For a while now I've been planning on making a Paper Ninja for all you Paper Ninja's to download and make. Time to put that idea into practice!

Here's a late version, in this case made from blue card. I have all the parts layed out - just need to colour the design and take assembly photographs. The final version will most likely be black with an uncoloured version included in the downlad file. I'm hoping to finish it off and post it tomorrow.

Keep up to date: Receive the latest blog post by email

Rate this post:

Summer of Sport!

Check out these new paper models I made for Brother International.

Click the image left to see them in animated action on my Instagram account.

You can download and make these soccer players from the brother website by clicking on the links below.



Player 14 Player 62 Goalie

Keep up to date: Receive the latest blog post by email

Rate this post:

Download Keyboard Kat
Become a Member for free access to this and other files on the site.
See the Membership page for more details.

Already a Member? Log in Here

Keyboard Kat! Turn the handle and the cat tickles the ivories whilst nodding along to the beat! Members and Patrons can download the parts for free at the link. Non-members can join in the fun for £2.50

Click the picture to the left to see the model in animated action on my Instagram feed.

Once you have downloaded the parts, print out the pages onto thin card. (230grm/67lb) are ideal. The colour version is printed on both the front and back of the page. Print out the front of a page, flip it over and return it to the printer then print out the back.

Once the ink is completely dry, score along all the dotted and dashed lines, cut out the holes then carefully cut out the parts.

The base and top are basically the same but the top has this extra hole in it. Fold in the sides to make right angle triangles then glue them down.

Fold in the end tabs on the end pieces to make triangular tubes.

Glue the cam follower spacer to the underside of the top between the two small marks on the top.

Glue the box ends to the box top. Note the alignment and position of the end with the holes, it is important that it is fitted the right way round.

Fold round the box and glue it down.

Glue in the side flaps.

Fold in the small tabs and glue them to the inside wall of the box.

Roll up and glue the four tubes lining up them as accurately as possible with the edge of the glue area.

There are various parts that are double thickness card shown below. Fold them round and glue them down as shown. Once the glue is dry carefully cut out the parts.

The three cam followers are all made the same way.

Fold over the main body and glue it down to make double thickness card.

Fold round the tab at the end to make a small triangle tube

Fold up the stiffener as shown

Glue the stiffener to the cam follower.

A small coin (20mm diameter, 4gm weight) is used as a weight for each of the cam follows. I used UK pennies. Fold a scrap of card tightly round the coin and glue it down as shown.

Glue the coin to the end of the cam follower.

Fold the tab with the triangle piece under the cam follower and glue it down.

The three cam followers completed.

Fit the cams to the square cam shaft. The single lobed cam fits in the centre. The two lobed cams should be at ninety degrees to each other. I didn't glue them so that I could try different cam profiles at a later date. Glue one of the axle tubes into the square tube. Don't fit the other one yet.

Assemble the handle in three steps.

Thread the cam shaft into the box then fit the final axle tube into place on the right side of the picture. No need to glue it, friction will hold it into place.

Thread the three cam followers into the box above the cams and glue them to the box end as shown.

Glue the handle into place. The view from the other end. Turn the hand and the cam followers should move up and down.

Assemble the two arm axles as shown.

Glue a strap to each arm axle.

Fold a body sides round an arm axle and glue it closed. When you pull the strap the arm axle should turn. Make up the other body side in the same way but with the pull strap on the other side of the axle.

Join the two body sides using the body front as show. The pull straps should be at the back of the body on both sides.

Roll the body right round and glue it down.

The arm parts. Note that the left and right arm parts are different, don't mix them up. Shown here are the left arm parts.

Fold found and glue the upper arm. Glue the lower arm to the back tab on the upper arm.

Glue the upper and lower arm together.

Glue the arm cover into position. (This part is the same on both arms.) Make up the other arm in the same way.

Gently open out the hole in the arm with a chop stick or other suitable implement.

Both arms assembled.

Turn the arm axles so that the internal swing arm is horizontal then glue the arm onto the axle so that the forearm is also horizontal.

