well, is it? ^_^

masters, teachers and peers - machinist edition

I call these guys The Machine Shop Mafia.  They all know each other via YouTube, and a bunch of them have been getting together at meet-ups around the country for various things.  I haven't included everyone in that circle of YouTubers, only my favorites who I follow faithfully...

Tom Lipton, OxToolCo - Tom is like the uncle I never had but wish I did.  He seems so genuinely nice, and calm, and un-excitable that for me, watching his content is like a mental oasis, a micro-vacation.  Tom is a lover of tools, especially precision measuring tools, but he is also a lover of precision generally, and therefore, he also owns and obsesses over the laboratory standards and instruments which are used to calibrate the high-precision measuring tools which are used in a machine shop.  As a tool fanatic, he also has a great appreciation for shop-made tools, the unique fixtures, tooling, and problem-solving widgets that machinists - or indeed, anyone with opposable thumbs - create in order to make their daily work a little easier.  I have made many tools to solve problems in the shop, but none of them were useful more than once, and none were made to last.  Tom's own work and his appreciation for the work of others, inspires me to try to do better. -- https://www.youtube.com/user/oxtoolco/featured

Adam Booth, Abomb79 -  Don't take this guy on in a 4-jaw aligning competition. As near as I can tell, and I apologize if I got this wrong, Adam is a 3rd generation machinist, who worked in his dad's shop, who in turn worked in his father's shop.  As a result, Adam strikes me as the consumate competent machinist; he's probably forgotten more tricks and tips than I will ever know - every time I watch one of his videos, I discover some new time-saving technique that makes me smack my forhead, or the existence of a tool I didn't know existed and now positively must own because it's fundamentally better than what I've been using all my life. -- https://www.youtube.com/c/Abom79/featured

This Old Tony - Tony is the funniest guy in The Machine Shop Mafia.  Blink and you'll miss it.  He does a lot of work restoring or upgrading eccentric old machine tools.  He seems to get a lot done in a very short amount of calendar time, so I wonder whether he sleeps. -- https://www.youtube.com/c/ThisOldTony/featured

RobRenz - I found RobRenz two days ago via some comments that Tom Lipton made about him in one of his videos. Anybody that Tom thinks well of is somebody I need to know about.  He seems to be into very high precision (physical) metrology. -- https://www.youtube.com/user/ROBRENZ

Cà Lem - I just found this fellow this morning, via a comments conversation between Cá Lem & some of the other fellows listed above. He is a machinist, makes nice tools, also does restorations -- but as far as I can tell, HE'S JUST A KID!! - https://www.youtube.com/c/CáLem/featured is his channel, but watch this amazing video to get a perfect summary of why his channel is so respected by the other YT machining pantheon: https://youtu.be/skMvRMGVybM

Clickspring - Does a lot of clock related stuff.  Features a lot of very finy, small, fiddly work, like a jeweler, clock-maker, or watch-maker.  Beautiful craftsmanship.  I learned about how to "time" screw heads from him. -- https://www.youtube.com/c/ClickspringClips/featured

 These are the machine shop folks I look up to, when it comes to truly advanced machining and toolmaking.  But I am not qualified to teach what they do.  I intend my blog to be for beginners.  I consider myself basically competent as a home shop bodger.  I do not call myself a machinist because I am not one - I have not worked as one professionally, nor do I have the skills of a professional.

When I watch the videos of the people listed above, I am very much a dog watching origami.

 Fortunately, I have a good friend who is a professional toolmaker, with whom I have a pretty good relationship, although I think he has done me far more favors than I have done for him.  I also did a very small amount of paid part-time (piece) work in his job shop which AFAIK worked out fine for both of us, which helped me understand some shop viewpoints and "ways of working" which were of a larger scope than the simple tasks I was performing.

 He helped me evaluate and decide on buying my lathe, for which I am grateful, and much more to the point, he sold me a Bridgeport for well below market value for which I am in his debt.  And he lets me bug him with the occasional question.  I can't figure out how to pay this kind of thing back, either, and it eats at me sometimes.  I have a lot of treasured friends like that, it is the way I am most fortunate, and I am baffled how I earned such people in my life.

 Frankly, that's how most of my professional education has gone - I hang around people who are smarter than me, I pay close attention to what they do and how they do it, and I ask a lot of questions.  For most of my life, I have managed to get paid to do this - I've been doing a sort of high-level On-The-Job-Training, without pursing any college.  Bonus: many of my friends are professional nerds with similar shared interests, so much of the time I (used to) spend socializing or recreating, I was learning tech skills too.

