Prop Tarantula Leg Development

Intro

The tarantula legs are all detachable, much more so with the connection system I designed. They are constructed from pipe lagging covered 22mm plastic pipes. These have been jointed with inserts made from bendable foam hair curlers, with a loop of 3mm garden wire tied together with duct tape. How this is done can be seen on the Paul Jones DIY giant Spider Halloween Prop tutorial Rough Guide I was following at first.

Primary Instruction Video to Start With

The tarantula legs are all detachable, much more so with the connection system I designed. They are constructed from pipe lagging covered 22mm plastic pipes. These have been jointed with inserts made from bendable foam hair curlers, with a loop of 3mm garden wire tied together with duct tape. Pipe lagging was glued onto the pipe sections doubled up at the spider end of the legs. A heat gun was used to narrow down the centre of each leg section. After this the joints were taped over with clear more stretchy duct tape to seal them in with stretchy joints. Hair extensions were tied to the 2nd leg sections with cable ties as seen in the Paul Jones DIY giant Spider Halloween Prop Tutorial Rough Guide video. Most of my photos are for my own work so did not take extensive photos when just following the video. However, the legs have been beset with problems that I have been trying to fix..

Problems

• The leg joints were way too loose, so even just the head in foam, the legs could not hold the weight before buckling sideways.

• Attempts to paint the legs were a problem as the paint would not stick and just kept flaking off.

• The hair extensions just kept fluffing out matting and knotting and any attempt to glue them just looked awful with white blobby mess.

• When the legs were attached, they just slid on the lino, (Contact with Paul got the suggestion of adding spikes to the feet for use on grass.

Finding Solutions to Problems

Leg Stiffness

In the video I was initially following the joints in the legs that were done with a loop of garden wire taped to bendy hair curlers plugged into the tubes covered in duct tape.

Paint Flaking

Whilst handling the legs it was found that the spray paint did not stick to the pipe lagging and was far worse where the clear duct tape joined the pipe. Paint was just peeling off and flaking off. The smooth slippery surfaces were a big problem.

What had been noticed on the eye spheres covered in frog masking tape was the paint stuck to them as it did to rough surface points on the legs.

Solutions were found to cover all the exposed duct tape with frog tape with rough edges so not so obvious, but what was done first was to use duct tape to remove as much of the loose paint as possible, much like waxing with the paint sticking to the tape.

A wire brush was used to roughen the foam surface and break it up. After this strong spray glue was used to stick on the left-over foam dust and foam fragments to further roughen the surface to help paint stick to it.

Frog Tape Painting Issues.

The original joints were skinned over with non stick slippery duct tape. Whilst this was stretchy, the paint did not stick, the frog tape was the opposite. The paint sticks, but the tape has no tensile strength, so kept tearing on the outside when the legs were bent

On the inside of the bend the tape concertinas becoming a problem when spray painting as brightly coloured, blocking the spray painting.

Leg Stiffness

Multiple attempts were carried out adding more and more wire, twisting the wire to stiffen it and using thicker wire. This ended with multiple loops of twisted 3mm wire. However, this still could not support the spider’s weight when just foam let alone at later stages after adding my leg connection components, washers and encasing in fibreglass and filler plus paint.

Purchase of wider diameter pipes plus both single plane hinge joints and ball joints that could be locked into place would be the next solution to look at. To do this some sort of adapter for the leg connectors or a whole set of new 3D printed connectors would also be needed. This would require 1 if not two new reels of 3D printing filament a good £20 each as well as take over a week to do the 3D Printing at the time is around 11 hours each. It would however enable the first section of legs closest to the head to be pointing up far more vertical and a more acute angle which would help as the legs would be going up and down not reaching out widely.

To replace all the wire and hair curler joints with the lockable ball and hinge joints to form armatures. Armatures that could be locked into poses would require this would good 30 joints, 14 of which would be ball joins and all would need to be lockable without having large extruding controls would be very costly both in times of time and money for all 8 legs and the 2 fore arms. This is likely to be a 3-figure sum

Costs are now 10 times over run so will have to leave the legs as just for show with a support stand underneath the head and body.

A system of curve track joints was designed on Solidworks that would enable a form of lockable hinge but the costs looked prohibitive for 30 plus joints as well as time. More so it would be so obvious the spider would lose its organic appearance.

Spider
Title & Intro

Page

This was a double bed size prop Tarantula, originally intended as a cool Halloween front of house prop as well as portfolio piece to discuss project development.

Finished project page.

Spider Project

Development

Projects Accounting Costs

Spider Initial Research & PPP Testing

To start the project was looking into existing props and Halloween tableaus and how such a project could be done.

Initial Proving Principle Prototyping & scale modelling.

Spider
Development

Head

The main central part is the head to which all other parts are connected and would be the section to connect stands and load supports.

This involved the most substantial development and most restarts.

Spider
Development

Body

This had a similar basic structure to the head but a lot simpler. It does have its own issues and problems.

This had to be re-opened for upgrades to strengthen the connections to the head.

Spider

Development

Legs

The legs required repeated and costly redesign and rebuilding building to try and build enough strength into them to be able to support the weight of the spider, as well as look realistic and bond the paint to them.