Furnished content.
(from Lumberjocks.com)
Being a senior citizen my hand strength seems to be waning. SWMBO has been hinting that she could use something to help her open some jars.
The other day I was browsing the internet and saw this Jar Opener that cost about $20.00 ($14.75 on sale). I thought that with all the wood scraps in my shop and broken bandsaw and old hack saw blades I could easily make one of these.This is the perfect project to keep me busy during this pandemic.
I started with drawing the plans in Sketch Up. Then down to the shop to build it.I started by laying out a 7-3/4 inch circle on a scrap piece of 3/4 plywood. Drew a line down the middle. Then 1 inch from the edge of the circle I drew 2 lines 30 degrees on either side of the line to form a 60 degree angle. I then cut the circle. Then I cut 2 pieces (yellow and blue in illustration above).HINT: If you have enough scrap wood around the circle layout, you can cut the lines that make the 60 degree angle first. Use a piece of scrap (guide board) that has 2 edges that are parellel and bigger than the board your circle layout board. Align one of the parallel edges of the guide board to the line to be cut and screw it to the circle board in a waste area. Use the other edge of the Guide board against the table saw fence to cut the line. Repeat to cut the 2nd line.Then the circle part can be cut on a bandsaw.
Although this illustration shows cutting kerfs in the yellow part I actually cut the kerfs in the blue part. So make a note of this if you try to build it. Also note that in the final assembly the blue and yellow parts are reversed.
Before proceeding with this step, you need to identify what saw blade you are going to be using. I would suggest using a blade that is at least 1/2 inch wide like a hack saw or bandsaw blade. You will need 2 blades about 6 inches long. I used an angle grinder with a thin cutoff abrasive blade to cut my blades.The blades need to project 3/16 to 1/4 inch from the wood.I used a Japanese pull saw to cut the kerfs because it makes a really small kerf. To create a depth guide to make sure the kerf depth would be even I used double stick tape to attach a scrap of 1/4 inch plywood to one side of the pull saw. The edge of the scrap was located a distance from the fine teeth of the saw so when the saw blades are inserted they project the proper distance from the wood.
To guide the saw 1/4 inch from the side of the blue part I clamped a scrap piece of 3/4 inch plywood on top of the 1/4 inch depth guide and extended it below the teeth of the saw so that it would ride against the side of the blue part.
The blue part of the jar opener was then put in a vise and the saw was used to accurately cut the kerf the right distance from the edge and to the correct depth. The second kerf was cut after I flipped the blue part in the vise in the similar manner.
The 7-3/4 inch circle bottom piece was cut from a scrap piece of 1/4 inch piece of plywood. Then the yellow and blue pieces were glued to the bottom piece. REMEMBER flip the blue and yellow piece when gluing this assembly.After the glue set I sanded the edges of the circles to match. I also used a round over bit to finish the edges of the blue and yellow pieces.
The saw blades now have to be sized. I cut my blades to a length so that when inserted into the kerfs they were about 1/4 inch shorter than the kerf. This allowed me to glue a thin piece of wood at the end of the blade to help keep it in the kerf. If the blades do not fit tight in the kerfs use a little epoxy to secure the blade in the kerf.NOTE: The blades should point toward where the angle meets.
This is what my blades look like after installation. The blades that I used were 1/2 inch bandsaw blades.
All thats left to do is drill and countersink the mounting holes and applying some finish. I used mineral oil on mine.
This is the my jar opener mounted under the cabinet.I like it and SWMBO likes it too.NOTE: If you want to build this you can save my illustrations and youll have enough information to do it.Thanks for looking. Comments appreciated.