hollow punches to make pistons

[jackssmirkingrevenge]

I often advocate the use of solid rubber pistons for coaxials punched out of thick rubber sheet using a sharpened section of chamber tubing. Turns out there are tools specifically made for the job:



Metric and imperial sets with most common diameters are available online for not much, some examples:

http://www.ebay.com/itm/Stainless-Steel ... 43ae8465cf

http://www.ebay.com/itm/NEW-6PC-LARGE-S ... 3ca69180bb

http://www.ebay.com/itm/12pc-Hollow-Met ... 27c4d00b61

These would be especially useful to those making penguns or similar small caliber pneumatics but are struggling with the piston element.

[wyz2285]

Cool, but now that I can make solid nylon pistons...
If you found out earlier, I probably have bought one.

[jackssmirkingrevenge]

Apart from pistons these would be useful to make sabots too, I'm sure you could cut through thin plywood for example.

[warhead052]

I had actually looked at that not long ago, planning on getting some at some point so I can make small pistons.

[Crna Legija]

I have a set that also marks the center of the circle perfect for making sealing faces and gaskets for bolt/washer pistons, it wasn't cheap $200 that's 10-60mm in 5mm increments

[Zeus]

Personally, I wouldn't run out and buy these, they might not fit the barrel as tightly as a piston cut with the housing material.

Excellent idea though, and it'll be ideal for sabots.

[Brian the brain]

Ehmm..

This is new to you?

I have a complete metric set of them...

[jackssmirkingrevenge]

This is new to you?

I spotted a set in the maintenance room at work, had never seen them before. I have a set of home made sharpened tubes so never felt the need to seek a "proper" alternative...

[Petitlu]

I also, including a number of 20mm for cutting rupture discs

[Brian the brain]

I have a complete metric set of them...

But this is still true:

they might not fit the barrel as tightly as a piston cut with the housing material.

then again; a set of these will come in handy.
I've used them on several occasions, for spudding and cutting engine gaskets alike.


The set I have allows for coaxial use of two at the same time, cutting perfect washers as a result.

The seal for the counterbalanced valve was made by cutting a ring out of some thick teflon sheet.

So yeah.. I can recommend them.