Wednesday, November 30, 2011

Repoussé, s'il vous plâit

Repoussé is a French word meaning, perhaps, "repushed." It involves beating sheet metal into useful forms. Usually copper or brass is the victim. The tool of choice is called, unsurprisingly, a repoussé hammer. Now these hammers are not hard to come by. In fact, in a pinch, you could walk into your local auto parts shop and find a body and fender-beating hammer. If they have a small one you are in business for under twenty bucks. After all, beating dents out of fenders is in fact repoussé, so it is not surprising the tools are the same. In fact, I own one; $16 at NAPA auto parts. Much too big for what I want, though. I'm the miniature dude; in winter at least. So I decided to roll my own repoussé hammer.

We started with a piece of cylindrical steel, probably a broken socket wrench handle. I think I found it somewhere. We put it in the lathe and used a parting tool to cut it to the proper length. Five minute's work with a hacksaw confirmed that hacksawing is not the way to go. Tough stuff. Even so, it is very difficult to part off on a lathe. Even the super-guys in Model Engineeering magazine quail when parting-off time comes. But eventually we got out a usable piece. We then turned it to shape in the lathe.
The diameter of the poll is about 15mm. I did not take one measurement in the entire process; all done by eye, Very liberating. Above I am turning out the poll end of the flattener, This is actually an ex post facto pic; that is why the tool is retracted so much. But note the chuck whirling about. Do not get your fingers anywhere near a spinning chuck. If you do, you will lose some fingers.

With the form of the hammer established, the next job is to drill out a slot for the handle. Toughest part of the project. Ideally, one has a milling machine. With this and proper tooling, one can cut slots at will. I do not own such a machine. So we do it the hard way, on the drill press. I could not figure out how to hold this piece on the milling attachment on the Taig lathe.
We want to drill a 10x5 mm slot. More or less. Ideally we would drill overlapping holes. Then we could get rid of the extraneous material by filing. The trouble with drilling is that the drill wanders. It looks very rigid when you take it out of its index box. But it isn't. It will bend as much as 2-3mm and that is a disaster. That is why you center-punch holes for your drills. The center punch makes the drill bit fall into the center punched dimple. This was a real ordeal; but eventually I got it done. Next job was to fit a handle to it. I had a convenient piece of alder lying around. So on it went; a matter of whittling, nothing more.
And there's my repoussé hammer. Ideally the thinner end, the one to the left, would be domed, i.e. spherical. But doming is a matter beyond my simple equipment. I will file it some; but still, not bad for one day's work; spread over two days. The piece of copper lying on the bench hook is the hammer's first victim. It flattened out in no time!

Once again in the land of ideals, a repoussé hammer should have a "whippy" handle. Yeah, well. Maybe next summer I'll fit one. Right now everything is frozen solid.

Saturday, November 26, 2011

A tree falls at Chalupy

We have had, as my son would say, a November rich in weather events. 60 cm of snow. Then some very strong winds. Then more snow. The winds, however, caused several trees to abandon their roots and succumb to the lure of gravity. So, in my driveway, due to Murphy's law, I found a hung-up aspen. By good fortune, it hung up in a willow tree and missed taking out the shop roof. So it had to be removed. John did the dirty work, or most of it. The first thing was to prop it up so it would not crash to the ground, crushing the removers of the tree.
We used a stepladder to prop it up while John sawed it loose. All the cutting was done with my faithful handsaws. On a job like this, were you to use a chainsaw you would be cutting above your waist and that is very dangerous. Old-fashioned handsaws are indicated.

Next job was to cut off the hung-up portion of the tree.
Can't see the shop roof in the picture, but the tree is brushing it. Once we (John, actually) cut off the forks, the tree was ready to pull out. Now that piece of tree must weigh 300Kg, much too much for two people. Here's where machinery comes in.
I carry a long chain, about 5m, in the car; attach this to log and car, and drive forth. Tree came loose smoothly...
and we muscled it off-driveway.

