Tag: Repairs

The hard-floor brush for our old Samsung VAC-9048R vacuum cleaner began scratching the hardwood floor, which called for some investigation & repair. The Fine Manual doesn’t even mention the hard floor brush, so it’s obvious I’m on my own (as is usually the case). Believe it or not, we actually discussed buying a vacuum cleaner, but the new ones have poor reviews, bulky & awkward plastic widgets on the handle, or suffer from other glaringly obvious faults; although this one is aging poorly, it’s at least workable. Plus, I bought a lifetime supply of bags when it was new and it’s not dead yet.

So, we begin…

The rollers that used to support the front of the brush have worn down, allowing the bottom cover to erode on the floor. The right side ran through something sticky in the recent past:

The left side may not be sticky, but it’s in no better shape:

Remove the two obvious screws, pry the front edge up, and the whole cover plate pops off to reveal the two rollers. They pull straight out of the shaft support brackets molded into the top frame. Even their metal shafts show grievous wear:

The rollers consist of a hard plastic hub supporting a flexible rubbery tire, turning on a 3 mm steel shaft that’s worn on one side (which was downward, of course). The central holes in the rollers probably used to fit the shafts, but they’re now worn to 4 mm ID. The tires were probably a lot larger in diameter, too, back when they were new.

A bit of rummaging in the Basement Laboratory Warehouse Wing produced a bag of vibration isolation bushings that had about the right consistency to become tires:

They’re much larger than necessary, but are now, shall we say, fully depreciated and ready for a new, if somewhat downsized, lifestyle.

Unfortunately, they don’t fit onto the existing hubs, so I can’t use the hubs as a template. Fortunately, I have a lathe and some random nylon stock (with crosswise notches that didn’t pose much of a problem):

I came to my senses before converting this into a 3D printer project. If I had to make more than two hubs, it’d be a good idea to solid-model and print them, even if they’re just barely large enough to allow solid infill:

I’d go for a 3 mm ID to increase the wall width; these have a 4 mm ID to fit the brass bushings described below. There’s no significant overhang and they’d print with no problems. Maybe next time?

The isolation bushings cut easily with a sharp razor knife, so I pared them down to a bit over what I estimated to be the finished roller OD and width:

The 10-32 screw in that shiny new hub serves as an arbor in the lathe, where I held a Dremel tool with a sanding drum down on the compound rest, ran the lathe at its slowest back-gear speed, and sanded the bushing down to what seemed to be the right OD for the tire:

The white snout in front leads to a shopvac that caught most of the dust. The front of the lathe chuck shows it wasn’t perfectly effective and I should have worn a dust mask; my glasses didn’t collect much dust, so maybe my lungs didn’t, either.

A trial fit in the floor brush body showed that this one was slightly too large and the sides needed tapering. The inside view:

The outside view, with the cover just slightly unable to snap closed:

Grinding a bit more off produced a pair of 15.5 mm OD tires which fit nicely. Some careful razor knife work smoothed and tapered the sides:

Brass tubes (from the stash of cutoffs) compensate for the flat on the severely worn steel shafts; a fix that turned out to be much easier than building new shafts:

Then reassemble in reverse order and it’s all good!

I wrapped a layer of silicone tape around the large and slightly worn hard-plastic rear tires, even though I’m sure that won’t last very long at all:

The shop doodle giving all the sizes:

Now, if that doesn’t count as a gonzo repair, I don’t know what would… [grin]

So I finally got around to spraying some 10% bleach on an inconspicuous section of the roof (*) to see whether it would have any effect on that black fungus / mildew / crud. It’s too soon to tell, but in the process I discovered that the sprayer nozzle didn’t produce the nice, round pattern it used to. I completed the mission and took the nozzle to the basement. The problem was obvious:

Soaking it in vinegar didn’t have any effect; whatever made those deposits wasn’t soluble in water or mild acid. A few minutes with an awl and a (manually turned!) Dremel grinding point restored it to good condition:

You’d be more careful cleaning the orifice of a fine spray nozzle, but this is for a hand-pumped garden sprayer: Good Enough.

As soon as the weather clears, we’ll see if the situation up on the roof has improved. If so, I get to spray the rest of it.

(*) The whole north slope over the garage, in case you’re in the market…

A few days of high & gusty winds braided the cords of the aluminum fish school wind chime hanging over the end of the patio:

It’s obviously an old, much-repaired relic.

My Shop Assistant added those blue fins many years ago, quite some time after she and a friend lost one of the fish while using them as digging implements. An unmarked replacement fish, crudely bandsawed from black-coated aluminum, began swimming in stealth mode amid the school.

Sometimes it’s not the object, it’s the memories…

There never seems to be a good time to drain your water heater and check the anode rod, but I finally found a Round Tuit…

Pursuant to that comment, I drained a few gallons before applying the six-point 1-1/16 inch socket and loosening the anode rod without fuss or bother. I couldn’t get a good finger grip on the bolt head inside the enlarged hole, but a long-nose Vise-Grip pliers did the trick:

The first look showed a solid bar of corrosion:

You can see the 3/4 inch socket wrench in the background: I didn’t need the breaker bar this time!

The magnesium anode rod corroded down to the steel core wire just under the bolt head:

The entire rod was about half a foot shorter than the new one, but I cannot tell whether that much corroded away or rods have gotten longer (they’ve certainly gotten more expensive):

I sawed the rod to get it out of the heater, because I also wanted to see how much magnesium remained inside the corrosion. Quite a lot, as it turned out, so I suppose I could have reinstalled the rod and left it for another few years:

I don’t know where all the corrosion products went, because the water heater drained uneventfully, without clogging the valve or depositing a pile of crud at the end of the hose. There were a few particles, but nothing like the residue from the aluminum rod.

Then I cleaned off a new magnesium rod, tilted the water heater to get enough clearance, installed the rod with a wrap of PTFE tape, and reinstalled the water supply lines. I suspect the next owners of the place will be looking at it a decade down the calendar…

If I had more guts and less sense, I’d chuck the bar stubs in the lathe and turn off the corrosion to get some nice steel-core magnesium rods. The prospect of extinguishing a magnesium fire in the basement doesn’t entice me in the least.

Long ago, in a universe far away, IBM gave Mary a desk clock as part of that Technical Excellence Award:

The double-stick foam tape holding the plate on the front aged out a few years later, at which point I cleaned off the solidified goo, drilled 2-56 clearance holes in the plate and tapping holes in the clock base, installed four pan head stainless screws, and neatly aligned the slots. That’s what it should have looked like from the beginning; this was, after all, a Technical award…

The clock movement failed recently and I got a drop-in clock insert from Klockit to put it back in operation. The fit wasn’t quite solid, but two wraps of silicone tape around the case under the ribbed friction-fit band solved that problem.

One new movement cost just about as much as the shipping, so I bought a pair with black and white faces.  Mary picked the white face for this clock, which left the black movement as a spare.

Tomorrow: what to do with a spare clock insert.