Author:
• Saturday, October 18th, 2014

diamond nagura

There are the good reasons for using a diamond stone as a nagura. This is not a novel idea – the intent here is to present a clear rationale for it. However, there’s also a significant practical problem involved.

All of this applies to synthetic finishing waterstones. I think most or all of this probably also applies to Japanese natural finishing stones but I defer to those with more knowledge about those.

The reasons for a diamond nagura:

1. It’s fast. The slurry is raised faster and the surface of the stone is refreshed faster than with any other type of nagura that I have tried. Whatever you perceive to be the benefits of these effects, as discussed in the previous post, they arrive faster with a diamond nagura.

2. The slurry consists of grit solely from the finishing stone; no new grit is added. This removes the uncertainty of introducing another grit, often unknown, from a stone nagura, along with the uncertainty of the amount of it that gets into the slurry based on the relative hardness of the bond in the main stone versus the nagura.

3. It is very capable of crushing the grit in the slurry. I first learned about this several years ago from So Yamoshito, a Japanese tool vendor in Australia and expert on Japanese natural stones. I wrote about it then. The rationale for specifying 1200 grit diamond is that it is fine enough to readily crush the loose fine grit in the slurry yet coarse enough to raise the slurry quickly. The latter effect is apparent.

I can’t directly prove the crushing theory. Furthermore, for it to be of value, the crushed particles would have to retain good cutting ability as finer particles. After working with this for years at the sharpening bench, it does seem borne out by the blade edges it produces.

By the way, what about just using the slurry created by flattening the finishing stone with a coarse diamond stone, say 220 grit? Yes, that’s pretty good but the crushing effect is better with the 1200 diamond. Also, a lot of water is used in flattening and the process tends to swipe the slurry off the finishing stone.

Now for the problem. When you rub a 1200 grit diamond stone, even an Atoma with its surface made of tiny dots of grit clusters, on the wet finishing stone, it sticks like crazy. This is very annoying and then it tends to carry away much of the slurry when you remove it.

I tried using smaller continuous surface diamond stones but they were no better. Then I tried a DMT 6″ x 2″ inch 1200 diamond stone with the “polka dot interrupted surface.” This reduced the sticking but still not well enough. It needed to be smaller.

The little DMT polka-dotted pocket stones were too thin to grip in my fingers. So I hacksawed a 2″ x 2″ section off the 6″ x 2″ stone, which you can see above. It works pretty well. The small size and the perforations eliminate most of the sticking.

Note that I do not consider flattening to be a function of the nagura. In fact, a reasonably evenly-distributed rub of the small diamond nagura should not significantly change the flatness that has already been established well by a coarse diamond flattening plate. I flatten stones at the end of a session when they are fully wet and so they are ready to go for the next use.

The best solution, I believe, would be a 1200 grit diamond nagura, about 2″ x 2″, with narrow channels extending to the edges that would reduce sticking and allow the slurry to flow away from the nagura and remain on the finishing stone. I am working on prototypes using 1″-thick ABS plastic for the base and various applied diamond surfaces. I’m hoping this results in a nagura that is the bee’s knees, but in any case I will report on this soon.

Category: Techniques  | 5 Comments
Author:
• Friday, October 10th, 2014

nagura

Several reasons are usually given for using a nagura on fine grit waterstones. These include: to raise a slurry, to remove unwanted deposits in natural Japanese stones, to refresh the cutting surface of the stone, and to flatten areas of the stone.

Let’s think about what’s going on when a nagura is used, recalling what we can directly sense at the sharpening bench.

The slurry

When the little nagura stone is rubbed on the finishing stone, a paste, or slurry, is generated. It is sometimes claimed that the slurry actually does the sharpening, but it seems questionable whether loose abrasive particles in the slurry are really cutting steel. There are microscopic photographs of blade edges and stone surfaces, but to my knowledge, no direct visual recording of the actual cutting action at a microscopic level. We can observe the effects but not the actions that produced them.

The thin edge of steel plows most of the slurry but perhaps some loose particles are held by the stone’s surface texture, enabling them to cut. Maybe it burnishes the steel. Maybe it creates a variable grit surface on a synthetic stone somewhat like in a natural stone.

In any case, we can sense that the slurry improves the feel and ride of the blade on the stone and reduces sticking, all helpful effects. So, whatever it is actually doing, the slurry at least feels good.

