Cutting!

Today I moved up to the cutting tent following the pieces that we laid out, and began cutting.  Many of these joints on the bridge need to be really precise because of the huge forces being exerted on them, so the cutting needs to be very precise.  All of our cuts are knifed along the drawn lines, and then I ran my saw right down the line.  Occasionally the saw (I'm using Japanese saws) would wander a bit in some of the deeper cuts, and I would have a belly on the face to chisel or plane flat. 

My cutting was periodically interrupted for the sake of moving some of the larger timbers for the second lay up, as well as for the false works (aka cribbing or trestles) that we will use to move the bridge in to place.

This is Bruce drilling some holes with a precise jig he built earlier.  These holes need to be pretty spot on to line up with the corresponding points on the top of the bridge.  These will hold the tension rods that connect the top and bottom chords, which are the long single sticks that run along the top and bottom of the truss.

Baron enjoying the big square mortise machine.

Me using my new saw to cut a joint, and the pile of sticks with completed joinery.

This evening I took some time and roughed out a couple of spoons from an Apple tree that we trimmed when setting up cutting stations.

More of the Same

Today was mostly the same as yesterday, finishing the layout.  We did label all of the parts for reassembly, I should have taken a photo of that.  It's a pretty simple, but really cool system.  Some people will start cutting tomorrow, and some others will begin laying up the second (downstream) truss.

Above you can see the beginning of the cribbing that will allow us to slide the fully assembled bridge into place, and then will be removed.

Because this blog is rather empty of cool exciting things, here's also a picture of Will doing some precision joint cutting the other day:

For more detail, and a wider eye than mine, take a look at the official TF Guild blog:
http://chesterbridge.wordpress.com/

Learning Scribe Rule

 We spent all of today working on the first layup, as its known in these parts.  This is one truss that will make up one side of the bridge.  Layup included establishing the top and bottom chords (beams) in their respective relationships (parallel and centered), measuring for the vertical posts, and laying those in their respective places.  With everything carefully shimmed into level and plumb, or as close as you can get with semi green rough sawn lumber, we began marking for the joints.

When I was preparing for this trip, I searched high and low for information on timber frame layout, and all I could find was that there are two primary ways: square rule and scribe rule.  I know that square rule focuses on the idealized timber within the actual timber and that scribe rule deals with laying out all of the timbers and marking them in relation to one another.  I also know that many modern frames use a combination of the two techniques for different components and applications.  What I could not find on the internet was anything more useful or detailed than what I've written above, so I was unable to even learn the theory behind these techniques.

Now that I am here, learning some of the fundamentals of scribe rule, I see why that is.  This is really difficult stuff to convey in words without being able to physically perform the operations and demonstrate it in real time.  I think that a well made video could do wonders for learning the basics, or even more advanced techniques, but you really need to be able to see and hear what is going on for it to make sense.

The main tools we used were a variation on the plumb line and a pair of dividers, as well as a pencil and a small ruler.
 

The frame in lay up, with the bottom (in the picture) posts not yet aligned.

Will demonstrating the technique.

Building a Bridge and Eating a Pig

A crew of local and remote volunteers cutting parts.

Will cutting a critical joint to precise tolerances with the chainsaw, trimmed to closer tolerances with a few chisels and planes.

We had several locals come out and cook up a whole pig for everyone today, I think we have enough pork to feed an army for the rest of the week!  It was superbly done.

A stack of knee braces ready to fit into the frame.

Below you can see what I worked on all day, that single beam all the way on the right.  It was two beams this morning, we spent quite a bit of time laying out and then cutting the six foot long scarf joint in the middle to make a 37 foot beam in the end.

Official Day One

Today was the first official day of the Wason Pond Bridge project.  We spent the day building sawhorses.  We will end up with 10 pair, 20 horses total.  We built these assembly line style, doing them one operation at a time.  We're a little more than halfway done with final assembly, and the rest of the horses will take probably no more than an hour or two to finish up if we have a few guys doing them.  My little Makita impact driver really got a workout today!  I even had to change the battery a couple of times.  

