the Carpentry Way: Riddle of the Shinx                                                          

Riddle of the Shinx

One piece of equipment I have been lusting after for some time now is a chō-shi-a-ge-kanna-ban, a term which translates to 'super finishing planer', or, among those familiar with the machines, 'super surfacer'.

These machines are uncommon outside of Japan. I would suspect that if you asked 100 woodworkers in this country (or yours), more than 95 would not have heard of, seen -much less used- one of these machines. Funny enough, they were produced in the US around the turn of the 20th century, probably in small quantities, never to be seen or heard of since. I remember thumbing through an antique machinery catalog (maybe of 1904 publication or thereabouts) at a used book store in San Francisco and seeing a drawing of a fixed knife planer with what looked a lot like a car tire above the small table to drive the wood over the knife. I wonder how well that worked?

A few super surfacers have made their way into the US market - it would appear that an attempt to market them in the US was made in the late 1970 to early 1980's, without what might be called huge success. It's doesn't seem like they caught on, and the reasons for that are fairly clear to me. More on that later.

A super surfacer is essentially a fixed knife planer using a conveyor belt drive to push the wood over the knife at great speed and pressure. In a way, they are a powered version of a cooper's jointing plane:

(above image from the Guinness Collector's Club)

A conventional power planer makes a rotary cut, which leaves scallops in the wood surface, and is primarily used to dimension material. A super surfacer takes a very thin shaving, just like a smoothing hand plane, and makes the final surface on a stick of wood - it's not used for dimensioning, unless you're looking to adjust a dimension by a few thousandths at a time. In some cases the surface left by the super surfacer can be improved further with a little attention from a very sharp hand plane, and in other cases the finish from the surfacer is about as good as with a hand plane. The combination of pressure and speed seems to allow the surfacer, with a blade sharpened typically to around #4000 grit, to perform surprisingly well, regardless of grain direction or the presence of knots.

Here's a video showing a Marunaka 'Super-Meca-S', their newer 'basic' machine:

I think the video fell down a bit on showing the planed surface quality,  but it can be tough to photograph. I never get tired of listening to koto music, and must have watched the above video half a dozen times by now. It's available in several other languages.

These machines are fairly quiet - hearing protection isn't necessary - and unlike sanders, produce no dust. They do not require a huge amount of electrical power like the bigger wide belt sanders. They are also very fast, a feed of about 1m. per second or so.

Just like there are portable job site power planers, there are portable job site-use super surfacers as well. And just like the 'shoeboxes', these small portables run on 100v. and tend to make a bit of noise, probably due to a reduction gearing mechanism in the belt drive. Here's a 4 minute video of a newer Makita portable, the LP1802C, and shows various aspects of the machine in detail:

This is a model in current production, one of 5 models Makita offers. They make a couple of different portables, a semi portable one, and a couple of large shop machines. Hitachi and Ryobi also offer super surfacers. The light duty portable machines have the knife above the fixed table surface (into which the drive belt is fitted), which is similar to the shoebox planers with their fixed bed and movable cutter head.

A typical shop-use super surfacer will process material to 10" (250mm) in width and 7" (180mm) in height. The portables can handle up to 7" width and 6" height material. There are larger machines however. Marunaka makes a machine designed expressly for shaving Paulownia wood, up to 24.4" (620mm) width:

The two principle manufacturers of industrial quality super surfacers in Japan are Marunaka and Shinx. Marunaka is likely the best known company in the west for making super surfacers, though I think they may well be better known these days for making edgebanders and veneer slicers. They make quite a few models of surfacer (I confess I'm not clear on why there are so many different models as the specs are very similar between some of the machines they sell).

 Shinx was founded in 1964 as Shinko Machine works. They are based in Shizuoka Prefecture and have 210 employees. Besides super surfacers, they make planer knife grinders, panel saws, some hulking CNC machines, machines for beveling metal plate, venturing also into LED products and medical equipment. They even make a specialized CNC machine for shaping surfboards.

One common point to many of their machines is the use of linear motion rail technology, instead of ground ways, or sliding collars on columns. Linear rails allow for high precision guidance of the parts, smooth motion, low friction and high rigidity. The benefit of low friction and easy movement comes into play with the unique design characteristics of the Shinx surfacer.