The next issues are what composes the slurry and what happens to it.

Are there particles of the finishing stone, the nagura stone, or both in there? Particles of the softer (more loosely bound) of the two stones will presumably predominate. This should be considered when the two differ in grit size. For example, a nagura that is softer and coarser than the synthetic waterstone with which it is paired will be probably be counterproductive.

With fine natural Japanese waterstones, nagura selection is an art unto itself. Consult a knowledgeable purveyor of these stones. The nagura also is used to remove defects in natural stones that can damage the blade edge. This function is, of course, not relevant for synthetic stones.

So, what happens to the particles in the slurry? Are they left intact or crushed to some degree? If the nagura could crush loose grit to a finer size, that would seem to be an advantage assuming these crushed particles retained their cutting ability.

The surface of the stone

We can see and feel that a nagura refreshes the surface of the stone by removing metal and glazing. Much like dressing a grinding wheel, cutting particles are better exposed at the surface, ready to cut steel.

As for flattening, there are better ways to do this accurately than with a nagura, though with natural stones a nagura might be helpful for some local flattening as it is used intermittently for its other benefits in the course of sharpening.

A solution

There may be more questions than answers here and you may be thinking that this is all a little bit interesting but enough already. I agree, I’d rather get back to woodworking. However, at least restricting the matter to synthetic waterstones, which most woodworkers use, there is a simple solution to all of this, to be discussed in the next post. The background discussion of this post will support why I think the solution makes so much sense.

Category: Techniques  | 4 Comments
Author:
• Wednesday, October 08th, 2014

Chosera 10K

I guess I can’t quite leave sharpening alone. About six months ago I switched to using a Naniwa Chosera 10,000 as my primary finishing stone.

I had been using a Shapton 16,000 glass stone for this purpose and could have left well enough alone because it is an excellent stone. It’s fast, the grit is very consistent, it’s convenient because it requires no soaking, and it gives a great edge. However, the drawback for me has always been the lack of excellent tactile feedback from the blade on the stone surface.

This is particularly important for freehand or semi-freehand finishing of the cambered edge of plane blades where the feel of the edge on the stone is critical. Even when using a honing guide for simple non-cambered edges, the delicate feedback near the end of honing is helpful and reassuring that the angle and edge are right.

I had read reviews claiming the feel of sharpening on the Chosera 10K stone was outstanding and that is just what I have found. That’s the big difference and it really matters. Moreover, it cuts just as fast as the Shapton, maybe faster, but is practically more efficient because I have fewer do-overs. There is also no tendency for the blade to skip as on the fine Shapton.

The Shapton is 16K and the Chosera 10K, so does this mean a step down in edge quality? Grit number is just one factor is producing edge quality. Others include the particle shape and how it fractures, the consistency of particle size, the density of the particles and how they present at the surface, and the properties of the binder. In practical shop use, the Chosera has been producing edges not one bit less sharp or otherwise of lesser quality than the Shapton. In fact, I think it’s better, if only because I can better feel those last whispery kisses of the sharp edge on the stone to get it just right.

The minor downside of the Chosera is that it needs pre-soaking. Various recommendations can be found for this including that soaking is optional. I’ve found it needs 15 minutes. Less soaking, 5 or 10 minutes, makes the stone too quickly drink up the water you splash on when starting to sharpen. When finished sharpening, I flatten it while it is still wet with the Shapton diamond lapping plate.

I still use a 1200 grit diamond stone as a nagura and remain convinced this enhances the action and feel of finishing stones including the Chosera 10K, as well as the quality of the finished edge. (More to come on this soon.) I did not find helpful the nagura that comes with the Chosera.

This is an expensive stone but at more than one inch thick, it will last a long time. The bottom line is that it has made my sharpening more assured because of the excellent feel.

Category: Tools and Shop  | One Comment
Author:
• Wednesday, September 17th, 2014

Here’s a great idea for your next woodworking project!

The Patriot Guard Riders of New York, members of the 1/4 million-strong national PRG, honors United States military veterans. One of their efforts, the Veteran Recovery Program, has as its mission to identify and honorably inter the unclaimed cremated remains of veterans. The Northeastern Woodworker’s Association, based in the Saratoga Springs, NY area, contributes to this effort with some of its members crafting superb wooden urns to contain cremains. They have been aided by generous donations of lumber from Downes and Reader Lumber and Leonard Lumber, suppliers to Curtis Lumber.

