Zip3, the best k'nex gun in my arsenal. Its a pump-bolt action knex gun that's contained within five layers of K'nex. I've been working on this gun since its initial post about a year ago. As all my knex guns go when I post a preview, usually I have a rough working gun that looks decent. Zip3 was the same way, that's why I've spent the time to build my ninth version of Zip3 which is the best version so far.
As far as internals go, it a hasn't changed much from the preview: now it can be dry fired, slightly better trigger, uses one broken piece on the gun and three per magazine. It also has however gotten longer, a larger cleaner pump, more pump rod support, and larger magazine capacity. The trigger is still the weakest part of this concept due to very tight space constraints, but its capable of holding back 3 rubber bands (2 #64's and slightly smaller one).
Overall this gun is my piece de resistence, the best I have and I apologize for missing my deadlines for those looking forward to a post, I procrastinate far too frequently. I also apologize for the quality of some of the pictures, I thought it was just a camera issue and really it was just dirt on my camera lens! Anyway I'm back and ready to answer questions if you have them, just leave me a comment.

Alright let's get building this beauty!

Step 1: The First Layer

Well all K'nex guns start the same way, lets start by buiding this massive first layer. I also show a detail piece I use as support. Note that this piece is purely for support and doesn't make the gun 7 layers, the gun is fully functional without it. For those who are building another layer for the final step, you don not have to include the blue spacers on the black rod.

Step 2: Little Pieces

Well as the name suggests, this step is to put all those annoying little pieces on the gun. If there is any questions feel free to ask in the comment bar.

Step 3: Trigger, Chambering Mechanism, and Barrel

Alright we are done with those annoying little bits of gun parts, we move to the larger sub-assemblies. Starting with the dreaded and heavily revised trigger mechanism. The hinge is attached to the yellow connector and then taped tightly with electrical or any other tape. Make sure the tape does not interfere with the joint. After that you get to see how I build bolt action mechanisms. It relies on two elastic powered arms, the lower pushes the ammo up and the top levels the ammo as it is chambered. This allows you to unjam the gun easily by lifting the top chambering arm, which will allow the rod to slide down the barrel. Finish this step by building the top of the barrel.

Step 4: Grip and Trigger Guard Assembly

Now for the grip and trigger guard, which I believe ties this entire gun together. The entire step is pretty straight forward, however as you can see I use a little cut piece in the trigger. This piece is optional! I would highly recommend this piece for people who intend on using this gun a lot, because this will allow a more responsive trigger.

So, if you plan to have this gun assembled for about a week, I'd skip it. If you plan to have your gun together for longer than that, please use that piece.

Step 5: Pump and Final Assembly

Alright now it's time to build the pump! I revised this part over fall break, producing a larger and more comfortable forward pump. Notice the step order; build the pump rods, the pump, add the top layer, then the last pieces of the pump.

Step 6: Rubberband Placement

If you made it this far Congradulations! You have finished all the K'nex parts of the gun and now it's time to add the rubberbands. This gun is a bit finicky on band placement on the chambering arms. Make sure that the bottom chambering arm is tighter than the top chambering arm. This doesn't mean that the top chambering arm should be loose either. Regardless tighten a loosen the arms to ensure the yellow rod is chambered straight in the gun.

Step 7: Magazine

Well, you have the gun now for the magazines! Make sure to make two of these if you can to enjoy the full potential of you gun. Also if you have any previously broken y-clips, I'd highly recommend placing them on the tabbed side of the magazine, and the taping them to the orange connector.

Step 8: Finished!

Good Job completing your very own Zip3! I'm glad that you took the time to build or look through the ible of this gun. I must say that I personally love the Zip3 system and I plan on applying it to several new guns in the future. If you've built Zip3, I'd love to hear what you think about it and see pictures if you have any. Anyway it's been a pleasure as always, thanks for building!

JonnyBGood