Project Information
My oldest daughter and I make a craft item that we sell. I have made several different sleds to cut the material but have needed a way to locate a pilot hole for a screw eye exactly in the center with out measuring. The craft item varies greatly in size depending upon what material I am cutting. My first effort worked, somewhat, but with sales increasing I needed something better.
This was made from a wooden hand clamp from Harbor Freight and scraps from the shop. Part of the scraps was a section of maple bowling alley.
The first picture is the finished jig.
The second picture is of the core of the unit. The threaded rod from the hand clamp is held in place so when it is turned the jaws would open. Did you know that you cannot find a left-hand acme nut? To hold the rod in place I made thick washers from some UHMW and held them and the rod in place with a nail acting as a roll pin. The most important part of this was making sure the wood and washers' thickness was so, when the jaws were close, they both were snug against the wood.
The third picture is how I had to modify the clamp jaw. I had to drill a relief, so the washes were not in the way of the jaw closing. By clamping the jaws to the center block I was able to drill holes for guide rods. This was necessary to keep the jaws parallel since I was only using one of the threaded rods to operate the unit.
The fourth picture shows how I had to cut the center block and the jaws for an aluminum track.
The fifth picture shows the completed unit at my drill press. Sorry the picture is up-side down, but I tried to correct it, but nothing worked.
The sixth picture is another view of the jig where you see a black knob to the left. Once the jig is centered and clamped to the drill press table, I need to move the jig to place the bit over the place I want the hole and then tighten it down.
I made a centering block to positioning the jig. I located the center of the block and drilled the hole. I then turned the block 180 degrees to test it. I was off by 1/132" Not bad. That is more than enough for the craft item.
This was made from a wooden hand clamp from Harbor Freight and scraps from the shop. Part of the scraps was a section of maple bowling alley.
The first picture is the finished jig.
The second picture is of the core of the unit. The threaded rod from the hand clamp is held in place so when it is turned the jaws would open. Did you know that you cannot find a left-hand acme nut? To hold the rod in place I made thick washers from some UHMW and held them and the rod in place with a nail acting as a roll pin. The most important part of this was making sure the wood and washers' thickness was so, when the jaws were close, they both were snug against the wood.
The third picture is how I had to modify the clamp jaw. I had to drill a relief, so the washes were not in the way of the jaw closing. By clamping the jaws to the center block I was able to drill holes for guide rods. This was necessary to keep the jaws parallel since I was only using one of the threaded rods to operate the unit.
The fourth picture shows how I had to cut the center block and the jaws for an aluminum track.
The fifth picture shows the completed unit at my drill press. Sorry the picture is up-side down, but I tried to correct it, but nothing worked.
The sixth picture is another view of the jig where you see a black knob to the left. Once the jig is centered and clamped to the drill press table, I need to move the jig to place the bit over the place I want the hole and then tighten it down.
I made a centering block to positioning the jig. I located the center of the block and drilled the hole. I then turned the block 180 degrees to test it. I was off by 1/132" Not bad. That is more than enough for the craft item.