In solemn ceremonies befitting the honorable service of the deceased veterans, the urns are placed by military honor guard in inscribed chambers in a cemetery columbarium. Read about one such ceremony at Saratoga National Cemetery in this article from the Times Union, which also gives more information about the program. [The photos of the ceremony are used in this post with the kind permission of the Times Union.]

I learned of this program when I visited the PRGNY’s booth at this year’s fabulous NWA Annual Showcase in Saratoga Springs. As a woodworker, and especially as an American, I was honored to participate by building the urn pictured below and shipping it to the program.

Heartwood readers, here is an opportunity to step up and use your woodworking skills and creativity for a great and honorable cause. The urn can be made in any shape, design, wood, and finish to yield an interior volume of 230 cubic inches. Urns have a fixed top panel but are filled via a removable bottom panel fastened with screws. A small plaque with the name of the veteran will be placed on the urn. The urn you build will be permantly placed, in ceremony, in a sealed inscribed compartment 10″ wide by 14″ high by 18″ deep that holds two urns, in an outdoor columbarium.

Contact Bill Schaaf, the coordinator of the program for the PRGNY, for more details and to arrange shipping your completed urn. Your work will surely be deeply appreciated.

Category: Resources  | 4 Comments
Author:
• Tuesday, September 16th, 2014

hand planes

With their new line of customizable hand planes, Lee Valley/Veritas continues their impressive record of innovation in woodworking tools. Within each plane size, you can choose the blade steel, the handles (thankfully), and the frog.

The most compelling option, in my view, is the choice of frogs, and particularly in a smoothing plane. This gives us yet another way to vary the attack angle. This is simply how high is the angle (from horizontal) of the top surface of the blade at its very edge. In other words, it is the angle at which the blade meets the wood. This is one of several factors, a critical one, in reducing the dreaded tearout of hand planing.

Let’s look at the mainstream options for attack angle that we’ve had so far

In bevel-up bench planes, the blade is usually bedded at 12°, though I continue to assert that 20° – 22° would be better. The attack angle is determined by the bed angle plus the sharpening angle of the most distal bevel, usually a secondary or micro bevel. For example, a blade with a 38° secondary bevel sitting on a 12° frog, gives a 50° attack angle.

By maintaining multiple blades or re-honing a single blade, you have your choice of attack angles. By the way, because the wear occurs more on the bottom surface of the blade, the Charlesworth “ruler trick” is especially helpful when sharpening bevel-up blades.

In bevel-down planes, most are made with 45° frogs but Lie-Nielsen offers a choice of 45°, 50°, and 55° frogs for most of their great bench planes. I like the 50° frog in my L-N #4 smoother. The attack angle in a bevel-down plane is usually determined simply by the bed angle. The nifty exception is the back bevel, which is a tiny bevel on the (otherwise) flat side of the blade. For example, in addition to conventionally sharpened blades for my #4, I keep one prepared with a 10° back bevel to produce, with the 50° frog, an attack angle of 60°.

What’s new

Now Veritas, with their awesome manufacturing capabilities, offers a full range of bevel-down planes with your choice of frog angle from 40° to 65° in 0.5° increments. Furthermore, extra frogs can be ordered that can be easily swapped into your plane. So, you could outfit your #4 smoother with a 45° frog and an O-1 blade for a project in pine, then swap over to a 57.5° frog and a PM V-11 blade for a project in figured maple. The caveat is, of course, that I haven’t used these new planes so I cannot judge if their innovative design actually performs well at the bench.

All of this means we have more choices and a greater, though happier, burden of choosing. Obviously, each of us does not need or want every tool and option available, so it is more important than ever to make intelligent choices in tools.

Category: Tools and Shop  | 2 Comments
Author:
• Sunday, September 07th, 2014

poplar and bubinga

Woodworking instruction and practice usually make use of easily worked woods such as poplar or pine. This is practical – it makes learning easier and fosters confidence.

However, when moving on to more cantankerous woods, the techniques may not be fully applicable. Not only quantitative changes but also qualitative alterations in technique may be necessary. This may surprise and confound the learning woodworker and, as I often say, that includes all of us.

For example, the adjustment in cutting dovetails in red oak after practice in poplar is not just that you have to swing the mallet harder. The tolerances for sawing and fitting that work for the more compressible poplar won’t produce good results in oak. Chopping to the baseline is also different in oak. It helps more to clear the bulk of the waste with a coping saw, yet once done, there is actually less tendency for the chisel to push back beyond the baseline when chopping if it is done in appropriate increments.

