Prop Safe

 

Prop safe with door closed

Prop safe with door closed

This prop safe was built for a recent theatre production. The top sign is hinged on the top and folds down for transport. A steel rod that drops inside the safe supports the sign when it is up.

The safe is made of timber with swivel castors attached to steel support plates on the base. Shaped timber blocks decorate the tops of the plates where they protrude from the sides of the safe.

To minimise mechanical problems with locks and latches a simple magnetic latch was used on the door. This avoids any potential for locks catching or failing to open during a performance.

Side view of safe with door open

Side view of safe with door open

Steel rod that supports the top sign when it is hinged upright

Steel rod that supports the top sign when it is hinged upright

Movie Camera Prop

Prop movie camera on dolly platform

Prop movie camera on dolly platform

A recent project involved making a very simple movie camera prop for a theatre production. The camera had to look as if it was built from bits and pieces by children playing movie makers.

The camera body was a simple plywood box with bits of PVC pipe, rubber sink plugs and brick vents attached. It was attached to a metal tripod which was attached to a dolly base. The base has swivel castors so the unit can be easily moved about on stage.

Side view of the movie camera body

Side view of the movie camera body

Detail of the tripod and dolly base

Detail of the tripod and dolly base

Practical Catapult

Practical catapult primed for firing

Practical catapult primed for firing

This small practical catapult was made for a recent theatrical production. The design was based on a Leonardo da Vinci drawing of a catapult. Modifications had to be made in order for the catapult to operate as required.

The main power for the catapult was a length of rubber cord similar to bungy cord. Two children’s motocross push bikes were recycled (pun intended) for the wheels and steering mechanism. The bike parts were attached to the timber framework with custom brackets which were then lashed with sisal rope to give a more lived in look.

A steel ratchet mechanism was built to ensure reliable operation of the release of the catapult arm. Clicking on the photos below will bring up a larger image.

End view of catapult

End view of catapult

Catapult released

Catapult released

The ratchet mechanism

The ratchet mechanism

Closeup of the release mechanism

Closeup of the release mechanism

Oversize Chicken Eggs

Giant chicken egg

Giant chicken egg

These oversize chicken eggs were made for a theatrical production. The oversize eggs are 60cm high and made from fibreglass for strength so they can be sat on.

The first step was carving a polystyrene oversize egg so a fibreglass mould could be made. The mould construction is described in another post. After the mould was finished two oversize eggs were cast. After the fibreglass halves were joined together they were painted.

One of the oversize eggs was made with a broken top so something could *hatch* from it on stage.

Assembled cracked egg

Assembled cracked egg

Cracked egg with top removed

Cracked egg with top removed

Making A Giant Egg

Completed egg shells

Completed fibreglass shells painted in shellac ready for finishing

The first step in making a giant egg is to make a giant egg – so a mould can be made.

Depending on the size of the egg you want to make will dictate how you go about making the egg form. Since the egg we needed to make was about 60cm tall it was decided to carve it from a block of polystyrene. Since the egg shape is symmetrical it is best to turn it on a lathe.

Preparing polystyrene block for turning

Preparing polystyrene block for turning

The polystyrene has to have plywood boards glued to both ends so a lathe faceplate and tailstock centre can be attached so it can be turned on the lathe.

The corners of the block are then cut off at 45 degrees to make turning a bit easier on the polystyrene. If this is not done it is likely large chunks will break off when the lathe chisel is applied to the turning block.

It is very, very messy turning polystyrene on a lathe so ensure the work area is covered with something to collect the shavings and clean up regularly as you work. This will minimise the polystyrene getting into every nook and cranny of your workshop.

Polystyrene mounted on the lathe ready for turning

Polystyrene mounted on the lathe ready for turning

Basic shape completed on the lathe

Basic shape completed on the lathe

Completed polystyrene egg

Completed polystyrene egg

The polystyrene is removed from the lathe and the two ends trimmed. Sandpaper is used to smooth both ends until their radius makes a smooth transition around the egg shape. It is important to get the shape exactly right with no obvious flat spots or sudden changes in the radius.

To support the egg while making the mould a box was built to put the egg form into so the middle flange can be made with plasticine. Once that has been done it is given a coat of PVA mould release in preparation for fibreglassing.

Ply box for making the top half of the mould.

Ply box for making the top half of the mould.

Flange finished around egg

Flange finished around egg and mould release applied

After the top half has been fibreglassed a timber support is fibreglassed on the mould so it sits horizontal when put on its side. The egg with the first half of the mould attached is removed from the support box and turned upside down to expose the underside of the egg form. This is cleaned up, PVA mould release applied and the second half is coated with fibreglass as described in previous mould making posts.

