the Carpentry Way: Riddle of the Shinx (II)                                                          

Riddle of the Shinx (II)

Well, I pulled the trigger and have purchased a used Shinx 3XV-360 Super Surfacer in Japan. Here are some pictures of the exact machine I bought:

The machine comes with the factory side tables and tool kit. It has been completely gone-through by the machinery rebuilding company I am dealing with and is in excellent condition. It's three-phase, 200v., and I have three-phase, 208v. power, so no issues there. One thing that makes Japanese machines attractive for import, besides the comparable voltages to North America, is that they are all built to work on 50Hz or 60Hz, so other than changing out the plug on the end of the cord, they are pretty much plug and play.

Infeed side, with table removed:


Control panel:

The machine has had one previous owner, and was not used much apparently. I paid about $5000 for it. It is still in Japan, as I am saving pennies to cover the shipping and crating costs, which, given the machine's size and weight (over 2000lbs) adds another $3500 to the price. Then of course there are likely to be brokerage fees and customs duties when it arrives in Boston, plus shipping to Western MA where my shop is located, so I expect that all-in, I will be looking at $10,000 for the machine. I consider that a good deal, though the shipping was more than anticipated. I'm psyched to at last obtain a good surfacer!

A few readers alerted me to a used surfacer for sale in the US, and while I had already known about it (it's been on the market a few months), I found the video produced by the sellers somewhat humorous - especially the opening scene - so I thought I'd share it here:

The board being thrown to the floor in the opening scene (how's that for the surface finish?), along with the continual shuffles of taking the board back around to the front to feed it again, illustrate well, I think, why having the side support tables, along with an auto-return function, is worthwhile on a surfacer. But the Royal Phoenix 10 by Marunaka is a pretty old machine, so fair enough. It was too small for my needs as well, but perhaps it will fit the bill for someone out there. No idea of the asking price.

I did a bit more digging into the history of fixed knife planing machines, as I had once seen an advertisement in an old machinery catalog for a primitive example. While I couldn't locate that example again, I did come across a bit of interesting information. Fixed knife planers were made in the US from around the 1850's. Here's an example, the Wilder Fixed Knife Planer, as shown in March 26th, 1853 issue of Scientific American:

Notice that the idea was to place a series of fixed knives - 8 in the above example - above the drive table (which had a form of conveyor system).

The earliest US patent I could find for a fixed knife planer was patent #8098 (May 20th, 1851), by William Beardslee, a machine configuration which placed the fixed knives in a vertical orientation:

As it turns out, what drove the innovation in terms of these fixed knife planers had less to do with trying to find a planer which would leave a glassy smooth finish, than it was to work around certain limitations of rotary head planers at that time, and, more significantly, to work around the patent monopoly and licensing costs then associated to most planers with cylindrical cutting heads.

While powered planers can be traced back to the 1790's in England, a certain William Woodworth of Hudson New York invented and then patented a 4-sided planer intended for producing tongue-and-grooved floorboards in one go - this is the infamous US Patent #5315X, for December 27th, 1828:

Several companies licensed the rights to make the machine, but Woodworth and his later heirs were extremely zealous in collecting fees for use of the design - known then as the Woodworth Planer Monopoly:

He and his partners built these machines, and sold them to operators who were set up in franchised territories. Franchisees charged $7 per thousand for custom planing, $3 of which went to the patent holders. This generated a huge profit and a war chest to intimidate anyone who might build or operate a machine designed for rotary planing of S4S lumber. Because of litigation costs, operators quickly settled and complied with patent-holder terms.

In that time the Patent Law allowed inventors to apply for patent extensions of 7 years, and Woodworth's heirs kept applying for these extensions, adding slight tweaks or improvements to the design, some of which they did not actually invent - like pressure bars - so as to apply for fresh patents. Like modern modern monopolists savvy in getting their way in the political process, the Woodworth's had an array of lawyers, editors, congressional 'friends' etc., that allowed them to keep the advantages accruing to their patent. According to Judith MacGraw's book Early American Technology: Making and Doing things from the Colonial Era to 1850, page 316, the patent was generating $15 million annually for the heirs, so it certainly was a cow they had grown fond of milking.

