Wednesday, June 22, 2022

well, this is awkward..., which is to say, Google, lied to me.  So here's the thing: this blogging platform provides quite a lot of statistics about visitors to the blog, including per-post granularity.

 And the stats page has been telling me for months that nobody was reading a damned thing I wrote.  So, I felt I was wasting my time.

 So now I have some human feedback telling me that - shock, surprise! - Google's shit is broke here too, just like search, just like YouTube...

 I have plenty of trivia I could write about, but virtually none of it is particularly important or note-worthy, with the possible exception of an upgrade to my surgical-style shop light, which is finally getting the ceiling mount it needs, so that the @#$^)* salvaged Ikea Stolmen post - to which it was formerly attached - can get the hell out of the middle of the shop...

 Well, I'm pleased that anyone is getting anything of value at all out of all this blather.  Both I and my other half are recovering from various hurts, so it may be a while before much more appears here...

Sunday, May 15, 2022

no more readers

 I see no point in continuing this solitary masturbation.

Tuesday, April 26, 2022

The Vehicle Flashlight

 ahem: flashlights (oi, electric torches) for the car glovebox...
 (classic problems solved... but w/ money, as usual)

• many folks keep a flashlight in the glovebox or trunk of their vehicle.
  This is sensible and good.

• vehicle environments are tough on cheap flashlights, tending to destroy
   cheap housings, damage/scratch up the lens, vibration may break
   filament-based bulbs (still shipping in some otherwise good flashlights!),
   they aren't bright enough, they don't last very long, and worst of all, both
   time and temperature will reliably destroy the batteries so that when you
   finally need that light, rather desperately, five years later, by the side of
   the road at 3AM in the rain... it's as dead as "post-rock".

• solution:
   - for the housing, buy the least expensive, 2-cell D-size Maglite (Mag
     Instruments), one that comes with an incandescent bulb, not their newer
     LED-based junk.  Why?  The body is all we care about, and we're going
     to replace the bulb no matter what,  and this is the cheapest way to get
     the body.

  - replace the lens with a 'toughened glass', anti-scratch coated replacement
    lens from whoever - mine came from Weltool

  - replace the bulb with an established, name-brand, LED upgrade of at least
    3 watts, (5 is better).  I think I bught mine from Nite-Ize, not sure; MAKE

  - replace the batteries with 3V Lithium Thionyl Chloride (LiSOCl2) primary
    cells from Saft, Tadiran (German), or Tenergy (discount line made by Saft,
    nearly as good, and somewhat cheaper) - these cost $13 - $25 EACH. 
    Although they are not rechargeable, they store ≈ 4X the energy of the best
    alkaline primary cells, in addition to their other wonderful properties.

 The resulting torch will not self-discharge appreciably for ten years, regardless of temperature cycles.  I have personally used the Saft branded batteries for SAR ground truth tags and remote nvironmental data acquisition sensor kits which went in both desert and glacier environments, in uninsulated Pelican cases, left in place for months to years!

 The bulb will be much brighter and more efficient, using less current, than Mag's own LED bulbs.

 The glass lens will not get scratched up from rolling around with the other junk in your glovebox or trunk for six years before you finally need it.

 As for the body, Mag makes a REALLY good housing for the money.  Only way to get something better is to spend 4X as much on the body for incremental improvements.

 I once left a 4-cell D size Mag lite on the hood of a jeep (it was dark) I noticed I'd done so when we pulled out onto the highway again, and it rolled off at about 25 - 35 MPH and endo'd on the pavement 3 - 4 times... worked fine when I picked it up, (they used plastic lenses back then which did not break, but would scratch from a stern look) and only had cosmetic dings on the edges of the lamp housing and end cap.  If you're paranoid, the end cap will hold a spare LED bulb just as well as it does the spare junk bulb that comes with it from the factory.

 There is, unfortunately, one remaining and glaring defect of the Mag torches which neither they, nor I, nor the internet community, have a solution for, and the reason for this situation is named Anthony Maglica, the owner and founder of Mag Instrument, whose policy it is to sue, in court if necessary, genuinely and aggressively, anyone who makes an accessory that interacts with Mag's patented features.

 It's that damned, miserable reflector, which results in an absolutely HORRID beam, something quite below today's widely accepted standards.  The reflector needs to be changed to an "orange peel" surface to fix this, and Mag doesn't think it's important enough.  But the reflector has a patented cam feature which, acting against the sliding, spring-loaded (and patented, ahem) lamp holder, provide a desirable focusing feature, permitting the operator to have a wife flood shitty beam of light, or a tight and narrow shitty beam of light.