 I grant you it's not for everyone - especially if you are a Reading/writing type* learner.  Although I am an avid and strong reader, that's not how I learn best - I am half Visual and half Kinetic style learner, in that model, so YMMV.

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* the so-called "V.A.R.K." model of four types of learner, developed by Neil Fleming in 1987

Saturday, August 8, 2020

strange dreams

 I took a nap (something I almost never do) and I dreamed (something I don't do enough of, because I use weed too often) that I had made some little shop tool for a lark and sent it to -- huh!  I guess it was a dream-amalgam of multiple people that I watch on YouTube: Abom79, OxToolCo, and ThisOldTony, on YouTube, and "he" mentioned it with pleasure on his channel.

 I guess I know why I had the dream; watching those guys has rekindled my interest in making things in my shop, rekindled my interest in machinist and tool-making skills, and they are the reason this blog has been rebooted.

 Well shit: with that obligation in mind, I now feel compelled to send one of them in particular (because one of them was more inspirational to me than the other two - something that he will appreciate and use. 

 Having a smoke in my shop just now, right after I woke up, I immediately thought of two shop-made tool ideas, neither of which I have ever seen anywhere, and both of which would be terrifically handy: one would be useful all the time, as it is a method of making a very fine adjustment attachment for an indicator holding arm.  This idea was partly inspired by the incredible amount of suck contained in the so-called "fine adjust" of the cheapo Harbor Fright magnetic base I bought yesterday.

 The second is a small Jacobs chuck with copper-faced, steel-backed jaws; to be used for holding work, not a tool.

 I know how to build the former, it's just fiddly. I don't actually have an idea yet for how to make the latter; but it's a neat idea, I'll have to think on it.  Also, I don't own (yet) the required tools and materials to make the indicator holder, but the materials are cheap and the tools are on my list already so when I have them, I can start working on it.

Sadly, I have a bad track record for finishing things - I hope I get it done while he's still alive. >_>

Friday, August 7, 2020

cute torque wrench

 A little more on that cute little torque wrench I picked up this morning. One of the things which was different to my eyes is that the torque-sensing bar is two bars, one above the other in the vertical plane. I've been pondering this, and I can't really figure that this represents any great advantage over a single bar with the same stiffness. Perhaps it is more linear.

 This one is a Model 34830 from Blackhawk Tools.  Judging from the construction style and a bit of searching, it appears that Blackhawk last made this style of wrench in the 1950s.

 Like any good torque wrench, the handle has a pivot point upon which your elbow-grease is supposed to bear. Making the handle a round knob is smart, as it improves the odds that a naive user will use the thing correctly, even if it's by accident.

 The thing is in fantastic shape for its apparent age.  There was a lot of grime on the photo-etched (raised lettering!) plates on the handle end, but a few swipes with some penetrating oil and some light brushing made it look as above.  The plate under the pointer states "2% Permanently Accurate" which should be true unless one manages to somehow bend the main bars, or put dents or nicks in them - you sorta have to abuse the hell out of these things to ruin them.  If the pointer doesn't point to zero when you pick it up, you bend the pointer - which is soft for a reason - until it does.  Don't worry about bending the main torque bar(s); they are hardened and tempered - if you can bend them, something is very wrong. So, even though I don't have a torque calibrator / meter to check it with, I am 99% confident that it will be close enough for my not-going-to-the-moon work.

 I shelled out a whopping $15 for this item, and it took me less than five minutes to clean it up to my satisfaction.  I am content.

used tool "haul"

  Trying to make videos for y'all with just a phone is not working.  I've got a proper SLR which - in theory - takes HD video, but there seem to be some write problems with the card, which is - again, in theory - much faster than it needs to be to record HD video. My theory is that the card is not what it claims to be, and is in fact a fake.

 Regardless, I haven't got a proper camera (like a GoPro) nor even a tripod for the moment (coming, this year, I hope), and the whole shakycam thing isn't me; I don't like to watch it, so I shouldn't subject you to it, either.

 Instead, you get a photograph and a few thousand words.

 I went expecting to find a convolute abrasive (deburring) wheel, but didn't.  I had hoped to find a good quality indicator holder, but did not expect to, and I didn't.

