Tuesday, July 29, 2014

This doesn't Dovetail

Visiting a house in Connecticut the other day, I came across a coffee table:


A standard type of commercially produced furniture, with the drawers being continuous from one side to the other. Nothing special. A little expressed joinery at the table top corners is a nice touch.

At first glance the corner blocks are dovetailed together:


Looking closer though, only one board is dovetailed:


I understand that someone might want to simulate dovetails in some manner, to give the look but at a cheaper price point, however in this case the amount of labor required to do the simulation is scarcely different than it would have been if the pieces were actually dovetailed. All four corners of the table are the same. I guess they must make up stock which is trapezoidal in section to simulate the dovetail pins.

Simply bizarre. At least it is solid Black Cherry though.

Thursday, July 17, 2014

Boxy Lady

At long last some freight from Japan showed up today. Fortunately the box was just narrow enough to go through the freight door, which is only about 47" wide for some strange reason - a 48"~50" opening would be more convenient I guess:


I wheeled the behemoth down to my shop space, and was keen to get the box opened to see what the winds had brought. I knew what was supposed to be inside at least....

A first crack into the plywood box:


A relief then to find that I had received the same machine I bought, in the condition I bought it in, with no shipping damage or missing parts:


A while later I had the box side walls off to reveal the little lady:


Ships are assigned a female gender, so to speak, so why not surfacers?

I find that a johnson bar, pallet truck, and some 1" pipes are mighty handy for maneuvering machines around single-handedly:


At this point, I wasn't totally sure about the exact location for the machine, and it was physically larger than I had imagined, but it came with a long extension cord, which made it possible to set up if even on a temporary basis to check things out. So I wired a new plug onto it and plugged it into an existing outlet to power it up. First I needed to raise the drive unit up to get the support tables out.

Then came the moment a while later - does it work? It would be an awfully heavy ornament after all.

A piece of hinoki from the old MFA gate reclamation seemed the appropriate material with which to christen the machine. I pushed the drive belt feed button to confirm the 3-phase was correctly wired - it was. If wired wrong, the belt would have rotated the wrong direction, which would just have meant swapping a wire around, no big deal. Sometimes we get lucky with the wiring, heh-heh.

May as well see what happens when wood goes in one end:


Seems to work just fine - I was pumped!!

Some people say that super surfacers are only good for softwoods. I know that to be false, however seeing is believing as they say. I know there are doubters out there, some professionally trained as doubters in fact. How about some curly bubinga? This can't possibly work - or can it?:


Oh damn! This isn't working at all:


Yep, looks like super surfacers are only good for softwoods, what was I thinking?:


Some people may refuse to accept pictures like the above at face value, or any information that might contradict their world view, and I'm okay with that. Horses also tend to be calmer with blinkers on, and I'm kinda surprised a human version hasn't come about yet. Hah- I tease! Sorry! The stubborn ones out there know who they are.

Meanwhile, back in the reality of my shop, there is wood of all kinds to be surfaced and it will be interesting to see how the chō-shiage-kanna-ban handles various materials as I become more used to operating the new machine. For now, it looks like it will save me considerable labor on the bubinga.

A view of the underside of the two knife cassettes - the standard re-sharpenable knife type is fitted at the moment, and there are two of them:


There's a rubber plug on the top at the back that I was curious about:


Turns out it is for fitting a hand wheel so that the drive unit can be manually raised and lowered:


Depth scale is in metric and shakkan-hō:


What else is going on here? Well, it has a foot-pedal operated control unit:


Here are the insert knife cassettes and 10-pack of blades, along with the manual and a couple of dry lube sprays provided as a courtesy by the seller:


There is a modest tool set, which fits into its own compartment in frame of the machine:


Not quite sure what the metal dowel to the left is for at this point.

Here's the super surfacer most of the way to being set up, except for some remaining wiring work- and the small Hitachi bandsaw tucks in there nicely:


It will take a while to get used to seeing it in the space. Tomorrow I'll probably move the surfacer another few inches closer to the post, and maybe 6 inches closer to the jointer, and then I can put in the dedicated wiring. I've already picked up the 3 phase plug and receptacle, so I just need a few EMT fittings and pipe yet.

To make space for the new machine, I moved the chopsaw over to the other side of the jointer, and managed to tuck the hollow chisel mortiser in at the end:


It was like a game of machine tetris in there the past few days as I figured out how to accommodate the new surfacer into the space, but it seems to have come together well. I figure another day to button things up and then I can get back to making stuff, save for a few mods needed to the dust collection piping now that the little bandsaw has a new spot.

Thanks for coming by the Carpentry Way.

Wednesday, July 16, 2014

2014 Northeast Tour (Part 2)

For part 1, click here.

---------

From Woodstock we traveled south on Rt. 106, to the county of West Windsor, where a few more covered bridges were to be found. The first one we came across is called Best Bridge, a fairly modest affair:


This was built in 1889 and spans 37 feet over Mill Brook.

