Sankyo rocker build

[browne92]

Hello all. Haven't posted in a while, but I check in most every day. A great many projects keeping me busy.

A young lady brings me a Sankyo that won't pay out. I take it apart to find the jackpot rocker is crumbling. So I decide I'm going to make a new one.

I start by gluing it back together and taking a picture of it. I then load the picture into AutoCAD and scale it to actual size. This lets me take measurements that would be impossible for me to take otherwise.

rocker0.jpg
I took all my measurements in millimeters because I planned to write a router routine to cut these out for me. For now, I'll be using the mill to make one out of aluminum.

I start by milling out the functional parts of the shape. The arm that rides on the trip lever, the clearance for the jackpot light under it, the place to bolt down the ball holder, and the pivot point. Note that the blue is a dye that allows scribe marks to be easily seen.

rocker4.jpg

At this point, I reach my "You big dummy" moment. I realize that I did my metric to imperial conversion wrong and drilled the pivot hole in the wrong place. I feel so NASA when I do that.

So instead of scrapping the part, I decide to fix it. I can't just drill a new hole, it would overlap the other (I wasn't off by THAT much). So back to the mill to bore it out oversized:

rocker5.jpg

Then to the lathe to turn a brass insert to press fit size. This means that the part is .003" bigger than the hole it's going to fit in.
rocker6.jpg

Then mash them together. Didn't even need the press. Just used the vise.
rocker7.jpg

To be continued next post...

[browne92]

Then drill the pivot in the right place:

rocker9.jpg

Now that I got that straight, I start milling off any excess that gets in the way of covers fitting on or the way it moves. Sorry to say, I didn't get a picture of this point.

So into the machine it goes and it works about 4 out of 5 times. I decide it's too heavy, so I mill off some excess aluminum to lighten it up:

rocker10.JPG

The finish is poor because I didn't know where I was going with this, and by the time I got it to the shape I needed, I was limited on how I could hold it to lighten it up. So the area to the left got cut with the side of the end mill, which gives a poor finish.

I tested it quite a bit yesterday and it worked every time. I'll come back later with pictures of it as installed. The next step will be to try one out of plastic.