Monday, May 24, 2010


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.


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