Monday, May 24, 2010

O what a tangled web we weave

So far we've cut down trees, chopped up wood, made poles, crossbars, wheels, and assembled the frame. If hounds were attached to the poles (and a dog in harness) there would be something to pull.

To make the cart useful it needs a bed. Again, there were many options, from lashing or trenailing some boards, to a simple ladder frame for lashing a load to.

In the end I decided a wattle or basket weave would match some of the historical record, as well as being both strong and light.

Ideally the way to do this would have been to find a "basket ash" of the proper size and splint the necessary splints. Since I lacked a suitable basket ash I ripped splints by eye from long lengths of green tulip poplar. Ripping long, thin lengths from green wood with the table saw is not recommended. All my fingers are still attached, but then I'm not merely a lunatic: I'm a careful lunatic. :-)

After the splints were ripped, the widest were laid out on the bed of the cart and rough cut to length.


Then the splints were clamped with a temporary cross brace at the back and cross pieces were woven in. This was made easier by using a long dowel to pry apart the splints.

There is no cross piece at the axletree and all the splints lie flat on top of it. When the bottom of the bed was woven the front was also temporarily clamped, and the cross pieces were clamped with spring clamps to the frame. Everything was then left for a few days to settle and dry.


The sides then followed much the same procedure. They were originally held in place by friction, but I later trenailed them to the frame. Where the cross pieces of the bed rest on the frame they are simply held down tightly by the bottom batten of the side. The pieces holing everything together at the tops of the sides are clinch-nailed with cut copper nails.


The final pieces of the bed were cross bars front and rear. These were originally tacked with long cut copper nails, but the end grain did not hold well and I eventually trenailed them with "trenails" made from wooden axles from some old 'pinewood derby' car kits.

All that's left to cover is the iron work for the hounds, swingle tree, axlepins, and harness. This is going to require digging out the camera because I didn't take pics when I was making them. They'll be up on Monday after I get back from MKA&S. Also starting Monday, in time to get it finished for Pennsic will be the "Oseberg" wagon. I'm working on plans in Google Sketch-up and it's slow going, but I'm digging in the pitons and climbing the learning curve.

Lastly, for your viewing pleasure...

This is a shot of my daughter Caitlin's "Fairy glade in a forest at night" bedroom. The bed is a "talan" or "flet" such as the elves of Lorien use :-) Its tree trunks, and the supports for the bookcases were made from horse-chestnut trees that had to come down due to storm damage, and the ladder from some overgrown areas of tulip poplar that needed to be cleared.

Being now a teenager, and fairy-glens being "for little kids," the theme was recently changed to a tropical beach by the addition of a wall mural, and tropical plants and new lighting.

McK

Frame



Wheels are kewl, but to make all that work practical we need to mount them to the poles and a frame. There are innumerable options for this stage. After a lot of thought I concluded the best way would be cross bars at the front and back with mortise and tenons to the poles, with the poles slid through mortises in the axle. Thus no fasteners required, and as the green wood shrinks it pulls all the joinery tighter together. Above is a view from the back with the wheels mounted on the axles.


This is the right (starboard) pole passing through the axle tree.




This is the front cross bar tenoned into the starboard pole


And here is the rear cross bar tenoned into the starboard pole.

There's nothing exceptionally complicated about the crossbars. The poles were set parallel about the right distance to clear the dog's shoulders at the front and two boards were ripped to slightly longer than the width of the cart. The were then tenoned with the shoulders set to the inner distance between poles. The mortises were angled slightly so that the crossbars tilt out at their tops about 7 degrees.

The Axletree though is much more complex. I could have simply cut a board, driven some bolts in for axles and left it at that. But anything worth doing is worth overdoing.

The axletree began as a slightly curved cut billet from the same tree that provided the wheel hubs. Since oak is a heavy dense wood it is desirable to trim the piece of unneeded excess, which also produces a more aesthetically pleasing look.

After some work with the drawknife it was run through the planer and then squared by eye with the table saw and a little work on the jointer.

You can see the top, front and back have been squared, and the bottom (with some bark still on) shows the natural curve of the board.

A dowel from one of the hub fiddles is used to mark out where the wood will be cut away for the axles.

Unfortunately, the step-by-step of pics of the axle seem to have wandered off... My first thought was to make a springpole lathe and turn the axles but due to the curved grain and some beetle channels it started to be a PITA. So I switched the improvised lathe bed to a fiddle and proceeded to use a saw and draw knife to shape the axles and cut out the arch from the bottom of the axle.

