Stormy Weather and a moose

Yesterday we had the worst snowstorm of all the winter. In April, no less. It dumped 30 cm of snow, or one foot if you prefer, in the course of a day. The Weather Service was right on the ball (this time) and called it with ample warning. This morning I looked out my front porch.
The mountains in the foreground are caused by snow sliding off the roof. When it does so it makes a noise very like an earthquake. Ouch -- but it is just snow. The snow is right up to the level of the porch railings. The temperature at the time of the picture (8 AM) was about 1C -- above freezing. So the snow is wet. Grrr. I went out and started my snowblow routine, and sure enough I had great difficulty. Wet snow is terrible. The machine, heavy though it is, can't get traction. I need chains for the snowblower. Sigh. I worked two hours, by which time I was exhausted and had done maybe 20 meters. Only 150 (?) to go. I must get the GPS out and measure my driveway. Tomorrow we will go again. Just like January. Such is life in the Alaskan bush.

While I'm here, I might as well post a moose picture.
This guy -- I assume it's a guy because (a) it is very large and (b) it has no offspring in tow -- was munching near the airport, twenty meters from the Parks highway. I love moose. But don't get too close to them. They could get upset with you and tromp you to death. They weigh far more than us humans.

Nuts!

In the last episode, we had made a screw. Now we have to make a nut, in the greek manner. According to Hero, the greeks split the nut -- but I am getting ahead of my narrative. The nut should be bored to the inside diameter of the thread. Let me see, 16mm outside (OD), 2 mm depth of thread, so that's 14mm. I do not own a 14mm drill, so the first job was to bore the 14 mm hole on the Taig.
You may say this is cheating. Use of power tools! But if I hadn't done it I would still be waiting for the 14mm bit to arrive in the mail. Boring is a very accurate way to get a given diameter hole. You put a boring bar in the tool post, and you can adjust it to the nearest thou -- .001" or .025mm. The nut is held in the 4-jaw chuck. OK, we have a nut blank. The greeks then split the nut in half. They rubbed lampblack on the crest of the bolt, and then made an impression on the nut. Fortunately my kerosene lanterns needed cleaning, so I had an ample supply of lampblack.Because the nut is 14mm and the OD is 16, we can't get an impression anywhere except the edges. But that's OK, we can pencil in the threads. Now we have to chisel out the valleys in the nut. This proved to be very difficult. It's all end grain, notoriously difficult to chisel. I was reluctant to call mission control in Houston.
So I decided to take a break and look ahead to the next step, using a chase to cut threads. Using some old files, duly annealed, I filed up a pair of chases, one inside and one outside. For the inside one, I drew up a paper pattern, pasted it to the chase, and filed away. 4mm pitch, 2mm depth. For the outside chase I used the inside one as a pattern.
All my learned books recommend a much smaller pitch than 4mm. But it is very difficult to file say a 1mm pitch without a microscope and a set of very small files -- actually, I have some; jeweller's files or swiss pattern files. Still difficult. The old file, horizontal in the picture, is the inside chase. It is used to cut the inside thread, as in a nut. The vertical old file is the outside chase. Now, chasing is in the future, but as it turns out, the inside chase came in handy.

I finally broke down and called mission control. Houston said "use your burins, dummy! Out." Oh. Thank you, Houston. Last year I was experimenting with carving stuff on endgrain, and I made two or three burins for the purpose. A burin is just a very narrow chisel with a lozenge edge, used to cut endgrain! Brilliant, Houston. So I dug out the burins and used one to cut the beginning of the thread. Once the thread was established I could use the inside chase to widen the grooves.
In the still life above, the burin at the top and the chase next to it. You can see the half-nut scooped out with the chase, and all we have to do is the other half of the nut. Once you get a good fit, you have to glue the hut halves together. I suppose the greeks used a band as well, since I very much doubt they had any Elmer's glue.

In another episode we will look into my adventures in chasing threads. This looks difficult, and it it is. But I have hopes. Stay tuned.

The Taming of the Screw

After making the Doctor Buggy, I was at a loose end for a day or so. It may be March, but there is plenty of snow on the ground. I observe signs; for example the parking lots in Willow are melting. Liquid water seen! However, if you try walking out at my place you will be up to your knees in snow. Can't ski on it. Soo-- what to do next? The answer was provided by a Swedish blog -- all about slojd, a Swedish word, usually translated as "craft." In the blog, the cutting of threads is discussed. Now, cutting threads in wood is a fascinating subject. There are all sorts of ways to cut threads. This is because the lowly screw, available for pennies at the hardware store, is a supremely useful object. My idea is to try all of them, except for a screw-cutting lathe, which is rather expensive. Let's go back in time, as far as we can.