The bridge is a simple arched truss, placed atop carrier beams and employing tie rods to hold up the roadbed:


Underneath the deck, there is only scissor bracing:


Here's the foot of the arch meeting the carrier - double-notched and reinforced with two bolted straps, and a large wedge or two at the back to tighten things up:


A short distance away was Bowers Bridge, originally constructed in 1884~86, however a victim also of Hurricane Irene.

The storm waters washed the bridge 200 yards (182m) downstream:


(image from FEMA)

It's now rebuilt and back in place:


The newly rebuilt bridge incorporates some of the original pieces, notably the deck and most of the arched chords, and sits 18" higher.

Some online bridge sites give the construction date for the bridge as being 1919, but this cannot be correct, given some of the graffiti:


Simple framing for the common rafter roof look like a lot of barn framing, and support for the deck is by way of a tied arch like the Best Bridge just down the road:


The under deck with scissor bracing:


The joint between the foot of the arch and the sill piece:


We continued on south, entering the county of Weathersfield, where we came across the town of Downers and their bridge, a Town lattice truss spanning 120':


Constructed in 1840 by James F. Tasker, and restored in 1975~6:


Like the Middle Bridge in Woodstock, this Town lattice has two runs of top chords:
 

The lower chord supports an additional set of braces which meet at the ridge:
 

The braces make for a much stronger tie between the roof and the walls, and stiffen the structure considerably. I tend to associate them to old French framing practice. I well remember an engineer's article in an old issue of the Journal Timber Framing, where they found the addition of such braces to the standard knee-braced shed building, a standard Timber Framing Guild class project, finally made the building adequately stiff.

A view out of the window of Black River:


Next on the tour, further south in Springfield County, was Bartonsville Bridge, yet another bridge which suffered considerable damage from the Hurricane:



The good news is that this bridge, originally constructed in 1870, has been rebuilt and reset into position on improved foundations:


This is a Town lattice truss, spanning 151' and with single run of top chords:


I found the attachment of the braces to the side of the lattice a little unusual. Also new to me were the angled braces between the truss lattice and the walls, just visible in the above photo. They are so acutely angled I'm not sure what they really add in terms of strength or stiffness. It looks like the wall cladding kind of hangs on the rest of the structure, like a jacket

A view of the juncture between wall and roof framing:


A very well braced bridge with lots of galvanized bolts. Gotta wonder if the consulting engineer wasn't a bit twitchy about using treenails on the lattice instead of bolts:


Under the deck we see a combination of scissor bracing and tie rods:


Another view:


Nearby was the Worral Bridge, a Town lattice constructed in 1868 by Sanford Granger:


Love the sign:


Another bridge where the braces, at least some of them, terminate on the side of the truss web:


A view of the roof structure:


One last bridge, which no longer sits across a river, but has been relocated over a drainage ditch as a tourist attraction, the 'Victorian Village' covered Bridge:


I include this one as it is an example of a more archaic framing style, using a modified kingpost with straining beams:


Simple roof framing with a few added braces atop the crossbeams:


Stiffening a rafter here and there will make for an undulating roof plane over time. It would have made more sense to place a purlin and brace against that, but well, it is what it is. It's kind of a shortened and thrown-together mish-mash of an old bridge formerly called Depot Bridge (1872), incorporating other bridge parts, and some metal reinforcement underneath. Cars can still drive over it though.

That's all the bridges for this year. There are plenty more to be seen however so look for another post in this intermittent series in the next year or so. Thanks for visiting!!

Monday, July 14, 2014

2014 Northeast Tour (Part 1)

In 2012 my wife and I took a summer trip up to Quebec and returned in a loop coming down through Maine.

2014 finds my wife changing jobs, and to celebrate/take a little break, we decided to spend a couple of days up in Vermont at a bed and breakfast. Along the way, we came across several interesting structures, and I snapped a few pics which I thought would be fun to share here.

One of my favorite forms of domestic architecture are rural American train stations, as they are one of the few building forms you will see with significant eaves. The Japanese like deep eaves because the area underneath the eave, typically furnished with a wooden veranda, or engawa, is considered part of the living space and they like to spend time there. Thus is it an elaborated space in architectural terms. The train station has deep eaves also because people are spending time in such a space. Though the level of elaboration falls a bit short of what is seen in Japan, I nonetheless quite like the overall forms of these structures and am always interested to see how they chose to frame the eave, as it presents somewhat of a challenge to the carpenter.

This station in Vermont is a stop on the Green Mountain Railroad, at Chester Depot:


The curved lower roof is pleasing, to say the least.

This picture shows the zone of shade provided by the eave:


Why don't more houses have decent eaves, hmm?

