Welcome back once again to the wagon shop here on Main Street, Joliet, Montana. In the past I have touched on doubletrees that is used for a buggy pole such as this 2 seat buggy I've been working on. Well there's also a doubletree that is used more for heavy wagons or for skidding logs, or for whatever. Now the style of a wagon doubletree is inherently different, but some fo the same physical properties, the physics of how they work are very similar between the two. Well I have had discussions in the past on the design and style of the wagon evener on a doubletree. Sometimes this also called the doubletree of which two singletrees attach. Well there is an old school style that puts an arch at the back of the evener to take the stress as the horses pull forward on this doubletree. Often times today you're going to see at auctions, and listed in catalogs, that the evener is built with a wedge to the front of the evener. Well I have had a discussion with different individuals, Amish, non Amish trying to explain why the significance is that are should be to the rear. So this week I'm going do a simple test, put these eveners under stress, put them in a hydraulic press, and just see what the reaction is under pressure on these two different styles of eveners. Well, to keep this somewhat of a fair test I have a piece of timber that is 10 inches wide and it's not quite good enough for me to use in bending bows so I'm going to take a chunk out of this and take two eveners out of this same board. A ten inch wide will provide me two, five inch eveners at the center. So as much as possible, using the same board, I'm going to put these two styles of eveners to the test, hopefully that it is a somewhat of a fair test. Now even the same board can have a little bit different qualities, just depending on how this board was cut out of the tree and I realize that, so this isn't a 100 percent fail-proof test, and I'm only gong to do it once, so it would have to be repeated numbers of times to actually get an accurate result, but this is going to be my simple, hometown, here in the shop test, on just how well these two styles of eveners stand up. So I'm going to build a pretty heavy frame that I can test these eveners in. I don't want the frame to give, so maybe I've kind of over killed it, and then put this in the press to do the testing on to see just what kind of pressure these eveners will take. Well I have two cameras so I'm going to set one camera on the gauges this 50 ton press, and see if I can monitor how much tonnage is exerted on these eveners and I'm going to operate this, it's an air over hydraulic, but I can also operate by hand. I'm going to do that so I can do it slow and have the control, more than I can have on my air operated press. Now I realize this may not be an all conclusive test. This is only one sample, 2 eveners taken out of one board. Even out of one board side by side depending on the location in that tree, when that board was sawn, there can be some inherent differences just in each of these eveners also. But, I think it makes the point that the rear side of the evener is under tension, while the forward side is under compression. So, to my thinking, again, the strength needs to be added to the back side of the evener as the forward stress is exerted in that center pivot point, strengthening that evener, whereas when the bulk of the material is left up front that is under compression, the back has a tendency to break a little sooner because the front is not allowed to compress. You know, this second one there was actually some compression just as if I was steam bending that piece of wood. So it was able to gibe under the increased strength of the back curve and, anyway, that's just my philosophy on building eveners. And I have noticed in working with old carriages, hitch wagons, drays, heavy vehicles, so often times, often times, often times, the curve is to the back of the evener. Unlike the modern eveners that are being sold today where the wedge is put to the front. Anyway, simple as it is, this is my simple test to try to see if my theory held true. And, I'll continue to hold to my theory. So once again thanks for following through this simple test and Thanks for watching!