We start with the Greeks. As we all know, without olive oil the entire greek civilization would have never gotten out of caves. Modern Greece would come to a crashing halt as well, if deprived of good old olive oil. But to make OO, as well as wine, you need a press. The press is best operated by a screw, because, you see, a screw is an inclined plane wrapped around a cylinder. This gives you both mechanical advantage and control. Hero (of Alexandria), year 100 AD or so, described the screw-making process very well. And Bergeron, in his 18th Century Manuel du Tourneur, does the same thing. The Chinese, who seem to have invented almost everything, did not get around to the screw till the time of Bergeron. So how did the greeks (and I) make a screw with only primitive tools? Well, we start with a wooden cylinder and a piece of paper.

The wooden cylinder is a piece of lilac 16 mm diameter. The piece of paper has been cut 4 mm wide. This is the pitch I picked for my screw-to-be. The pitch of a screw is the distance the screw travels in one complete (360 degree) turn. I pulled 4mm out of a hat, but I was aware that if it was too much finer I would have trouble with the next step. And I used the Taig lathe to turn it down -- I can adjust the diameter down to better than 0.1mm in wood. But I could have done it on a pole lathe or used a rounder plane, so this is no big deal. If you try this at home, and have no lathe, go buy a dowel at the hardware store. For a first attempt 25mm would be better than my 16. When cutting paper I found that a knife and a steel ruler are much better than scissors.

OK, now wrap your piece of paper around the cylinder. Hold it down with tape.
Since the ancients had neither paper nor tape, I conjecture that they used leather and thongs. Now this wrapping business is critical to the future of your screw. (A posteriori wisdom). If you leave gaps or if you wrap too tightly, the pitch will be irregular. Bad news. The ideal is to leave one saw width between the wraps, because the next step...
...is to take the thinnest saw you have and cut down between the wraps. Above, I have put a piece of tape on my faithful miniature Dozuki to make the depth of cut. The tape has come adrift. Tape does not stick to wood very well. Masking tape works better than "scotch" tape. If we were careful, we have a spiral groove running down the cylinder. How deep? Well, that's another parameter in the screw business. I used a nominal 4mm which came down to about 2 mm when I got through. I will explore this aspect of screw lore anon.

Now, your saw cut is the valley, or the trough, of your thread. The middle of the unsawed portions is the peak, or ridge, of the thread. So you take the appropriate chisel and cut down from ridge to trough. In my 16 mm screw, I have to use a microforged miniature chisel.
More after-the-fact wisdom: turn a stub (about the depth of thread) on the front of the screw. It holds the tape, and is a guide of how deep to chisel. This phase of screw cutting is not at all difficult, but it demands care and can get a bit tedious. At the end:
We have a respectable screw, if not a perfect one. This screw is a "demo" since I stopped to take pictures as I went. If this screw was for decorative purposes we'd be through. But it isn't. So the next stage is to make a nut for the thing to turn on. Making nuts the greek way is quite a production, so I will leave it for the next post. Again, if you were trying this at home, a larger diameter would be helpful. Not so much eyestrain, and small chisel errors don't hurt so much.

But I think that this screw-cutting business is fascinating. We have to look at chasing, taps and dies, screw-copiers, screw-cutting lathes, -- almost endless! Until next time, happy screw cutting.

Driving me buggy!

"I have wheels, Houston, and I have running gear. What do I do next, over?" Houston obligingly answered, "bodywork, dummy! Out". Much obliged, Houston, you're quite right. So it's time to make a buggy body. The dimensions are no sweat. We have the cardboard model, remember? But the wood is another matter. We could cut rear end out of solid wood, but however we look at it we are going to need thin sheets about two mm thick. So we saw them out, and then plane them. This was actually the most time-consuming activity of bodyworking. I did not buy so much as a toothpick for this model.
Above, the rear end is being glued up in my homemade clamp. Woodworkers, regardless of scale, will all agree that you can never, never, have enough clamps. The one above is a bit large, but perfect for its purpose. Next we glue and pin on the front end. For pins I use thin wire, #22 I think, and drill the holes with a jeweler's drill.
There are quite a few clamps in operation. The toolmaker's clamp, along with the jeweler's drill and bits to suit, are available from Lee Valley, my favorite tool place.