 Anyone who has brought to market an orange peel replacement which has the angled rear stub / cam surface to activate the focus feature has received a C&D letter, and one accessory manufacturer was taken into court and sued out of existence.  So if you decide you would much rather go with another brand of housing on moral ground, I certainly cannot blame you.  Mag doesn't care about users.

 There seem to be some reflectors which don't focus, which might fit, it's hard to tell, since the sellers can't even use the NAME or say that it FITS "Mag Lites" or anything similar, or... Cease And Desist!

 I have no tested solution for this issue, yet.  My own torch still has the shit factory reflector.

 Some folks have said that a stock reflector may be hand-spattered judiciously with clear acrylic spray, using a small brush and flicking the liquid, or just carefully spritzing with a spray can, to achieve a fake (and sub-optimal, vs. a mirror-coated surface) "orange peel" surface.  This sounds reasonable, but I need to buy a plain, legit, replacement Mag reflector first, in case it doesn't work out well.

 As, if, and when, I'll probably make a small post about the success of failure of same.

Thursday, March 31, 2022

patting my younger self on the back (even though he only got a C+ or a B-)

  When I was in high school metal shop, for my senior year project (or one of them, I don't recall) a few of us built belt sanders, from scratch. Now, when I say from scratch, I don't mean we made our own ball bearings or motors or sanding belts.  Don't be silly.  But we did make both the top and bottom pulleys from scratch: we turned them on a lathe after cutting disk from billets we had cast under Mr. Lurie's watchful eye in the shop foundry from recycled cans and VW engine scrap from the auto shop.

 We bent plate steel and stick-welded it to make the frame.  And so on.  That's what I mean by "from scratch".

 It was a pretty dope school project for a high schooler, now that I think about it.

Now, the backing plate which went behind the belt was supposed to be TIG welded in place, because using stick would warp the 1/8" material too badly. No student I ever knew managed to get TIG qualified somehow, so in theory, Mr. Lurie, the instructor, was supposed to do that one weld for us.

 Somehow, he was always too busy working on his airplane project to get that part welded on mine.

 Also, I never got around to putting on any top coat, only primer, because I was busy working on Mr. Lurie's fucking air plane.

 So because it was incomplete, I got either a B- or a C+ for the project (I don't recall which) and it wasn't even my fault!  Oh, I was mortally outraged, I was.  Then I was mad at myself for not seeing it coming.

 But here's the thing; it is now forty years later, and I used that same belt sander again yesterday.  Not a week goes by that I don't use it for something, unless I am sick in bed.  It has been one of the best gifts I ever gave myself.  It is fucking indestructible.

 And it still only has primer paint on it, but I did just order some new rubber feet for it.  I noticed last week that the ones I installed 40 years ago are really showing their age...


<-- the upper pulley holder is just two straps with notches slotted into each other.  A compression spring inside the square tube riser keeps the belt tight.

 You can't hurt the top pulley by using it as a contact wheel, but it's solid aluminum, not soft, so it's not friendly toward delicate work.

  Note crown angle on pulley to help belt stay centered.

 Side shot of top pulley support showing simple construction from .125 x .7 cold-rolled strap.

 Mr. Lurie must have sold us pretty damned good dust-sealed bearings for those top pulleys, because they are still quiet and smooth.

 I wonder how many of my fellow students who built these over the years, kept them their entire lives, all the way into their retirement?

 Hey, we were rank amateurs at casting, and the "aluminum" was a really random mixture of stuff, so there were a few casting defects in our pulleys... but we did use actual top and bottom steel mold casings, "green sand" mix, a wooden form to make the billet, sprues, parting compound, all that.  Pounded the sand in ourselves, and so on.

 In 1976, when I entered Peoria High School, Peoria, Illinois, a student could graduate after taking metal or auto shop for four years, and go straight into a well-paid professional apprenticeship in any number of local large businesses.

 By the time I came home on leave from the USAF in 1981, one year after I graduated, not one of those jobs remained in existence.

 The midwest was a good place to be FROM...

Sunday, March 20, 2022

A Poor-Man's Skyhook

  A few years ago, I suffered some serious muscle strains in my lower back and glutes, which gave me a temporary bout of sciatica and scared the crap out of me.

