Saturday, August 31, 2013
Thursday, August 29, 2013
What says "thank you" like a beautiful cannon? I just finished this new piece. Its a six and-a-half inch long aluminum cast dahlgren pattern cannon. It also came out exceptionally nice.
Boring out the barrel
Facing off a wheel
Now the other side gets formed
Center drill for the hole
A complete wheel
Cannon pieces ready for assemly
Glueing up the carriage
Thursday, August 1, 2013
A month and a half ago, two friends along with myself decided to build a large trebuchet. I had built a sizeable trebuchet before using recycled wood from my old deck. It stood about 8 feet tall and hurled a projectile over 100 feet. The materials were not of high quality though which limited the power of that siege engine. The new trebuchet was to be larger but most of all stronger, built of better materials and constructed with superior methods.
The frame would be be built from pressure treated 4x4 posts and 2x4s. All the joints would be glued and pinned with wooden dowel for a more tradional look and good strength. Special attention was paid to the throwing arm. The earlier trebuchet was failing at the main pivot. The steel bar serving as the axle stood firm as the wooden arm sagged downward under 70 lbs of counter-weight. The hole through the arm had gone out of round and generally allowed for lots of wobble. The new trebuchet would have a laminated wood throwing arm with flange bearings to take the load and reduce friction for better performance.
Flange bearings, one inch steel axle, and bolts.
This trebuchet is designed to shoot an object weighing two pounds well over 200 yards
The frame, to be glued and pinned
Throwing arm glued and clamped
Posts all mitred ready for assembly.
Because this engine is planned to have a great range, firing it in the neighborhood is right out. That makes transporting this beast necessary. Each side will be glued solid. These solid sides will bolt to the base. Lateral bracing has been designed to bolt on as well.
More to come!
Thursday, January 3, 2013
One of the holders which came with the quick change tool post was a cut-off tool holder. These are used to part off a piece after its been turned. You can also use them to cut narrow grooves for anything.
Usually the are made with a carbide tip on a steel shank. An idea came to me the other day. Why not cut out a rectangular section of a scrap circular saw blade? Cut it so that a carbide tooth remains on the end, and you have a great edge and since the teeth are thicker than the blade, it won't bind either.
This last picture shows some grooves I began to cut. I will be parting off three segments, but first they need a hole bored through for a project...
Not bad. The cutter took a minute to cut out with an angle grinder and the carbide tooth cuts the aluminum like butter. Nice shavings come off.
This worked so well that I will have to find a thicker blade to make a cutter which can handle deeper cuts. Its an excellent reuse of old saw blades, which often still have a few sharp teeth to use.
My parents bought me a quick change tool post for Christmas.
As you may have gathered from the picture, its made in China. Nonetheless, it seems like a decent tool post. Close tolerances and nice ground surfaces leave me impressed.
The tool post came with a rectangular slab of steel 1/2 an inch thick. You machine the T nut for the lathe. That was an interesting process. I reinforced a piece of angle iron, secured it in the groove, used a fly cutter to mill it vertical, mounted the steel blank on this. An end mill went into the chuck. With this setup, I milled the T-nut down to size. More on that later. I have some videos that will go up on my youtube channel.
Here you see the other holders that came with it. From left to right: A 5/8" boring bar holder, a knurling tool (Its also serving to hold my dial indicator), my threading tool holder, a cut-off tool holder, and my right-hand tool holder. The left-hand bit is in the mounted holder.
The beauty of these tool posts is that the nut on each holder keeps the position of the bit. To change bits, you just turn the handle, remove the current tool, and slide the new one on. Once you've set all the proper heights once, its done. Changing tools no longer takes time. The height is set.
This tool post allows me to take advantage of brief periods of time. I can go out to the garage after school, spend 45 minutes, and actually accomplish something because of the time it saves.