When dinosaur puppets are built (for example by Only Dinosaurs in China), they are built first as a skeleton, then the electronics and wiring are added and finally the foam and skin are wrapped around the skeleton.
This is very convenient for the people at the factory and very inconvenient for field repairs. It would be nice to think that the puppets are so well built that they don't need field repairs unless you have an accident but unfortunately that's not true. Your dinosaur puppet will break in multiple ways and in multiple places through normal use, and many of these failures are impossible to repair. Unless you're a Dino Doctor, of course.
Let's have a look at some of the common problems and see why they're so difficult to fix.
Broken welds
When the puppet is made, the skeleton has no stress on it other than its own weight. Add foam and skin and all of the welded joints in the skeleton become stressed. Add a performer and some of those joints have so much stress on them that they will fail. It is only a matter of time.
The factory uses very thin stainless steel tubing to build the dinosaur's skeleton, partly because it's relatively stiff and light and partly because it's easy and cheap. They weld this using laser or TIG welders which are fast and precise and of course they are welding the joints in the open air. Oh - just in case you don't know - welding is a method of connecting together metal parts by melting the joint. The molten metal flows together, forming a fused joint. Welding is fast, easy and generally reliable because the two joined parts act as if they are one piece of metal. Welding can be done by an electric arc (a big spark) or a laser.
Stainless steel melts at about 1500°C and the welding process can reach temperatures much higher than that - from 3000°C to 10,000°C. In the open air that's no problem at all. Wrap that skeleton in highly flammable foam and welding becomes impossible.
The polyurethane foam that forms the body of your dinosaur is cheap and easy to work with. However, heat it to 200°C and it releases toxic gases. Heat it to 300°C and it spontaneously ignites. Try welding a dinosaur skeleton and the heat required will cause the dinosaur's foam to catch fire and the last place that you will want to be is the inside of a cocoon of toxic, burning foam. Imagine the worst possible scenario and you'll be about right.
Incidentally, this is why I won't allow Lithium batteries inside our dinosaur puppets. I'm sure you've seen the videos of Lithium batteries catching fire if they're damaged or if water gets into them.
Another problem is that if you or your local handyman has a portable welder, it's most likely an arc welder. These are useful for steel thicker than about 2mm, like the mild steel tubing that's used in garden furniture. The steel tubing in the dinosaur is very thin, probably less than 0.5mm. Try to weld that with an arc welder and it will vapourise. Even if the foam didn't catch fire, you couldn't weld the skeleton with an arc welder. You could probably repair a broken weld, very carefully, with a laser or TIG welder, but then the machine might cost more than the dinosaur.
Some of the components are so thin, small or inaccessible that there's no way to reweld them anyway. Here's a neck attachment that has snapped off a Velociraptor's control column.
Overall, then, welds break easily because they're badly designed and badly built, and they're hard to repair because it's almost impossible to reweld them.
Loose screws
You might think that you must have a screw loose to have bought a dinosaur. Instead, you find that you were probably quite sane and instead it's your dinosaur that has a few loose screws. The reason for this is very simple - when they build the dinosaurs at the factory, they put screws where they really shouldn't use screws.
Think about how a screw works - when you turn it, it moves in or out. Therefore, when you put a screw in any position that rotates, the screw will tighten or loosen. When you put that screw vertically, gravity will make it prefer to loosen or tighten, depending on which way up it is. I think you know where I'm going with this.
By the way, I'm calling these components screws rather than bolts because that's what they are. If you go to a hardware supplier to find replacements for lost screws, it's useful to know the difference.
Many of the screws in the dinosaur are used to hold joints in place; joints which move by rotating around the axis of the screw. The natural movement of these joints will tend to make the screws come loose and fall out. Almost all of these will cause a catastrophic failure of your dinosaur and could even injure you.
Instead of screws, a better alternative is a straight pin with a hole in the end called a Clevis pin. You then push a thin sprung pin called a R clip through the hole and that secures the pin in place. You can rotate the pin as much as you like and it won't come loose. If you find a loose screw, I would strongly suggest replacing it with a Clevis pin. Most of them are M6 size, a few are M8.