Dealing with hung-up trees across your driveway is a common Alaska winter activity. Several things come to mind, should you ever have to do this. One is that a chainsaw is very dangerous when you cut above waist level (actually it is always dangerous. But using it high above ground is really, really dumb). Another thing you must remember is the way the tree is going to sag when you cut it. In this case, when you cut from above, because it is hung up it will eventually pinch the saw. You then must underbuck, that is cut from below the tree, cutting upwards. It takes some skill to meet the top cut. This is true whether you use a chainsaw or do it by hand. Finally, when it comes to pulling trees, use a vehicle --- tractor, truck, car --- to do the pulling. A big tree weighs a ton. Literally. Don't try to move it by hand, or if you must, invest in a Peavy.

More snow forecast next week. Blew out the driveway again today; snow over Thanksgiving. Not much, though.

Saturday, November 19, 2011

Piano hinge (but no emu eggs)

The day after I posted on my mini-bending brake (having rashly stated that it were easier to find emu eggs in Alaska than miniature piano hinges) my eye fell on an old clamshell-type glasses case. I had saved it because I plan to make a cell phone case out of it. But my mind ran piano-hinge mode. I said to myself "how is this varmint hinged?" As a matter of fact, as a few moment's work with a craft knife revealed, there's a miniature piano hinge in it!
The hinge was held in place by bent-over tabs. It took a while to unbend them and get the hinge out. Above, there it is. Granted, it has bumps in unlikely places, but as some Shakesperean character said, "t'will do, t'will suffice." Now to install it in the brake. I rabbeted out some space for the hinge, so it would not protrude and mess up my bends. Fortunately I had some tiny brass screws on hand. Voila:
The two pieces to the right do the actual dirty work; but the hinge is marvellous -- the thing doesn't shift when I am bending. A few tests confirms that it works perfectly, like Mr Gingery's larger scale brake does.

But it does leave me with the problem of emu eggs. I looked all over but still have found none. Moral: stuff is where you find it. Unless you are looking for emu eggs.

It has been very cold, in fact, on the Chalupy weather record, this is the coldest November ever. -32C this morning. A bit too cold for me to venture out, so I have been waiting until 2PM to go skiing. Then it's only -23C, still awfully cold for November. I expect we are getting the full PDO without La Nina modulation. I may explain this cryptic statement in another post. But it is very cold. Glad we have the woodstove; saves a fortune in fuel oil.

Wednesday, November 16, 2011

Puttin' on the brakes

The word brake in English has at least two meanings. One is the device used to stop a car; but the other has to do with bending sheet metal. We are here to understand the second meaning. A brake is then a device to bend sheet metal. Also, I am not going to tell you why I am bending all this metal. It's a Christmas present, OK?

Now bending sheet metal is easy. Bending it along a perfectly straight line is considerably more difficult. The catalogs will sell you all kinds of brakes to do this bending, for $100 and up. But, thanks to Dave Gingery's book Sheet Metal Technology we can do it with three pieces of wood. I am, as usual in this season, making miniatures; and furthermore I am using sheet copper. Copper is an unusual metal here in Alaska, but I found a lot of it in an antique store some years back, and it is much easier to work than sheet steel or even brass.

So what we need is three pieces of wood, in my case some house trim I picked up for free somewhere on my walks.
These pieces are 90x70 mm -- the second dimension approximate, it is no doubt some RGU. The three pieces have one edge planed absolutely square; most trim has rounded corners and you don't want that at all. Two of the pieces are connected with a hinge. The best thing would be a miniature piano hinge, but it would be easier to find emu eggs in the bush here than a piano hinge of any kind. So I used the old Alaska standby, duct tape, for a hinge.

Now, to use this thing, take your sheet copper and carefully scribe it where you want the bend to be. I use a carbide-tip scriber, but if you are doing copper you can scribe with a knife, such as an X-acto (tm, of course) knife. Then very carefully align the scribe mark with the edge of the lower piece (previous picture). Put the squared edge of the third piece on top of it and align it with the scribe mark, even more carefully. Correct it, because everything slips. Now clamp the lower piece and the third piece together. You have a sandwich of copper between two pieces of wood.

Now bend up the top hinged piece to 90 deg. and, if you aligned it all perfectly, you will have a handsome 90 deg bend in the copper sheet, right along the scribed line.