Whups; I didn't include anything for scale... the surface plate is 18" x 24", the brass wire wheel is about 4" across,  the little torque wrench is about 8" long, and the dial indicator is 2.5" across.

 What I did find was (clockwise, from left):

  • a cheap Harbor Fright indicator holder with magnetic base, new in the box, for less than what Harbor Fright charges.  The "fine adjust" screw is a course thread, instead of a fine-pitch thread, so it's nearly useless - not a "fine adjust" at all, and the magnetic base is just strong enough to be used, not nearly as strong as any name-brand base... but that's typical Harbor Freight junk for you.  In this case, the real thing costs 10X what I just paid.

    In the photo above, I've attached a big old Federal indicator to it, just to show how it is used.  Come to think of it, I picked up that indicator at Charlies quite a few years ago, for about $10 IIRC.

    The position and angle of the arm and indicator can moved around a fair bit, and the magnetic base allows it to be put in a lot of odd but handy locations on mills, lathes and so on. It's not really intended for use on the surface plate...

  • a small (100 inch-pounds) torque wrench in great condition...

  • a real all-brass wire wheel (most wire wheels which look like this are not solid brass wire, they are brass-plated steel)...

  • a couple of cold chisels that just needed the heads dressed, a few bucks each. One of these may have been ground down (sharpened) so far that all the hard steel is gone, and might need to be re-hardened. Most folks won't have what's needed to do that, and I myself have had mixed luck, so we'll see.  They were cheap.

 While I like the folks at Charlies just fine, and I try to support small and local business whenever I can, I'm finding that with each passing year, their stock is a little shabbier, their selection a little more miserable, and over-all, the place seems less and less a used tool store and more like a junk shop.

The thing is, there aren't any alternatives that are better.

where to buy used tools in Denver

 Frankly, it's hard to buy used tools without wondering whether they are stolen.

 In Denver, the most common place to dispose of stolen tools is Mile Hi Flea Market.  I personally hate the place and I never go there any more.  I know, with 75% certainty, that the last time I was burglarized and my air compressor was stolen, it was out at the flea market the very next day.  I once bought a large  (and incomplete) Craftsman brand set of taps and dies there, but that's it. And I regret that purchase.

 The second most popular place to "fence" stolen goods is pawn shops.  There are mechanisms in place intended to make pawn shops less attractive as disposal routes, but it still happens. Also, pawn shops usually know what their stock is worth, only rarely do they offer good bargains. Usually their shit is overpriced.  However, I once found an old L.S. Starrett (that's a name brand synonymous with quality) dial caliper in a pawn shop for $10, and it was a funny story...

 I was out with one of my bros, driving down Colfax (the main drag" of Denver, and the longest street in the USA, and home to at least three sketchy business districts in three different parts of the metro area, so a fair amount of pawn shops) and we were talking about this very subject - where to find used tools at affordable prices - and I mentioned pawn shops because at that time I had had one or two bits of good luck and hadn't yet sworn them off. My buddy expressed much skepticism, and as it happened that we were passing a pawn shop that very moment, I abruptly pulled over and suggested we have a look.

And inside we found those calipers, they were missing a locking knob which knocked the price down, but more to the point, they hadn't been priced -- some less-organized pawn shops don't price everything the minute it comes in the door, some will "wheel and deal" -- and it turned out the guy behind the counter didn't really know what dial calipers sold for, and he definitely didn't know that Starrett is one of the desirable brands of machinist's tools.  So I bought them for $10.  The used price should have been $40 - $50 at the time.  My brother was so surprised he was almost disgusted.  It was a fluke, and a moment of luck. It might also have been the last time -- 1989 or so -- that I ever set foot in a pawn shop, because I think they are disgusting, predatory businesses.

Probably the best place to buy used machinist's tools - hell, any used tools - is at estate sales.  Estate sales have lower prices than garage sales, and estate sales advertise what sorts of things make up the majority of the property - if there is a big record collection they will mention that, and if there is a bunch of tools or machinery, they will mention that too.  So there's no need to waste your time traveling to sales all over town - only go to the ones with the stuff you want.  But understand that lots of other experienced tool-users have the same idea, so you have to turn up on the first day of the sale, the moment they open. There will be a short line of other early birds just like you. There is sometimes a little rush for the good stuff on the first day.  You used to find estate sales advertised - along with descriptions of what was for sale - in newspapers, now you find them on dedicated web sites, such as: https://www.estatesales.net/ (an example I just found with a search engine, I know nothing about the site, or even if it's any good)

This morning I am going to run down to a place in Denver called Charlie's 2nd-Hand Tools, a place I've been before, where I've had decent luck.  It's a very low-rent looking, sketchy-looking old building, right in the middle of downtown, in between the shiny sky-scrapers, immense old churches, homeless shelters, and busy-busy big business office buildings.