The point is that however you like to do it, it pays to reconsider techniques based on the wood at hand.

Hand tool enthusiasts seem to like chopping mortises with a chisel and making tapered sliding dovetails entirely by hand. Fine in pine, poplar, mahogany, and so forth, but how about bubinga? Similarly, I like to hand plane to the final surface whenever practical but for blister maple, hey, it’s time to reach for scrapers or the random orbit sander.

Likewise, someone working almost exclusively in mahogany will surely have accommodated his techniques to that wood and the design style in which he works. That’s good, but it’s not likely that you can transfer all of those techniques and habits to a substantially different wood or style, and certainly you cannot do so unthinkingly.

Woodworkers work in wood, and wood is a very diverse product of nature. We’ve got all sorts of tools – planes with different angles, saws with different teeth, machines with different cutters, and so on. As for anyone good at any skill, a good woodworker ought to have a range of techniques to thoughtfully employ as needed when building in different woods. Further, it pays to be open to expanding that range when encountering unfamiliar woods.

Category: Techniques  | 2 Comments
Author:
• Tuesday, August 26th, 2014

jointer knife alignment

Let’s explore a simple method to verify the alignment of jointer knives, which is necessary when changing or adjusting them.

The first goal is to have all of the knife edges across their full widths in a consistent relationship to the outfeed table. The top of the arc of the knife edge should be very slightly above the level of the outfeed table. Secondarily, perhaps after the edges wear down or the jointing performance needs adjustment, the overall height of the outfeed table can be tweaked.

There are several good approaches to dealing with this, some involving dial indicators and specialized accessory equipment, but I prefer a low-tech method. Though well-known, how accurate really is it?

Here is how I perform the test, starting with unplugging the machine. A block of wood, about 3/4″ thick x 1 1/4″ x 4 ½” long is carefully jointed (by hand) and marked with 1 mm gradations. As you can see, I like to label the jigs I make with a description and reminders. It is placed in a reference position on the outfeed table (photo above, at top).

Then, the cutterhead is carefully rotated by hand to allow the knife edge to “grab” the block and advance it through the portion of the edge’s arc that is above the level of the outfeed table. The block is deposited as the edge “lets go” and continues its arc below the level of the outfeed table. (Photos below.) Note that a wooden test block is better than a metal ruler, which the edge doesn’t grab well.

jointer knife alignment

jointer knife alignment

The beginning and end of this arc define a tiny chord of the knife flight circle. The height of this chord is the amount of projection of the knife edge at its highest point above the outfeed table. The test is repeated at three or four places across the width of each knife.

Now let’s correlate this height with the lateral travel of the test block, which is the length of that tiny chord. A mathematical formula involving the Pythagorean theorem gives the results, tabulated below, for the 72 mm cutterhead knife flight circle on the Hammer A3-31.

Knife

Projection       Chord          Chord

(inches)          (mm)          (inches)

.0005             1.9             .075

.001               2.7             .106

.002               3.8             .151

.003               4.7             .184

.004               5.4             .213

.005               6.0             .238

.006               6.6             .261

The method is very accurate! A mere .001″ of knife projection moves the block 2.7mm, which is easily distinguishable from no movement, which signifies no projection.

However, note that the relationship of the knife projection to the advancement of the test block is not linear. The first thou of height advances the block 2.7mm – about 3mm. However, a height difference from .002″ to .003″ only advances the block about one more mm (0.9mm).

Fortunately, I want the knives to be a only about one thou, two at the most, above the outfeed table so all I have to do is see that the block advances about 2-3 mm, or 4mm at the most, and do so reasonably consistently across the blade width, for all of the blades. Indeed, the Hammer manual recommends 2-3 mm of travel.

So, there it is: a low-tech, accurate method. But now, after having analyzed it a bit, I have more confidence in it and can use it more intelligently.

Category: Tools and Shop  | 4 Comments
Author:
• Wednesday, August 20th, 2014

Hammer A3-31

This final installment in the series will discuss changing blades in the Hammer A3-31 and some summary thoughts on jointer-planer combo machines. [The entire series can be viewed here.]

