Over the years I have given this box to give to teachers that have helped my daughter, later to raise money for mission trips, and now to people that have made a difference in my life. Like the doctor that preformed the 6 heart by-passes and the nurse that helped me through the recovery room that night.

The pattern comes from an old issue of American Woodworker. I “carve” the top with a sanding disk chucked into my drill press. I let the grain of the wood dictate the shape of the “vain” on the top. All are different. Most of the time I use mahogany, but one time I made one from purple heart. Never again will I do that.

First, I made a frame 1/2” larger than the panels. I used some finger jointed pine because it is straight and true. I attached a lip around the inside edge 1/8” deeper than the thickness of the rough panel. You need to take your time to build this part very accurate. I placed four drywall screws into ends of the frame to hold the panel in position.

I built a sled to carry the router across the panel. It needs to be very stiff. There are stops on each end of the tray and guides on the bottom of the sled.

I used a ½” diameter pattern bit to do the surfacing of the panel.

When you place the panel into the frame just brings the screws up enough to hold the panel from moving. All of these panels are over size. Now you should find the lowest spot of the panel and use this as your starting point for setting the depth of your router bit. I set my router to have very little travel up and down.

It is better to go over an area several times than to take all of the material off at one time. This will create a lot of chips. I would go about 3 to 4 inches and then vacuum the area.

It takes me about 15 minutes to set up and do a side. You can see two of the finished panels, stacked on each other, for how flat I was able to get them.

I am sure that I saw this same idea somewhere in the past. I am not that smart. I hope that this may solve a problem for you in the future.

My original bridge is 36” wide with a base of 96 “and a rise of 18”. The most important part of building this project is making the template. There is a math formula for finding the radius to lay out the arch. It is R= D squared plus H squared divided by 2 H. R is the radius we are looking for. D is one half of the cord or base. H is the height of the arch from the cord line. In my case the radius was 73”

I made the pattern from ½” thick mdf and used my router to cut it out. I made a long arm that I could attach the router to and located a pivot point 73” from the edge of the router bit. I used a spiral bit for this. I then drew a line on the floor (wood floor in my shop) that was longer than my radius. I marked my pivot point and then measured 55” (73” less 18”) and at this point I made a line perpendicular to my radius line. This was where I attached the mdf for the pattern. After I cut the top of the arch, I moved my pivot point the distance that I wanted for the thickness of the pattern, in my case it was 5”. Now I have my pattern.

With the pattern made you can determine what size 2” x’s you will need to make the riser from. I position the pattern and with a sharpie pen outlined the pattern. This will give you about 1/8” oversize drawing. I made my rough cuts on a band saw, but a scroll saw will work fine. Now attach the pattern to your rough cut riser with drywall screws.

I used a ½” pattern bit to cut the riser. You will not be able to cut all the way through the first time. You can use the first cut as a pattern to complete the cut. NOTE! Before you remove the pattern attach a straight edge to the riser flush to the pattern at the center end. Now you can remove the pattern. Make a Skil saw guide about 18” long and attach this to the riser flush to the straight edge you attached. Now remove the straight edge and use your Skil saw to cut the end of the riser. This gives a better cut then doing it with the router.

The bridge requires 6 risers and 4 spreaders to form the skeleton of the bridge. Four of the risers are just as you cut them, but the other two have to be modified. They will be the center risers. You need to cut off the thickness of the spreader on the end where the two halves of the bridge meet, and you need to cut a notch in the bottom part the thickness and width of the spreader. Now you need to rip the spreader for the center part the as wide as the riser is high. I made the other spreader a wide as I could. The width of the bridge skeleton should be 4” shorter then the bridge planking. This would give you a 2” over hang on each side.

In putting the sections together, you attach the outside risers to the spreaders, and then install the center riser. I used 3 ½” decking screws for this.

To install the bridge I poured a 4” thick concrete pad on each side that was level and square with each other. I position the bridge halves together with clamps and screwed the two top spreaders together. I used large concrete anchors to attach the spreaders. I made a piece to cover the point where the two halves joined. You can be fancy or plain as you want with this. I attached mine with carriage bolts and screws from the back side. The last thing is to attached the bridge planking and enjoy.