Friday, April 21, 2017

How to make, a mini DIY crossbow



















I made this toy bow out scrap pieces of 8mm baltic birch plywood. 

This was an experimental build and the design evolved throughout the making process.

I begun by designing my bow’s arches in a piece of plywood. Using carpet tape I glued two pieces of plywood temporarily together.

I then cut those pieces out, on the bandsaw. I used my rasps and sandpaper to finish the shaping. I also drilled the necessary holes using my drill.

I then used a spatula to separate the two pieces. To remove any remaining tape I used my heat gun. 

On another piece of plywood, I drew half the body of my bow and cut it out on the bandsaw. I then used it as a template on a piece of cardboard. I flipped the cardboard around and drew  the other half of the bow’s body.

Using two dowels, I temporarily placed the bows on the body. I predrilled two pilot holes and screwed two screws with washers in place. These screws will connect the springs with the bows using nylon string.

Following the same procedures, I mounted two springs on the body of my bow. These two springs provide the bow with the force it needs, in order to operate.

Using washers, threaded rod and butterfly nuts I mounted the arches in place. I also added two screws that act as stoppers, to prevent the arches from moving around.

I then added the string, that connects the springs with the two arches.

At the ends of the arches, I added two dowels. I connected them with another piece of nylon string. I secured the string in place, with zip ties.

I then made the front handle using 20mm plywood. I cut the shape out on the bandsaw. Using my rasps I created a chamfer on it’s edges to make it more ergonomical. I glued it in place. I predrilled and countersinked two holes. I secured the handle with two long screws.

I then used the bandsaw, to cut two arrow guides. I glued and nailed them in place. 

The back handle slides in place. I also used the bandsaw to cut a piece out in order for it to receive the cock of the trigger. I temporarily added all the pieces of the trigger in place and freehanded the shape of the cock. I used the bandsaw to cut the cock in shape.

I glued a small piece that acts as aiming point. It also keeps the arrow in place.

I glued and screwed the back handle in place. I secured the cock in place using a small nail as pin. 

On both sides of the bow’s body, I added two screws. A rubber band is wrapped around the screws and the cock. This mechanism acts as spring to keep the cock down.

The arrow is just a dowel. I cut a groove on it’s edge on the bandsaw in order for the cock to have something to grab onto. I then sharpened the tip of the arrow on the disc sander.

My mini toy crossbow is now ready. Although I did not make it really powerful, it still needs to be treated carefully. If you decide to make one, do not use it against live targets. A piece of cardboard or styrofoam are perfect targets for playing and enjoying the toy with safety.

I hope you liked it!

Wednesday, April 12, 2017

How to make a DIY wood turning side scraper










This kind of tools are really expensive. So making them is often a good solution. 

I make these tools from old files. Files are made of really hard, tool steel. This makes them ideal for making tools, knifes etc.

The handle of my side scraper is made of a piece of maple.

I made this tool for smoothing the inner sides of wooden bowls.

First of all I used a chalk to design the basic shape of my tool. 

I then used the angle grinder to cut the shape out.

To clean the teeth of the file I used the front side of the angle grinder’s disc. I then added a sanding disc to smooth the tool even more.

I made the handle out of piece of maple. In greek it is called “κελεμπέκι” (kelebeki). It definitely is a kind of maple but I am not sure if it is exactly the same tree you find in other parts of the world.

To smooth the board flat, I marked the surface with a chalk and used the plane perpendicular to the grain to remove fast a lot of material. The chalk helps me see which spots the plane didn’t cut.

I used the sole of the plane to check the board for flatness. Then I planed the board with the grain to smooth it out.

I then used the bandsaw, to cut the wood in two pieces.

I used the steel blade as a guide to mark the area of the handle. I used the router with a straight bit to open up the grooves. I then finished the grooves with a chisel.

I glued and clamped the two pieces of the handle. I did that with the steel inside the handle. After everything was secure I removed the steel part of the tool.

