SpudFiles

I've been working on a launcher on and off for a while, and I've finally got it finished and tested it today. Nerf vortex would not leave barrel at 50 or 70 psi. I did not have a chance to experiment more. I think if I lubricated the barrel, it would lower the friction between the barrel and the vortex enough to fire at lower pressures. It will be used around other people, so I don't want to take pressure up too high.
Launcher is PVC with a Mylar burst disk with resistance heating wire as the trigger for mechanical failure. Is PVC susceptible to corrosion from petroleum based lubricants? If so, what would be a lubricant that would not damage the barrel or the nerf football?

What about possibly shaving down the sides of the football with a file, and I think possibly some sort of silicon oil would work. I know it won't eat away at anything.

i thought about silicone, but pure silicon oil is expensive, and the spray kind at walmart has petroleum products and eats plastic. I would also like to avoid cutting the football, because it would not be a standard part anymore. A friend of mine mentioned grease might work better than oil, because it would not have to be re-applied as often and it wouldn't dry out as quickly.

A glycerin based lubricant would be safe for plastics. Any good massage shop or pharmacy should have the non oil based lube. KY is a popular brand. A glycerin soap is another source.

white lithium is what i use for my piston cannons, and it works awesome

Berkut wrote: Nerf vortex would not leave barrel at 50 or 70 psi.

What is the barrel inside diameter?
What is the barrel made of?

Is the problem the ball or the fins?

Typically a SCH40 PVC pipe ID is about 2.047 inch nominal which is larger than the Nerf Vortex football outside diameter of 2 inches. The fins have a larger diameter dimension.

Note that the fins can be trimmed a little if that is the problem.

Are you referring to a Nerf Vortex Mega Howler or the Pocket Vortex?

A spray on dry mold release with PTFE works great to reduce some of the friction in the barrel.

At work we have a graphite spray lube that's wet when you spray it but drys up quick and then is really hard to clean off. not sure what it is called because it in German.

Crna Legija wrote:At work we have a graphite spray lube that's wet when you spray it but drys up quick and then is really hard to clean off. not sure what it is called because it in German.

what good is that if it drys up?

Because it can still lubricate when it dries. Are you not familiar with graphite?

Yep what MrCowley said.

talc powder works good

Are you sure it's barrel friction that is the problem, and not that your chamber is too small for lower pressures? What's you Chamber:Barrel volume ratio?

Agreed, 70 psi and a decent chamber should have ripped that nerf vortex apart if friction was truly the issue.

yes i know what graphite, but the spray lube i dont like, only the powder stuff , but i wouldnt use it in my piston cannons

I would recommend against graphite if it isn't for something self-contained, like a piston valve. The reason for this is because loading a projectile and recovering/re-using it later tends to result in the buildup of graphite on one's person, clothing, furniture, domesticated animals, friends and relatives, Mike Rowe and pretty much everything else within several kilometers.