Know your dinosaur

One of the challenges facing you if you need to repair your dinosaur is knowing what the various bits are called. Finding spares is not that difficult once you know where to look and what to ask for.

Let's look at some of the common components in three categories; mechanical, electrical and bodywork.

Mechanical

Screws and bolts. A screw has a thread all the way along its length and is generally used to secure two or more components together, such as securing a table leg to the table top.

A bolt has a thread only at the end. The unthreaded part normally goes in the middle of an axle, such as a castor on a trolley or the wheel on a suitcase.

Screws can have recessed hex heads for Allen keys or they can have hex heads for spanners. They can have lots of other types of heads too, just not generally in your dinosaur.

Most of the screws in your dinosaur are Metric 6mm size or M6. Some, for example in the neck joints or large tail joints, can be M8.

Sometimes the factory use a Clevis pin instead of a screw. For anything which rotates, a Clevis pin is a must because a screw will always undo itself over time. Incidentally, a bolt is a better choice for a rotating axle than a screw, but the manufacturer uses screws anyway.

A Clevis pin is a straight metal pin with a wider section at one end and a hole through the other through which you insert a R clip or a cotter pin to keep it in place. Cotter pins are designed to be installed once whereas R clips can be inserted and removed easily. R clips are definitely better.

The cables which operate features such as the eyes and mouth are a steel cable running within a steel spiral sleeve, covered in a PVC outer sheath. These are called Bowden cables. They are used elsewhere to control bicycle brakes, motorcycle clutches and bits of industrial machinery.

The ends of the Bowden cable can be terminated in all kinds of different fittings to attach in different ways to mechanisms. In your dinosaur, there might be barrel ends inside the control levers and loop or ring ends by the eye and mouth mechanisms. These ends are swaged onto the cable. Swaging is like crimping but better. A swaging tool applies pressure from multiple directions to compress the fitting around the cable.

If the inner steel cable is damaged, it will drag inside the spiral sheath, generating a lot of friction and heat. You'll feel that the operation feels wrong, it will feel stiff or the eyes or mouth will fail to open or close normally. It's important to check and replace these cables as they will inevitably break. Because of the difficulty in replacing these and because they are custom made at the factory, you'll find that your dinosaur already has spares in place and it's not a huge task to swap the cables over. It's an awkward, messy, painful task, just not a huge one.

One of the design features which makes the task painful is that the factory installs the cable ends using Clevis pins (good idea) and cotter pins (bad idea). To add injury to insult, the cotter pins they use are like needles so be careful when removing them. Rusty, oily needles, probably covered in germs.

Electrical

The electrical system in your dinosaur runs off 12V DC, just like an old fashioned car battery.

The camera and monitor are actually a car reversing camera kit. You can easily buy replacement cameras and monitors. Unfortunately the camera is screwed to a metal bracket inside the nose which can't be accessed once the dinosaur is built. You'll also find multiple different connector types available for both cameras and monitors so make sure you get the right one if you need to replace either (obviously).

The most common connection for cameras and monitors is the same as for CCTV cameras - an RCA phono for video (yellow) and a DC barrel jack for power (red). If you see a white connector, that's not used. If you see a green wire hanging out of a connector, that's also not used, that's for when the kit is used in a car. When the cables to the camera and screen fail, you can easily find replacements which you can either make up yourself - the cable type is nothing special - or you can buy cables already terminated with RCA and barrel connectors.

The DC power connectors (red) are 2.1mm / 5.5mm DC barrel jacks. That means that the inside pin is 2.1mm in diameter and the outside sleeve is 5.5mm in diameter. These connectors and premade cables are readily available but they do come in different sizes which look the same. For example 2.5/5.5 looks the same from the outside but won't fit.

Some dinosaurs come with a camera kit which connects through a Jansite 4 pin connector. This is designed to allow easy cable routing through a small hole in your car's dashboard or bodywork. In a dinosaur this is of course redundant but the connector is part of the kit. If you were replacing the whole system then this wouldn't be a problem, but if you're only replacing the monitor then you might have to replace the whole system anyway, or cut and reconnect the cables.

If you have a dinosaur which squirts water then the water system is simply an aftermarket car windscreen washer which is easily sourced and replaced. A kit comprises the bottle with built-in pump, some PVC tubing and a nozzle. 

Bodywork

The best glue to use to repair your dinosaur's body and skin is contact adhesive or impact adhesive - it's the same thing. It's a smelly, yellowish gooey gel that looks like caramel sauce. You put a bit on each surface to join, wait until it starts to dry and then press to the two surfaces together.

Don't use Gorilla glue and don't use silicone sealant.