Thursday, February 28, 2008

And today...a video - #73 - Take one

Here is what I built have so far...

Really, though, I still have a lot more to go...


Wednesday, February 27, 2008

Track day 3

Here is my progress as of today. I still have a lot more track to build. I always build the loop d' loops first because they need their space. It's much easier to build around them, than to try and fit one in.

This is the loop d' loop close up. It has 10 loops in a row. There will be more then 10 loops total, but the last section is not build and added yet. This phase of building is fun and challenging. Even though things get to go wherever I want them, that doesnt mean that it is easy to decide where everything should go...

Monday, February 25, 2008

#73 In Progress

I started building the track today. I installed the 3 switches needed to turn one path into 4 paths. The ring turns slowly so that approx 3.5 marbles per minute are released onto the tracks. It takes 1:15secs for one marble to get picked up from the bottom and get released at the top.

This is a closeup of the track. I still need to brush off the welds spots to clean them. When a sculpture has more than one track I always make and install all of the necessary track splitters and then go from there. The third switch will have fewest marbles.

Want to see how it moves so far? Watch this short movie.


Saturday, February 23, 2008

10 hours later....

I ended my Thursday with an idea of how I was going to make the ball ejector for getting the marbles out of the ring at the top. I had something started, and spent that night thinking all I had to do was go ahead a finish it. Unfortunately, it did not work out that well. I worked on that particular design until about 3:00 pm, on Friday - I wanted to give up as it just did not work. In fact I remade that part 5, count them, 5 different times. All a failure. The main problem being the wire that was supposed to push out the marble didn't travel into the hole far enough. The secondary problem was I had to make it work, at any cost of time. Finally I scrapped what I had, and after something to eat, tried again. After all of the problems I had been having with the first design, I was starting to get an idea of what I needed to change to make it work.

This picture (above) shows the ejector pin fully extended into the hole. You can see that the pin coming out from the wood ring is just about to pass the lever, and let it fall back to it's resting position.

This is design that works. There is a pin sticking out under each hole. This pin pushes into an arm, that in turn pushes into the bottom of the three white bearings. Since the fulcrum is off-center, the top will move farther than the bottom is pushed. Meaning: The bottom is pushed in about 3/4", and the top will move out 1 1/4". This shot (above) shows the pin just about to push into the lever.

This photos shows the pin fully extended into the hole in the ring. The 1/4" rod that is now straight out is a counter weight. It's weight will make the arm return when the pin passes. It will work better than a spring because it will have less pressure, and gravity will never fail. The rubber is to keep it quiet when it drops back to it's resting position.

Finally, here's a view from the top. The white bearing on the right is to keep the ring in the same position at the top, and so that it cannot shift and rub on the ejector pin. Lots of testing and retesting to get to this point, but well worth it. It works flawlessly, and is a joy to watch. (now that it works!)

Now on to track, track and more track. : )

Thursday, February 21, 2008

Ring lift and frame completed

For me, this is my blank canvas!

I finished with the first phase of my current project. The first phase is the frame and lift, and the second phase is the track and elements. The ring is 6ft diameter, made from walnut, and has 8 holes for picking up the marbles. The next step for me tomorrow will be to make the lever that will push the balls out at the top, and the track where the balls will be picked up from the bottom. I'll post another picture tomorrow with details of how the marbles will be pushed out.

Below is a close-up of the right idler wheel. This wheel is adjustable so the pressure of the wheel against the ring can be changed if needed. I threaded a piece of 1/4" stainless steel rod, and cut it to length. It is inserted into a nut that's welded to the idler supporting arm, and is adjusted by two more nuts on either side.

Below is the arm that is not adjustable. The blue washer is the ball cage from a thrust bearing, and will eliminate wear in the long run. Getting the idler roller the right shape took a little while to get just right. The wood ring only contacts the idler with the chamfer on it's edge.

Finally, this is how the drive roller is mounted to the frame. I have a C clamp holding it on until I get to the hardware store and purchase the 1/4-28 nuts I need. Good enough for now. To keep the steel from twisting I added the support "kicker" under the motor. Since the wheel is almost 10 inches from the wall there is quite a bit of torque applied to the 1/2" steel tubing. I'll have a movie posted soon.

Tuesday, February 19, 2008

Mill and Lathe

Here is the Mill and Lathe that I have been using. Each machine has it's intended use. In a Lathe the part turns, and the cutter does not. In a Mill the cutter turns and the part is secured in the vise. Not much to say here, but, wow, I could not do 10% of what I want without these two machines. The lathe is great for making the nylon bearings used in any moving part I make. The mill is great for making the square aluminun pads for mounting my motors. Of course, if you do buy one of these machines, that is only like half the cost. The other half of the cost is all of the tooling you will have to buy to make it do what you want.

It's been fascinating to learn how to use these machines properly. : )

Friday, February 15, 2008

Finshed with the machining

I have finally finished the drive wheel for the ring lift I am making for my next project. The drive wheel is powered by a 10 RPM AC motor. The motor is attached to a shaft that rotates a rubber and plastic wheel, which in turn rotates the large wooden ring that will lift the marbles to the top of the sculpture. The drive wheel will contact the ring at the outer edge. The base and bracket are made from aluminum. The coupling from the motor to the drive shaft is made from stainless steel. The drive wheel itself is made from rubber (center) and plastic end caps. The shaft is stainless steel also. The motor is from McMaster Carr. $45 - I have at least 40+ hrs into this assembly.

This was a very complicated process for the beginner machinist, like me. I won't bore you with the details of construction. This drive wheel will be mounted at the bottom of the frame to support and turn the wood ring lift that Gene built for me. I didn't build the wood ring because I don't work with wood, just metal. Besides the motor and thrust bearngs, everything you see here was made from scratch with a Lathe and Mill. I learned a lot! I wish I could say that I knew what I was doing and just did it, but the reality is that Bill helped me the whole way. I did do all of the work but Bill helped me with the process and what tools to use when, and why. I will probably get Bill's lathe, as he is 80 years old, but I would be much happier with a few more years of experience under him. Bill told me today that if I had to take this design to a machinist he would charge me $3000 to $4000 to complete everything you see in the photo above. Ouch. That wouldn't be a problem if your customer is going to pay for it, but how do you get a quote on something you are not sure of how to make yourself? My answer is to do it yourself. Piece by piece. To be fair I used several tools I had no idea existed, let alone how to use them. But now that I know....well...knowing is half the battle...

This is the wood ring that will lift the marbles to the top. The drive wheel runs clockwise, so this wood ring will rotate counter-clockwise. There is a small groove inside each of the holes to keep the marble from rolling out. I will need to make a mechanical lever that pushes the marbles out when they reach the top. The steel frame is made from 1/2" stainless steel square tubing ($80 per 20 ft) which is cut at 15 degrees. (30 degree total)
I bought a book "507 mechanical movements" very informative. With it I will be able to find just the right movement to get the marbles out. I will put a pin in the inside of the ring to actuate the arm that will push the marbles out, but first things first. This is the mock-up of what the frame will look like. Actually it is missing one more circle that will go to the left and intersect the other two rings, the last circle being smaller by at least half. This will give me framing to connect the two idler rollers to as well as the supports needed for the track and elements.

4 tracks total, should be very nice. Josh, the buyer, wants it to be elegant and quiet. I will have to pay special attention to the tipping arms, and anything else that makes noise.

I will post again soon as I get more done. Back to the shop!