Friday, January 16, 2009

plans, page 4

It's been an interesting past few days here at the McKennawerks. Interesting along the lines of the ancient Chinese curse: may you live in interesting times. First the pellet stove in the workshop died--and it get's cold down there of a night, then the oven died. Lemme tell ya; disassembling an old England pellet stove is a P.I.T.A. The lower feed auger motor is fried (sigh) so it's going to be chilly in the McKennawerks for a while. On the oven front, we bought a floor demonstrator of a built in microwave/oven unit at MegaLoweMart a year ago for waaay below list that's been sitting in storage awaiting phase 3 of the kitchen remodel. So can you guess who's been installing an oven, hmmm?

Anyway, time to get back to fun stuff.

Some points that have occurred to me to note in the last few days.

More concerning tires; theoretically, one could use bandsaw tires. This would require carefully cutting the wheels to fit the tire, and possibly dadoing the rim as well. I've never tried it myself, and given the cost of bandsaw tires compared to auto heater hose, don't intend to. But it is an option that would probably work.

I was asked to clarify how to keep the wheels from coming off. In a purely philosophical sense, I'd suggest temperance, moderation, forethought, and maintaining a sense of optimism in the face of adversity. As to wagon wheels--in a typical axle/wheel assembly the wheel is held on by a hitch pin slid through a hole drilled near the end of the axlerod. In order, from side to side, is a hitch pin, fender washer, wheel hub, fender washer, axletree, fender washer, wheel hub, fender washer, and hitch pin.

Hitch pin, fender washer, outer hub

Inner hub, fender washer, axletree
Fender washers are somewhat thinner and have a smaller hole in relation to overall size than standard washers. When you assemble them all the parts should butt tightly together. You may need to add extra washers if you are off in drilling the hole in the axlerod. The way to do it is: make the axletree and wheels, the slide the axle in place, and place the washers, then mark to drill the holes.
I want to point out again, that this isn't the only way to do things. I use a variety of approaches in my wagons. Each one is different. It keeps things fresh or me. Don't be afraid to innovate when you make your wagon.
I also want to again mention that woodworking is craft. If the parts were made from metal or plastic, fairly stable materials, and machined to close tolerances, you could just cut up all the parts and fit them together. That doesn't work with wood. Especially when you are making mortise and tenon joints. Make the parts in a logical sequence, and test and fit each piece as a you go.

Let's talk about how to make the wagon usable for dog drafting.



Let me preface by again noting that I am not a dog person, have never drafted dogs, and have no intention of doing so. I have studied wagons and carts, and crawled in over, under and around many working and historical examples. I do own a draft horse (a handsome black Frisian/ Percheron cross) and have worked with draft tack.

A dog cart is not appreciably different from a harness racing sulky, except for size and some of the arrangement of the traces given the different anatomy of horse and dog. I've spent the last week or so doing some extensive googling and reading on dog drafting. A reader (thank you Lady Teresa) sent me some links that hadn't come up when I googled them. There still aren't many dog cart plans out there that I was able to study: three, in fact. One is a variation of the pvc plans published several years ago (which amazingly enough I saved, and even more amazingly found where I filed them), one is a very basic wooden cart, and one is a more elaborate version very similar to a sulky, which has cold laminated bentwood parts.

But it's really not a very difficult to construct, and the plans are all similar in dimensions. I'm eventually going to address how to make the traces. But if you're really into dog drafting I figure you'll already have that info, or have been to the same websites I went to. So onto how to make this puppy...
The dog drafting poles assembled to the axletree


You'll recall we made the more decorative front axle tree. Now we're going to add in mortises for the hounds for the poles. Again, I do it this way because it breaks down for transport. You can simply attach them to the axletree with glued butt joints, and make the dowel disassemble instead. I'll show a mock up of this, too. I had the hounds already from an old project that I never went anywhere with (I never throw anything out ;-)


Note, this method will not work with the tongue we had used on the basic version. So we'll also need to do a tiller with hounds.

If you don't have a hollow chisel mortiser there are a couple of ways to do the mortises. First is to drill out the center of the hole then trim with a chisel and file. If you have a decent sabre saw and a good blade you can also use the sabre saw to nibble out the corners after you drill the hole. If you have a table saw and clamps you can rip the axle tree, into 3 pieces, one the width of the mortise, then cut mortise-wide pieces out of the piece that's the width of the mortise and glue them back together. The glue joint; if you use titebond II or gorilla glue, is actually stronger than the surrounding wood.

