Thursday, September 27, 2012

Two gadgets

As you know, I have been making shaped planes and John has been melting aluminum (aluminium, for my British readers)  to make castings. Now both of these activities have groundwork to be done. In my case I make my own plane blades from scratch, namely scrap steel. I cut my blades from circular saw blades. In John's case, he cannot obtain very fine-grained sand without importing it from the lower 48 states, at enormous expense, so he sifts it by hand from what he can find. Both these activities have one thing in common. They involve extensive manual labor.

A circular saw blade is cheap. A used circular saw blade is free. It is very tough steel. It may even have carbide teeth, which cannot be cut (or sharpened) by anything short of a diamond cutter. I collect used circular saw blades. But they are difficult to cut with a hacksaw and the process finally got to me. So I built gadget one.
Long ago I acquired, at a thrift store, a used Makita hand-held circular saw. It had no blade guard, so it went really cheap. I used it on construction projects.  Now I really hate power tools, but this is an excellent one of its kind. So what I did was to put an abrasive cutoff blade on it (ACO).  This is much better than buying an angle grinder. I made a sort of tablesaw out of it. I bolted it to a piece of scrap "table" I had lying around. I am a wood scrounge.  The hardest part was bolting the thing to the table. Circular saws are not meant to be bolted to tables. The manufacturers want you to buy their tablesaws, which I consider an invention of the Devil. But with this gadget I can cut up a circular saw blade in minutes. I can use both hands on the work. I can use the sides of the blade as a rough-and-ready grinder. Mind you, I am no stranger to the hacksaw. But neither am I a 100% purist. Hand tools only? Well, there is a limit. Just try hacksawing a circular saw blade yourself. And of course the whole thing bolts to the faithful shop Workmate, the greatest British invention since the steam locomotive. I have it weighted down with about 50 Kilos of logs, so it isn't going to move easily. I can use both hand on the work. I can cut metal or even rough-grind it to size. Invaluable for making metal objects, such as plane blades.
 Gadget two is a bit more specialized. It is a power sand siever or sifter.  I did not invent it. I found the idea on  the myfordboy blog, on his YouTube channel, video #31. This is a blatant knock-off. My thanks to myfordboy. It is a power sifter based on a reciprocating saw, the kind called a sawz-all in the trade. No doubt a trademark. I picked this one up for about $10 at a yard sale; the trigger is very dicey. But it works.

The reciprocating saw drives an arm connected to the saw. Arm is connected to sieve. The cost, apart from the $10 reciprocating saw, is zero. It's all someone else's offcuts, plus some salvaged strapping steel as guides.  By the way, it is very difficult to drill holes in sawz-all blades. I had to use a drill press. Even then it was difficult. Also had to add weight to the thing. But the thing works. It sifts as fast as you can shovel the sand in.

 Note the duct tape, known as "gaffer tape" in the UK. Without this commodity, the state of Alaska would grind to a screeching halt. I do not remember the official motto of this state, but the unofficial motto is "if it moves and shouldn't: duct tape. If it doesen't move and should: WD-40." Oh, how true.

Sunday, September 23, 2012

John melts metal

 John has been working on casting molten aluminum. See previous posts under lables "flowerpot furnace" and "forge." The molten aluminum is poured into sand molds, and that is a whole 'nother story. But for now let us look at the evolved process. First, you find some scrap aluminum. Then you melt it in a furnace. John was originally into the Gingery charcoal furnace. So he built one. After some experimentation, we found that the Dragon Lady is the way to go. Put your scraps into a crucible (currently an old plumber's pot, destined to melt lead) and turn the Dragon Lady loose.


The Dragon Lady makes short work of the melting. Much faster than charcoal.  When the Lady gets going you can't see what is happening. But it is turning into a liquid at a great rate. There is a lot more to this. I recommend the Dave Gingery series on building your own machine shop from scratch. Especially Volume 1; you can Google on Gingery and get many hits.

After about ten minutes the scrap aluminum is poured into a sand mold. That is material for another post. In the meantime, if you are interested in sand casting, do look at myfordboy's blog, q.g., and look at his videos.  This is a great blog; I am adding it to my follow list.

More to come.