The black line on the head is not a mouth, it is actually a slot for a strap to fit through!

Thread the final strap through it and glue to the inside of the head.

Assemble the nose and whiskers and glue them into place.

Work your way round the head gluing the front of the sides.

Glue on the ears.

Thread the head strap down through the hole on the body then glue the head to the body.

Assemble the stool.

Glue the stool to the box.

Thread the three straps through the hole on the legs then glue the legs to the body.

Thread the straps down through the hole in the stool and out through the back of the box.

Fitting the straps to the cam followers is the same process for each cam.

Turn the cam until the cam follower is at its maximum height. Pull the strap so that the forearm is horizontal and mark with a pencil where the strap meets the cam follower. Cut off the excess strap approximately 5mm below the mark then crease the strap at the pencil mark. Glue the strap to the cam follower.

Assemble the keyboard as shown.

Fit the keyboard to the box so that the keyboard is under where the arms fall naturally.

With the arms at their lowest point you may need to make small adjustments by gently bending the forearm so that they just touch the keyboard.

Glue the tail to the cat, and glue the name plate across the front of the box to complete the model.

Once the glue is dry, turn the handle to bring the Keyboard Kat to life!

Keep up to date: Receive the latest blog post by email

Rate this post:

Sun 1st May 2016

End of last year and beginning of this I worked on a series of four Tabletop Wars books. There are four books in the series, each with six to eight projects that you can make with things you might find around the house such as old pen tubes, lolly sticks and pencils. I've finished my part of the Tabletop Wars books, now the publisher works their magic! Here are the latest versions of the front covers. They look great don't they! Publication is set for 1st August. Mark it in your calendars. There are more pictures of the projects from the books on my Instagram feed here.

Castle Attack. Break the Siege
Small Launchers Traps and Triggers

Keep up to date: Receive the latest blog post by email

Rate this post:

I've put together a first draft of the Keyboard Kat mechanism. Click on the picture, left, to see it in action. It still needs a bit of work on the movement, for example, the arms need to lift a little higher but apart from that I'm pleased with how it is going. I hope you like it too!


Keep up to date: Receive the latest blog post by email

Rate this post:

Sun 24th Apr 2016

Late stage prototype for the cat part of the Keyboard Kat model.
I've added a head. No sides on this prototype yet but they'll be added later. I've also changed the design of the arms, bending the elbows inwards moving the hands closer together. Finally I have shortened the body and added legs.

The pull straps work nicely for moving the arms up and down. They protrude through the base of the cat and will be connected up to a pair of cam followers.

With the cat seated on a suitable piano stool the straps will be hidden from view.
Next: The base and cams. The project seems to be coming together quite nicely :-)

Keep up to date: Receive the latest blog post by email

Rate this post:

Thu 21st Apr 2016

Inspired by all the piano playing cats on the internet I'm working on a cam powered keyboard playing cat model. Here's the sketch. Turn the handle and the Keyboard Kitty pounds at the piano keyboard.

My plan is to have two weighted cam follower in the base, one for each arm. When the cam is in the down position it will pull the arms upwards. When the cam follower is lifted the weight of the arm drops the arms back down again. Because the arm is operated with a pull rather than a push I can use a simple strap to operate the arms rather than having to make a rigid push rod. Hopefully this will make the mechanism simple to construct.

Here I've put together a prototype arm with a linkage and axle.

In my prototype I've fitted each arm into a separate body half. This allows the two axles, one in each shoulder, to move independently.

A simple wide strip of card joins to the two side together.

Pulling each strap raises the approriate arm. Just like that!

Here's my artist impression of how it might all fit together.

Keep up to date: Receive the latest blog post by email

Rate this post:

Thu 14th Apr 2016 is based around the Drupal content management system. This makes it flexible to use and easy(ish) to maintain. The time has come, though, to move from Drupal 6 to the latest version. This is a fairly major undertaking so I'm using it as an opportunity to upgrade the look and feel of the site and streamline the membership system. The new website will have all the same content and features plus it will be responsive, the technical term meaning it will resize to fit whatever device you are viewing it on be it laptop or smart phone. I'm also hoping to add $US pricing in the download shop.

