SpudFiles

Hey guys,

I'm not sure if you've read kashmunni's adjustable hop up but you may all know that in a bbmg the rubber will wear away extremely fast. So I've thought of another way to build a hop-up that is durable and adjustable. Doing this will probably slow down the rate of fire but it should increase the range and power.



Just a picture of what the hop-up looks like. Basically the ball bearing sits on top of the barrel with a quarter of the bb hang down into the barrel. The blue stopper is the adjustable bit wear you push down on the spring for more hop-up and vice versa.

How to make it adjustable? It works as the spring becomes more compressed the harder for the bb "leaving the barrel" to push it up (it's common sense). The ball bearing used should be much denser than the ball bearing that's being fired for obvious reasons.

Why does it get more power? It's just theory but when the bb becomes jammed the pressure is built up until the spring cannot handle the pressure causing the spring to push up and bursting a small amount of air out. It's probably better to position the hop up but it's just an example.

Just to see how the thing works from this link on spudfiles.

http://www.spudfiles.com/forums/viewtop ... caca4e710f

Opinions on this idea? Was going to use it for my next cloud.

It should work fine, but I'm 98% sure that another member had this idea. I think it was JSR... Well great minds think alike eh?
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That is a good idea lilbro. One piece of advice though: The metal ball bearing would be smooth, which isn't good for friction. The rubber used in hop-up units on Airsoft guns is basically designed for that. It's not smooth so it can build up lots of friction. I suggest roughing up the ball bearing with sandpaper before using it, so it will be able to build up more friction.

Good luck, look forward to seeing it in one of your portable cloud guns soon. (I love totally portable BBMG. Hand pumps ftw!)

Looks like a good concept. I've thought of using a strong magnet, but that's only for ferrous metalic shot of course.
I've also wondered about induction (current generation could be useful or undesirable in some instances) if a magnet is used and metal passes through it rapidly.

Guess the spring area should be as small as possible since like you stated air/gas will enter that space. Thanks for the diagram 8)

You will need a very tight barrel for this, or else the pressure will not build up, but the air will just slip out.
If it is that tight, then its nice indeed!

Kash munni wrote:That is a good idea lilbro. One piece of advice though: The metal ball bearing would be smooth, which isn't good for friction. The rubber used in hop-up units on Airsoft guns is basically designed for that. It's not smooth so it can build up lots of friction. I suggest roughing up the ball bearing with sandpaper before using it, so it will be able to build up more friction.

Good luck, look forward to seeing it in one of your portable cloud guns soon. (I love totally portable BBMG. Hand pumps ftw!)

Actually it doesn't really matter if you use a metal ball bearing, because the friction in it has already been solved by the force acting upon the spring. The spring is pushing down and therefore should be enough force to produce a backspin on your bb. If rubber was durable I wouldn't have brought this up lol. But it's a good fact though.