Thursday, September 20, 2012

The garden is icumen in

It is raining. We need to build an ark, not a snow splitter (about which more later).  And Google just changed their interface out from under me. I detest that. It makes life no more interesting. Is it any easier to blog? We shall see. I have been programming computers for longer than most Google programmers have been alive. I am not impressed by "novelty" any more. Novelty is a nuisance.

Anyway, fall is here. We had to get the garden in. We have already had the first frost; -2C on September 5 or so. Now intelectually I know that potatos will survive a frost. But I get edgy. The tops died. Potatos, as we all know, grow underground. So I got antsy. And I had this unusual extra labor force available. BOthe John and Fluffy are in residence. So it's off to dig potatoes
or potatoes, as the case may be. So John did, literally, the dirty work. First we have to dig the potatoes. On the whole I prefer potatoes. Strunk &White me if you will.

Anyway the rows have to be spaded. And I have but one row. John found it hard work. Agricultural manual labor is indeed hard work. Especially if you are used to machinery to do hard work! Then you grub around in the spaded ground to find the potatoes. Here is Fluffy helping me do the dirty work.
 After that episode it was time to get the oats in. Now in less harsher climates, the oats would have been taken in long ago. This is Alaska, remember? We have have to do things earlier. In retrospect I should have gotten the oats into the ground earlier. But we learn by experience. The oats I got were raised (probably) in Saskatchewan. With all due respect to Saskatchewan, they have a milder climate than we do. Not too many people raise oats any more, especially in Alaska! So we scythed the oats.

The scything was quite difficult. I should have peened the scythe (see previous posts on scythe). And John and Fluffy had their first go at the scythe.The ground was very wet; it has been raining a lot. The oats were not quite ready. But again, we learn from experience. I got antsy. Perhaps too soon. Now I have to thresh the things. Expect a post on the subject. The oats are now in the "barn" awaiting threshing. We are learning, after all. All the books are written for the lower 48 states. If only I could read Norwegian, Swedish, or Finnish I suspect would be better off, but unfortunately I do not have access to their literature.  I must go by what I have learned from books. Very, very few people grow their own oats; those that do live in the lower 48. 

  Anyway there is a payoff. Here it is.

 It does not appear in the image but it may be enough potatoes to last the winter. I apologize, Google. Your new improved streamlined interface is indeed better. Forgive my rant at the start of this post.


Wednesday, September 12, 2012

Department of de fence

When I went to make my first molding with shaped planes, I roon realized that you need to use a fence to guide the first cuts of the plane. Whoever made the video I cited earlier uses a plow plane. With the stuff I'm using, said I, I'll never get my plow plane to track -- the fence extends a full 30cm below the level of the stock. To get around this one. I must make, I said, a fence for the planes. It must be adjustable. And if we can use it on Makita-san the bandsaw so much the better. So off we went. First I looked at the bandsaw. Now bandsaws have a slot about 16mm wide running down the table, parallel to the blade. Mine came with a miter gauge, but no fence. I find miter gauges useless, but there you are. You can buy a fence, of course, but I never buy anything I can make. So I made a fence.
As you see, it is but two pieces of wood and two hardware store steel rods. I would like sturdier rod but I didn't have any! The brown piece of wood, species unknown, is from my daughter's old dining room table. Never waste wood! In it I cut a rabbet (or rebate) so that it would just fit the slot in the table. This turned out to be 16.33 mm, which convinced me it was RGU; sure enough 5/8". Sigh. Now to cut the rabbet I needed a fence. But that was what I was making! So I had to improvise. Eventually I did it.

There is a strange mortise in the piece of wood to the right, the slider. It came with the dining table, and serves no purpose now, but I hate to waste wood. As a bandsaw fence it works beautifully. The rods are epoxied into the leftmost wood, the fence itself. No fancy joinery here.

Now I have to adapt it to my vise. This means cutting a slot the exact width of the mortise slot in a piece of wood, which can then be clamped to the vise. Long ago I built Roy Underhill's bginner's workbench and acquired a woodworker's vise to go with it. It is 16 cm in grip. So I took off, bolted it to my general-purpose kitchen table and I now have a decent vise for wood. So time to cut a precision slot 16.3 mm wide. If you have a rabbet plane exactly that wide, you are done. But I don't. So I used the Peanut, Veritas's miniature rabbet plane.
Here you see the old/new vise, the slot being cut, Peanut posing for the camera, and shavings all over the place. This is very slow work. I am still at it. Peanut is much too small for this work (6mm wide), but everything else I have is too large. The fence will ride in the slot (I suppose it's a dado, but along-grain) I am cutting. I have clamped an old steel square to the works to keep Peanut from going astray. A fence, in fact. I suppose I could have made a 16.3mm rabbet or dado plane. That would take several day's work, though. I should be finshed tomorrow. All this to make moldings to make picture frames.

