The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Tag: Improvements

Making the world a better place, one piece at a time

  • Tour Easy Rack Mounting Hack

    Photo 1 - Spherical Washer
    Photo 1 – Spherical Washer in Action

    A recumbent’s comfy seat doesn’t have a seat post, so standard rear racks don’t fit very well. The usual solution involves nylon cable ties and some cursing, but that just didn’t appeal to me. Here’s how I mounted an ordinary JandD rear rack on our Tour Easy ‘bents.

    Because both the angle and position of the seat support struts changes change with each seat adjustment, you can’t simply bolt the rack to a plate across the struts. This is a job for spherical washers, as shown in Photo 1, which allow both angular adjustment and rigid mounting.

    Photo 2 - Rack Mount Parts
    Photo 2 – Rack Mount Parts

    Even if you’ve never heard of a spherical washer before, your bike parts box may already have some: one old brake pad provides the two washers you’ll need for one rack. Each washer has one convex and one concave piece, which you must assemble with the curved surfaces nested together and the flat sides out. You need one washer on each side of the angled plate. The six spherical washers in Photo 2 show the details.

    You’ll also need a ¼x½-inch rectangular aluminum bar long enough to span the seat support struts just in front of the rack, three 10-32 or 5-mm stainless-steel machine screws and washers, and a pair of padded tubing clamps. You can get all that from your favorite home-repair store.

    Drill a hole in the middle of the bar and a matching hole in the middle of the rack’s front face. I used a 10-32 tap to put threaded holes in the rod, but you can drill clearance holes and use nuts.

    Photo 3 - Mounting Screw
    Photo 3 – Mounting Screw

    Put a spherical washer on a screw, insert the screw through the rack, add another washer, put the screw into the crossbar, align the crossbar on the seat struts, and finger-tighten the screw. Photo 3 shows the screw from the top of the rack.

    Slip the tubing clamps on the seat struts as shown in Photo 4, mark the clamp openings on the crossbar, remove the crossbar, and drill the two holes.

    Photo 4 - Bottom View
    Photo 4 – Bottom View

    Reassemble everything, apply Loctite to the threads, and tighten the screws. Remember to loosen all three screws before you adjust your seat position!

    I wrote this a while back for the late, lamented Recumbent Cyclist News, but it never got into print. I found the files while looking for something else; seems like this might be useful to somebody.

  • Changing the Xubuntu 8.10 GDM Login Splash Screen

    OK, this is frippery and I admit it, but I vastly prefer my login background to theirs…

    My GDM background
    My GDM background

    The right way to change the background is to create a whole new gdm theme and then fiddle gdm to use it. Easier than that: tweak an existing theme’s XML file to point to your image.

    The default Xubuntu theme for gdm is in /usr/share/gdm/themes/xubuntu, so cd there. This is a command-line thing …

    The background is stored in, oddly enough, background.png, a 1680×1500 image that doesn’t mind being stretched or cropped or smushed to fit your screen.

    Copy your favorite background image to that folder, perhaps renaming it on the fly:

    sudo cp /path/to/my-new-background.png danger.png

    I don’t know if JPG images will work, as I just saved that screen capture as a honkin’ big PNG; knock yourself out trying other formats.

    Adjust the first stanza in Xubuntu.xml to point at the new background file:

    <!-- background -->
−
<item type="pixmap">
<normal file="danger.png"/>
<pos y="0" x="0" width="100%" height="100%"/>
</item>

    Squash the Xubuntu logo (in logo.png) so it’s not so obtrusive and move it out of the way of the background text. Modify the stanza that displays the logo file:

    <!-- ubuntu logo -->
−
<item type="pixmap">
<normal file="<strong>logo.png</strong>" alpha="1.0"/>
<pos x="<strong>50</strong>%" y="<strong>70</strong>%" width="scale" height="<strong>10%</strong>" anchor="n"/>
</item>

    Log out. Enjoy…

    FWIW, replacing the background is far easier in KDE (3.x, at least), which has an actual GUI interface (System Settings -> Advanced -> Login Manager). But, of course, KDE 4.x is on the outs with this dual-screen box.

    And don’t you love those Beware Static Damage warning stickers on the Nostromo’s scuttling control panel?

    Default Xubuntu GDM background
    Default Xubuntu GDM background

  • Vital Browser Addition: Readability

    Short version: Go there, read about Readability, set it up, and browse happily ever after.

    Longer version: Readability chops away all the overdesigned Webbish crap around the text you want to read, reformats it in a single block, and lets you read without distractions.

    My configuration:

    • Style: Novel
    • Size: Large
    • Margin: Narrow

    I put it as the top bookmark in the sidebar, where I hit it rather often.

    It also works well for printing: nytimes.com articles now print quite legibly in four-up mode, which saves a ton o’ paper.

    Bonus: you can even print those pesky blogs that don’t print in Firefox.

    Minor disadvantage: if you want to print a whole article, you must get all the text on a single page. Some blogs / news outlets don’t let you do that, for reasons that should be obvious when you consider how nice Readability is.

    Just do it.

    You should, of course, be using the Firefox Adblock Plus Add-On to quiet your browsing even more. There used to be an ethical question about using ad-supported sites while running ad-blocking software, but that seems to have died out with the advent of pop-up/pop-under ads, animated GIFs, and relentless Flash junk.

  • Vanquishing the Power Vampires

    Every gadget comes with its own battery charger wall wart, every single one of which dissipates a watt or two even when it’s not charging. Add ’em up, multiply by $2 per watt per year (check your electric bill; that’s closer than you think!), and realize that you could afford some nice new tools just by unplugging the things between charges.

    But that’s too much trouble and, really, AC outlets aren’t meant for that many mate/unmate cycles. I had one contact fall loose inside a power strip a while ago and the carnage was spectacular.

