Topknot's Functional Spear. Close Up Video Out In The Sun. 03/03/2013


Active Member
This is just a tid bit that I have been working on. I'm hoping that with in the next month or so I can show you much more.
I will let you all know that I have it to stage that has been tested and it works very well.
This is the test video of the pulley
mechanism that I designed for the final tube extension.
Extension test video-
These are a few pics of the blades that will be on the first extension. I used 1/8 inch pvc and glued additional edges pieces then ground them into shape.



I don't want to give the whole thing away but here are some pics of the spring loaded
blades I designed to pop out of the handle. There will be 2 on each end. It's the best I
could do to match the CGI ones in the movie.

You can see the rod (which will have to be visible) that will pull the blades out of the handle as the extensions come out.

I ended up liking the look of the rod. It adds some extra dimension. The next few are of the spring mechanism
in the paddle that holds the blade.


And finally the test of the spring loaded blade coming out of the handle. Not the actual handle by the way.



Well-Known Member
LOL i did wonder how long before you would give in and spilt the beans Jeff.

No turning back now, you have to complete that puppy, and.................we shall be watching :)


Active Member
Hey Darth, the square tubing was for 2 reasons. First, because of the design I found that it worked better for the rack and spur gear assembly. As I look at it now I might have been able to use round. When you see what I have planned and the finished product you will see why the square stuff works better. Secondly, I like the industrial look of it. The square tubes reminded me of the square pillars inside the ship in Predator2. That is actually why I did all the runes and designs on the extension tubes. There will be more pictures to come. I was going to wait and put everything up at once but I may add a few pics later today. By the way, thanks for the comments all.


New Member
Terrific! The spear and disc have always (well, since P2) been my favorite Predator weapons.

So, the plan is that you are going to build a small motor into the center of the spear?
Very clever compund use of the gear to both extend and advance the pully.

BTW, I loved your feet huntorial. When my wife told me that I am going overboard, I showed her how much work and detail you put into your feet.


Active Member
Just cut the rest of the blades out. Used a band saw then finished them with a file.


I had to make this little guide for my Dremel so I could router the blood grooves.


Active Member
So here are some new photos. This is the control panel. All four sides will look identical except this will be the only one with a control panel. It was fabricated entirely from pvc.






And here it is finished. The screw on top will be filled with a light putty ( so I can get it out when I need to) and paint over.



And the insides. Like I say in the video I put flashing lights in as i doubt I could have squeezed a board in
for a count down. I only had so much room to keep this panel the same thickness as all the others.


And last but not least the latest video update. Let me know what you think so far.http:// th_034-2.jpg


Active Member
So here is the motor that is going in the spear.


This is the motor and the gearhead by the way. Here is a shot from inside the main body tube. You can see
the spur gear that runs the rack gear in and out.

Here are a couple of shots of the first set of extension tubes with the spring loaded blades that it drags
in and out with it. You can start to get the idea of what I am tring to accomplish.



Here you can see the spring loaded blades are tucked into their respective tubes on the main body.


That's all I have for now. Let me know what ya'll think. I'm still pluggin away at it.


Well-Known Member
i missed the last two updates. an incredible amount of work you have put into this. it's looking really great.
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