With some jointers and planers, changing blades is a tedious chore. Long ago, I struggled with the old spring-loaded jackscrew system on a jointer. Brutal. By contrast, changing blades on the Tersa cutterhead that was in the Inca jointer-planer was almost unbelievably easy and fast. The OEM system on the Dewalt DW735 planer was quite easy, and now with the Shelix cutterhead with carbide-tipped inserts installed, changing blades is practically a non-issue.

The system for changing and adjusting the blades on the A3-31 is very good, though not quite the slam dunk of a Tersa. Each of the three blades has holes that neatly register on bosses on the blade holder, which is secured in a slot in the cutterhead with four hex socket screws using the provided T-handle wrench. (See the photo above.) This is easy to do, though a cutterhead lock would make it easier.

If necessary, the blade holder-blade assembly can be adjusted for height with the four adjustment screws within the holder block. These can be used to make a consistent projection of the knife in relation to the outfeed bed across its full width. Further, the height of the outfeed table is adjustable to set its overall relationship to the arc of the knife edges.

The factory settings, which I assessed when the machine was new and the knives were fresh, were excellent; no changes needed! So, when I installed replacement knives, everything should stay the same, right? Well, it worked out pretty well, maybe actually well enough, but not quite to my satisfaction. Somehow, despite great care on my part, gremlins sneaked in and I had to fiddle with the height adjustment screws to get an a consistent projection across the width. (This is not a matter of a difference in the overall projection related to worn versus fresh knife edges.) The manual explains a simple assessment procedure to help get it right and I am happy with the results. Note that perfection is not necessary for this. By the way, another option is the helical insert cutterhead available for the A3-31 from Hammer.

Here’s the key: the machine performs accurately, consistently, and efficiently. I get the results I need to make high quality things from wood. This is what matters.

In summary:

1. For the reasons explained in this series, I highly recommend a 12″ jointer-planer combination machine for the small shop woodworker.

2. After 2 1/2 years experience with the Hammer A3-31, I heartily recommend it. As with any machine, there are a few shortcomings (for this fastidious woodworker), which I’ve covered, but this is an excellent machine that can be a great partner as you pursue excellent woodworking. I cannot fairly compare it to corresponding offerings from Minimax, Jet, Rojek, Grizzly, and Rikon because I haven’t used them, and I’d bet the $7,000 Felder AD-531 outshines all of these, but I can say I’m very glad I have the Hammer A3-31.

Author:
• Wednesday, August 13th, 2014

Hammer A3-31

Now for a look at the parts and systems of the Hammer A3-31 that can be adjusted and tuned, with particular consideration to the ease, accuracy, and durability of the adjustments.

Jointer beds

When the machine arrived, the beds were slightly out of parallel to each other across their widths (i.e. in twist) – by .006″ over the 12″ width. Not bad, but having seen the potential in the excellent flatness of the beds, I wanted to improve their alignment.

Since the alignment of the outfeed table to the knife arc was fine from the factory, the twist was easily removed by adjusting only the two bolts (see the photo above) on the operator side of the infeed table to make the tables parallel within .001″.

Next, using a long straightedge, I determined that the infeed and outfeed beds were tipped along their lengths toward each other. The gap at the middle was 0.018″. To my mind, this is like have a concavity along the full length of a jointer plane sole and would make accurate jointing difficult at best.

Again, the correction was made by adjusting only the infeed table. This was a more complicated adjustment involving the pair of bolts on the operator side and a pair of setscrews, accessed under a removable panel, on the hinge side. Each of each pair of screws must be adjusted by a different amount. To make a long story short, I did a little trigonometry to prevent having to do it by trial and error. The result: cha-ching! The beds are parallel along their length within .001″.

Unfortunately, the Setup Guide, which covers these adjustments and is available as a pdf on the Hammer website, is out of date (copyright 2005). It references an earlier design of the machine and much of the adjustment parts have changed. Fortunately, Hammer makes knowledgeable technicians available by phone who were generous with their time in helping me understand the machine.

I called Hammer this week in anticipation of this post, and they favorably received my suggestion to update the Setup Guide. The User Manual, included in print with the machine and also available online, is more current and clearly explains assembly, basic adjustments, operation, maintenance, and so forth.

Planer bed

I tested this on a performance basis by planing an 11 3/8″-wide board, and by planing two narrow sticks simultaneously sent into the planer at the outer width of it. From the factory, the planing parallelism was within one thou. Wow! This is adjustable if ever needed.