    What to do?

    Recharging Corner
    Recharging Corner

    Find an otherwise unoccupied flat spot (or build a shelf near an outlet), buy two or three Power Squid adapters (you don’t need surge suppression for this assignment, so get ’em on sale cheap), plug all your chargers into the Squids, and turn everything off with a single switch when you’re not charging anything.

    Bonus: You certainly have some low duty cycle power tools that always have dead batteries when you need them. Plug ’em into the Squid you use most often for other batteries. That way, they’ll get a boost whenever you charge something else, which should keep ’em up to speed.

    I set this tangle up before Power Squids existed, so I just plugged a bunch of Y-splitters into an ordinary power strip. It makes for a fearsome tangle of cords, but at least it’s out of the way atop the never-sufficiently-to-be-damned radon air exchanger in the basement.

  • Pocket Camera: Griptivity Thereof

    Casio EX-Z850 and homebrew case
    Casio EX-Z850 and homebrew case

    I carry a small camera with me at all times and find it invaluable for recording details and documenting events; now I never say “I wish I had a camera!”

    This one is a Casio EX-Z850, which trades off nearly everything in favor of compact size. It has great battery life, enough resolution (the optics could be better), and manual controls (so it serves nicely as a microscope camera). It’s obsolete, of course, but you get the idea.

    I have bigger & better cameras, but this one is always with me and that counts for nearly everything. The camera in a cellphone or PDA is not the same as a real camera.

    Unfortunately, the thing has the griptivity of a bar of soap: all stylin’ metal and plastic. The black nubbly surfaces in the photo are my idea of a Good Thing: chunks of stair-tread tape providing enough traction that the camera no longer flies out of my hand with the greatest of ease.

    Despite that, I always slip the lanyard over my wrist when I take it out of my pocket; often I do that before removing it from the case. That nervous tic saves me the cost of a new camera about twice a year.

    If your camera fits into a desktop charging / USB cradle, as this one does, make sure you don’t stick the tape where the cradle fits against the camera. It’s really tough to peel off after the adhesive sets up…

    Mary made that nice packcloth (she says “Cordura“) case, with a fuzzy fleece liner facing the LCD panel. The hook-and-loop closure is a tad noisy in quiet places, but it’s better than buttons or a zipper for this application.

    I’ve learned to not keep tissues in the same pocket as the camera.

  • Sherline Collet Extractor Pusher

    Sherline taper / collet tool pusher
    Sherline taper / collet tool pusher

    After a while you realize that whacking the drawbolt to extract a tapered tool or collet can’t possibly be a Good Thing for the spindle bearings, particularly on the 10k rpm head. So you need one of these, a low-effort / low-skill version of the beauty described in Sherline’s Tip 15.

    It’s basically a length of all-thread rod with a nut epoxied on the top, a nut soldered to a sleeve that locks to the spindle, and a brass tip epoxied on the bottom to push the taper out.

    Drill a suitable hole in the nut for a steel rod, add heatshrink tubing on both sides so it doesn’t fall out. If you’re clever, you’ll make the rod short enough that it fits in your tool tray along with all the other itsy-bitsy tools and parts.

    Bore out a steel cylinder to clear the top of the Sherline spindle and drill a small hole to exactly match the hole in the side of the spindle. Turn down the end of another nut to fit inside the cylinder and silver-solder them together. Maybe epoxy would work here, too.

    Find or make a steel locking pin that fits the small holes, make a cute handle for it, press in place. Take some care that the handle radius clears the headstock pulley. It’s a very good idea to have a much better fitting pin than I started with; a too-small pin will goober the top edge of the spindle hole. Ask me how I know…

    Turn the end of the all-thread down to a little post, drill a slightly larger hole in the brass tip which you turned to fit down the spindle bore, goosh together with epoxy. Hint: spin the cylinder on the all-thread before epoxying the tip in place.

    To use:

    • Remove drawbolt
    • Spin cylinder up the all-thread a bit
    • Insert extractor in the spindle
    • Line up small holes, insert locking pin
    • Insert tommy bar in spindle
    • Turn the extractor handle & hold the tommy bar: don’t torque the locking pin!
    • Cup your hand under the cutter to catch it before it hits the part / table
    • … profit!

    This goes a lot faster than it sounds and feels much nicer than beating the crap out of my precious Sherline head.

  • Sherline Y-axis Leadscrew Bushing

    The far end of the Sherline Y-axis leadscrew isn’t supported, which really doesn’t matter much because the motors can’t drive the screws all that fast. But, if you’re like me, you think about dropping something heavy on the screw and maybe bending it just enough so it doesn’t work.

    What to do?

    Sherline Y-axis leadscrew bushing
    Sherline Y-axis leadscrew bushing

    The next time you replace the bellows covering the leadscrew, add a scrap of plastic with a suitable hole bored in it. Measure your leadscrew (metric & inch diameters differ!), poke a hole with enough clearance to make you happy, then cover one side of the block with double-stick tape.

    Run the Y axis to about 30 mm from the far end, unbolt the motor mount, slide the table forward, put the bushing on the screw, slide the table back, affix the bushing to the column, screw the motor mount in place, and you’re done.

    If you’re really fussy, make sure the bottom of the plastic block bears on the frame, but that’s in the nature of fine tuning.

    This will cost you a bit of precious Y-axis travel, but the bellows need about that much space to fold up and you’re not losing much more than you already have.

    The end of the X-axis leadscrew isn’t supported, either, but you can’t drop anything on it.

    Sherline hot-rodders with super-fast high-torque nitro-breathing motors run the risk of bending the leadscrew by having it whip around, but that’s a whole ‘nother subject.