Now comes the wheeling, so we put the wheels on the running gear.
I have dowel axle pins put in. There are also wire pegs sticking up. These are to match the springs. Amazingly, the buggy is attached to the running gear only by springs. So I had to make the springs. These were made out of an old bandsaw blade, annealed, teeth ground off, formed around a block, and wired together. For this wire, I use the kind of wire that holds lettuce together at the supermarket. Free with my salad. Strip off the paper and there you are. You can just see the springs in the next picture.
The springs, "elliptical" they are called, are being held in place by even smaller toolmaker's clamps. This whole business is all about clamps. I could not deliver the buggy that way! So I made a nut out of a piece of very thick wire, courtesy of Mat-Su Electrical co-op; they left about a foot of cable lying around after wiring up somebody; I pounced on it, cut off a little section, and laboriously drilled a Morse #70 hole through it; then I forced it on to the wire, and it acts as a nut. So then we attach the wheels permanently, with pins (they can turn); we carve out a seat, put on the rear deck, and ta-da (music, please, Houston! Thanks):
The Doctor Buggy is complete. Much remains to be done on this tableau. We need a horse, for instance, to draw the buggy. And the harness, and the shafts. We need a doctor to drive the buggy! We need a nurse and at least one patient. But this is a long-tem project. Making models is fun. I still have a lot to learn about wheels, for instance. But for the moment it will do very well. I wanted to put steel tires on the wheels, but had no suitable steel on hand.

ChalupyLeaks: The Doctor Tableau

The recipient of the secret project is now aware of my intentions, so all can be leaked. The project (which will take a long time, spring is here) is a tableau for my doctor. I am transposing (translating?) her practice back to the year 1910 or so. Now, the first thing a doctor would need in 1910, in rural practice, is a Doctor Buggy. In those days the doctor went to the patient, not vice-versa. I did my homework and learned a lot about carriages. There are all sorts of styles. There are phaetons, victorias, sulkies, dogcarts, landaus, coaches... the list is almost infinite. But the favorite vehicle of the rural doctor was a Doctor Buggy. Much to my surprise, you can still buy these things, in full size. Some restored, and some new. Some people are still building buggies! Of course, you need a horse to go with it, but provided you can feed Dobbin in the winter you are immune to gas prices. Here is the prototype:
I shamelessly stole this image off the 'net. Handsome, isn't it? If you google on "doctor buggy" you will be overwhelmed with images. Note that the front wheels are definitely smaller than the rears; why this may be I wot not. It caused headaches.

So now the question is how to build this thing. In everything I read, not one dimension was mentioned. Scale drawings not possible. So I went about this another way. I built a cardboard prototype, with barbecue skewers for the wooden parts. Here is version 0.0:
Now you know what the wheels are for! My next step was to unearth the Amazing Skeletor. I have mentioned him before. He is a barbecue skewer-and-wire mannequin, to a scale that all my tableaux follow. It is about 30:1 -- 1 unit tableau = 30 units full size. Why? I dunno. I feel comfortable at that scale. It is very small by model-builder's standards, who like 20:1 or 24:1, or 12:1. When I put Skeletor in the driver's seat, it was obvious that the ramp between seat and front was much too large. Nice thing about cardboard, you cut it with scissors and paste it up. After some experimenting, we came up with v1.0:
Ahhh. Sleletor looks quite comfortable. By george, we've got it! The next step was to build the chassis, or "running gear" might be the proper term.
Compared to the wheels, this was the proverbial piece of cake. But the front axle swivels, just as in the prototype. Note the piece of wire sticking out of the front axle. This is where the spring fits in. (It is also the swivel for the front wheels.) If you look at the prototype, you will see that the body is attached to the springs and the springs to the running gear. It is a suspension, in fact, with no shock absorbers.

Making this buggy was a two-month job. So I will split the posts on it. The wheels took by far the lion's share of this odyssey. The bodywork was much easier, and I'll post it later. And I'll tell you about the springs, which were much harder than I had anticipated. This is because proto-buggy, v1.0, has springs bent out of beer can material. Very easy to bend. Lots of flex. Not so steel! So stay tuned for Doctor Buggy, episode II, on this channel.

Liquid water!

