Introduction: Walking Papercraft Mech Warrior

About: Recently finished a Ph.D. in Mechanical Engineering. Still love creating in my spare time

A paper Mech Warrior made to appear to walk when a crank is turned. This model is designed after the Madcat/Timberwolf type from the video games.

This is my first attempt at designing my own papercraft automation. It was inspired by an addiction to the Mech Warrior video games and was originally a birthday gift for someone similarly addicted.

There are two options for downloading. the first is a template I have coloured and the second is blank template for people inspired to make their own
If you would like the Photoshop, SVG or just about any CAD file type, just let me know and I will upload them.

Step 1: Gather the Materials

For this project you will need:

- Paper
- Printer
- Sharp knife
- Metal ruler
- Cutting mat
- White glue

To get the paper I suggest checking around common printers, people tend to print off some doubles, nearly blank and blank pages. At my university you can get scrap paper that will work for this by the handfuls. If you are lucky you can get some thicker paper leftover from posters, which is great for this type of project.

With a bit of luck you can even save a printer from the dump and print the pattern for free. To get a printer start by asking people you know who might have such things laying around. It is also good to try asking at corporate offices. I asked at a place I worked and was able to get a black and white laser printer with a full toner cartridge for free. Since there isn't too much colour in these textures it won't make much of a difference if it is black and white or colour printer.

However, it is important to but new blades for the knife and change them when they are dull. Some people will just use a dull blade, which destroys the cutting mat and results in a rough edge on the paper.

The metal ruler is not necessary, but it makes life much easier to cut long straight lines.

Step 2: Print the Pattern

Take your free paper and the attached file and print it, use the backside of the paper if there is something on the front. The back side won't be too visible when the Mech is finished.

Step 3: Cut and Crease Page One

Start by cutting out the holes in the parts marked with a red X followed by the parts themselves.

It is good to cut them in that order because it its easier to handle the parts and less likely to cause damage when they are still attached to the page.

The next task is to score along the fold lines (if needed) and crease all of the parts, following the legend on the front page of the pattern.

A valley fold is a dot-dash line. Fold the paper so the side with the pattern becomes a valley.
A mountain is a dashed line. Fold the paper so the side with the pattern becomes a peak.
There are also dot lines, these are guides for where to glue other parts, so it ends up in the correct position. These are not to be folded.

Step 4: Parts 1-4

Take part one and glue the tab to create the beveled corner (First picture). It is important to not glue the top flap down yet.

Next glue part 2 into a square. I find it easier to align the sides if it is folded in half and pressed together(2nd picture). Some people use a small metal rod on the inside of the part to the flap to the part.

Thread part 2 through the hole in the the middle of the top flap of part 1. Apply glue to the flaps on part 2 on the underside of the top flap of part 1 and glue the parts together (the pictures will hopefully make this clearer).

Glue parts 3 and 4 to the side of part 2 (see pictures). Start by applying glue to the bottom flap, line it up and press it in place. Next apply glue to part 2 where the parts overlap and press them together.

Step 5: Parts 5-6

To assemble parts 5 and 6 start by folding part 5 into a square shape, the same way as part 2.

Glue the four tabs on part 5 to part 6 following the guide lines.

Fold up the sides of part 6 and glue the corners together.
Finish by gluing the remaining flap of part 6 down.

Step 6: Cut and Crease Page 2 (and Part of Page 3)

Cut out all of the parts on page 2 as well as part 8 from page 3.

Cut out the paper marked with a red X first, followed by the outside lines, working your way from one side of the paper to the other.

Fold all of the lines as seen in the last picture below.

For parts 21, 22, and 24, there is an X near the center that needs to be cut and folded outwards. The flaps allow these parts to be put over and glued to the main axle (part 20).

Step 7: Glue Parts 7-8

Start by gluing one (not both) side flap of part 7 to part 1 (as seen in the picture below).

Now glue a shorter flap of part 8 to the leftmost side of part 1 (as seen from the open side). Align them so the bottom of part 1 lines up with the bottom of the flap of part 8
Work your way around the outside of part 8 gluing parts 1 and 7 to it. For the last flap you will need to glue part 7 to part 8 as well as part 7 to part 1.