 I've only been in two or three times, but I found good deals, and the folks running the joint seemed friendly and willing to do a little wheelin'-&-dealin' on prices if you're actually spending some money and not being a jerk. I've spent less than $100 in there so far, and I will take $100 in cash (I can't remember if they take credit cards or not) this morning, in part to limit my spending if I find too many things I want.  I am going with the purpose of finding a convolute abrasive wheel or two (looking for "New Old Stock"), which is where I found my last one at a good price ($10 for something that costs $85 new) but I will also look over all of their indicators, indicator holders, machinist's tools, and machine tool accessories, because there's loads of stuff I still need but don't have.

 A Noga base and arm would be a great find, for example, but I ain't holding my breath. A good "tenths" (.0001 divisions) indicator or dial test indicator would also be very welcome. I'd also consider cutters, tool holders, anything at all that I need and don't have if it's cheap enough.  Ooh, they just opened, and I have to work today too, so I'd better run.  I'll report back on anything I find.

Serial Number 5 was Alive!

In case you missed it, after many, many aborts, Starship (test vehicle) s/n 5 finally launched on a 150 meter "test hop", lifting off from a very basic test stand to a few hundred feet of altitude, traversing horizontally a few hundred feet, and landing again on a very simple flat concrete pad.

It appears to my admittedly ignorant eyes that having virtually no exhaust management or flame diversion / suppression on the launch stand resulted in the fire in the external engine space that we can see in the video. I am confident we will only see that once. ;)


For those who haven't been following every little detail of SpaceX's new rocket design, please keep in mind one fact when looking at this vehicle: this section is meant to be somewhat close to the upper stage, which will have the crew / cargo section attached on top... but there will be a whole other rocket - a whacking great booster called Super Heavy - which goes under this thing!

The last I heard, the Starship upper stage will have six Raptor engines on board: three atmospheric engines and three vacuum engines.  Only three will operate at one time.

But Super Heavy will have thirty-six, no wait, thirty, no wait, twenty-seven... um, once they finish increasing the performance of the Raptor and figure out how many they are actually going to use (ahem), there will be, er, a whole bunch of them on the tail end of the big booster that will sit under this Starship upper stage.  Super Heavy will be a BEAST, developing about twice the thrust (and noise / vibration) of a Saturn-V launch!  If you aren't aware, that is a lot; until Blue Origin's big rocket goes live, Starship + SuperHeavy will be the most powerful rocket, with the greatest lifting capacity, in history.

Note: the main difference between the atmospheric and vacuum versions of an engine
are the size of the exhaust bell (commonly called the 'nozzle', but it's important to
recognize that this most-visible portion is only one third of the three parts of a
rocket engine nozzle).  The purpose of the exhaust bell is to capture and contain
the rapidly-expanding gasses as they leave the combustion chamber, preventing
them from expanding sideways, and redirecting that expanding pressure to the rear
where it can do some good, like pushing the vehicle forward. Gasses that go sideways
don't push the vehicle forward.

When the vehicle leaves the atmosphere behind and begins to travel in regions of low
pressure and finally the vacuum of space, it becomes much easier for the expanding 
gasses to go sideways instead of backward, so a much bigger and longer bell is 
required to redirect those gasses to go straight back.

 It is also important to understand that this test vehicle is not a good representation of what the final Starship upper stage will look like; this is little more than a test article intended only to prove the functionality of the basic parts of the rocket's systems: the fuel tanks, the structure, the engine and Thrust Vector Control system, the Reaction Control System, and some basic navigation / orientation.

 There will be several more test hops until the basic launch sequence is thoroughly characterized and understood, bugs in Raptor's performance and stability are worked out, and possibly some facility upgrades (cough, exhaust management, cough) are accomplished.  One thing is certain: they sure as hell aren't ready to test 30 Raptors firing at once, yet!  That will be a sight to see.