This patent monopoly was a big deal at the time, and still cited in a more than a few case Law Studies today. The situation came to a head in 1850 when Woodworth's son, William W., applied for another extension which would have perpetuated his patent until 1870. This created a public firestorm and mass rallies and letter-writing campaigns were organized. Finally, in 1856 the Woodworth patent was allowed to expire. The repercussions of this patent monopoly and its stifling of innovation changed US Patent law, as the 1861 amendment stopped the use of extensions altogether, setting the term to 17 years at most.

Baxter D. Whitney created and patented a planer in 1837 which planed on one side only, and this managed to evade the Woodworth patent. In time it became the archetype of the modern powered planing machine:


Whitney evidently felt the fixed knife planer also had merit, as they patented their own version in 1857, US Patent #17,992:

According to the entry at, apparently the frames and crude bearings of the rotary planing machines did not leave the smoothest of surfaces, and the fixed knife planer was created to address that deficiency. The patent application further states,

"This machine will be found particularly well adapted to smooth the surfaces of thin stuff such as is used for the hoop or sides of light wooden boxes (cheese boxes &C.) and veneered stuff."

Once the Woodworth patent faded into the background however, the rotary planer came to be the predominant machine used for wood planing, and the fixed knife planer disappeared from the scene by the beginning of the 20th century. Knowing how precise the blade grinding and knife set up of the super surfacer needs to be, I suspect that these early American fixed knife planers didn't work all that well, or at least did not lend themselves to use in a mass-production context, by uncaring workers just shoving stuff through machines. What has driven a certain amount of woodwork machine design in the US, besides economy in price, is that they be easy to use with a minimum of training (means labor costs are lower for the machine owner, and the labor easier to source), and can process as much material as possible (the more through-put, the more potential profit). The fixed knife planer likely did not fit so well into this mold.

I was looking on Japanese patent sites trying to get a sense of whether they might have taken the idea for the super surfacer from these early American machines, and at this point I suspect not. I think it is is a case of later parallel development. Looking at the Marunaka company website, I noted that they were founded in 1936, and they did not start working to develop the super surfacer until 1970. At that point, I doubt there were any examples of the early American fixed knife planers anywhere to be seen. I am curious to know if there were any brands of super surfacers in Japan in the period from 1900~1970. I haven't been able to find any examples so far of such old machines on any Japanese sites.

Anyway, back to the surfacer I have purchased, and which currently sits in a warehouse in Saitama Japan....

As mentioned in the previous post on this topic, just as there is no point buying a hand plane or chisel without having the means to sharpen the tools, there is little point having a super surfacer if one does not have a blade grinder. Shinx makes a fully automatic blade grinder, the SLA555:

These come in three sizes - above is shown the middle size, which can grind and polish a width of 650mm.

Trouble is there are not a lot of used blade grinders for sale in Japan at the moment, or of any brand of automatic grinder for surfacer knives for that matter. I prefer the automatic grinder as it will leave the most perfect knife surface, especially compared to manual-feed grinders, which are also hard to find for that matter. There is also a semi-automatic type of grinder produced by several manufacturers, also thin on the ground in Japan I have found.

After an extensive search, I found a couple of used Shinx grinders, but the machinery rebuilding company I have been dealing with said that neither was in acceptable condition - not good enough for them to put their name behind at least. I also learned that the price of a good grinder was likely to be about the same as I paid for the surfacer, and with the cost of crating and shipping added in, import duties, etc., I was looking at another $10,000.00. With this being tax season-  and yes, a chunk was bitten from my bank account - I don't have much spare cash floating about, so I was thinking it would be several months wait until I would be in a position to purchase a grinder. Even then, it was by no means guaranteed that I would even be able to locate a suitable machine.