 The injury happened when I lifted - single-handedly, the twelve-inch Bridgeport rotary table off of my mill table.  It weighs 130 pounds.  Oooops.

 When I recovered enough that I could sit up in a chair in front of my computer again - or stand up, or walk - I started shopping for material handling solutions for this kind of lifting that I could apply in my small, cramped shop.

 The first thing I found was the SkyHook, and to be sure it is a thing of beauty and a joy forever.

 It also costs thousands of dollars, and thats just for the little yellow crane, before you even get into additional accessories like the cart, or attachments to mount the crane post to the tool post of a lathe, or to the t-slots of a mill table...

 Don't get me wrong, I've seen these in action in videos, it is clearly a nice tool if you can afford it, and when this topic came up between me and a good friend of mine who has money, I suggested he buy one.

 But my budget is more beer than champagne, so decided to build one.

 What I will end up with will not be as easy to use, or as smooth in adjusting of the height.  Mine won't have the chain feature (instead of cable) which prevents the load from twisting - a nice feature.  Mine will automatically brake the load, because I am using a cheap electric hoist instead of a fancy gearbox, friction clutch, and handwheel.

 Mine will also cost less than $200 all up, because I already had the cart, the high-weight-capacity expensive casters I needed just - showed up - in the alley one day (I kid you not) the hoist was about $100, and the additional steel bits I need are much less than $100.  In fact, I have all of the steel and parts except the vertical piece of pipe, plus whatever I come up with to go over the pipe and swivel on it (with a thrust bearing).

 The rig will look something like this:

 The jib extends 24" from center, or 12" past the edge of the 24" wide cart.  With some weight in the bottom, I shouldn't need to extend the casters on the hoist end on out-riggers, to lift any tool (or likely work) I can think of - I am unlikely to work on anything that approaches the weight limit of the hoist.

 Some time next week I will run out to my favorite scrap metal yard and buy the vertical bit.  A standard corner post for chainlink fence would be the right material, except that it's heavily galvanized and I need to weld on this, so I need tubing or black pipe.  The good news is that plain carbon steel is cheap, because right now, so am I.

Wednesday, March 16, 2022

cheaper welding gloves, some words on the air compressor mounting, and... can we talk about workbench design & use??

  Welding gloves: the heavy insulated suede ones suitable for heavy stick welding are kinda stiff and fatiguing when you're doing MIG or TIG which doesn't throw much, or as much, slag.  On the plus side, they are cheap - about $20 - $30.

 For those who do not need as much protection, there are nice, lighter-weight, calf-skin or goat-skin gloves with long gauntlets, commonly called "MIG gloves or "TIG gloves" available from welding suppliers for $50 - $75.

 The first time I saw these was when I took an introductory MIG welding class from my local welding supplies vendor (the intro class came free with the purchase of my welding machine) and the instructor was wearing them.  I promptly sought them out.

 It turns out there are IDENTICAL calf-skin and goat-skin "rose gauntlets" available from garden stores and suppliers for $25 - $35.  Perhaps they are not sewn with kevlar thread, but I've yet to care.

 Now then, some final words on how I mounted my air compressor, since I just yesterday finished doing so.  Industry standard calls for some rubber pads between the unit and the floor, but I went a little further, because I was - justifiably as it turned out - concerned about vibration being conducted into the concrete pad of the garage... and thence to my wife's office / treatment room.

 To that end, I added rubber washers between the bolts and the legs, and a second set of pads and rubber washers between the elevation stand and the floor as shown in the photos.


 This turns out to not be overkill at all.  While no vibration is detectable in the cement floor next to the compressor, I found out shortly after installing that resonance in the slab means there are places far away from it where vibration in the floor is quite noticeable.  If I hadn't been a Tesla nut back in the day, it might not have occurred to me to even check.

 That vibration - at the worst point in the garage I could find, which blessedly was not in or near my wife's office as it turned out - was measurably less (accelerometer app on the phone!) after installing the second set of rubber blivets between the riser and the compressor, vs. only having the set between the riser and the floor.

 Locking nuts were used so I could leave the rubber minimally compressed while preventing anything from moving.  The rubber means the compressor can be tilted off vertical by about five degrees, until you run into the steel bolts and washers and it won't move any further for love nor money; the anchor bolts in the floor are set firm.  I am entirely okay with this state of affairs.

