Laser-cut Extension Claw: Recreating My Favorite Toy

I got this plastic claw toy decades ago on my first trip to my city's science museum.

I recently graduated with a degree in Mechanical Engineering.

Whether or not this toy precipitated my academic career, I'll leave for you to decide, but either way I wanted to pay homage to one of the coolest toys I have ever owned.

This is also a fun and easy-assembly toy for most camps - use it to pick things up outside, inside, on high shelves, really anywhere. It also teaches the basics of moving parts, using nuts/bolts and laser cutting.

The reason the claw persisted as one of my favorite toys is because of how useful and user-friendly it is.

So without further ado, let's jump in and reconcile my 3 year old and 23 year old selves with one slick project.

Materials:

1X: 1' x 2' sheet of 1/8" plywood (If you go thicker, you will have to edit the design)

7X: M2 x 12 nuts and bolts (The design can be easily changed for larger hardware)

1X: Rubber band

Tools:

Laser cutter that can handle 1' x 2' plywood (the design can be easily modified for smaller lasers too)

Software:

Inkscape (or another dxf/svg editor, though nothing beats inkscape)

I will say that modeling in Fusion360 was more of a formality for this project, just to attach some dimensions easily to the interesting shapes of the claw, the handle and the connectors.

I had basically drawn the design in a notebook and just modeled my hand sketches.

I won't go into detail how I modeled this because it would read like a tutorial for Fusion360 and I think we'd all appreciate if I just share the files and move on.

The reason I did model it was so that I could easily export the shapes to dxf files for the laser and make my life so much easier in the next step. It's very easy to do so - you just right-click on each sketch and "save as DXF". (I shared a picture illustrating this)

I used Inkscape for my vector editing software (I stan Inkscape)

By clicking File > Import and selecting your DXF files, you can bring the designs into inkscape.

You may have to scale the import by 25.4 (convert inches to mm) if it prompts you.

You can click on the object and see the dimensions in inkscape to verify it was imported correctly.

If you wanted to make any changes to the hardware size or the arm length, you can do so easily in this step.

Now, normally you would have to take the time to arrange the pieces to fit on a 1'x2' plywood board, but I have taken the time to do it for you - and I was able to fit two full kits on one board.

I have provided the file for this as well.

I went to my local makerspace Maker's Workshop, and used their laser to cut the pieces you see here.

Cutting on a laser is really as simple as uploading the SVG file from the previous step, placing your material and making sure the cut is aligned with the material in the laser.

You just click go, and you should get the slick pieces in the pictures.

You can start by screwing on both claws to the large base board and adding the "fingertips" the claw as shown in the picture. These have all been fastened with the m2 screws.

You can then start attaching the handle. You lay the handle on top, aligning the rectangular holes as shown. Then you slide in the vertical key piece and have the L-shaped part poke out from the bottom as shown.

It is important that you move to the next step after assembling ONLY these two parts of the handle.

Use nuts and bolts to fasten the coupler stick to the moving end of the claw. Add a round spacer in between the coupler stick to the claw.

Make sure the slide the rubber band onto the two coupler sticks as shown BEFORE fastening the other side to the handle.

Finish fastening the couplers to the handle as shown. This is why we did not add the horizontal key to the handle underneath - it would have blocked screw access to the coupler-handle joint.

After you fasten the coupler to the handle, you can slide the horizontal key in place on the bottom of the arm as shown.

You can then use an extra long bolt and a nut to fasten a spacer to the top-middle hole of the claw. Next, wrap the rubber band around the extra long bolt.

I added a couple extra handle-looking pieces that you can glue to the outsides of the handle, that way the grip has some extra strength and thickness.

You have now completed the arm!

Congratulations! A fully functional robot arm is useful for many things: reaching into tight spaces, picking up trash off the ground for town cleanup days, and so many more! Anything your hand can hold, so can this arm, but further away!!

Anyways, I hope you enjoyed this build of my favorite toy. Happy making!