While the glue dried out, I heated the blade in my homemade propane torch mini forge. After heating it to red hot I dipped the steel in oil. I then heat treated the steel in my oven at 180 degrees celsius for 2 hours. I cleaned the black patina with the angle grinder and a sanding disc.

I cleaned the edge on the grinder while dipping the metal in water to prevent it from burning. 

I then mounted the handle on the lathe between centers. To make that easier, I temporarily glued a piece of wood in the open side of the handle.

Using a scraper and a bowl gouge I turned the handle true. 

I then used the angle grinder, to cut a piece of metal tube for the front end of the handle. Using a caliper and a flat chisel I created the tenon that wood receive the metal tube.

I then used a bowl gouge to shape the outer curves. I used a spindle gouge for the inner curves. I shaped the back of the tool with a skew chisel and smoothed everything out with a round scraper.

I sanded the handle from 100 to 320 grit sandpaper. I finished it with a paper towel and Yorkshire grit. This is a woodturning abrasive paste. It contains, oils, beeswax and tiny stone fragments.

I then added the metal tube in place and sanded it flush on the disc sander.

I glued the blade of the tool in place with two part epoxy.

I then set up the angle on my grinder’s base to match the angle of my round scraper.

I then grinded the bevel of the tool. During this procedure, I often dipped the blade in water to prevent it from over heating. When I created a wire edge on the tip I removed it, on an oil sharpening stone.

My tool was now ready, I tested it on a scrap bowl I had and worked really nicely in smoothing the inner sides!


Thursday, April 6, 2017

How to make a kalimba using the lathe











I made this kalimba (aka thumb piano) using a few scrap pine wood pieces I had in my workshop.

I begun by drawing a circle with my compass on a piece of pine and cutting it out on the bandsaw. 

I then mounted the wooden circle on a face plate and turned it true on the lathe. I used mostly the bowl gouge for this job.

I then used a skew chisel and a spindle gouge, to create a mortise at the bottom of my piece. This way I can mount the piece on my chuck. 

The body of my kalimba is actually a mini wooden bowl.

I used wood filler to fill any imperfections on the wood and then sanded it.

I reversed the piece on my chuck and used the bowl gouge and a spindle gouge to hollow my bowl.

To make the top of my kalimba, I split a piece of pine on the bandsaw. I then mounted my hand plane upside down on my vise and used it as a jointer to joint the two book matched pieces of my top. I then glued the two pieces together. 

I used the bowl as guide to mark the circle I needed and cut it out on the bandsaw. I also used my disc sander to sand both edges of my top smooth.

I opened up the sound hole of the top, using a hole saw on my drill press.

I glued the top on my bowl. After the glue dried, I remounted the kalimba on the lathe and turned the top flush with the body, using a spindle gouge and sandpaper.

To make the kalimba’s metal keys I needed a springy steel material. I used an old hacksaw blade for this job. I cut it to size with my angle grinder.

To create a finger rest on my keys, I heated the metal to red hot with my blow torch and then using a hammer and my vise’s anvil I forged the edge to expand the shape of the steel. I then shaped all the keys to my likeness on my grinding wheel.

I used the angle grinder again to cut a metal rod to size.

I used a file to flatten one edge of the rod. On my drill press I drilled two holes, while using oil to prevent my drill bit from overheating.

I then shaped a scrap piece of niangon wood on my disc sander to make my kalimba’s bridge. I also cut two big nails to size using my angle grinder. I glued them in place with two part epoxy glue. Before that I used a V chisel to open two V grooves. This way the nails would sit in place while the epoxy dried.

I then predrilled, screwed and glued the bridge in place. 

I applied 8 coats of clear, glossy varnish from a spray can. I sanded between coats with 300 grit to achieve a better finish.

My kalimba has 5 keys. This way I can tune it to a pentatonic scale. I used a guitar tuner to tune it. When you increase the length of the key you get a lower note. Decrease it and you get higher pitch.

My kalimba was now ready, I hope you liked it!