Shinx has a number of patents on their surfacers. One unique feature is that their surfacer can read the thickness of the stock as it is fed and instantly adjust position and pressure of the drive belt. This allows material with an uneven or convex/concave opposite face to be fed through the machine. They also employ a double knife stock, in which the knives can be configured in four different ways to suit manufacturing practice, and the knife cutting height can be quickly adjusted without the use of tools.

Here's a look at the Shinx 3XV-36, the predecessor of the current production model:

I must admit I've been coveting one of these for a while now. 2100 lbs of smoothness.

So, back to an earlier point: why aren't super surfacers more prevalent in North American shops? Most people hate the drudgery of sanding, and dislike loud machines, so what's not to like here? They're a lot cheaper than widebelt sanders.

I have a theory about it. Over the years, I have seen the odd surfacer, an import from the 1970's or 1980's, come up for sale on Ebay, Craigslist, IRS auctions, etc., and I notice a lot of them have the appearance of a tool which was used a few times and then quietly pushed back in the corner or left out in the yard. They remind me of the handplanes one sees in antique stores, where you can almost read the history in the appearance. Let's see, it was once grandpa's plane, and he used it as a professional cabinetmaker. Then he died and the tools got handed down in the family, at some point reaching the 'one' who figured it was just a simple looking tool and how hard could it be to use? And that 'one' had no idea how to sharpen a tool, or  understood how critical sharpening was to the effective functioning of the tool. And they couldn't seem to get the lever cap to go on the tool. They tried to use the dull thing once, blade likely poking through way too much, and tore a mess out of some piece of wood. Damn that tool! The 'one' tossed the plane on a back shelf somewhere, to be forgotten. A symbol of frustration even. Grandpa's legacy as a craftsman, proud possibly of his well honed and adjusted tools, and now?  Junk.

You see the tool years later on the shelf at the antique store, missing parts and looking beat to shit. It tells a story - and it's not about grandpa.

The super surfacers I have seen on the used market tell me a fairly similar story to those hand tools in the antique shops. You could imagine seeing one of these surfacers at a woodworking machinery show in 1981, and thinking, wow, this is pretty slick! Or, possibly by watching the video at the top of this post - - maybe it will get the juices flowing in at least the odd reader out there.

There's a critical piece of the puzzle being left out here though. It's not all about the surfacer.

You see, when you buy a surfacer, you don't just buy a surfacer. You buy two machines: a surfacer, and a machine to grind and hone the surfacer blade(s). Just like a handplane, the blade needs to be sharpened with a fair amount of frequency if it is to cut well. Buying a handplane without any means to sharpen the blade wouldn't get you very far. And, like a handplane, the blade needs to be set up with a certain amount of finesse if it is to take shavings cleanly and perform optimally. When you buy a surfacer, you must also buy a surfacer knife grinding machine, or kenma-ki , or you may as well buy neither.

I've observed a lot of different woodworkers and carpenters, and if there is one thing that runs through as a very common trait it is a reluctance or aversion to sharpening. I'm not going to explore the reasons for this here, but it is an extremely common thing. Setting aside hand tools and their sharpening, there is the sharpening of saw blades, planer knives, router bits, etc.. Let's face it: most woodworkers will work with dull tooling for far too long. HSS knives cut great in a planer for the first while, but then they go dull and cut poorly. So, why are those knives still in the machine 3000 linear feet later?

This attitude towards sharpening - just leave those blades in there and keep shoving the wood through, really doesn't work with a super surfacer. Not even a little bit. While the rotary planer with dull knives will leave a wooly or slightly chipped out surface, likely a bit glazed from the blades beating down on the grain, a super surfacer with a dull blade, and 1m. per minute feed, will either not cut at all, or....the cutter is raised and raised until...really nasty tear-out takes place. There's a nice piece of wood ruined goddamn it. This machine sucks! So, the machine remains a puzzle or an annoyance and is shoved into the back of the shop to collect dust.

I have come to this theory about why the super surfacer machine has never caught on, for a number of reasons, but one of them is that I have never seen a super surfacer for sale in this country with a blade grinder anywhere in evidence. The two machines must go together, no two ways about it. The other is a culture of expecting or wanting the easy way out of a thing, always, and machines or tools which require finesse and care in set up and maintenance are going against the cultural grain to an extent, sorry to say.

I'm hoping to have surfacer in my shop one day in the not-too-distant future- and a grinder too! I've been searching for one in Japan in fact, and may have found something.

Thanks for coming by the Carpentry Way. As always, comments most welcome.