Then I hit upon another idea. Looking at the Shinx machine brochure for the surfacer they currently produce, the EX-36, I noticed that among the four choices of knife arrangement that were offered, there was an option for 'スローアウェイ式', which transliterates to suro-awei shiki. Here's a fine example of an English word rendered in Japanese katakana script - suro-awei means 'throw-away' ~shiki is a Japanese word which means 'style'. Otherwise known as kaeba-shiki (替え刃式), disposable quick change knives are offered as an option on Shinx surfacers, along with other brands. If the factory offers them as an option on a machine of this quality, I suspected that the quick-change knives at least met performance requirements. More importantly, from my perspective, was that they represented an alternative to obtaining a grinder, shipping it, setting it up with power and water, allocating precious space in my shop to it, and so forth.

I sent a mail to the company asking them for more information about the quick-change knife option, wondering if the same could be retrofitted to the machine I had bought, how much it would cost to retrofit, how much the replacement knives cost, and whether they thought quick change knives were a good idea at all for surfacers.

I kind of presumed they might poo-poo the idea altogether, as they are in business to sell refurbished machinery, and would probably rather sell me a $6000 grinder than retrofit a part to the machine I had bought. To my surprise, they replied that they said that they thought it was a good idea. And not an expensive option either. All I would need to change out is the knife holder, which would cost $950.00. The disposable knives come in a 2-pack for a little under $80.00. The quick-change knives, as they are not re-sharpenable, can be made of a much harder steel than the HSS used in the grindable knives, and thus they last 3~4 times longer than the re-sharpenable type. Also, changing the knives out only requires a short period of time - loosen one bolt 1/2-turn, and slide the knife out and a new one in, then re-tighten the bolt. The quick-change knives are located using magnets, and there is no time required for dis-assembly, grinding, reassembly and precise setting of the knife to chipbreaker as with the conventional knife stock. No setting jig required either.

I thought about it for a bit and concluded it was worth giving this option a try. After all, if I found that this option wasn't working out performance-wise, or was costing more than I thought, the I can always opt to return to the conventional set up later on, and acquire a grinder and have it shipped over. Instead of having to scratch together $10,000 for the grinder+shipping, etc., I could look at spending $1600, which would get me the quick change knife holder and a 10 pack of blades (20 blades total), which should see me along a fair while, given the durability of the knives. The difference in price between going the grinder route and the quick-change knife route is more than $8000, and that buys 100 pairs of knives, leaving aside the other costs of setting a grinder up in my shop, and the time associated to changing out, sharpening and re-fitting the conventional knives to the surfacer.

Although the quick change knives are a consumable, and thus represent an on-going operating cost, the conventional grinder also had consumables in terms of the grinding and polishing wheels, and the knives themselves, which after multiple sharpenings will also need replacing, along with the chip-breaking knife. So, it's worth a shot, as far as I am concerned, to try these quick-change knives. I will give an account of their performance at a later date, after I've received the machine.

One last point for today's post: some out there have suggested that super surfacers are only suitable for softwoods, however my experience with them in the past, along with things I have seen and heard personally, does not bear this assertion out. I see that an older Marunaka machine actually had a chart on it giving the turntable cut angles for various woods (lower half of the picture below):

The row along the top of the plate with the Japanese on it lists Japanese wood species, some of which are not described in the English below, like sen, shitan, and so forth - not to mention the line up of names does not correspond precisely either. There are 28 woods listed in Japanese, 20 in English. Noble fir sits close to the 50˚ mark in English, but in the Japanese above it is just shy of the 40˚ mark. That matter aside, it does show that the manufacturer at least considers the machine capable of shaving woods as dense and hard as ebony and rosewood. I am now thinking that 0˚ is perpendicular to the material, so really hard woods will be cut with the greatest scrape, while soft materials like balsa and Paulownia can be cut with the knife at 50˚ to the direction of feed, with the greatest slice. Skewing a blade, after all, lowers the effective blade angle. That's one of the main reasons, I suspect, that super surfacers do such a good job: it's always a shearing cut. Interesting too is that this means that the surfacer can operate at greatest width with hard woods which must be tackled with more of a scraping cut, while the width capacity for the softest woods, due to the greater shear angle, is lowest.

All for now-  thanks for dropping by the Carpentry Way. To read about the machine's arrival and installation, click here.