What is a double pendulum, how does it work and what is it for?
A double pendulum is a simple mechanical device which exhibits chaotic motion. The double pendulum is particularly interesting because compared with many other chaotic systems (like the weather) it is extremely simple. A double pendulum is made up from two arms which are connected to each other. The first arm or pendulum is connected to the wall or a solid structure through a bearing set and the second arm or pendulum is connected to the first one through another bearing set. When you spin this system the arms rotate exhibiting chaotic motion. A chaotic pendulum is truly fascinating to watch.

How long does the chaotic pendulum spin for?
Depending on how hard you spin it will keep going for approximately 30-45 seconds. Special attention has been given to ensuring that friction is reduced as much as possible.

One of the bearings is loose. We didn't think that this was normal seeing as how the other 3 bearings are press fit. Is this a defect?
Three out of the four bearings are housed in a high tolerance press fit. The fourth bearing is housed in an equally high tolerance loose fit. At first glance this may appear to be a fault, however this is a design feature is to reduce friction load.

How heavy are the chaotic pendulums?
Approximately 900g (2lb).  

How big are the chaotic pendulums?
The chaotic pendulum has a maximum spin radius of 340mm.

Are the chaotic pendulums easy to install & setup?
The chaotic pendulums are easy to install. All you need is a Philips screwdriver and a suitable solid wall to attach it to with the three supplied screws. It should take about 5 minutes to do it properly. Universities often find the alternative direct mounting option useful. To direct mount into a steel beam an additional bolt and spacer is supplied. Drill and tap an M6x8mm hole into the steel beam or structure and attach the pendulum directly to the steel beam using the supplied hex tool.

Can I pay with a credit card if I don't have a Paypal account?
Yes, the Paypal service will accept credit cards even if you don't have an account with Paypal and you do not need to sign up if you don't want to. It is very quick and easy, just like a normal credit card service.

Do you ship outside the USA? How much is shipping & handling? Can you deliver quickly in an emergency?
Yes, we ship anywhere in the world. Our shipping & handling rates are a fair indication of real cost (actually in some cases we lose money) and we charge a flat rate regardless of how large the order is. To ship within the USA you are looking at approx $8US and to ship outside the USA the shipping cost is approx $17US. Our deliveries are usually very quick however if you would like an urgent shipment you can pay a little extra and receive your goods over night from within the USA and in 3-4 days for international shipments.

Can we wholesale this product?
Yes, please click here to contact us to find out more information. Alternatively, register for a wholesale membership to gain access to bulk wholesales prices through your account. 

As a school or university can we get a discount?
In summary, yes you can, however you need to register for an account. When registering please ensure that you include the university or school name within the billing or shipping address for confirmation.

Can you customise the product?
Yes, we can do a custom build with any colour scheme and engraving combination. The packaging design can also be modified to suit your needs. We find that this is ideal solution for corporate gifts. One customer from MIT recently requested the Euler-Lagrange equation to be engraved on the pendulum which ended up looking fantastic. If interested please click here to contact chaoticpendulums.com.