 Frankly, the readily-available "industry standard" black rubber pads are much too firm for the weight of my air compressor - softer ones would do a better job of absorbing and dampening out low-frequency vibrations... but they are what's available for reasonable sums of money (about $4ea) and they are an improvement over nothing.

EDIT, much later: cable-type vibration/seismic mounts would not have been overkill for this project, but they weren't in the budget.  Soaking up large-amplitude, low-frequency vibrations is hard.

 And finally, I'm gonna yammer briefly about how my perception and use of workbenches has changed.

  This is the only real workbench I have ever owned.  I still use it to this day because it is an indestructible beast.  However, when I built it, I owned fewer hand tools, and it seemed reasonable to make the back of the bench out of pegboard, so I could hang and organize my hand tools all over it.

 Even after I acquired enough tools that I had to buy a small tool chest - well, it seemed large at the time - it made sense to me to keep the most-frequently-used tools on the bench pegboard where they'd be handy.

 Eventually I needed more storage, and the upgrade path for people with money would be to buy the  rolling cart and two-drawer riser which matched my machinist's chest.  But since those were very expensive, I used a slowly-distintegrating wooden chest of drawers - found free in some rental - for over twenty years.

 Finally that nasty old thing became more of a liability than an asset, so when I received a small inheritance of a few thousands bucks from my mom's old bank accounts, I bought a full-sized (well okay, it's fucking enormous) proper professional's tool box to solve my growing organization and storage problem once and for all.

 And then I moved all my tools off the pegboard and into the tool chest because I wanted all my tools in one place to the extent practical.

 The moment I stared at the empty pegboard and wondered what I ought to do with all that new space, I immediately realized that I wish it to be a magnetic white-board with a hard enamel surface where I could put up drawings and notes, and that this would be TREMENDOUSLY useful, in fact, it would have been more useful than having the tools there all along, but hindsight is a real thing.

 So that's the new plan, when I get around to it, and can find the white-board material already made.  Not a high priority tho.

 One thing I do want to store at the bench - specifically, on the riser shelf above the bench surface - is fasteners.  I'm fairly certain I want to remove the fastener storage currently on the pegboard.  And I'm fairly certain I'm sick of walking back and forth from my shop to the storage drawers in the garage where most of my fasteners are currently stashed for lack of space in the shop.

Saturday, March 12, 2022

sanity-preserving tool #314,159

 These are internal pipe wrenches.  Ever wished you could remove a close nipple from another fitting without destroying the threads on it?  Ever had a pipe snap off at a fitting, necessitating the removal of the short, thin threaded section from the female fitting... somehow?  At minimum this tool solves those two edge conditions for you.

 My general rule on specialty tools is that if I "wish I had", or if I actually need to borrow or rent some tool more than twice in a year (give or take, depending on what it is, how expensive, etc) then I buy it*.  Three times in the past six months I found myself wanting to remove and preserve pipe nipples, and a few years back I struggled to remove a broken pipe-end from an in-situ fitting.  It was time.  They should cost less than $10 each.

addendum, much later: get several sizes. If you get one to work but it's a bit too small, you may find yourself pounding it out of the removed nipple with a vice and a hammer.  Apparently I need at least two more (larger) sizes than the onces I got at a national chain store where I moonlighted a few years back.

*within reason; use common sense and don't quibble.

Friday, March 11, 2022

gland (o-ring) seals: learn from my mistakes

  In my defense, I have only had occasion to design, specify, have made, or made myself, less than half a dozen o-ring sealed anythings in my entire career, either professionally or for my own projects.

 So a set of good habits had not yet been learned, so there was nothing to save me when I got hasty...

 The photo at right is what happens when you don't do a good job of deburring the receiving hardware's entrance (a bit of taper to compress the o-ring into its groove as the parts are assembled is generally a good idea whenever possible) to the ID, or say, screw holes the o-ring has to pass... I guess I'll be replacing this one.  The good news was that my local Ace Hardware had the perfect size in stock for $0.79ea so this was a cheap lesson.

 (Okay sure: it's only sealing against a few PSI of acoustic pressure in the intake muffler I built for my air compressor, so it's probably fine as is, but if you know ANYTHING about me... I couldn't possibly.  Workmanship.)

Tuesday, March 1, 2022

an "adult" project

  Not everything I work on in my shop is boring, ie; industrial or houseware repairs etc.  This project is an oscillating pump (push-pull) for a sexual massage device, it's a DIY clone of a machine which costs over $900 to buy new. O_O

 The pump proper is a re-purposed manual bilge pump for small boats.  I removed the valves, blocked one port, and removed the handle.

