Sunday, October 26, 2008

Driving the Lathe

I've been asked how I drive this lathe, since it's made to be line-shaft driven. The answer is in the image below:
I added a cantilevered track for a motor to slide on. I can slide the motor back and forth to make the belt drive sheave line up with the different diameter pulleys on the lathe headstock. The track runs the full length of the lathe because the headstock on this lathe can travel. Really. I can slide the headstock down to the tailstock end to do off-board turning. It's an interesting way to do things. The weight of the motor takes care of the tensioning on the drive. It works surprisingly well. The steel was all surplus, as was the wiring and the motor, so the whole thing was thrown together in a couple of hours for little to no money. It's ugly, but it works. I'll spiffy it up a bit.

Saturday, October 25, 2008

Resurrecting a Lathe

I've had this lathe for years. It's been sitting in the shed at my folks' farm for all of that time, but I've finally brought it home. I'm going to put a fresh coat of paint on the old girl, and this will be the story of that process. I think the lathe was made in Toronto quite a while back. Some time near the turn of the 20th century. It's also possible that it was merely sold by a Toronto company, and may have been made elsewhere some time previously. If it was, indeed, made in Toronto then it would have had to have been made after about 1910.
The first decision to be made is whether to treat this as a restoration or a re-creation. Do I try to maintain the ancient patina, and keep the aged look, or do I try to make it look the way it would have when it left the show room all those years ago? I'm leaning towards the latter. I think it would look dead sexy with a fresh coat of bondo, a new skin of gloss black paint, and gold pin-striping. Below is a shot of the maker's plate. Actually, maybe green... deep green... with gold highlights.... hmmm...

Tuesday, October 21, 2008

Thoughts on Kerf Width

The current push in dovetail saws is for the narrowest kerf you can get away with. My dovetail saw has four thousandths of an inch of set, which is a hair less than the thickness of a sheet of copy paper. That's not a lot.
Reworking the Crappy Crown Gent's Saw got me thinking about kerf because when I finished filing it the first time the kerf was still far too wide, I thought.
I did the test cut and the cut was fast, effortless and straight, but it was wider than I wanted.
Now I'm wondering about the effect of kerf on joinery.
Where you have two cuts forming an angle of significantly less than 90 degrees, a wide kerf will give you a poor corner. Either you will have a groove in one kerf wall, or you will have a slightly rounded inside corner. The narrower the kerf the less effect there is.
However, when doing something like a dovetail, the wider the kerf the easier it is to release the waste when chopping it out. The waste won't wedge as easily - you have more room for the chisel.
When cutting in general, the less kerf you have the harder it is to steer the saw, however having too much kerf is a poor choice, as you need to expend too much energy keeping the saw cutting straight.
The minimum amount of kerf is dependant on the wood being sawed, the depth of the saw blade, and desired radius of cut, when cutting curves. Green softwood requires a great deal more kerf than dry hardwood, a panel saw requires more kerf than a bow saw, and a turning saw requires more kerf than a dovetail saw.
I don't know if there is a magical formula out there where you can punch in your requirements and it tells you the proper kerf to use. I suspect most manufacturers just use traditional values as a basis point and modify it as required.
More mulling on this matter is required, but I'm starting to wonder if striving for the narrowest kerf is the correct path.

Monday, October 20, 2008

New Life for an Old Saw

I have an old Crown Gent's Saw that I bought new a long time ago (15-20 years) and never liked. It's got far too much set, won't follow a line, and basically cuts terribly. When I got it I had no idea how to fix up a crappy saw, so I threw it into a box and forgot about it. I found it a while back, but now I have good saws that I love so I had no intention of putting any effort into this saw. It could stay in the box.
Recently a thread started on the Canadian Woodworking forum that included the notion of refurbishing a Crown Gent's Saw. A suggestion that I made was not taken gladly by some, so I've decided that I will refurbish my own elderly Crown Gent's Saw in the interest of proving the point that the method works.
First, the saw. Here it is in its crappy glory.
It will be refurbished into a dovetail saw, so for that it will need a rip-pattern tooth form, and it needs to have its set radically reduced. First, reduce the set. Take a pair of hardwood blocks and lay the saw between them. With raps of a hammer you can squeeze the teeth together to reduce the set. Depending on the size of your blocks, it can take a surprisingly hard hit. Below is the setup that I used for reducing the set. A chunk of red oak (would have preferred something harder) with another piece of red oak as a 'punch'.