After cutting the waste away I was left with square axles, needless to say that is not an efficient shape, so I used the draw knife to slowly shave away the excess. The two bars on the side of the fiddle's bed are set parallel and the top is set to slightly higher than where I want the eventual diameter of the axles. The sloooowwwwww process is shave, turn the axletree a little, shave, turn, rinse and repeat.

Eventually we arrive at this:


and this:


You can see where I routed coves on some of the edges with a 3/4" radius bit. The mortises were cut to slide the poles in. The carriage bolt in the shot of the axle is there because when I went to cut the mortise I found more beetle damage that was not apparent from the outside. The board cracked between the mortise and the end during the first try fitting. I spread the crack slightly, shot in glue, and then bolted the split end back together nice and strong. I possibly could have relied on glue alone, but this is the most stressed point in the entire cart, so no sense taking chances.

To assemble; the front cross bar was placed in its mortises, the axletree slid on, then the poles pulled slightly apart and the rear cross bar inserted into its mortises and the wheels slid on the axles. The axle is not pinned to the poles as the mortises are so tight the showed no inclination to shift, and the bed (when installed) would provide further bracing.

The completed frame.

Next we'll talk about the cart bed.

McK

Saturday, May 22, 2010

Goodfelloes, part 2

Well, the internet is down for a tad so we'll just move along off-line and ya'll can catch up later.

I've been asked, "Can you use dowels for spokes?" The answer is yes, surely. I didn't use them here mostly because I don't care for a perfectly cylindrical spoke from an aesthetic point of view. This illustration from (which was one of the primary inspirations for our wheels) shows cylindrical spokes with the slightest taper.

The Djebjerg wagon also shows nearly cylindrical spokes.

The period wheel would have had a tenon cut on the end (you can see them clearly above) but this can be avoided in a small wagon or cart simply by controlling the depth of the mortises either by drilling or, if you've cut the mortise into the hole for the axle, placing a piece of copper or other pipe in the hole as a bearing.

It's harder to do at the felloe end, and would be best handled, I think, by drilling the mortise slightly deep and then dry fitting and shimming until the spoke "bottoms." Cutting the spoke long and trimming the spoke seems to me to be a more potentially frustrating method. Perhaps you could try using an expanding glue like 'Gorilla Glue,' but, I don't recommend glue on the spokes except as a last resort--fitting them is tricky and adding the extra complication of trying to fit them in within the glue's working time strikes me as a recipe for disaster.

The main problem with cutting the mortises for the spoke felloe tenons is that they must beexactly on the radius.

Here's the jig that let's you do that. (I might add that I wouldn't consider making spoked wheels without having a good drill press handy.) The jig is made from two boards set square (checked and marked with a try-square and screwed: accuracy is critical here) and a cut off from one of the felloes. This picture doesn't show it yet, but after the curved piece is mounted you should roll a piece of pipe so it comes to rest at the very 'bottom dead center' and make a reference mark.

The felloe then gets set in the jig like so:

Let me back up a sec. Normally when you're cutting you make the cut a bit proud of the line and go back and shape later. The felloe pattern should be cut as close as possible to a tight fit on the spokes, and the felloes should be cut as exactly as possible so they fit the jig (and the wheel).

I also see I missed a step with the spokes. (that's one of the problems with going back later from memory and picture files--oh, well...) once the spokes are all set nice and tight in the hub, the hub needs to be mounted in a hub fiddle again. I mounted mine over the table saw, but there are other options.

This has to square to the hub, to saw, to the dado blade, and (according to Thomas Aquinas) the universe. Use clamps. When the saw is fired up the wheel is rotated and the dado blade trims the end of spokes so they are perfectly centered on the axle hole. The hub/spoke assembly is then returned to wheel jig

and a combination square is used to set the distance from the tenon end to the shoulder.

On one tenon I found the shoulder too far from the end (the others all required little or no trimming).

This was fixed by gluing a wood "washer" in place and trimming with a coping saw and shaping with a Dremel to match the decorative cove of the spoke--the repair is unnoticeable.