After polishing the inside of the mould halves with wax fibreglass casts are taken and trimmed to the flange line around the mould on both halves.

The two completed fibreglass mould halves

The two completed fibreglass mould halves

Fibreglass casts for egg ready for joining

Fibreglass casts for egg ready for joining

To ensure that both halves of the egg are joined together securely they need to be fibreglassed along the inside centre seam of the egg. To do this an access panel is cut in one half that is big enough to get your hand inside the egg shell. Blocks of wood are attached to the inside of the shell around where the access panel will be cut. This allows for easy re-installation of the panel section after the work has been done.

You can see the alignment blocks in the photo below with the access panel removed.

Cutting out an access panel in one half

Cutting out an access panel in one half

Access panel removed

Access panel removed so halves can be fibreglassed together

The two halves are taped together with mylar tape to keep them aligned. They are then fibreglassed on the inside along the centre seam. Once this has been done the access panel can be glued back into position and all gaps around the panel opening and the centre egg seam can be filled with polyester filler.

After sanding smooth the fibreglass is given a primer coat of de-waxed shellac.

Halves taped in position

Halves taped in position for fibreglassing from the inside

Access panel glued back in position

Access panel glued back in position and gaps filled and sanded

The completed eggs can be seen in this post.

Abstract Display Tree

Abstract display tree

Abstract display tree

This abstract display tree is constructed from 18mm MDF and breaks down into two sections for ease of transportation. Its assembled height is 2.4m and the width is 2.1m.

The tree consists of two hinged MDF half sections that fit into a steel alignment bracket on the floor which makes it very stable once erected. Each quarter panel of the tree was laser cut in 18mm MDF from four different DXF files. The two quarter sections of each half section are attached together by hinges. Each half is free standing when it is opened up to 90 degrees.

After each half is opened out to 90 degrees is fits into the steel alignment star as shown in the photos below.

The two folded MDF sections ready for transport

The two folded MDF sections ready for transport

Alignment brackets

Alignment brackets for the folding halves of the tree

First half fitted into bracket

First half fitted into bracket

 first half in the bottom bracket

Another view of the first half in the bottom bracket

Second half fitted into base bracket

Second half fitted into base bracket

View of top locating bracket

View of top locating bracket

Oversize Tiffany Style Gift Box

Oversize Tiffany style gift box

Oversize Tiffany style gift box

A dance prop in the form of an oversize Tiffany style gift box was required for a competitive dance routine. The box was to be big enough to conceal the dancer inside and light enough so it could be carried onstage for the routine with the dancer inside. It also had to be strong enough on the top so the dancer could perform her routine on the lid.

For rigidity the dance prop frame was constructed using 12mm hollow square steel with extra braces in the base and lid sections for additional support. To keep the weight as low as possible it was clad in 7mm marine ply which was liquid nailed to the frame. Small hand cutouts were cut in the sides to enable it to be carried and a small lip attached to the front of the lid to make opening it easier.

When the dancer burst out of the oversize box by throwing open the lid it put considerable stress on the lid stays. These were custom made using 3mm flat steel to stop the lid opening too far so the dancer to get out and close it easily. Another 30cm square wooden replica of the oversize box was built to act as a step to facilitate the dancer stepping up onto the closed lid. This was incorporated into the routine to make the transition as seamless as possible.

Tiffany style box opened

Tiffany style box opened

Heavy duty hinge stays

Heavy duty hinge stays to support the lid

Silk Flame Campfire Prop

Battery operated silk flame campfire prop

Battery operated silk flame campfire prop

This silk flame campfire prop was made for a theatrical production that needed a safe but realistic campfire effect onstage. Real pieces of timber were arranged around a circle leaving a space in the middle to accommodate a rectangular light box.

The light box was made from ply with several non-symmetrical holes cut in the sides with orange gel glued over them. Two small electric fans were mounted in the bottom of the light box along with three amber 12V automotive stop lamps mounted on the inside of the box.

Three layers of 10mm egg crate diffuser was fitted on the top of the light box to stabilise the airflow and to provide a platform to mount the silk for the flame effect.

Two of the 12V lamps were connected to a flickering candle effect so their intensity varied over time. The fans and lamps were run on a small 12V 9Ah battery. A long lead with a switch was used to control the campfire when it was on stage.

Timber arranged with a space for the light box

Timber arranged with a space for the light box

Top view of light box with the egg crate diffuser removed

Top view of light box with the egg crate diffuser removed

Below is a brief video of the silk flame campfire in operation.