In this application rolling of the o-ring is forbidden.We use tools that look like funnels. Put the wide end of the "funnel" over the piston and slide the o-ring over the pointy end. Just need to roll the o-ring up to the wide end of the funnel and when it goes off the wide end it pops right into the piston groove. It might be easier to find a cone-shaped something that you could custom-size to fit your piston perfectly- often quicker and easier than trying to load those pliers up with rings, and simple enough to make a custom sized tool.
Wish I had a photo of one, much easier to understand with visuals.
Pen caps and golf tees work for much smaller o-ring installs, too.
Matt
The pic is a sheep banding tool. I've ordered one to fiddle with. I'm looking at 2400 orings a month. The machines are about $10k each. I've already spent at least $400k on this project. It's starting to rub me wrong.Check the vet store for the tool that they use to put the bands on sheep. Kind of like the pic you posted.
Already designed this but alas it requires two operations so is not optimal. It's still in the running but hopefully not for long.Hmm. I'm picturing a thin, slitted cylinder, driving the o-ring off a smaller o.d. cylinder.
Or a thicker solid cylinder driving the o-ring off a smaller o.d. thin, slotted cylinder.
There are possible approaches to avoid rolling.
This seems like a great idea. I also have need for the product to be packaged.Job it out to a sheltered workshop, such as Pride Industries.
They thrive on repetitive tasks such as this.