Broken wiring
You can try a little fun experiment. Pull one of your hairs out, if you have any left after running a dinosaur business, and snap it. Now do the same with one of the wires in your dinosaur. Your hair was tougher.
There are three basic problems with the wiring in the dinosaur puppets. The first is that the wire used in the factor is the cheapest, nastiest, thinnest wire they could find. The second is that they attach it to the skeleton with cable ties, making it very difficult to repair. The third is that they use connectors which are either wholly unsuitable for the task or unavailable outside of China.
By far the most challenging repair is the camera. I've seen cameras damaged by rough handling but I've also seen them fail. They can't be replaced because they are car reversing cameras screwed to a metal bracket on the dinosaur's nose. There is no way to gain access to that bracket in order to replace a broken camera unless you want to risk having to sew up the dinosaur's face.
The solution is to rip the old camera out through the nose and place in a 'bullet camera', the type that would fit through a small hole in your car bumper. Removing the old camera will look a lot like the scene in Total Recall where Quaid removes the tracker. This will stretch the skin around the nose but there's no realistic alternative. Reaching down through the access on the top of the head means that you have to cut through the solid foam of the muzzle. Cutting the inside of the mouth and reaching up is the only alternative, which has its own problems.
The cables running to the monitor and camera are problematic too. Partly this is because the cables are routed across the control column and down the spine and partly because of the way the power is distributed to the monitor and camera, making a simple plug-in replacement impossible. In short, you have to cut and rejoin wires to replace the cables to the monitor and camera.
The final challenge comes with a faulty monitor. You can readily buy car reversing monitors (7") from any online electronics retailer such as Amazon or eBay and they all seem to fit the same snap-in back plate. Push in the two tabs at the sides of the screen and the screen pops out. The challenge is that there seem to be several different types of connector which are not easily interchangeable.
Broken electronics
The control boxes that power the dinosaur's electronics are a marvel of modern technology, integrating many functions into one compact unit. They contain wifi for transferring sound files, sound effect production, power distribution to the cooling fan and camera/monitor and much more. Well, to be fair, nothing more. And, to be fair, they don't even perform those basic tasks reliably.
Sound problems
Out of all these functions, which do you use? Routing the power to the fan and camera is pointless and introduces more points of failure. Have you ever installed new sound files?
The only real purpose of the box is to provide sound effects, and for that we have to include the buttons mounted on the control column which are, of course, completely unfit for their purpose. Only Dinosaurs make a metal frame and weld it to the control column and the PCB (Printed Circuit Board) then screws into that frame. The silver caps on the buttons will fall off almost immediately if they are not already lost in the bottom of the shipping container. The tiny screws will come loose and fall out because they have no grip washers on them. The switches build into the hand levers will fail so that your sound effects are constantly repeating.
All in all, an attempt at a neat design hampered by poor build quality and choice of components.
Camera and fan problems
By routing the power to the camera and fan through the control box, Only Dinosaurs have introduced an unnecessary point of failure. Inside the control box you might expect to find a simple, reliable connection directly from the battery input to the fan and camera output. Not so. They have instead decided to build a power regulation circuit, possibly because of their switch from Lead Acid to Lithium batteries. It's not a bad idea in principle but, as usual, in implementing this idea the manufacturer has given us a poor design with poor quality components.
The end result is that the voltage regulator in the circuit fails. Not gracefully and quietly but with a bang which causes a voltage spike which then destroys the camera and screen. Thankfully the fan is a very simple device so, although you'll be blind, you'll at least be able to enjoy having your sweaty air circulate around you. Well, you would, if the voltage regulator hadn't given up the ghost and cut power to the fan.
The short term fix is easy - bypass the control box and wire the fan and camera/monitor directly to the battery. To get your sound effects back, you could get the control box repaired though it's probably easier and cheaper to get a replacement from the manufacturer.
Getting a replacement sounds great until it arrives and you find that they've changed all the connectors again. My solution is to make up short cable adapters that go from the control box to a connector strip, that's a strip of screw connections. This makes field repairs much easier.