Saturday, September 8, 2012

Shaped planes, Part V: new guy on the block

I know, you may be tired of this shaped plane business. It has been quite an obsession. But the old hollower just did not work. I had to remake it and this time, as an experiment, I decided to try a pattern I found in David Finck's book, Making and Mastering Wooden planes, q.g. Great book. This is not a Krenov-style plane. It demands a different blade outline, as you will see. First we cut a triangular mortise in our block of wood, which we shape to the blade outline. In fact the outline was exactly the outline of my previous plane, which in turn shaped my rounder plane. The rounder works quite well. So I used it to shape the bottom. Easy. Five minute's work.

Lay out your plane. Draw lines on the wood. Layout is critical. I may put a post in on the subject. Then saw out the mortise down to the required depth. In my case 1cm. Then chisel out the waste. Do this very carefully.
For the record, the dimensions of the block are 140x21mm. Not responsible for the 21 mm dimension, no doubt some meaningful number in RGU. As you see, I have two ramps. The left one will be the called the blade ramp. Once cut it will never be touched. It is a 45 deg. angle with the sole of the plane. This is standard pitch for a plane. If you plan to cut hardwoods you might want a classic York pitch, 57 deg. The other one is the wedge ramp. I happened to cut this one at 60 deg. It is not critical. You will cut the wedge to suit it. My ramp is one cm deep; 10mm for the units nannies who keep insisting on obsoleting centi- and deci- prefixes. Fie! Computerization strikes again. If you can't multiply by ten in your head, you have real problems and should be back in first grade. And would never read this blog in the first place.

Next chore is to shape the blade. Critical. My blades are (so far) all of 10 mm radius. So I cut out a piece of circular saw to approximately the right shape. I must tell you how I do this, it is a nice journey all by itself. Draw your blade on paper. Cut it out oversize. It can be done with a hacksaw. A grinder is nice too. Do not worry about the radius too much at this point, but leave a generous (2mm at least) allowance. So what we have at this point is something like this.
Actually I made several mistakes. I did not cut enough oversize. No matter. Same old story; easy to take off, impossible to put on. One mm off. Fix later.
In order to aid fitting, you will have to make a cutout on the non-ramp side of the plane. When you do, cut on the wedge ramp side of the plane. Never touch the ramp! Lesson learned from the first plane.
It really helps if you have put the layout lines on both sides of the plane. I did not. Mistake. Lay the thing out completely on both sides! Learn from my mistakes.

Next step is to the blade to an exact circular radius with a 25 deg bevel. Very easy to grind the shank, for instance, down to 10mm flat. But grinding a circle with the proper radius is no joke. If your hand is steadier than mine you might do it. But at the same time you have to grind a 25 deg bevel on it. For superman? Child's play. For the rest of us it is time to cook up a jig. As you can see, the center of curvature is right at the corner of the shank. I filed up a small (ca. 1 mm) cutout there. As for the jig, here's v0.0...
Lot of things going on here. The whole thing is done on my TSO (Tormek-Shaped Object) wet grinder. The bottom part of the jig comes from the kindly asiatic manufacturer. Let me call it the table. Bolted on to that is an aluminum bar, exact dimensions unimportant. About 10mm from the end of the bar, middle of the pic, is a finishing nail, about 0.7 mm nail. Again some RGU system. I drilled the hole undersize, pounded it in, and used superglue to make sure it stayed put. I later improved this jig to grind ulus, but this one will do for now. My angulometer is being used to set the 25 deg bevel angle. This is done by pulling out the table support, also supplied by the manufacturer, and by rotating the table around the support. Now the blade is free to rotate on the nail, and all you have to do is rotate the blade. The blade does tend to come off the nail. So you have to hold it on the nail by hand. By the way the grinder rotates away from me. If I turned it around I wouldn't have this problem! But I prefer grinders rotating away. This jig cries out for improvement, which is why I improved it later.

