My Star Shooter cocktail came with a non-functioning drop target. After some inspection, I found one target broken, and another had been wired back together:
Far left is a functioning target, I pulled it out in case I needed it for measurements. Turns out I could have left it in the machine. Middle is one that had broken. By the looks of all the goo on the plunger, they tried to duct tape it back together, but that didn't work, so they drilled a second hole through the plunger and wired it back together. The one on the right apparently broke, the plunger fell out, and was lost.
I took the middle one apart and found this:
It uses a two piece plunger, part steel and part plastic (nylon is my best guess) with a 6-32 stud molded into it. Since I didn't have any nylon available, and no way of molding a stud into if I did, I decided I'd make my replacement out of aluminum:
This is the first of two replacements. My only concern with using aluminum is that plastic would have some 'resiliency' to it...a little 'shock absorber' effect if you will...that aluminum won't have. I was curious about the weight, my replacement came in about 3 grams heavier than the original. I don't see any problem there. I drilled the end and tapped at 6-32, made a stud by cutting the head off a 6-32 X 3/4" screw, and used a drop of Loc-Tite to hold it in. A 1/8" roll pin will couple the target to the plunger.
Next was to turn the metal portion of the plunger:
My replacement on the left. The finish isn't very good, but my lathe and I both have the same conditions...age and wear.
The finished pieces, ready to install:
I could have spent a lot of time with an edge finder making these parts dead-nuts on, but I didn't think it needed that level of precision, so I did a lot of eye-balling. The slots milled in the tops of the aluminum pieces are a bit off center, some of the drill depths are best estimate. But I installed them last night and they worked well. Only time will tell when it comes to durability.
I am by no means a machinist, more a hobbyist, but it was quite gratifying to get my machine working again with a couple of pieces of scrap metal and a few hours in the work shop.