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This project is an incremental improvement to the crank slider mechanism used in the sssnake model. The modified side pieces in the crank make it easy to change the the throw of the crank and hence the range of movement of the push rod.
These three animations show the three included crank sides. Once the model is assemble the throw can't be changed as the parts are glued together so you need to pick the correct size before you complete the model.
Perhaps a later project could include adjustable crank slide length. For now, this project includes crank sides length 8mm, 16mm and 24mm.
Members can download the project for free. Thanks for signing up!
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| 8mm | 16mm | 24mm |
Print out the parts onto thin card. I've used coloured card here.
Score along the dotted lines, cut out the holes then carefully cut out the parts.
Fold the push rod ends in half and glue them down to make double thickness card. Once the glue is dry cut out the holes and then carefully cut out the parts.
Choose the length of throw that you want then glue up the two parts of that size, in this case the 24mm sides.
Glue together the push rod.
Glue the two push rod ends onto the grey areas making sure that they are lined up.
For each of the three pins; roll them round then glue up the end so that it lines up exactly with the point of the arrows and the edge of the grey area.
Assemble the crank shaft as shown in the picture.
The pin with the green arrows is slightly shorter than the other two. It fits in the middle.
Assemble the handle in three steps.
Glue the two square sections up. Fold one section into the other and glue. Roll round the long tab and glue it down.
Fold the tab at the bottom of the box to make a right angled triangle and glue it down.
Glue the two box parts together. Assemble the slider tube, Glue it to the tab in the box lid. Glue one edge of the box lid into place.
Slide the push rod up through the slider tube. Fit the crank shaft through the holes in the side of the box and glue the box round. Glue the box lid down.
Glue the base tabs into place and then glue the four long tabs to the inside walls of the box.
Complete the project by gluing the handle to the shaft. Use this as the starting point for your own character based projects. Send pictures of what you make!
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So I started watching the new series "Defiance" on the TV when this mysterious glowing space shape thing appeared on the screen. I'm afraid that was as far as I got through the program. When I finally looked up from trawling through the ever fascinating Geometry Junkyard and the Wikipedia pages on 3d shapes Defiance had finished. I'm afraid that happens a lot. I do like to go to the cinema with #truelove. She really doesn't approve if I use my phone to explore internet rabbit holes at the pictures so I tend to be able to watch films right to the end without getting distracted. Just so long as I stay awake.
Anyway, it turns out that the shape is a Rhombicosidodecahedron. It is made from 12 pentagons, 30 squares and 20 equilateral triangles. There is all sorts of fascinating information here on the Wikipedia page. I tried out a few nets before settling on one with five parts spread over two pages. If you are a member you can download the parts and make your own for free. Non-members can join in the fun for £2.50
Score along all the dotted lines (there are loads. Sorry.) then carefully cut out the pieces. Fold along all the crease lines before you start the assembly to ensure crisp creases.
There are a total of five pieces. Two large, slightly different from each other and three smaller pieces all the same as each other. Find the two larger pieces. One has a black dot on a tab, the other has a black dot near an edge. Glue the tab with the dot to the edge with the dot. Line up the parts as accurately as possible.
Accurately glue one of the remaining three pieces to the central pentagon. Use the picture above to help with orientation.
Glue the other two pieces to the central pentagon, again using the picture for alignment.
Starting from the central pentagon, work your way round and up gluing down tabs to make the 3D shape.
Work your way upwards...
...until only the last pentagon remains.
Complete the shape by gluing down the last pentagon. Nice!
The questions remain. Was Defiance any good? Did anyone watch it? Should I go back and try watching it again? What other 3D shapes will distract me if I do?
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#truelove and I spent the weekend in Glasgow. Very nice it was too. On the train I treated her to a tasty carrot cake which came in this elegant box.
The package opens out and folds flat for storage but becomes remarkably rigid when folded into a box.
Here it is opened out with the hill and valley folds marked out in pen.
On our return home I transfered the the basic design to an Illustrator file and scaled it to fit on a single sheet of paper.
Here's the layout on screen with colours added.
If you are a member you can download the file at the link at the top and make your own.
Score the dotted / dashed lines and cut out the parts.
Glue the sides at the grey blobs.
Fold in the centre tucks...
... then fold down the lid.
Finish the box by adding cakes!
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The co-axial crank slider mechanism is designed to be a starting point for your own projects. As the handle is turned the outer tube moves up and down 90 ° ahead of the inner tube creating an organic, fluid motion which can be harnessed for your own character designs.
Members can download the parts for free, thanks for signing up! Non-members can download the project for the usual £2.50.
Print out the parts onto thin card (230 micron / 67lb) Score along the dotted and dashed lines and cut out the holes before carefully cutting out the parts.
There are four paper pins that need to be made. Pre-curve the pieces round a pen or pencil then roll them round so that the edge exactly meets the points of the red arrows. Apply glue to the inner surface and glue the pin together.
Make up the two crank centre pieces as shown.