Once the set was reduced it was time to file. I put the sad saw in the saw vise and got out my smallest saw file - brand-spanking-new. Only the best for the crappy old Crown Gent's Saw. :)

Now to file it to a rip cut. First I ran a mill file over the top to joint the saw. Not that I expected the jointing to be off... this saw had never been sharpened (or used, really) so the teeth should be in factory condition, but by taking a light jointing pass I can more easily see where I am in the filing process. After filing the saw I tried it out. I had done two test kerfs in a piece of white pine before starting on refurbishing the saw. The test board can be seen below. The two 'before' kerfs are each the result of 50 strokes of the saw. The 'after' kerf is the result of only 12 strokes of the saw, and I had to stop because the spine had hit the top of the board and I could go no deeper. The saw now cuts fast and straight, and all for about 20 minutes of effort. If I had it to do over again I would have done some more beating on the wooden blocks to reduce the set even more. The last kerf in the test board is from my Medallion dovetail saw. Only 8 strokes. Nice. Much longer saw, though, so it has a bit of an advantage, there.

Anyway, that was my refurbishing of a Crown Gent's Saw. It's not hard, so if you have one that you hate then have a go at fixing it up.

Saturday, October 18, 2008

Dovetail Angles

Dovetail angles are often described by the ratio of rise to run. Historically, in the western tradition, dovetails would be made with an angle of 1:6 for softwood, and 1:8 for hardwood. This equates to about 9.5 degrees and 7.1 degrees from normal to the end of the board, or basically 9.5 or 7.1 degrees away from being a finger joint instead of a dovetail. Some people feel that the easiest way to get by in the dovetailing world is to use 1:7 on all material as a compromise. This equates to an angle of about 8.1 degrees.
My question, of course, is who cares? We're talking about less than two and a half degrees difference between the whole range of them. Who is going to be able to tell what ratio you used when looked at from any kind of a distance. A person with a good eye might be able to guess, but you'd need to take a gauge to the piece to be sure, and anyone who takes a gauge to anything I made deserves whatever disappointment might be forthcoming. :)
So what do I use? I use the 1:6 ratio for all woods. I figure if it's going to be a dovetail then I might as well pick the one that looks the most like a dovetail.
Below we see a quickly cobbled dovetail that I just did this morning for the sake of illustrating this point. This joint has two tails. One is at 1:6 and one is at 1:8. Even right side by side and zoomed in it's not that obvious that they're different angles. At most you might think that it was a minor variation caused by hand-cut joinery. Certainly it wouldn't scream at you from across the room. So I, for one, don't get all excited about dovetail angles.

Frank Klaus, master cabinetmaker and father of dovetail excitement on this continent, doesn't use a gauge. He eyeballs the angles. He doesn't even measure out the spacing. He eyeballs everything except the depth of the cut (which must match the thickness of the board being joined to). Despite his carefree methodology, his experience is legendary and he can cut seemingly air-tight dovetails in the time it takes most experts to do the layout.

Friday, October 17, 2008

Dovetail Gauges

There are a whole bunch of different dovetail gauges on the market. I've bought a few, and made a couple, and these are what I have left. At the right in the image above is an adjustable bevel. This is the traditional way in many western cultures to gauge your dovetail angle. You set the bevel to the angle you want, then use it to mark the work. This works, but the adjustable bevel is relatively heavy, and the angle could creep when you set the gauge down and pick it up again for the next board, etc. The adjustability can be a drawback. The next gauges, moving to the left in the image above, are the Veritas Dovetail Markers. Very inexpensive, very light, generally inoffensive, but they lack an important feature, and that is being able to mark the angle and the square line on the adjacent face with the same tool and placement. It is a great luxury to be able to set the gauge in place and mark both lines without moving the gauge, thereby guaranteeing that the marked lines are in the same plane. The lack of this ability is a failing of the adjustable bevel, as well. At the far left in the above image we see a dovetail gauge that I made. I'd seen a gauge in Ernest Joyce's "Encyclopedia of Cabinetmaking" which I thought was almost perfect. It was a double-sided affair that had two angles on it, so that one gauge could be used for hardwoods and softwoods. Rob Cosman found the same image, and uses it, (and sells them) himself. I didn't like that it had two angles on it. It wouldn't take that much inattention to pick up the gauge and use the wrong side. Also, you had to flip the gauge over to change the direction of the angle when you're marking the other side of a dovetail. I would prefer to have one gauge for each angle that I'm likely to use. The first one I made was like Joyce's original, but I soon started modifying it, then started over when I realized that the two-angle design wasn't good for me. To this end I made mine with only one angle, but both edges have the same angle so it can do both sides of the dovetail by just sliding it back and forth. No flipping and flopping, and no chance of using the 'wrong' angle. This was the best gauge so far, and in some ways is still my best gauge.
The last is the best commercial gauge I have. After using my wooden gauge for some time I discovered the Veritas Dovetail Saddle Marker. it is a commercial version of mine. I guess great minds think alike. :) It has all of the features of mine, and is larger. What makes mine still a bit better is that it is much lighter, and warmer in the hand (being wood instead of metal). If you want to buy a commercial dovetail gauge, I think your best bet is the Veritas Dovetail Saddle Markers.