Digital handwheel

This accessory, which I have found very helpful, was calibrated using the information in the Setup Guide. Reading it takes a bit of getting used to because the numerals indicate decimal inches while the hash mark increments are actually metric that approximates imperial. It is really not a problem though.

Hammer A3-31

Fence

Setting up the fence accurately went according to directions, though it does take some care. To maintain a consistent angle, it is important when adjusting the side-to-side position of the fence in use to hold the sliding bracket down firmly on the extruded track while tightening the knob.

In summary, the A3-31 can be tuned to a high degree of accuracy. There are some finicky steps for those who want to tune it really well. Some documentation is lacking but help is available.

The most welcome feature is that the adjustments hold solidly over time and when converting back and forth from jointer to planer mode. This is invaluable.

Next: one more installment – knife changing and an overview.

Author:
• Friday, August 08th, 2014

Hammer A#-31

Let’s take a detailed look at the Hammer A3-31.

When considering a new machine or any tool, I first assess the quality of the key parts that cannot be altered by the user but are accessible to direct evaluation. Here’s how the A3-31 stacks up in this regard.

1. Bed flatness is excellent. Against a Starrett straightedge, the jointer infeed table is within .001″ along its length and .002″-.003″ on the diagonals. The outfeed table is just a hair concave along its length, .003″-.004″, and the diagonals are off by only .002″-.005″. The planer table is within .002″ along its length and .003″ on the diagonals.

This all is excellent, well within Hammer’s spec of .006″, and is an important factor in how accurately the machine can be tuned. Furthermore, the beds are heavy and constructed with thick ribbing, as seen above.

2. The planer feed mechanism does not balk with 12″ wide boards. The steel drive rollers control the board unyieldingly, yet the indentations made by the infeed roller are shallow enough to disappear when the final pass is very light. With good technique, snipe is about as minimal as it gets.

The feed speed is 6.5 meters/minute (21.3 feet/minute), which makes the three-knife cutterhead at 6000RPM produce 70 cuts per inch, typical for jointer-planers in this class. Compared to the DeWalt 735 (with a stock cutterhead) at 96 cpi in “dimensioning” mode and a phenomenal 179 cpi at the slower “finishing” feed speed, the A3-31’s 70 cpi may seem a bit rough but in fact it seems to strike a good balance between producing an excellent surface and working at a good pace.

Hammer A3-31

3. I like the Euro-style safety guard better than the spring-loaded “pork chop” style. I always use paddles for face jointing and it is easy to pass the board under the narrow guard, which is height-adjustable using the knob at the far left in the photo below.

Hammer A3-31

For edge jointing the guard can be adjusted laterally to expose the minimum width of cutterhead. It would be better if the guard was hinged so half of it would hang down when it is adjusted very far toward the user side of the machine – but it’s not in that position too often so it hasn’t been a problem. The hinge feature is present on the company’s higher priced models.

Hammer A3-31

4. Dust collection, as I mentioned earlier, is just wonderful, for jointing and planing. This helps a lot in my small shop.

5. The construction of the aluminum fence makes it very stiff. It is flat within .001″ in all directions and I cannot detect any twist. It is adjusted back and forth by using the knob (to the right in the photo below) and sliding the bracket on the extrusion track.

A slight complaint is that the squareness of the fence to the table cannot be made exactly consistent throughout its full adjustment range and most of its length, probably due to minute errors stacking up. However, the discrepancies are quite small, and by finding favorite locations for the fence, I have had no problem getting nice square edges on long boards.

Hammer A3-31

From the back view, you can see that not much sticks out – only the rear cutterblock cover. For most fence positions, the net depth of the unit is about the same with the jointer beds down or raised.

Hammer A3-31

Other key components that I cannot directly assess seem very good based on indirect observations and working with the machine. Machining and part formation looks neat throughout, with no ill-fitting components. The motor has excellent power and does not get overheated. Hand adjusted parts, such as the planer bed adjustment are very smooth, and the machine runs with that nice low hum suggestive of quality.

The same outfit that makes Hammer machines also makes the much more expensive Felder line. A Felder 12″ jointer-planer lists at over $7000 (ouch, my hand just cramped up at the keyboard), which is more than twice the price of the Hammer A3-31. I figure that the expertise and institutional experience applied to the Felder line must bleed over into the Hammer line. I’d bet it’s more than half the machine for half the price.

Next: The final next installment in the series will cover tuning and results.