Glue the two crank centre pieces together. Notice that the square holes are facing in opposite directions.
I'm pleased with the new design for the crank sides. They are each made from a single piece of paper and their size and therefore their throw, can be changed very easily. Make up the two crank sides as shown.
I'm planning to create a single crank slider project using this design shortly.
Fold over the push rod ends and glue them down to make double thickness card. Once the glue is dry, cut out the centre holes then carefully cut out the pieces. there are four push rod ends.
Make up the short push rod as shown. Notice the triangular section tube. This give rigidity to the piece.
Glue two of the push rod ends into place using the grey areas for alignment. Push one of the pins through the holes in the push rod ends and make sure that the pin is at 90° to the shaft before the glue dries.
Fit the other push rod ends to the other push rod in the same way.
Glue the ends of the pins into the crank middle as shown. Make sure none of the glue gets onto the push rod ends.
Glue the crank sides and remaining pins to complete the crank shaft.
Assemble the slider tube and glue the slider tube end into place as shown.
Thread the slider tube over the long push rod then glue the tab on the long end of the short push rod between the two tabs on the end of the slider tube.
Fold up and glue down the tabs on the bottom edge of the two box sides to make right angled triangle tubes.
Glue the two box pieces together along one edge. Fold up the box and fit the crank assembly into place.
Fold the box round and glue it closed. Glue down the two flaps on the box base stand the box on a flat surface as the glue dries to make sure that everything is square and flat. Fold the long tabs into the box and glue them down on the inside walls of the box.
Assemble the outer slider tube and glue it to the hinge on the box top.
Assemble the handle in three steps. Glue up the two square tube.
Fold up and glue one tube into the other.
Roll round and glue down the long tab.
Glue the handle to the pin.
Complete the model by threading the lid down over the push rod and gluing it to the box.
This is just the starting point. Use this mechanism to bring your own characters to life!
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A crank slider driven snake. Turn the handle and the snake rocks back and forth. Is it charmed or is it about to strike!? Build your own and find out.
This project is free for members to download - thanks for signing up! Non-members can download the project for £2.50
Print out the parts onto thin card. Note that the three sheets come as a colour version and a line version. the colour version is printed on both sides. Print out one side, flip the card over and return it to the printer then print the other side. Score along all the dotted and dashed lines and cut out the holes before carefully cutting out the pieces.
Fold over the crank shaft ends and glue them down to make double thickness card. Once the glue is dry cut out the centre holes then cut out the pieces. Set them to one side.
There are three paper tubes to make. Each is made from tightly rolled paper. I roll the paper round a chopstick to make a smooth curve. Roll the tube so that the end lines up exactly with the edge of the grey area then glue down the end. Assemble all three tubes like this.
Glue the long push rod together the make a square section tube. Glue the two push rod ends into place using the grey areas for alignment. Fit the longer round tube into the push rod ends and make sure that it is running square to the main push rod before the glue on the push rod ends dries.
Make up the two shorter square tubes and glue one to each end of the round pin as shown. Make sure that they are lined up with each other and the pin remains free to turn.
Glue on the two spacers and the two longer square tubes as shown above. Make sure everything stays lined up!
Glue the two remaining pins into place as shown.
Assemble the handle in three steps. Fold the two square sections and glue them down. Fold and glue one square section into the other. Roll round the long tab and glue it down.
On the two box sides, fold up and glue the triangular section tubes to make right angled triangles.
Glue the two box sides together.
Fold the box round and fit the crank shaft pins into the circular holes in the box.
Glue the box together.
Thread the lid and slider tube down over the main push rod. Glue the lid to the box and then glue the bottom flaps of the box down making sure to keep everything square.
Fold in the four flaps and glue them to the inside walls of the box.
Glue the handle to the drive pin.
Glue the two parts of the snake together.
Complete the model by gluing the small tab on the top of the main push rod to the back of the snake's head and the snake's body to the top of the box.
That's it. I hope your ssssnake looks sssssuper!
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The hypocycloid mechanism is used to make a compact, simple gear box that reduces rotational speed. In the case of this animation the reduction is 7:1. Follow one of the lobes of the six pointed rotor with your eye and see how it advances one notch anticlockwise for each rotation of the blue rotor. By adding two similar mechanisms back to back it is possible to multiply up the the gear reduction ratio
Using FlashThe blue piece is an off-centre drive shaft connected to the main drive. The output of the drive would be from the front.
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A working paper squeeze box accordion to print out and make. It only plays two notes but hey, it works and it is made from paper!
Members can download the parts for free as usual, non-members can download the parts file for £2.50 from the link above. The file comes as a coloured and no-coloured version.
Print the bellows on to standard printer paper, print out the rest of the parts onto thin card.
Score along the dotted and dashed lines and cut out the holes before carefully cutting out the pieces.
Pre-crease along all the scored lines of the bellows piece.
Glue along the back of the edge opposite the grey edge with a glue stick.
Roll the tube around and glue it together as accurately as possible.
This is tricky so take your time.
