Introduction: High Performance Grappling Hook
We carry a lot of different things. Sometimes we drop them. Instead of leaving your everyday carry items out of reach, get your grappling hook!
This is the sequel to the original grappling hook I posted. The first one worked great but didn't stow so well. Here's what I'm working on now. It's a cross between a mechanical claw and grappling hook. When it touches down, gravity pushes the jaws open. Lifting it closes the jaws around your prize. Now I feel better about all the quarters I've lost in claw machines.
I sell these at my shop (click here to check it out)
So what makes it high performance?
- It can be used just as a 2 pronged hook.
- It "Bites" objects that might slip out of a grapnel.
- Installing the Cross Hook makes it a 4 pronged grappling hook.
- Compact enough to be stowed on a back pack strap.
- Can be dismantled for more compact storage.
Step 1: Cutting Aluminum
Grab a section of 1/8"x3/4" aluminum bar from the hardware store. I think it cost about $7.00 for a 3' section. Cut six sections each 3" long. I used a scroll saw to do this. Once that was done I placed it in my mini mill to square up the edges. Don't forget your safety glasses.
Step 2: Drill and Round Over
After marking the holes with a center punch I placed the pieces back in the mill and drilled out the holes. It's important the holes line up you so may want to clamp the pieces together and drill them all at the same time. To round over the edges to each piece I used a de-burring bit in my mini lathe.
The jaws are cut by moving the x and y axis at the same time. This is where all my etch-a-sketch training came in handy. Once they were cut, I rounded them over too.
Step 3: Add the Hardware
The pieces are stacked in an alternating pattern. For the prototype I used plain old nuts and bolts. The very top joint is held together with paracord. Now that it's all together I tested it out on a few different objects. Off to the computer!
Step 4: AutoCad Design
I love me some AutoCad. I started out with a basic 3" x 3/4" rectangle. Next I rounded over the edges and placed the holes. That made the linkages. The claw part took much more work. Since the parts overlap and mirror each other, the curves had to match up nice. It's hard to imagine on screen but printing out the parts in paper and cutting them out helps. When I was happy with the file I sent it to a local laser cutter.
Step 5: Laser Cutting
I picked up the parts and put them together just like the prototype. I did upgrade to better hardware though. This was cut out of Delrin which is a high strength plastic.
Step 6: Review
It's been fun to make this. I'm still perfecting the design.
Some ideas include:
- Incorporating a magnet into the design or making a magnetic attachment for magnetic retrieving.
- Adding a secondary function to the cross hook. Like making it a gear tie or adding a hex tool cut out.
- Modifying the linkages so a rubber band forces the jaws closed. That way you could tie it to a pole and use it as a "cherry picker".
- Making an XL version or using titanium.
Thank for reading.