Some of the timber was also sorted out and prepared for the preparations.

Today was very hot, I think I probably drank over 4 liters of liquid and I still felt dehydrated and overheated.  A dip in the pond at the end of the day felt great.

Below you can see the weir that the bridge will span. 

The Beginning

Yesterday after work I emptied out my car and started to pack by piling all my tools on the ground around the trunk.  It was at this point that I realized I was in trouble.  Luckily I got nearly all of it in without too much difficulty, and even had room for some camping gear and a bag of clothes.  I left behind one toolbox and a few miscellaneous tools that I don't anticipate needing.

This morning I took my time getting up, loading the last couple of things, and hitting the road shortly before 11.  After a largely uneventful drive, I arrived at Wason Pond in Chester, NH at about 2.  I met a couple of the other early birds (official arrival day is tomorrow), and I'm now at McDonalds a few miles down the road enjoying a cold drink and some internet.  Today was hot.  I think I'll be taking another dip in the pond when I get back.

Here are a couple shots of the site and the lumber.  In the second photo, the concrete you can see toward the end of the wood stacks are the two sides of the span for the bridge, about 18 or 20 feet by eye.  Tomorrow is going to be setup day and I need to sharpen a few things I ran out of time for this past week.

Salvaging Wood and New Saw

  

A house that I've been working on got a new boiler, which came in a nice simple crate made of White Oak, Cherry, and maybe some Maple.  I spent a few minutes at the end of the day pulling it apart and saving the nicer pieces.  The slats are 1/4"-1/2" thick, maybe 3" or 4" wide, with some other assorted size pieces.  I guess I can use the thin stuff for some cute little boxes or some other little project. 

Yesterday I whipped up a quick handle for that sawblade I mentioned in my last post.  I used some riven Maple from the back yard, axed and knifed to shape, cut a kerf in it, and secured the blade with a bolt and a small screw lower down to keep the blade from rotating around the bolt in use.  It's not pretty but it will do the job.  I'm pleased with the blade so far, a bit thicker and seems like much better quality than my old cheap Sharksaw (my first handsaw from a few years ago).  Now that I have my nice one, I can relegate my Sharksaw to construction work, not that I ever use it for nice cuts anymore.

It's Been A While

It's been a while since my last post.  Once Spring kicked in, work picked up, so I've been working a fair amount.  I've been goofing around with spoons a bit, but nothing worth posting.  I've also gone on a couple of camping trips, spending time with my friends, running and biking quite a bit more than in Winter.

This week I'm going to be heading up to Chester, New Hampshire to participate in the covered bridge project that the Timber Frame Guild is putting together.  It will be a 9 day project, during which an entire covered bridge will go up.  I'm really excited.  I've started to put together my packing list, which includes all of my tools and maybe an extra shirt or two.  I had the thought that it might be handy to take my Underhill-Roubo bench, but I don't think it would be that useful.  It would also be very difficult to get into my little car.

In the next couple of days I will probably be spending some time sharpening, oiling, and tuning up all of my tools, or I might wait until I get up there since I'll be a day early.

For this project, I just bought myself a nice new RazorSaw 10 1/2" dozuki blade and a 220/600 grit 2x6" DMT plate.  Looks like I might have bought a blade that's not compatible with the handle I have, though, so I might have to whip something up.

That's all that's happening for now, I'll try to stay on top of this blog more.  I'll definitely be taking some pictures at the bridge project, so keep an eye out for those in the next couple of weeks.

Oh, and the bandsaw I got broke right after I bought a nice new 80" resaw blade, didn't even get to put it on.  If anyone wants to buy the blade (or the saw for parts, for that matter) drop me an email.  The carriage that the top wheel rides on snapped in half, old cast iron...  Most of the other parts are in good shape though.