Here we see the hounds with the crossbar installed. As I noted these were sitting around the shop. I'd suggest that when you drill the hole for the crossbar don't drill through the hound all the way. Drill the hole about one inch deep and it will hold the crossbar in place--like on your average toilet paper holder.

To make the hounds take a 2x2 piece of stock and trim of 1/4" of each side on the table saw to a 4" tenon with your tenoning jig ;-) Ok, I admit it, I've had a neato Delta tenoning jig for years, and I still use the router or dado blade to make tenons--but Norm would use the jig ;-)

You want the hounds about 8.5" long total, with a tenon about 4" long. The cool way to attach the tenon is to use a wedge, but I usually just drill a hole that slightly underlaps the axletree and use a piece of dowel as a wedge.

To make a wedge mortise; if I really want to be fancy like when making a Glastonbury chair, I use the hollow chisel mortiser, but for wagons I go with the simpler, if not quite so meticulous method of drilling and smoothing with a dremel.



In order to taper the mortise for the wedge we need to make a simple jig. Cut a wedge at 15 degrees from the end of a piece of 2x4, flip it over (remember all that stuff from high school geometry about opposite interior angles :-) and set the the hound on it in the drill press and drill straight down. Then remove the wedge and finish drilling out the mortise.

Oh, yeah! Very important when you make the hounds mark the top and port or starboard of the hounds. You're cutting the tenons to fit the mortise, and as Justin Wilson used to say, I gar-on-tee that if you you've cut them with test fittings due to wood variations they'll only fit one mortise one way tightly. I suggest port and starboard rather than right and left, because if you use right or left sooner or later you'll be wondering, was it my right or... Make sure you cut the mortise so the taper is wider at the top.

Once you've drilled out the mortise, clean it up with a small sanding drum on the dremel. Cut the angle on the wedge to 15 degrees and round the edge to match the diameter of the drill bit. This method works best if you use a 23/64" drill bit, and a piece of 3/8" plywood for the wedge. Remember 3/8" plywood is narrower than 3/8". It fits the dremel sanding drum perfectly. This produces a nice tight mortise, tenon and wedge.

The Poles



The poles can be made of straight stock, say a 1x2. But with a little more work we can produce a nicely tapered set of poles. If you look at the plan you can see how to lay out the tapered rip cut on a 1x4. You can do this cut with a sabre saw, but it's very difficult to do a long rip cut with a sabre saw without a "ripple" to the cut. If you have a table saw you can do the long straight cut as a "plunge cut" with an improvised taper jig.

To make the taper what we want to do is pass the piece we're cutting through the table saw at a diagonal. The problem is our rip fence and blade are parallel--the system is designed to keep the edges parallel. The way around this is to rip a 6" wide piece of plywood (I always seem to have lengths of luan sitting around the scrap pile) and temporarily attach the work piece to it at an angle.
First rip the plywood strip, then move the fence in about an inch and do a plunge cut to rip a slot almost the length of the ply.

Then mark up the workpiece as in the plan's cutting diagram. Then line up the slot in the jig piece over the angled line on the work piece and attach them together with brads. Flip over the pieces. Use a set square to set the fence so that when you plunge the workpiece down on the blade the cut will be in the slot.

You'll want to mark your rip fence to line up with where the blade comes up through the table so you know where to stat and stop the cut. Here I've used masking tape on the fence and marked across the workpiece where the cut is to stop.

Here the workpiece and jig have been plunge cut about 5" in on the far end and ripped down to about 5" from the near end. You can see the jig went through straight, but the poles have been cut in a mirror image taper.

Remove the workpiece from the jig, and finish the cuts with the sabre saw. Attach the poles back together, one atop the other, and use the sander to match their shapes. Round the edges over. Then drill them for the crossbar. Mount them in the hounds on the crossbar and measure for the splinter bar. Cut and glue and screw the splinter bar in place. In this version I've butt jointed the splinter bar to the poles, but if I were serious about dog drafting, I'd probably go the extra step and dado the joint.



Here we see the poles assembled to the hounds. The splinter bar is the crosspiece cut from the same 1x4 stock as the poles. The swingle tree is attached to the splinter bar with a carabiner. The eyes at each end of the swingle tree will be attached to the traces.

Here is another view of the hounds, poles, splinter bar, and cross bar.

This doesn't have anything to do with wagons except it was hanging on the wall near the pole assembly. It's the hovercraft (minus the skirt) my daughter Caitlin built for her 5th grade science fair project.
I'm sure when I reread this tomorrow I'm going to find all sorts of things to add to it, but I've been working on it for five days and it's time to post.
McK

No comments:

Post a Comment

Post a Comment