Please bear with me over the next couple of weeks as I poke around on the website internals - I'm aiming to keep disruption to a minimum but just so you are warned...

Also, if you have any feature requests, now would be a good time to ask :-)


Keep up to date: Receive the latest blog post by email

Rate this post:

Wed 6th Apr 2016

I'm experimenting with ways of tuning the pipe on the twitterer project so that I can hopefully create a bird box automata where the bird sings a song with changing notes.

I've tried two different ways of tuning the pipe. Firstly, with an outer sleeve that moves back and forth, this works in the same way as a trombone hanging the length of an open ended pipe. It works fine and the pitch changes maybe five or six semitones between the extremes of travel.

My other option was to use an inner piece that worked as a piston. This inner tube is blocked off at the end inside the main pipe. As it moves it changes the length of the closed pipe. It work really well and has over an octave of pitch change between its extremities. This is the option I'm going with, next to connect it up and move it via a cam shaft.

Keep up to date: Receive the latest blog post by email

Rate this post:

Download Twitterer
Become a Member for free access to this and other files on the site.
See the Membership page for more details.

Already a Member? Log in Here

Twitterer Type 3

In the previous blog post I showed a design for a crank driven bellows to be used at the heart of a bird box project. I have taken that basic design and made it more sturdy. I liked the way the bellows in the previous model were completely visible so I've fitted the crank to the inside of a box but kept the bellows on a pair of slide rails outside the box. You can see the result in animated action on Instagram by clicking the picture to the left.

If you are a Member or a Patron you can download the parts for free, thanks for your support! Non members can join in the fun for a small fee.

The first page of the file needs to be printed onto normal printer paper. The remaining pages need to be printed onto thin card (230gsm / 67lb) I used coloured paper and card for a colourful model. Score the dotted and dashed lines. Cut out the holes then carefully cut out the parts.

The push rod ends are made from double thickness card. Fold them over and glue them down. Once the glue is dry cut out the hole and cut out the parts,

Assemble the push rod and glue the push rod ends into place.

Roll up and glue down the three axle tubes.

Fit the shortest axle tube into the push rod.

Make up the two crank pieces.

Glue the crank pieces to the axle. Leave a small gap between the crank pieces and the push rod so that it remains free to turn.

Fold up and glue the flaps on the box pieces making triangular tube sections.

Assemble the sliders.

Glue the slider to the glue area on the box side making sure that the holes are lined up accurately. The large arrow in the glue area points up to the top of the slider.

Glue together the two box sides. Glue down the top flaps on the box but not the base flaps.

Assemble the handle as shown.

Make up the bellows top and base by gluing down the card to make double thickness.

Glue together the two parts of the cross piece.

Thread the crank into position and glue in the two remaining axle pieces.

Glue down the base flaps then glue the side flaps to the inside of the box.

Make up the two sleeves.

Thread the sleeves into position.

Glue in the cross piece keeping it as square as possible.

Turn the model over and glue the push rod tab to one side of the crosspiece inner.

Glue the handle into position.

Make up the pipe body and pipe end.

Glue the two parts of the pipe together lining up the end with the glue area on the body. Blow through the pipe to make sure it works. Make small adjustments to the position of the pipe end if necessary before the glue dries.

Glue the pipe to the bellows top plate lining it up over the hole.

Before starting the bellows pre-crease as many of the folds as possible. Roll round and glue down the paper to make a tube.

Starting from one end fold down one row at a time observing the hill and valley folds marked on the paper.

Glue the bellows end plate to the tabs on one end of the bellows.

Glue the other end of the bellows to the bellows end plate with the pipe.

Once the glue is dry glue the tabs on the bellows end place to the inside top of the sliders.

Let the glue dry then glue the bottom of the bellows to cross piece to complete the model. Let the glue dry completely

Turn the handle and fill the room with a keening whistle!

Keep up to date: Receive the latest blog post by email

Rate this post: