I have a commission to build fourteen 8 1/2 inch high O scale trestle bents. I have been building these bents (HO / O scale - different heights) for quite a while. I have jigs but always thought them not really adequate for lining up posts and sway braces. I also cut my wood to size on the table saw. Setting the gap between blade and fence for 1/4, 3/16, and 1/8 and trying to run wood through has always been a hassle. I tried a few different techniques but most required some kind of jig on the outside of the blade always resulting in varying widths. For this build I built a thin strip rip jig I saw used on YouTube. This jig is awesome.
I also modified an existing glue up jig for gluing the bent posts to the top and bottom sills along with a new jig to line up the horizontal sway braces. While not perfect this is lot better than then what I did before.
Below is the wood I use. It is called Wenge and what you see is the natural color of the wood.
This is an HO scale trestle bent I modified for the bents. I added alignment spacers to help keep the posts lined up from bent to bent. There is some warp in the wood but all in all the jig works well. When I glue the top sill in place (difficult to see) I index it against a lie I drew on the left side of the jig. This keeps the sill centered on the posts. The bottom sills are two different lengths to mimic a mud sill (usually concrete) and shorter wood sill that sits on it. The bottom sill is lined up against the jig wall on the left side. I eyeball the second sill when I glue it into place. I place bricks on the sills for a few minutes to set up the glue then rtemove the bent and clamp with small mini clamps - see below.
This is the jig I used to cut the 1/4 and 1/8 inch stock. The jib body is 3 1/2 inches wide giving me plenty of hand space to push wood through the blade. There is a catch on the back that can be loosen to act as a nack stop for the different thicknesses I need to cut. For example if I set up for a 1/4 inch cut I will set the back stop to slightly less than 1/4 inch so the blade does not cut through it. The attachment in front of the handle is a hold down to stop the wood from 'walking' up the blade as I push the wood through. In the photo below as an example I set up for a 1/4 inch cut using a 1/4 inch Masonite board
This is a close up showing the 1/4 inch cut off. The jig body is 1 1/2 inches high since most of the wood I use is 3/4 or 1 1/2 inch thick.
Once the top and bottom sills dry I glue on the opposite sills using a right angle to line up the sides and pressing both the top and bottom against the bench (on top of wax paper) to line up everything. I then use the mini clamps to let the glue cure.
Below is a new jig I made to line up the horizontal sway braces. Again the bent is registered with the bottom sill against a stop.
I let the sway braces set up a little then lift them from the jig and use mini clamps to let the glue cure.
I have not gotten that far yet but I will glue the opposite horizontal sway braces by lining up the opposite brace against a right angle.
The angled sway braces come next. They will be glued by eyeball only. Note the important thing here is that the horizontal braces must stick out about 1/4 from the bent posts to allow bracing form bent to bent. the angled braces must therefore stay inside the posts or they will interfere with the bent to bent bracing.
Joe
