What is Ball chain?Ball chain is a type of chain made up with small hollow balls connected by small rods.
Each ball is made from rolling a flat piece of metal over the interconnecting rods. The above picture portrays two interconnecting balls on the left opened,showing how the rods are secured.
Advantages of Ball Chain
- Smooth, chain that will not catch on clothing/skin
- Easy to untangle
- Each ball acts as a swivel
Disadvantages of Ball Chain
- Not as strong as our 7x7 stainless steel wire or welded oval link chain
- Will wear out sooner than our welded oval link chain when overly stressed.
Can I use ball chain on my fire poi set?This depends on the type and size of your ball chain, the weight of your fire head, and your swinging style.
Types of Ball Chain:Aluminum ball chain. Not suitable as it has a high thermal conductivity and breaks very easily. Be aware that coloured and decorative ball chains are quite often aluminum underneath.
Mild Steel ball chain.strong> Good with correct sizing, shorter life compared to Stainless Steel. Quite strong. Normally coated with Nickel for greater abrasion and corrosion resistance, however as coating does not effectively get inside the ball and the ends or insides of connecting rods, rust and abrasion wear will occur within the chain. Overheating will also cause nickel plating to come off mild steel.
Stainless Steel ball chain. Very good with correct sizing. Excellent longer life abrasion and corrosion resisting properties. Stainless steel has a much lower (1/3) thermal conductivity than regular steel and will heat up slower under a flame. Benefits of stainless steel include: Corrosion resistance, Fire and heat resistance (retains strength), attractive appearance, strength to weight advantage, high impact resistance, and longer life.
Sizes of ball chain that can be considered.
Size #13 (Ball diameter 1/4inch or 6.3mm has an average tensile strength of 90lbs or 41Kg
Size #15 (Ball diameter 5/16inch or 8mm has an average tensile strength of 120lbs or 54Kg
Poi spinning stylesIf you spin an 80cm POI set with 140gm Cathedral fire heads at 2rev/sec the force on the chain will be approximately 14 times greater at the bottom of the swing. Which is like having an unmoving 2Kg POI head pulling down on the chain.
If you spin the same set faster at 3rev/sec the force on the chain will be approximately 30 times greater at the bottom of the swing. Which is like having an unmoving 4.2Kg POI head pulling down on the chain.
If you wrap the POI around a limb you could effectively halve the spinning radius and hence double the force again.
Kicks and quick changes of directions will also put greater stress on the chain even over 100 times the resting weight of the POI head
Always allow extra margins for any additional stresses (forces and heat) you may put onto the chains.
If you like big fire heads, faster spinning with kicks and wraps you are better to look at welded oval link chains for you POI cords.
*"the force on your hand is equal to the mass times the velocity squared all divided by the radius."
How do I attach ends to my ball chain?
In order to attach quick links and fire heads or handles to ball chain it is recommended that you use a type "A" coupling.
The coupling has an eye for attaching quick links and attached bowl which cradles the ball chain.
Drop the ball chain into the cradle by passing the connecting rod through the slot in the side wall. