Thursday, October 30, 2014

Making A Pin Vise

A reader expressed some interest in my pin vise recently. Here's a view of  the vise.

It struck me that perhaps I have a saleable item here -- something that could earn me some money, if I could make copies of it for a reasonable cost.

It's been some years since I made that vise, and I made no record of how I went about doing it. In looking over the vise now, I have no idea how I produced the handle, with its 3/8" - 24 threaded stud implanted, like so.

I have a spare chuck that I can use, so I'll set about making another pin vise, this time with an eye to reproducibility.

A Complication

I have nothing on hand to use for the threaded stud, and the closest I have to 3/8" rod is 10mm rod. I'll have to fabricate a stud with a 3/8" - 24 thread on its end from 10mm rod.

Were I mass-producing vises, I'd want to obtain lengths of 3/8" - 24 threaded rod. That would simplify things a lot. Anyway, here goes with a fabricated stud.

- - -

Here's the stud blank in the lathe. I've just turned down the 10mm diameter to about 0.373", in preparation for threading.

And here's my 3/8" - 24 thread for accepting a chuck.

I'm not a qualified machinist, and I'm sure that shows, but the thread I managed to produce will serve.

Now I have to cut the threaded stud to length, and get it mated with a hardwood handle blank.

- - -

Here's the handle blank just bored for the 10mm diameter stud.

The handle blank and the stud are ready to be mated.

The handle blank and stud together, ready for the handle turning.

The 10mm twist drill working in the somewhat resilient hardwood produced a slightly undersize bore; the stud was a very tight fit in the handle blank's bore. That's both good and bad -- good because it contributes to a tight, strong assembly; bad because the wooden handle may be prone to split. Were I using 3/8" - 24 threaded rod for a stud, I wouldn't have had the problem -- threaded rod's major diameter is normally a little undersize of nominal. If I start making these pin vises using threaded rod, I'll have to epoxy the rods into the handles. As I recall, that's how I constructed the prototype.

Anyway, here's the whole thing chucked in the wood lathe, about to be turned.

And here's the handle turned and sanded.

All-in-all, I'm quite pleased with the outcome.

Since I'm making this to sell it, I'll install a roll pin through the handle/stud, to be absolutely certain that they'll remain securely locked together. Then I'll give the handle a coat of tung oil for a finish.

- - -

All Done -- SATURDAY, NOVEMBER 1, 2014

Here's the finished vise, along with one of the 1/8" x 1" roll pins I installed through the handle/stud.

The chuck's capacity is 1/16" - 3/8". The chuck was installed with blue threadlocker, so it won't loosen in use.

I'll put up an ad for the tool on Kijiji, and see if there are any takers.

# # #

# # #

Saturday, October 25, 2014

Noma Gran Prix Snow Blower -- Fuel Supply Tubing Replacement

The fuel delivery tubing on my son's snow blower looks a little decrepit, so I aim to replace it with new tubing.

It might appear to a cursory glance that replacing the fuel supply tubing ought to be a breeze. It's not. The fuel supply tube is clamped in place at a point underneath the flywheel. The flywheel has to come off to enable tubing replacement.

One is reminded here of the old saying, "If it ain't broke, don't fix it." If I do any harm to the machine's flywheel, I'm going to powerfully wish that I'd left it alone.

On the other hand, if the tubing ruptures while my son is clearing his driveway this winter, I'm going to powerfully wish that I'd replaced the tubing.

On balance, I may as well proceed cautiously with replacing the tubing; it's not threatening to snow yet, so I should have time to deal with whatever may arise.

Replacement Tubing

This is the stuff that's needed.

It's 1/4" (0.250") inside diameter by approximately 7/16" outside diameter reinforced tubing. I get it by the foot from the local small engines repair place.

Tubing Access

Attend to the following:

  • Output Chute Rotation Shaft -- Disconnect its lower end and swing it out of the way to enable heater box removal.
  • Heater Box -- Remove it.
  • Primer Tube -- Disconnect it from the carburetor.
  • Throttle Control Plate Assembly -- Remove it. Note/mark which hole the governor link connects to.
  • Electric Starter Drive Entry Cover -- If there's no electric starter, there'll be a small cover where an electric starter's drive would enter the cooling shroud. Remove it.
  • Locomotion Ratio/Direction Control Rod -- Disconnect its bottom end and let it dangle. (1/2" hex nut; 7/16" ball-stud hex.)
  • Cooling Shroud -- Remove it. (7/16" and 1/2" socket wrenches.)
  • Starter Clutch Cup -- Remove it. (15/16" socket wrench.) Put the nut back on the shaft part way, so the flywheel can't tumble when you break it loose.)
  • Flywheel -- You have clearance to get a 6", three-jaw puller in place, like so.

Hook the puller's jaws under the outboard rim of the flywheel, not under the starter ring gear.

Try to position the puller's jaws so they're directly opposite cooling fins, as is the jaw in the above photo. You want the puller to be acting on the strongest possible points on the flywheel's rim.

Tighten the puller, and whack the puller's screw head with a club hammer. If the flywheel doesn't break loose right away, keep tightening and whacking until it does.

With the flywheel off, you have easy access to the retaining plate that clamps the fuel delivery tube in place.

Two 3/8" hex head screws hold the plate in place. Remove those and the plate, and nothing is in the way of  replacing the tubing run.

The short, vertical length of tubing from the tank to the shut-off valve is 1 1/2" long. The long, horizontal length of tubing is 14" long.

The tubing is a snug fit at all the nipples, but it's especially snug on the fuel tank's outlet nipple. A little WD-40 on the nipples makes the tubing easier to install.

# # #

# # #

Sunday, October 19, 2014

Just For The Heck Of It, Let's See What's Inside

The power supply in my wife's desktop PC died recently. Here's a view of the corpse.

Decades ago, one could earn a living by repairing things like computer power supplies. Outright replacement cost of such items was fairly high, so it was worth a man's while to be conversant with their innards, and equipped to diagnose and correct their failures.

Those days are long gone. Replacement cost is now so low that it's not worth a man's time to take the cover off such a thing for a look inside. But, since my time is worth nothing, I can pursue futility all day long if I choose to, so let's take a peek.

Hmmm. It's a wonder to me that a thing of such complexity can be manufactured and retailed for about $30.00 CDN. I couldn't purchase a small fraction of its components for $30.00.

It doesn't photograph well, but there's evidence of one transistor that's blown its top, and other nearby items that are scorched.

So there we are -- one more addition to the landfill site or the scrapyard, and China can sell one more new power supply. The wheels of commerce still turn, but they roll right by the likes of me. So it goes.

# # #

# # #