The green connector shown below is only available in China and is not designed to be plugged in and out. It's designed for industrial applications where it's plugged in once and then left alone.
Battery problems (and Dragons)
Finally, the battery. Two problems here - how to attach them to the dinosaur and how to charge them.
The connections into the dinosaur change from time to time. At first, they were plug in connectors designed for motorcycles. Then, they were barrel connectors that you'll find on everything from CCTV cameras to computers and LED lights. Currently (2025) we seem to be back to automotive connectors again. The connectors also differ based on the puppet. Some, such as a simple Velociraptor, consume relatively little current. With only a fan, camera and sound effects, simple, low current connections are fine.
Others, such as the fire breathing Dragons, are very different. The smoke machines are adapted from mains voltage (240V AC) to run off the puppet batteries (12V DC). They're not ideal for the task but there aren't many other options, however the implementation doesn't help either. The smoke machine sits behind the performer and the smoke exits into a wide plastic pipe which runs to the Dragon's mouth. Usually this means that the smoke, which is vapourised glycerine in water, condenses as it it leaves the smoke machine and drips all down the performer's back. A better design would have been to place a smaller, lighter smoke machine in front of the performer. To achieve this, they could have stripped the smoke generating components (which are already modified for 12V use) from the heavy metal case and rebuilt the machine as a lighter version. The smoke wouldn't have so far to travel and would be in front of the performer.
However, the main problem with the smoke machines is that they consume a lot of power because they're basically an electric kettle. With a fairly large capacity, readily available battery, you get 7Ah, or 7 amp hours. That's basically 7 amps for a hour, 14 amps for half an hour and so on. One of those batteries is flat in about 10 minutes with the smoke machine on.
The Dragons were supplied with large Lithium battery packs. With no CE or UKCA markings, these would be illegal to sell. A quick peek inside the box reveals that they are nowhere near the capacity stated on the label and that their build quality is not something that I would put in the mix with flammable foam and human beings.
My solution is to convert the power distribution in the Dragon. One battery powers the fan, camera, sounds. The other battery powers only the smoke machine. The performer then only turns on the smoke machine when they need it, however most of the power is lost in just getting the machine up to its working temperature. Keeping the temperature dial as low as possible helps, though if it's too low, the glycrine/water mixture gums up the heater block.
In any event, if you're putting smoke fluid through any kind of smoke machine then you need to be regularly cleaning the machine. You can buy smoke machine cleaner or you can use water with a tiny bit of methylated spirits or isopropyl alcohol mixed in.
An amusing side effect of the use of a modified smoke machine is that the fluid reservoir is inside the machine. Of course, when you transport the Dragon it will inevitably end up on its side and any smoke fluid will spill out, into the electrics of the machine. After a while, it will stop working. By this point you'll be so sick of being covered in sticky glycerine from said spilled fluid that you won't care.
If you want to standardise on one type of connector and build adapter leads to go to your batteries, control boxes etc then I would recommend two options.
For low current requirements such as sound effects and camera, I recommend a DC barrel connector in the 2.1mm / 5.5mm size. These are the type that Only Dinosaurs used to supply and you can very easily buy short leads with the connectors already on them which you can then use to build a set of adapters.
For high current requirements such as the Dragon's smoke machine, the XT60 connector used for applications such as drones and remote control cars is ideal. It's easy to work with, reliable and has a high current capacity. You can also buy batteries with XT60 connectors already on them though, as I mentioned, I would not recommend using Lithium batteries inside a dinosaur. For the Dragon, however, you might not have a realistic alternative for long periods of use.
Mould
The dinosaur puppet is a large sponge with almost no ventilation. The internal fan doesn't remove warm, damp air, it just circulates it. The result is that after 20 minutes inside a dinosaur, you've lost a third of your body weight and that water has to go somewhere. Luckily, you are surrounded by foam which readily absorbs the moisture.
What happens to that moisture? Well, it stays inside the dinosaur. The warm, damp dinosaur body is the perfect place for mould to form. Mould spores are everywhere, floating around in the air and landing on every surface. Normally, the environment is too dry for the spores to germinate but in the right conditions, mould will spread rapidly.