As to which angle to use? Well that is a discussion for another day...

Tuesday, October 14, 2008

Puttering - good for the soul

This weekend was a puttering weekend. I installed a garage door opener so that I won't have to drag my weary carcass out of the car to open the garage door when I get home from work in the winter, I cleaned up the garage a bit, and worked on the new saw till. It's now structurally complete except I still have to make the drawer. I still need to put the finish on it, and I wanted to put a few plugs here and there. Unfortunately, the plug cutter I got from Lee Valley doesn't seem to be particularly good at being powered by a brace. I'll need to put a custom driver on it to fit the drive socket on the brace, or modify the stem of the plug cutter to be tri-lobular so the three jaws of the brace can hang onto it properly. I also did some mechanical work at the folks' farm to fix an old yard hydrant. It's ancient, worn out, and should be replaced, but replacing it would require knocking out part of the barn foundation, so basically I'm trying to make a silk purse out of a sow's ear because the price of silk just skyrocketed.

I have added a few new planes to the stable. I might have mentioned them before, but now I'm showing them off. :) At the back is a matched set of Veritas bevel rabbet planes, one right hand and one left hand, and at the front left is a Veritas rabbet trimming plane, and at the front right is a Veritas bull-nose plane, which would have made those stopped rabbets on the saw till a lot easier to deal with had I had it at that time. Next time I'll be ready!

Sunday, October 5, 2008

Tools of the Trade sale

I just got back from the Tools of the Trade sale (TOTT) in Pickering, Ontario. I think I did alright.

This was The TOTT of the Auger for me. I wanted a set of auger bits.

Right away I stumbled upon the two sets in ratty, smelly old fabric pouches, plus the brace shown, all for $20. I didn't try to haggle at that price. There are three bits with spurs missing, but there are enough duplicates that I've got at least one of everything.
The brace turned out to be a sweet user, and is now my second-best brace.

However, as is often the case I didn't stop there. I found a boxed set of 13 Irwin bits that cover more ground than the sets I already had in hand, so I bought them. That set included another expansion bit. All in excellent condition. Then I started wondering if I'd rather have Russel Jennings pattern augers, so when I saw a boxed set of 13 of
them I bought them as well. All in excellent condition, though the smallest one is actually an Irwin, not a Jennings. All told I spent less for these 46 auger bits than I would have for one set of 7 new Russel Jennings pattern augers from "Traditional Woodworker". Nice. I can use some of the beaters to make augers for end-grain applications where you don't want spurs.

Finally I looked at my list to remind me of what
else I had planned to get, and soon found a lovely Mathieson adjustable panel-raising plane, which I have wanted quite badly, and a downright devious match plane, which I have wanted even more. I'd never seen such a thing as this match plane, though they are apparently not as unusual as it seemed to me. The fence rotates on an eccentric mount to allow the same cutter to be used for both the groove and half the tongue, with another cutter mounted for the other half of the tongue. Bizarre, but effective. It was about twice the cost of a regular Stanley match plane, but it was too cool to resist. I've already tried it, and even with the nasty dull cutters in it it works a treat. Lastly I've got a big old Sorby in-cannel gouge, which I might convert to out-cannel... not sure yet... and a very nice saw set. Oh, one thing that I missed adding to the picture was a tiny little pair of fey-pattern dividers that I got for $5. Very nice, indeed.