The weak point in this device is the duct tape hinge. I will keep my eyes open (and consult the internet) for miniature piano hinges. In case you are wondering, a piano hinge is just a very long brass hinge; it is used for piano lids and hence its name. But duct tape worked very well for me today.

What was not so hot was the fact that power went out at 1145 and did not come on until 1733. In fact it went off again, very briefly, while I was doing this post. Such is life in rural Alaska, AKA "the bush." If you don't like it, don't live here! Soon I will do another post on the perils of power out.

Monday, November 7, 2011

The snowman cometh

Winter has beset us all of a sudden. It usually snows around the first of November, buy this time we got it in spades. First it was a 28cm (by the official snowpole which I stick in the middle of the yard in October) -- an unprecedented snowfall for November. So I blew it out. The good part is that I can now ski, so one gets a reward for each snowfall. And off we went to Anchorage for the weekend. Had to lay in those Costco groceries! Upon returning we found it had snowed in our abscence -- another 30 cm. The snowpole records perhaps 61 cm as of today, but it snowed last night too! So we couldn't get in, much less out, of the driveway. We trudged in and fired up Horatio snowblower.
This time -- an unbelievable luxury -- John got to do the dirty work. But life is never simple. If you look at the picture carefully, you will perceive that there is a lot more snow at the left of the feed screw on the left than on the right. When you are on the business end of a snowblower you can't see this. Indeed, the left (as you look at it) side of the snowblower had broken a shear pin. This is a sort of ordinary-looking bolt, calculated to break before you ruin something really important, such as the transmission of the machine. There are two of them, left and right. But without the shear pin, that side of the screw is inert. Not so curiously, it was very difficult to blow snow! In effect we had only half a snowblower. I had this experience before. My driveway is extremely rough; one big stone will do the shear pin in. I probably broke it when I sucked up a the big log I couldn't see. This is not suburbia. Fortunately I had one spare left. So, with some difficulty we replaced it. After that, John blew out the driveway in no time.
Note the huge plume from Horatio. We had a full snowblower at that point.

But the story does not end happily. It snowed another ohhh 10cm overnight, so we decided to blow out again today. Guess what? We broke another shear pin. I am fresh out of shear pins. I must regard, obviously, shear pins as as an essential winter supply item. Tomorrow I must go into Wasilla anyway, so I must trust to the foresight of Home Despot, er, I mean, Home Depot. If not I must make do with hardware store bolts, but that is really not a good idea. I'd rather rely on a puspose-built shear pin. But happiness is (a) a fire in the stove and (b) a cleared driveway so's you can get out. Remarkable how BMWs do not enter this equation. A beemer may be the terror of the autobahns, but it cannot cope with my driveway. A Unimog, now, might be a different thing; but they cost as much as my house.

Wednesday, November 2, 2011

Splitting hairs, er, wood

Once you have cut your firewood, you still have to split it. If you have to do this by hand, with a maul, as I have done many times in the past, this is no mean feat. It is a lot of work to split with a maul. Fortunately, as previously posted (try searching for the "splitter" label) my ever-loving children gave my an electric splitter for my birthday. A supremely useful gift. It is all a question of age. I can swing a maul and so can my son. But it is a lot of work! It is much easier to load the wood chunks into the Darthcartt and push them over to the splitteria.
John is loading up logs into the Darthcatt, prior to splitting. It is but a few meters to the splitter.
Then you stack it in the woodshed and that's it. It is still a workout, but not as bad as it could be. I am eternally grateful to John for doing this task. We have really left it late, and John is working on a load of wood that I actually bought as a pis aller -- worst case -- when I thought we couldn't do the woodshed and the wood after a month or more of illness. However, I think that wood is like gold. The more wood in the woodshed, the more independent you are of the price of oil, the absurd vagaries of politicians, and the world in general. I have cut at least as much wood as I bought, and that is a great comfort. The woodstove has been paid off -- it was paid off last year, in fact -- and the only trouble with it is, you tend to fall asleep in front of the wood fire. That's a lot more than you can say about your oil or gas furnace. To say nothing about electric.