Now turn the grinder on and start rotating the blade. As you do, hold the blade firmly against the nail. In a wet grinder, things happen in slow motion. On a dry grinder you ruin your work in an instant. And rotate the blade! I repeat, rotate the blade. If you don't you will grind a flat spot on the blade.

An ulu, by the way, has exactly the same problem. Got to grind a circular profile with a given bevel angle. The ulu jig works very nicely and you don't have to worry about holding the blade against the nail. I drilled a hole as close as I could to the center of curvature.There are two bars this time and a clamp to hold them together, but the principle is the same. Next circular plane blade I build will allow for a 7mm hole to be drilled at the center of curvature. This is jig v0.2.

And of course, you must harden and heat-treat the blade. Microforging; propane torch work. See previous posts. And hone it!

Anyway we now have a nice circular blade. Now we have to fit it to the plane. We want a zero throat opening at this point. The reason for this is that it is much, much, easier to cut wood away than to put it back. Gradually, with a chisel, open out the wedge ramp until you have a 0.5 mm throat or even less. The narrower the throat the finer the cut. Do not under any circumstances touch the blade ramp. Your final touch is to drill a hole to allow the shavings to escape. Do this last.

My hole is 22 mm because I happen to have a 7/8" Forstner bit, which drills a beautiful hole. Anything around that size will do. Drill tangent to the wedge ramp plus a few mm. Make a wedge 1 cm wide to suit your ramps and Robert est votre oncle, as the French most certainly do not say.

Plane works very well indeed. All wedged planes need extensive fiddling until you get the blade depth just right. Tap with a hammer. See Finck's book. Very pleased with this effort. I went to all this length because I have not found any source (besides Finck) who makes planes with shaped blades. Phew! Long post.


Wednesday, September 5, 2012

Shaped planes, part VI, and ulus

The time rapidly approaches -- indeed, it is already here -- when I start making gifts for the people in my life. So there will be some stuff here that is intended as a Christmas gift. Ah, but for whom? You don't know, do you? My two previous ulu recipients know they are not included. Or are they? You are not to know. So, cloaked in anonymity we proceed.

First of all we are making a shaped plane. In fact, we are rebuilding a hollower. The old hollower worked. It was my first shaped plane and I am fond of it. But we learn. The blade was not sufficiently rigid. So I made a new blade. I deconstructed a circular saw. I will have some more to say about this. You have met this blade in Part V. You have also met the body. Now the task is to grind the blade to some sort of edge.

You might be able to see that if you just held the edge to a grinder (of any kind) the grinder would eventually grind your edge flat, like a chisel. Not good for something like a hollower. It has to be ground on a radius. Now Superman (tm) can do this in his sleep. Me, I need a jig. So I devised one. It is a piece of aluminum bar.
The aluminum bar is bolted to one of the fixtures that came with my TSO (Tormek-Shaped Object). For those of you that don't know, Tormek is a Swedish firm that resurrected the old-fashioned wet grinder. And patented everything. But their patents are expiring rapidly, and the asiatic manufacturers are into the game. Better for me! My TSO cost about a quarter of the original article.

Affixed to the aluminum bar, about a buck at any hardware store for far more bar that what you need for this jig, , is a common brad. For the record it is 1.7mm in diameter. So I had to drill a corresponding hole for a tight fit, and super-glue the brad in place. Then I use my faithful angulometer to set the proper grind angle. For a plane, 25 deg. I am entirely sure that Tormek makes a precision jig for just this purpose. I am equally convinced that I do not have to spend $100 or so for it!

Next shot may be superflous. It shows the jig, the grinder, and the blader. It does help if you file a little cutout right at the center of the radius of curvature.
Now you turn the grinder on. Do not forget to put the water tank in place. Do not forget to take the water tank off when you are finished, else you will distort your wheel -- it will absorb water on the stationary part. As you grind, rotate the blade. You use your fingers for this. Be sure you keep the cutout in the blade (the center of curvature) pushed up against the pin. Since the pin is the center of curvature you will grind a very nice circle. I cannot call it perfect because if you use a micrometer you will see I am way out. But for practical purposes I am really, really good. At this point I go to hand sharpening.

This plane will be back in the next epoisode of the drama. But in the meantime it occured to me that I had also solved another problem, namely, how to grind an ulu. Now an ulu is an "eskimo" knife. We do not use that word in Alaska, preferring to call the natives by their tribe or group. I love ulus. They are marvellous cutting tools. See some previous posts.