You can also glue the remaining beveled corners in place now.

Step 8: Glue Parts 20-22 (Cam Assembly)

Take part 20 and glue it into a square shape and glue the end closest to the angled guide lines closed.

Slide part 21 over part 20 so that the longer side points away from the center of part 20.
To glue it in place apply glue to one flap, line it up, and press it down until it is dry.
Just glue one flap at a time, this way there is less of a chance for an error.

If you are having trouble applying pressure on the flap, try putting the handle of your knife in part 20. This provides a solid surface to press against, just don't cut yourself on the blade.

Repeat this process for part 22 and position the longer side in the opposite direction of part 21.

Step 9: Mount the Cam Assembly

Insert the cam assembly into the base shell. Start by putting the longer side of the axle through the hole in the side the top portion is attached to. Push it until the shorter side can fit inside the shell then push the cam assembly back through the hole in the other side.
Take you time with this step, if you rush it you are very likely to tear the paper.

Apply glue on the closed end of the main axle and press part 23 in place on it. You will want to make sure the corners of the axle are flush with part 23, otherwise the paper could get caught and bind the mechanism.

Slide part 24 over the open end of the axle, line it up with the guide line and glue it in place the same way you did for part 21 and 22.

Glue the remaining end of the axle closed.

Glue parts 25 and 26 into a square. Apply glue on the inside of part 25 in the end missing a section and attach it to the axle at a 90 degree angle. Attach part 26 in the same manner to the end of part 25, facing the same direction as the axle (See the last picture).

Step 10: Cut and Crease Page 3

A fairly straightforward step, just be sure to look at the second picture to see how to cut part numbers 12 and 16. There are also some lines to cut on the inside of parts 13 and 17, these are slots to hold a penny which acts as a counter weight.

Step 11: Glue Page 3

Start by taking part 9, applying glue on one half of the one white side and placing it on the underside of the base. This part helps reinforce the base, preventing it from flexing, which can cause it to break. If you are using a heavier weight of paper (about 40 lb and up) you may not need to use this part.

Now glue parts 12-19 into a square shape, refer to the pictures to ensure you are doing it correctly.
For parts 14, 15, 18 and 19 there is a flap on the end that also needs to be glued down. To do this apply a small bit of glue to the opposite side of the square (where there is a slight whiteout in the colour) and press in place. For parts 13 and 17 glue the end flap closed.

To create the cam follower assembly, start with part 12. Take part 13, apply glue to the triangular flaps and position them over part 2 as seen in the picture below.
Next apply glue to the inside of the flaps of part 14 and place it on the labeled portion of part 12 and make sure the seam on the end is facing away from the direction the upper portion of part 12 bends. Do the same with part 15, making sure the seam is facing outward.

Next take parts 16-19 and repeat the above steps, just mirror the side that parts 18 and 19 are glued on. Refer to the pictures because it is important to do this correctly.

Step 12: Install the Cam Follower

First take the cam follower assembly and insert a penny into the slot in parts 13 and 17. Next apply glue to the one loose flap and glue it to the base. The pivot point for the cam follower should be the outermost point of the guide lines on the base, not the middle.
Do the same for the other cam follower assembly.

To adjust the cam followers so they work properly, test them by spinning the handle. If the top parts fall down the side of the cam, pull them back up and while holding the lower segment, twist the upper half inward. See the pictures below for a clearer explanation. It also helps to bend the cam itself, lightly press the shorter side so it curves.

Take parts 27 and 28, apply glue on the back side and fold them in half. Be sure that you pull up the flaps on the ends, don't want them glued together. Apply glue to the remaining exposed back side of parts 27 and 28 and glue them on parts 15 and 19 respectively. You want to position them so that the edge of the part you are attaching lines up with the edge of the seam near the end. The pictures should make this clearer. This step is done now because you may need to change their position based on where the slits in the top flap of the base are.

To build parts 10 and 11 glue them to look like an inside corner. To attach them to the base, apply glue to the bottom of the part (the smallest complete side) and place it on the inside guide of part 8 so the side sticking up is against the cam follower arm. These parts are meant to help with guiding the cam follower arms if you are having difficulty with them. If they work fine before these parts are installed you will want to glue them in place so they don't actually touch the cam follower to reduce friction.