 The motor is a brushed DC gearmotor, 1/16 HP, 180V max, 300RPM max.  The original brand name machine uses a 90V Bodine, I'm using a Leeson, both are excellent brands.  Many engineers I know consider Bodine to be the premium/Cadillac brand of gearmotors.  But you will get a very well made, very long life unit from any name brand.  The voltage it runs on doesn't matter so long as you have the ability to smoothly vary the supply voltage with a good motor controller.

 The motor controller I am using is a Minarik (a popular name brand in small motor controllers) XL3025A PWM speed control, but unfortunately, the only one I could find cheap that was even close to useable... had a maximum output voltage of 130V.  Eventually I will want to replace it to get the max speed available from the motor (cheaper than replacing the motor!) but it's not a high priority.

 The proof-of-concept version I built used a $20 "router speed control" (just a basic minimum-part-count dimmer circuit with parts capable of tolerating inductive kickback) together with a full-wave bridge rectifier and a filtering capacitor.  Compared to that lash-up, the professional speed control has much better performance, some fancy capabilities mostly not useful in this application (such as braking or acceleration / deceleration rates), and much longer life / higher reliability.

 I had to machine a few parts of course, notably the crank-wheel and the part where the pushrod connects to the pump (where the manual handle was originally attached).

 The power entrance has a fused receptacle for a standard IEC cord, a power switch, and some noise filtering parts to keep electronic "hash" created by either the motor (which in theory ought to be filtered out by the speed controller) or by the switching of the controller itself.  I'm an amateur radio operator, and all forms of PWM control including light switch dimmers generate so much noise that they cause us "hams" to break out in hives.  I already had the power entrance module lying around with the switch, receptacle, and a common-mode choke, to this I added a CorCom RFI filter as well as a high voltage rated .01uF capacitor which, together with the choke, will add noise filtering AND help prevent spikes from the powerline from nuking my fancy speed controller:

 The more prurient details from projects like this will have to be found on Fetlife if you're into that sort of thing; this isn't that sort of blog. ;D

micro-update, compressor tweaks

 The stainless pot-scrubbers I'm using for stuffing in the compressor muffler finally arrived, and they are half the size of normal ones; "D'OH!!".

 You'd think I were an eBay noob, they totally got me cuz I was tired and rushed and as cautious as usual.  Oh well.  I would need a metric butt-load of them at this size!  So it's back to the other auction from Pakistan for 48 of the damned things for $16, since they specify right in the sale how big they are.  With a ruler in a picture, by god.  Ahem.  Anyway.

 As seen at left, I installed it when it was complete except for the stuffing, and even without the stuffing, the muffler is extremely effective, knocking down the intake port noise so far that the "knocking" of the compressor pump's mechanical noise is louder.  This is good.  The stuffing will just be a tweak, to kill the last bit of Helmholtz resonance in the big tube.  Any further noise reduction will require a total enclosure.  When that can happen will depend on when I get income again.  The original air filter at the bottom could be flipped 180ยบ so it doesn't stick out as far, if I replaced the pipe nipple at the top with one half an inch or more longer.

 Because we are still scraping by on the generosity of family, I'm still agonizing over when to pull the trigger on the air drying components necessary to run the blast cabinet (which after all was the whole point of buying a large and expensive compressor).

 Those bits consist of an aftercooler created from an automotive oil cooler, and a conventional industrial moisture separator installed between the pump and tank.  They will cost about $100, and will remove something like 75% of the moisture from the air before it enters the tank. This means the air entering the air plumbing of the shop will already by dry enough for all routine purposes (tools, mostly) and only a single minimal dying cartridge is required at the point of use for really fiddly applications like painting or a blast cabinet.  I probably won't even need drip legs at the various air drops, but I'll probably install them anyway.

 A desiccant drying cartridge will be installed right at the blast cabinet.  I don't have space for a paint booth, and if I did, I'd install an oven as well as a spray booth, and use powder-coating in the future.  And if I could breathe vacuum, I could flap my arms and fly to the moon.

 Frankly it's killing me to put all of this time, money, and effort into something which was intended to make money for the shop... yet the phone ain't exactly ringing off the hook, and I'm having trouble figuring out how to get the word out to potential customers.  I should change my ringtone to crickets chirping.

 More as it happens...