Hexapod progress report.
Page 2: Starter work.
10 Nov 04
Click and go
The next thing to do is to get the engine parts put together and have a unitary power hydraulic unit ready to use. That is the target for this winter on the engine part.
26 Nov 04. STARTER PROGRESS, problems techniques etc.
This next section describes the assembly of the starter components to the engine and the successful rotation of the engine under battery power. This generator-starter cranks this engine over without hesitation. I do not plan to use the generator part at this time but might add the capability later. (For now I'll just charge the battery off line whenever I need to).
The belt drive system mounted on angles under the base of the engine for easy removal and modifications (Which most of my designs usually need because on such project I am not working from drawings on which everything has been worked out. Bad habit.)
Now I can start this engine without wrenching my back. This was really great, mostly because I did not know if it would work because the people who sell the parts for the lawn mowers and small engines etc could not answer my question in the techincal detail that I needed for the design of this project.
The next posting will detail the fabrication of the mount for the hydraulic pump and its installation to the engine. I still don't have the dimensions for the hydraulic cylinders that I have been promised but more on that later. I think I can start on the frame, legs etc but cannot finish it all without them.
ASIDE: I should mention that the shaft on this starter is 0.666 inches in diameter with an 1/8th inch keyway and 20 tpi threads. ODD indeed!! So you will have to make the nut and bore the pulley if you decide to use one of these. The hard part is cutting the keyway in the pulley for which I had to make a whole new abbor for the key cutter. If I had known up front, I would have bought the pulley and the nut with the starter. However I wanted to use a smaller pulley to keep the torque available at the engine high in case I needed the two cylinder, or even four cylinder, version. I might have been able to machine the standard pulley down, but I don't know that because I don't know what the pulley looks like.
Detail of the wiring of the starter to the solenoid. I made the connectors out of 3/8 inch hex brass and machined the flats in them. The holes match the needs of the particular connection on which the connector is used. I drilled 13/64 holes in the ends for the wires and then soldered the wires tight into the holes. Heat the connector with a propane torch and keep feeding in solder in till the hole is full. The wires are stranded #6 wires for residential wiring. Works real well.
I'm using a deep discharge 12 volt RV battery for power. The power leads have been left long so I can position the battery as will be needed to balance the center of gravity of the hexapod (and later on there may also be space considerations that dictate battery location).
Above is the started push button and the safety interlock for it. The interlock is just a simple switch that will not allow the pushbutton to transmit its closure to the solenoid inadvertantly. The ignition switch for the engine itself is visible just under the white panel on the fan housing. I will not be extending the wiring for it.
The drive system is simple, cheap and effective!