Best way to make a piston?

[11bravo]

I've decided to add a piston to the rebuilt Screaming Eagle of my yute.
I've come up with two possible designs that can be built with what I have on hand.

https://pg.photos.yahoo.com/ph/gps_greg/detail?.dir=2fbe&.dnm=eb98.jpg

Which do you think? Another design?
I'm leaning towards the centering ring version.

Thanks,
Greg

BTW, the 'pistons' that I have on-hand are dowels.

 

[Ryan S.]

I woudnt put a piston in at all personally however I recommend the one on the left.

The one on the right could start to come up and then jerk to one side and jam up in the body tube and not push out your laundry

 

[Zippy]

I've got two PML kits. One that I built with the piston and one without. Just mentioning PML 'couse they use a piston. If I ever buy another PML I'll leave the piston out. The piston has allways actually worked fine in the one I included it in but that rocket (AMRAAM2) recently suffered a 4 or 5" long zipper and repairing it will be more of a pain becouse of that piston. All my other HPR stuff use kevlar cords and 'chute pads and thats the way I'm gonna keep building them.

 

[shockwaveriderz]

I like the CR version: less friction/drag ..just be sure to completely clean and test the piston prior to launch to avoid Ryan's concerns.... also consider a baffle to allow only gases to hit the piston......this would aleviate cleaning where the piston must slide....... use talc to "lubricate' the tube/piston prior to use...

 

[11bravo]

I had the centering rings in my pocket one day and forgot to take them out and wore the shorts a second day (yes, I wear pants and shorts two days before I wash them unless they get nasty) and the rings got kind of messed up.
I did epoxy them to a short chunk of dowel, but it doesn't look good for any chances it/they will be useful.
Also, the epoxy is just kind of nasty.
Oh well, live and learn.
Probably just go with a box of Kleenex as wadding.
Thanks all for your input; gave me some stuff to keep in mind.
Have a good weekend,
Greg

 

[Missileman]

Originally posted by shockwaveriderz
.... also consider a baffle to allow only gases to hit the piston......this would aleviate cleaning where the piston must slide.......

Wouldn't the baffle eliminate the need for the piston?