Monday, January 5, 2009

Parts, the tongue and "T" handle

Okay, two things. First, Blogspot's editor and preview feature leave a lot to be desired, and I'm still on the upslope of the learning curve, but we're getting there. I've had to go back and re-edit each new post several times because they don't appear on the page like they do in the preview. This is mildly annoying, but I mainly mention it so that those who are set up to follow the posts don't go, "Huh?!" every time a new post goes up. It's taking me an extra ten min. or so after each post to tweak it. If there are any blogspot experts out there who can offer any suggestions I'd appreciate it.
I take that back. this post has been majorly annoying. The problem seems to be with the pics. They are not in the same place in preview as the are in the posted version. Next time I'm going to try cenntering them above the text. This is the last time I'm trying to fix this one.
Second thing is: no tongue jokes. Honestly, in real-life I'm a PA, and I've been an Army medic and EMT. I've heard them all, and none of them are all that funny anyway. Except for the one that starts, "there're these two tongues, and they walk into a bar...." Never mind, that one's not that funny, either...

Okay, three things. I'd quipped earlier that there's no such state of being as having too many clamps, but what if you don't have any? Some alternatives are:

-- Long, 3/4 inch wide strips of bicycle innertube and wrap them around the parts. Even if you do have a rack full of bar clamps, this trick works well with odd shaped parts.
-- Use ratcheting cargo straps. I use these when gluing up shield blanks.
-- Temporarily screw the pieces together.
-- Spanish windlass. Just like the old tourniquet you learned to do in first aid. Wrap a loose band around the parts, slide a stick between the band and part and turn the stick, tightening up the band.
-- Duct tape. You can pull hard on it as you wrap it around the pieces, but it won't give you near as much pressure as the others.
-- Cinder blocks. If one piece will sit stably on top of the other pile a couple of cinder blocks on them.
It's time to coin a new term: tiller. I use this term to mean the piece attached to the tongue that you use to pull the wagon. Strictly speaking this is not a traditional name for a wagon part, but it helps avoid confusion, since on a large wagon the tongue is connected to the axletree by hounds, and in my wagons I seldom use hounds any more.

The tiller can be as simple as a plain piece of 2x2, or very elaborate. The three shown here are a 2x2 with the end sanded to a point, a 2x4 ripped down to allow a roundel on the end, and a tapered 2x4 with the edges rounded over on the router table. The "T" handle, as I've mentioned before should be 1/2" to 5/8" diameter close grained hardwood, and project about 6" to either side of tongue. On this wagon the tiller should be about 40" long.

This is the tiller, tongue, and axletree from a much more elaborate wagon. There are cutaways on the tongue part of the axletree, the whole tiller tapers in both width and height, the edges are routed, and the cheek pieces are fine grained hickory salvaged from an old tool box







Back to this wagon... The plain tongue we attached to the axletree earlier had the end simply cut to a 3.5" diameter circle with it's center drilled out to receive a sleeve and bolt or pin. While a bolt will work loose over time, if you use a clevis pin here it must be tight. You can shim it with washers, but any play between the cheek pieces and the tongue will be detrimental to steering and can lead to failure of the connection. This is the one time I will use a self locking screw on a 1/4 inch machine screw. But it will still work loose over the course of a long event--check it's tightness regularly.
Note that the curves of the two pieces fit together. This produces a far stronger and more stable join than two convex pieces.






The tiller can exert considerable leverage. This wagon was killed by some drunkenly exuberant fighter types trying to be a "war chariot" (I wasn't present at the time). Note that the wagon had successfully carried an adult before, and lots of heavy loads, but when a big guy in armor stood in the bed, and two strong guys jerked hard: crack!

This misadventure led me to redesign the front axletrees on my wagons. Note the metal bar screwed into the axletree and tongue, this is a hound. I no longer use hounds, rather I've beefed up the fifth wheel, but if I were making a wagon that I knew was going to be frequently pulling very heavy loads over rough ground I'd add hounds as well.
This wagon also had both tiller and tongue pieces in the joint convex, which proved less than satisfactory in the long run, though I should point out it made it through 4 pennsics before suffering it's ultimate mishap (and that was abuse). In the year of its third pennsic and subsequent ones, we became a two wagon family. If you think one wagon is useful, two are bliss.

This wagon also has the pivot on the tiller, something I no longer do. The metal plates were added after the bolt pulled through the end of the tiller in about the first fifty feet. Pine 2x2 endgrain has very little strength.






There are several options for the cheek pieces. One that I've used with success is a mending plate with a hole drilled in the center (where the blue dot is here) at one end. A better choice though, is to make cheek pieces from 1/8"x 1.25" x 8" pieces of welding steel flat bar.





This shows the damage that can occur from too much play in the bolt, and too thin a metal in the cheeks. Brass looks pretty, but is far too soft to serve. This is what happens with a moderate load with the cheek pieces made from metal strapping.






This is the arrangement of washers I usually use at the cheekpieces and tiller. On each side from the tiller out: fender washer, cheek piece, 1/2" washer, self-locking nut.




McK

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