Stachybotrys chartarum: This species is often associated with water damage and high humidity. It's known for its potential to produce toxins and is sometimes referred to as "toxic black mould".
Alternaria: This mould is a common allergen and can trigger hay fever or asthma in susceptible individuals.
Cladosporium: This is a ubiquitous mould found both indoors and outdoors. It can grow on a variety of surfaces and often appears as dark, spiderweb-like stains.
As you can see, mould isn't an inconvenience, it's a health hazard which will render your dinosaur unusable long before it fails mechanically.
Once mould has begun to grow inside your dinosaur there is nothing you can do to remove it, other than remove the dinosaur's body and skin and start again. The manufacturer conveniently lines the dinosaur with cotton fabric to protect the foam which provides a lovely organic surface for the mould to make itself right at home. Very strong chlorine bleach can slow the spread of mould but will not remove it and if you use bleach you then make the dinosaur unusable anyway.
What can you do? Once you have mould, your dinosaur's days are numbers. The only way to remove it is to prevent it from forming in the first place. For this, you need ventilation. If you're in a warm, humid climate then you'll need dehydration too. In the UK and most of Europe, plain ventilation is fine.
For our dinosaurs, I made a set of Dino Dryers which are extractor fans with long hoses that can be placed into the dinosaurs while they're in storage. Placing a dryer (or a free standing dehumidifier) inside the body of the dinosaur when it is in storage will potentially double its useful life - from 2 to 4 years.
Skin - and feet in particular
The dinosaur's skin is a synthetic fabric printed with a vinyl pattern. It's flexible, easy to sew, easy to glue and very easy to rip. You might have already discovered that if you're not careful when moving your dinosaur in and out of a vehicle or through a doorway, you can easily snag and tear the skin. You'll find that zips easily detach and the seams around the tops of the legs quickly come loose. Luckily, these problems are easy to fix with a needle and thread.
The soles of the feet are a much bigger problem. If you're often performing outdoors then the soles of your dinosaurs will wear through very quickly. Water will get in and you'll get very soggy feet. An alternative design would have had a hole in the bottom of the foot and straps to hold the foot onto your shoe. You could then have walked on your own shoes, probably with greater stability.
The most common adhesive that I've seen people use to repair dinosaur rips and worn feet is silicone. The problem with this is that silicone is not an adhesive, it's a gap filler. It's not sticky and it has a low modulus, meaning that it stretches and tears easily. I strongly advise you not to use silicone.
Unfortunately, the dinosaurs arrive from the factory with a thick pad of silicone sealant on the soles of their feet which then makes it very difficult to repair the feet with any other kind of glue. Eventually, the silicone will fall off and you can then use something more suitable - neoprene-based contact adhesive. To use this, you apply a thin layer to each surface, allow it to dry slightly and then press the two surfaces together. The bond is instant. When you take delivery of a new dinosaur from Only Dinosaurs, you'll get a bottle of contact adhesive which is luckily very good.
Once you can glue to the underside of the feet, you can give the dinosaur new soles cut from EVA foam. This is the type of foam used for play mats and yoga mats, though you can get it in different densities. An ideal design would have large Velcro pads sewn onto the sole at the factory so that you could attach your own semi-disposable soles of different densities for different walking surfaces. We have to make do with what we've got, so get foam pads onto your soles as soon as you can and your dinosaur will last longer while your own feet stay nice and cosy.
Conclusion
Dinosaurs, or at least those made by Only Dinosaurs, are horrible, badly designed, badly made, unreliable, hot, sweaty, complex, potentially dangerous machines. But the kids love them so what are you going to do?
Having spent perhaps £10,000 on a dinosaur by the time you've paid for shipping, accessories etc, you really want to make the full use of your valuable asset. If it breaks you can't just throw it away, but you might also struggle to fix it and that's something that I can help you with.
If you don't look after your dinosaur by regularly servicing it, checking for common faults and drying it, it last you a year which is not a good return on investment. If you do look after it, you could get 4 or 5 years regular use.