Okay, back to that felloe we left sitting in the jig. Drill out a mortise deep enough to fit the tenon and go back and dry fit. Oh, yeah, make sure when you marked the felloe you marked which mortise goes to which spoke. Dry fit the felloes to the wheel. When every thing fits together well it's time to glue the felloes together. Some builders recommend a dowel or spline in the joint between felloes for alignment and support. Since this wheel is for such a light weight cart I didn't bother. Instead, I used "Gorilla Glue" which expands into the wood on both sides of a joint, and in the case of pine, makes a joint stronger than the surrounding wood.

I slathered on the glue put waxed paper over the joints, and then used a strap clamp (cargo strap with ratchet) to pull the felloes tight. Then I applied heavy duty spring clamps to the sides so all the joints lined up nice. The waxed paper is to keep the squeezed out glue from gluing the strap and clamps to the wheel.

When all the glue is dry I popped the wheel in the workmate bench (a wonderfully useful tool) and sanded everything up nice and smooth.

If you look back to the first picture you see that between the spokes the wheel has been carved away a bit. This serves absolutely no function, but it is pretty.

After using a 1/2" round over bit and router to shaped the outer edge of the wheels I grabbed a plastic container I had lying around and marked the sides of the felloes to replicate the decorative cove. I cut these with a 45 deg. bit in a rotozip starting it as a climbing cut (with the grain) by eye. You need to be a little practiced at this or you risk the bit jerking you along and buggering up the cut, but the rotozip is a handy tool for this sort of thing.

Voila! Time to step back and admire your handiwork. Let me mention again that making spoked wheels is a lengthy, finicky, tedious, irritating process. From the description here it sounds like you only dry fit a few times, in reality it's over and over and over and over. I respect anyone who goes to the trouble of making spoked wheels, but truly, for most SCA uses I wouldn't bother. Though another nifty aspect is that once you've made all these jigs later wheels are easier, and you can make spinning wheels, too. (Fionnseach and I are working on one for a Creative Anachronist, to be blogged down the road).

Lastly, this is not a wheel, it's my first try at a loaf of rye bread with caraway, Yum!

McK

Thursday, May 20, 2010

A preview of coming attractions

I should probably mention at this point that dog carts are not my prime interest. Building it was often amusing, but I still regard wagons as superior to carts for SCA use, and as soon as I can finish up blogging the dog cart build I want to get back to small wagons. This is a shot of what's still my favorite build--the 'oseberg' wagon.





As you can see it breaks down completely for transport, and all the parts fit in the wagon bed (Duke Sir Rhinohide not included). The curved plywood bed is a little bit complicated to build, but it's amazingly light and strong.

I'll also be putting up plans for the first "Caitlin Hauler" which doesn't breakdown for transport, but is sturdy as all get out.


So for those of you who are looking for small wagons we'll be back there soon...

Up next, the rest of the dog cart wheel instructions.

McK


Wednesday, May 19, 2010

Goodfelloes, part 1.

Okay, so, I don't look like Ray Liotta...

The parts of the wheel that make it round are the felloes (sometimes fellies). In this picture you can see the hubs with spokes in the background and the board with felloe patterns in the foreground.


To make the felloe patterns a beam compass was used to layout two concentric circles. The inner has a radius equal to the distance from the center of the hub to the shoulder of the spoke's felloe tenon, and the outer has a radius about 3" wider.

The pattern was then laid over the spokes to double check fit, and was cut into four pieces with the ends about half way between spokes. Don't forget that this removes 1/2" inch total from the pattern (1/8" kerf x 4 cuts) the loss must be restored when marking the felloes for cut out or the pieces will not be a perfect circle.

To make the felloes I had hoped to be able to use some rough cut oak from a friend with a sawmill, but scheduling just didn't work out, so pine 2x12 that I had on hand was substituted.

When working with wheel a fixture to support them is handy. I made this one by screwing a '4" toilet flange' with a '2" into 4" union' to the work table. This view shows the felloes mounted.


Once the pieces were cut out I clamped them together with spring clamps and laid them over the spokes. Then I marked the felloes for the spoke mortises. Using a straight edge I 'shot' a line on the felloe side, then with the combination square transferred the line across the inner surface of the felloe, then crossed this at the dead center.




The next step was to build a jig for drilling the felloe spoke mortises precisely on the radius. This one is a tad complicated so I'll put it in a later post.
McK

moving on

So NSTIW reading a thread on "looking for a cart" on the medieval encampments list when up pops:

>Hi there.
>One of the best things I have seen about carts in the SCA is this blog.
>
http://mckennawerks.blogspot.com/2009/01/some-thoughts-on-wagons-for-sca-use.html
>There are plans. There is a description about making a cart and how to solve some problems. >There is some history on carts.
>I hope that this helps you.
>Cheers
>John of the Hills

Thank you for the compliment, John. This prompted me to go back and re-read this blog. Since last night it's had over 150 hits, so I guess there's some interest, and I'm thinking maybe I should continue it from where I left off.

