Monday, September 21, 2015

QUADRA-HEXA THING

Another workshop project has just been completed. I do not even know what it is called or what it would be used for, but for a lack of a better name I'll call it a Quadra-Hexa Thing because it has a four arm rotor on one end and six arm rotor on the other. Inspiration to build it came from looking at pictures of mechanical mechanisms. This thing uses ideas from two similar mechanisms incorporated into one.
Construction started by sawing a couple chunks out of 3/4" thick aluminum plate for the larger rotors.
Then to the rotary table on the milling machine to finish the arms.
The small rotors were milled out of solid 416 stainless steel bar. They are not very big, but time intensive because so many different surfaces requiring different setups.
The bearing standards were fabricated out of steel brazed together.
A coat of paint and a walnut base and it was finished as seen in the first picture.
It will rotate in either direction, and by turning the crank at either end. I was surprised how smooth it operates.
video
If nothing else I suppose it would make a good desk toy. It is fascinating to turn the cranks and watch the action.




Tuesday, September 8, 2015

WATER RAM

For something completely different this time I picked a water ram. They use the energy of running water to pump a portion of it to a higher location where it is needed. Although they are seldom seen, they are still in use in remote areas. This one of course is just a tiny working model standing only about 5" high.
It started by finding a suitable looking picture. It is a little difficult to read, but the lettering on the prototype reads "The Gould Mfg Co". Two patterns and a core box were required, as can be seen in the above picture.
This picture shows the sand mold with the core in place prior to putting the cope in place to pour the castings. After pouring the casting the sand core is removed leaving the pressure dome hollow.
Here the molten aluminum is being poured into the mold. Extra castings were poured in case there was a defect I would not have to do it over again. They all turned out OK.
With castings in hand the machining started. A few parts or operations each day until it was complete. Then came the testing to see if it would work. At first it would not, but after a couple minor changes and adjustments it took of doing what water rams do, Pump Water. Take a look!
The water supply for this model simply comes from a plastic bucket. A prototype would be placed near a stream.
video