I think it would look a little better with a hip bracket framed in, though the mitered line of the fascia is cleanly executed:


The backside of the station:


I looked up a few other stations on that line, and they have similar styling when it comes to the eaves-  like this station in North Bennington:


Next door to the Chester Depot station is another structure with a really deep eave on one side, presumably they park a vehicle under there in winter months(?):


We stayed the night at a b&b in Killington Vermont. The next day we traveled to Woodstock Vermont, which is a very picturesque little town. There we visited the Marsh-Billings-Rockefeller National Park and did some hiking around. We had hoped to do a tour of the mansion there, however despite being assured on the phone that we could just show up for a tour, the tour we wanted to take was full and reservations would have been helpful. Oh well.

Here's a look at what we missed:


Near the mansion is a white structure called 'the belvedere' with a conservatory and outdoor swimming pool. The exterior is quite detailed:


Curious though was the valley rafter under the eave, which is truncated for some reason, and presents a hodge-podge of framing:


It's common on run-of-the-mill framing of exposed eaves that the carpenter doesn't plan such detailing out very well, but on a building with such an elaborated facade it seems odd that the rafter spacing was not well considered. A case of sticking with standard common rafter spacing without considering what happens when things get together at a valley (or hip) - very common indeed.

In and around Woodstock VT there are a few notable bridges. The first one we came across is called the Lincoln Bridge and was constructed in 1877:


By far the most common covered bridge framing system around the northeast is the Town Lattice Truss, so I was surprised to see a Pratt truss with arch:
 

Another view:


The crossed tie rods are most unusual - this is the only one I've ever seen and apparently this is the only surviving example of this type. In a Pratt truss the vertical members, here supporting the arch, are under compression, while the diagonal rods act to resist tension loads. Patented in 1844 by Thomas Pratt and his father Caleb, the Pratt truss proved to be a very good design and saw adoption also with all-metal bridges.

Here's a closer look at the junction of the upper wall and tie beam - note the use of tension rods immediately underneath the knee braces:


The rods terminate outside the exterior cladding, which I thought was unusual:


Bit of a framing mish-mash here:


A view under the bridge deck - only metal rods used to stiffen the deck against lateral loads:


These metal brackets also capture the ends of a pair of double tie rods which run along each of the principal deck carrier beams, serving to keep the arches inside the bridge from flattening:


Another look before we move on - here focusing in on the roof and tie beam framing, which seems rather simple compared to the rest of the structure:


In downtown Woodstock there is a metal bridge which imitates the Lincoln bridge framing system quite closely, built in 1900:


Note the same arched truss with crossed tension rod system:


I grabbed one of the tension rods and found it rather loose. Looking down, I could see that its lower attachment to the truss had rotted off at some point:


Then I found another one with no lower attachment, just blowing in the wind, a bit hard to see in this photo though:


Not sure if anyone in the highway department is aware of this situation, but it needs some attention sooner rather than later. I'll give them a call about it.

Another notable covered bridge near Woodstock Vermont is the Taftsville Bridge, constructed of two spans in 1836. The bridge was heavily damaged by Hurricane Irene in 2011- this video shows the torrent of water which was striking the bridge at that time:



Irene caused some severe damage in this area.

In the aftermath, the bridge was in a sorry state, though the picture does give a clear view of the core framing elements:


In this bridge, the arches are carried directly by the stone abutments, while other arched bridges use a system where the arches terminate on the deck carrier beams.

The bridge has since been restored, and is in use carrying traffic today:


A view of the inside, showing the arches popping up above the deck:


This is a multiple king post trussed bridge with added arches-  you can see that the arches are using vertical rods to suspend the deck and do not act in the triangulated manner of the ones in the Lincoln bridge.

Here's one of the arches - notice the straining beam to the right, and the beams which connect to it, mimicking the arch to a certain extent:


 Here you can see the parallel use of an arch and truss frame system:


 In one location there were three straining beams for some reason:


A view of the underside of the deck, with scissor braced reinforcement and crosswise metal tie rods:


You can see in the above picture the kingpost truss posts sticking out through the main carrier beams, wedged in place.

A closer look at one of those connections:


Interesting piece of work - I enjoyed taking a look around:


One more bridge to be found in Woodstock and that is the Middle bridge, right in town


 One end of the bridge is unpainted, weathering naturally:


This bridge is a Town Lattice truss, a very common form, and a very strong design.

The other end of the bridge is painted:


Close up of the sign:


1969 is the year of construction - originally there was a metal bridge in this location. Middle bridge was damaged by fire in 1974 and rebuilt again by the same company, Milton Graton, from New Hampshire. His son Arnold continues the business today.

A closer look at the 2" oak pegging - treenails - on the lattice:


The design is quite stout, with a pair of tripled upper chords at the top, and a double run of doubled-up chords below that:


Part 2 will continue a look at some of the covered bridges I came across in Vermont last weekend. I hope this sort of material is of interest to readers out there.