I've had a lot of other irons in the fire this past year both mundane and SCA, and my irritations regarding the dog-cart and the A&S faire system have mostly simmered down, so I sorta feel up to doing this again.

Here's an older shot of the assembled cart. Since then I've added wrought iron parts for the swingle tree and hounds, and a drafting harness. We'll cover those later, for now let's get back to the wheels...

When last we'd met the wheel hubs were cut, rough shaped, and mortised and I was about ready to move on to the spokes. First, the hubs.

Once again the hubs were mounted in the hub fiddle and given another light sanding. There was some light checking from unequal shrinkage of the drying wood. This was expected. Drying billets of wood without checking is virtually impossible. If the checking had split through at one of the spoke mortises I'd have been screwed, but luck held and the checks are all minor and cosmetic. Eventually they were filled with homemade wood putty--sawdust (really fine dusty stuff from the spindle sander) mixed with glue. I know this method has been used since at least the 1700s. Though I've never come across a reference to a period piece having been filled in such a manner, it seems to me logical that if a period woodworker was faced with filling such a gap he would either cut small wedges of wood and drive them in or just ignore the checks, or stuff some oakum mixed with hide glue in the crack. We do know that in shipwrighting checks were filled with oakum/pine tar. Not having any oakum, and not liking the stickiness of pine tar, I went with this.

Wheel hubs check, thus hub irons (hub bronzes?) were put on the hubs. We have many of these found in wagon graves from the bronze age. To make them I went to the scrap pile and pulled out some 3" bronze fittings still soldered to some old drain pipe I'd pulled. Some work with the torch and the fittings were off, then the hub of the fitting was cut off with an angle grinder with a metal cutting blade, and cleaned up on the wire wheel.

Using the dremel with a coarse sanding bit I carved down the hub to slightly oversized (just enough bigger I had to use a hammer to start it). Then I took the hub outside, set the hub iron in place, put a piece of 2x6 over it and whaled away with a 10 pound sledge. Them suckers are on. Okay, were on. Some further shrinkage loosened one to the extent that I resoldered a piece of copper pipe in it, narrowing it and restoring the friction fit.The last thing to be done to prep the hubs for the spokes was to flatten a shoulder from the spoke to rest on (marked in red).

The mortises were labeled with roman numerals for the starboard hub and letters for the port. This is essential as the tenons are cut to fit a particular mortise perfectly, and when done will only fit that mortise. Once the hub irons were taken care of it was time to move on to the spokes. I mentioned earlier I had wanted to use green oak from a tree that came down in a storm, but the wood turned out to have been "beetled." So I eventually went with some seasoned oak from an old project. The first step was to cut out blanks (with extras). The center of one end was found and marked.

I made a jig to hold the spokes upright and square in the drill press and using a plug cutting bit shaped the round tenon that will go into the mortise of the felloes.



Once this was done the tenons were cut on the opposite end using the dado head on the table saw. These were all cut slightly oversize to the intended mortise and marked to orientation on the hub as well as the intended mortise hole.

I then made a jig to hold the spokes so a taper could be cut using the sliding compound miter saw.


The laser guide is a wonderful 'extra' to have on this sort of project. The front block used in the cuts is not yet attached to the jig in this shot.



This picture shows the second step. First, all the spokes had a taper cut on one side with all the blocking on the jig set "square." To taper the opposite side the the blocking already installed was left in place an the front block was reattached to support the angled side.

A decorative cove was then routed on the edges of the spokes. This gives them a lighter look, but has no structural purpose. I use a roto-zip with a 1/2" radius bit. The same jig as held the spokes for cutting the taper was used to hold them for this step. Finally the waste around the felloe tenon was cut off with a coping saw.

At point it was time to fit each hub mortise an tenon, a tedious and painstaking process involving innumerable dry fits and filing until each spoke required moderate taps of the mallet to fit snugly into the mortise and a good bit of effort to remove. For this part loose is bad. As the hub continues to shrink while drying the spokes will be held in place even more firmly.


Time for supper; the next post will cover shaping the felloes and finishing the wheels.


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