Starting on the row below the top end of the tube. Fold one parallelogram with four hill folds round the outside and a valley fold across the centre.
Repeat this process all the way round to complete a row of paralleograms.
Work your way down the tube to the row before the end.
Complete the bellows tube by folding in the ends. Notice that here the hill and valley folds are reversed.
The instructions for the two end pieces are basically the same apart from one minor change. The instructions here are for end 'b'
Make up the tapered blow hole.
Glue on the longer of the two 'b' pieces. This will be the vertical piece. Glue the tab to the grey area on the blow tube.
Glue the second 'b' piece to the grey area to make the horizontal bar.
Glue the top of the blow-hole to the box next to the slot arrowed. Note that it glues onto the side of the slot that has the largest area.
Glue the side of the blow hole to the side of the box along with the side tabs on the vertical and horizontal pieces. Make sure you line up the ends of the horizontal and vertical pieces with the edge of the box arrowed.
Fold up and glue the sides of the box.
The second box 'a' is basically the same but the horizontal piece is fitted slightly higher up in the box closer to the slot.
Fold down and glue into place the lids of the two boxes. Once the glue is dry you can test them by blowing through the holes in the sides. If they are not sounding clearly make sure that the centre of the blow hole lines up with the opposite end of the slot.
Glue the bellows to one box.
Glue the second into place. Let the glue dry completely.
Complete the project by gluing the handles into place.
Pull and push the ends to make the whistles sound!
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A set of paper bellows/springs to download and make. Members can download the template at the link, thanks for signing up! There are three designs in the template file, pentagon, hexagon and nonagon (9 sides) Check out the previous blog post if you would like to design you own with a different number of sides.
Print out the pages onto standard printer paper, not card. Score along all the dotted and dashed lines then cut out the page along the surrounding line. You may have to set your printer to "Scale to Fit" to ensure that the whole template is printed out.
The three pages look like this.
Pre-crease all the dotted and dashed lines before you glue the parts together. These instructions are illustrated with the six sides spring but apply equally to the other two.
Glue along the back of the edge opposite the grey area.
Roll the tube round and glue down exactly on the edge of the greay area.
Okay - now this is fiddly and a little tricky. Take your time.
Starting one row of parallelograms from the top. Pick a parallelogram. Fold the centre diagonal as a valley fold and the four surrounding edges as hill folds.
Once done move onto the next parallelogram on the same level and repeat the process.
Work your way round to complete the row.
Repeat the process with the next row down.
Work your way right down to the end.
Complete the spring/bellows by folding in the ends noting that the hill and valley folds are swapped in the ends compared to the main body.
...now if I can just fit some sort of sound generator, perhaps a whistle or two, into this mini squeeze-box...
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The whole point of video is the movement. It is what differentiates it from photography. Videography of a static subject comes to life then the camera is moving, however subtly. By moving the camera round the camera the solidity and depth of the subject becomes apparent. That's the theory. To that end I'm working on a way of steading my camera while I pan round the paper model I'm filming. I have an old generic gorilla pod to which I plan to fit wheels. Here's the story.
After a bit of experimenting it turned out that the rubber feet on the end of the gorilla pod legs covered a plastic cap. I pulled off both the rubber and the cap and discarded them
I now had a hollow hemisphere to which I wanted to bolt the wheel. I was concerned that the part would be crushed by pressure from the bolt so I decided to fill the space with Milliput. First of all I scratched the inner surface of the foot to give it a rough texture for the Milliput to key onto.
Milliput is a moldable two part epoxy cement.
It is used by thoroughly mix equal measures of the two parts. The resulting putty sets hard in two to three hours.
I mixed up enough to fill each of the three feet.
By slightly over filling each of the hollows I was able to apply a slight convex surface to each foot.
Once the Milliput was completely cured I drilled a hole through each foot using an 8mm drill bit.
A suitable bolt (75mm M8) fitted though the hole and a washer was added to ensure that when I fitted the wheel it didn't bind with the leg. The wheels I used were a set of 72mm roller blade wheels fitted with suitable bearings both of which I picked up on eBay.
I added a second washer then bolted the wheel into place with a lock nut. The bolts were slightly too long so I cut them down to size with an angle grinder.
Two more wheels and the job was complete.
And there we have it. I fitted the camera to the top, lined up the wheels so that the whole dolly moves in a circle centred around the subject. It is all looking good. The angle of the wheels can be changed quite subtly allowing the radius of the movement to be changed. The legs bend and flex allowing the height of the camera to change and it is fairly straight forward to point the camera down at the angle required.
I should have some film up shortly.
<--- edit ---->
I planned to add this project to Instructables.com. Turns out some-one got there before me.
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It's been a while since I've had a special offer on memberships so I thought I'd set up a Spring Special! Happy spring to everyone (in the northern hemisphere).
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More details about Memberships and what you get with each are here.
Both of these offers are valid until 31st March 2013 and apply to both new and renewing members. Thanks for your support! As you know, I literally couldn't run robives.com without you!
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