What I did really was to cut up a circular saw blade for other purposes. But every time I do it i think, "hmm, an ulu!" So I reserved about half the blade for ulus. They are gifts. For whom,? I refuse to say. Eat your heart out. Anyway ulus must be ground. And so our grinding jig evolves.
There is really no difference between an ulu and a convex plane blade. Both circular contraptions. Set the grind angle with the angulometer, and rotate the things. This jig is a little different. I found it convenient to drill a hole in the blade. It will be covered anyway by the handle. It is not in the exact center of curvature. But the error is small. A toolmaker's clamp holds the pieces of the jig together; otherwise it is the same as the previous jig -- but this version clamps both top and bottom. You rotate the ulu. same as with the plane blade, by hand, and it does a really nice grind.

Well, it has been a long day. To quote Mr Boswell, "and so to bed."

Saturday, September 1, 2012

Shaped planes, part V

My previous expenience with moldings disclosed that my hollower is not satisfactory. The plane chatters. This may be due to saveral reasons. The most likely is that the plane blade s not thick enough. So, sucker for punishment that I am, I decided to make a thicker blade. Double sucker that I am, I decided to use a different style, based on a picture in David Fink's book, Making and Mastering Wooden Planes (q.g.). Glad I did. I have learned a lot.

This style of plane is a lot more like the traditional wooden shaped planes.
Here you can see the overall scheme. We have a block of wood 145mm by 20mm thick by about 50mm wide. The bottom of the plane has been shaped to a 10mm radius curve, by guess and by gosh. In the block a mortise has been cut. Into this mortise will fit a blade. The blade for now is just roughed out. The mortise has two angles. The one on the left is critical. It is the bedding angle for the plane. The traditional angle for bedding is 45 deg and this is what I use, standard pitch. However for hardwoods you might want to use a steeper angle, like 57 deg which as I recall is called York pitch. These are traditional pitches, and assume the blade of the plane will be sharpened at 25 deg. If you do not sharpen the blade at that angle you will have some math to do. It is all about angle of attack. I recommend reading Garret Hack's The Plane Book, q.g.

It took me some time and a few trips to the 'net to figure out what the plane blade looked like. Mr Fink did not tell me. But eventually I figured it out. The roughed-out blade is shown on top of the plane. I cut it out from a piece of worn-out circular saw blade. This is almost 2mm thick. Approximately twice as thick as the old ripsaw-derived blade on my previous incarnation. I like this a lot. The thicker the blade the less the chatter.

The place where the blade goes in a not-so simple mortise. Leftmost is the ramp where the blade will go. I will call this the blade ramp. It is 45 deg, the bedding angle. If you go make one of these things, under no circumstances can you touch this blade ramp! At right is another ramp. It is traditional to cut this at 62 deg but I cut it at 60. Easier, (with a 30-60-90 square), to lay out and the exact angle does not matter; cut your wedge to suit. This ramp has two functions. One, it holds a wedge to keep the blade in place. So I will call it the wedge ramp. Two, you can see I can slide my 30-60-90 square along the plane towards the front (right in the pic) any amount I want. The amount I slide it towars the front will determine the throat opening. Planes are very fussy about throat openings. My rulae of thumb is that the throat opening should be about the width of the shaving you want to take. So my current strategy is as follows. The wedge ramp should be the thickness of the blade ahead of the place where the blade ramp comes out. The goal is for a zero throat width. I can take wood off. I can only put it back with great difficulty. In fact, only with Plastic Wood (tm).

So when we have fiddled with this a bit, we can get a decent fit.
A decent fit to me means that the blade will fit exactly flush with the bottom of the plane with zero overhang. So the throat opening is zero. That is what I want. To get away with this we have to look at the other side of the plane.
There is a blade-ramp shaped cutout on the other side of the plane. It hasto be deep enough to take the plane blade all the way down, until it is flush with the bottom. Took some doing.

My next post, part VI I suppose, on the subject will tell you about my adventures in throat-cutting. Fortunately, human life is safe. The only throat I intend to cut is that on the hollower plane. I must also relate my learnings on ramp-cutting. And there is yet the chip-escape hole to drill. So much to post, so little time.