Finally place parts 5 and 6 so the shaft goes through part 2 in the top flap and apply glue around the edges of the top and glue it closed. Position the inside as you do this so parts 28 and 28 go through the slots in the top and part 6 rests on the axle between the cams.

Step 13: Cut and Crease Page 4

Parts 34 and 40 can be a bit tricky so take your time and follow the pictures to cut them out properly.

To get a good curve for parts 31 and 37 hold the part in your hand with the outside of the curve down and rub the handle end of your knife along it like in the last picture.

Step 14: Glue and Attach the Leg Base

First glue the sides of part 29 together then attach it to part 2 by sliding it over, applying glue to the tabs of part 2 and pressing them in place.

Glue parts 30,33,36 and 39 into triangular prisms. Glue two of these to the sides of part 29 following the guide lines printed on it.

Finally, glue the top flap of part 29 down.

Step 15: Assemble the Legs

Start by assembling part 31 by wrapping the skinny strip around the edges and gluing it in place. To finish it, glue together the flaps with the holes. Once they dry you may find it necessary to trim the edges to clean them up.

To assemble part 40 start by gluing the bottom strip around a few flaps as in the fourth picture. Now glue the skinny strips on each side to the nearest tabs (5th picture).
Take one of the triangular prisms (like part 33) made last step and glue them in place as in the sixth picture. part 31 is there to help the alignment, it should be able to freely rotate around part 33. When the one side is dry glue the other side in place. Make sure the upper leg is oriented so it curves up from the bottom, like in picture 6.
Finish the lower leg by gluing the remaining flaps down (pictures 8-10).

To make the foot, start by folding up the sides and gluing down the two shorter sides. Glue down the other two sides and then the top flap.

To finish the leg glue the foot to the lower leg following the guidelines, make sure the slot in the bottom of the foot runs parallel with the direction of the leg.

Repeat this process to make the second leg from parts 37-41.

Step 16: Attach the Legs to the Body

To attach the legs, slip the foot over the protruding piece of part 27/28. Then slide the triangular prism through the hole in the upper leg.
Hold it in place by applying a bit of glue on the end of the triangular prism and sticking part 32/38 on. Keep moving the leg until the glue is dry, otherwise it could end up sticking. If it does stick run a knife along the inside until it is free.

Step 17: Cut and Crease Page 5

Fairly simple, just take your time with part 49 and be sure to cut out the hole in part 42.

Step 18: Construct Upper Body

To build the upper body start by gluing part 42 together, gluing the smallest flap last.

Glue parts 43 and 44 into cubes and glue them to the sides of part 42 as indicated by the guide lines.

To assemble part 49 start by gluing the smallest circle into a cone. Glue the next largest arc in to a circle and glue the smaller circle to it using the flaps. Glue the last section to the rest in to a semi-circle.

To attach part 42 apply glue to the remaining exposed tabs and glue it to part 42 as seen in the last picture.

Step 19: Glue and Attach Arms

Glue parts 45 and 47 into a square shape and fold the flaps in.

Now glue parts 46 and 48 by folding the end with the two circles in the texture (gun barrels) into a hexagonal prism shape. Apply glue to the back of this shape and fold the connected flap down. Glue and fold the remaining parts into a rectangular prism, gluing the top flap down last.

Glue the side of part 45/47 that comes to a longer point to part 46/48 respectively, following the guide lines. The two parts should be glued so one arm is a mirror of the other.

To finish the Mech Warrior glue the arms to part 42 following the guile lines and place the whole upper assembly over the red bar protruding from the leg base (part 5).

Step 20: Final Adjustments

If you find that some parts are not lining up properly, just try gently squishing them (or creasing them) into place, 9/10 times this will work. If you are still having trouble, leave a comment below and I will do what I can to help.

For those interested in the development process of this project, I have attached some bonus pictures of all of the prototypes that led to the final design. There are some additional notes on the pictures for those so inclined to read them.

Thanks for at least reading this far, if you do build the Mech Walker (or even just attempt to) leave a picture in the comments. It's always fun to see other people build things like this.

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