Today I got out and visited a couple of parking lots. To my utter amazement I spotted a puddle of liquid water in each parking lot! Furthermore, the temperature was +4C! As we know, that is above freezing, so it should not really surprise me; but it did. This happens around the time of the equinox, which according to my calendar ocurred on the 20th of March. Just a little after the Ides of March, fatal to Roman Emperors. Not being a Caesar, I did not worry much about the Ides. But could this be the harbinger of the long-awaited breakup? We had a long succession of very cold days in March, -20C in the morning, although it did get up above zero in the afternoon. The barometer was sky-high, 1040 mb and steady. But about a week ago the high dissolved. Temperatures rose. Clouds came, but no snow. I tried asking that well-known bird of omens, the raven, what this meant. Raven said: "cark!" Very difficult business, soothsaying. I wonder what cark means in Raven. At least Raven did not say "nevermore!" Plenty of snow on the ground still, although it has compacted down to about 50 cm. Well, we will have to see.

About this time of year everyone in Alaska is fed up with winter. Can't ski, too icy. The lakes will be too dangerous to walk on soon. Bicycling is downright dangerous. So it's walk on the roads. but at least it's warmer. And then comes breakup, mud everywhere. As I have said before, such is life in Alaska.

And the secret project is ready to be revealed. But I am a bit too tired today, so stay tuned.

Handy Bandy

I am at the end game stage on the secret project. All will be revealed very soon. But in the meantime I have acquired a new tool, a portable bandsaw. He has been named Handy Bandy. Handy is an asiatic tool. I got him for cheap at my favorite pawnshop, brand-new.
I had two things in mind when I acquired Bandy: winter use to hack out carving blocks and all the things I have to do this summer. Bandy is a weird contraption. The blade is twisted 50 degrees from the vertical (or horizontal depending on what you take for a reference). The boade actually twists by that amount. The instruction manual borders on the pitiful. No, it is pitiful. It is written in English, and its syntax is impeccable. It is the information content (none) to which I object. The net is not much better, it tells you how to cut pipe with a portable bandsaw and that's it. But what I want to do is rip branches anywhere up to 10cm diameter into rectangles. And indeed I have, witness the slab at the left of the picture. It took about five minutes -- it is an hour's worth of ripping by hand. Somehow, in spite of my hatred of power tools, I find this might have its advantages.

Of course, I started out macho freehand. None of these snapped chalk lines for us. Just press the trigger and go. The saw will immediately jam up against the work on the left side. It is very powerful, Superman would have his hands full (or, if you prefer, Wonder Woman would have her work, so to speak, cut out for her). After a while, I found out that the strangely shaped piece of steel in the plastic bag, along with two anonymous screws, is a blade guide. It gives you a reference. The blade on this saw has a weird twist, 50 deg. per "manual." The blade is actually twisted by that amount. The guide also helps you keep the saw sliding along the work. So I screwed the guide on. The saw is still a difficult customer to control. I persevered -- and then the blade stopped. Motor ran, but blade did not.

So I took Bandy apart, and found some weird stuff. Bandsaws have two wheels, the tractive wheel and the idler wheel. They also have guides, thrust bearings, and other stuff. The wheels and guides were immediately recognizable. But the wheels are sections of a cone. This is all due to the fifty degree twist in the blade. None of this stuff, except the tension, is adjustable, as far as I can tell. Oh yes, and the "tire" had come off one of the wheels. The tire is a rubberlike belt on which the blade is pulled. So I put it back. I cut some more wood, and it jammed up again. And again.

So now I have to figure out how the tires are put on the wheels. On a real bandsaw they are either cemented on (old-fashioned!) or made out of some stuff that you boil in water and expand. Then, while hot, you slip it over the wheel. When it cools, it by George will stay put. Shrink-wrapped, in fact. This saw is none of the above. But the tire has a skirt. I suspect the skirt has to be pinched by the wheel. Tomorrow I will have to take the wheel off. It is held by an Allen bolt. So we will see if the anonymous Allen wrench that came with this device will fit it. If it doesen't I have all kinds of Allen wrenches in the shop. But that's the ice axe and snow shovel to get in!

Meanwhile, I have found out that the way to rip is vertically. Clamp the piece in the workmate and saw straight down. However, you have to take off all knots, limbs, and protrusions on your left side with an axe. Else the saw jams against them. We all learn by doing. Stay tuned to the further adventures of Handy Bandy.

But why in Hades did they twist the blade fifty degrees?????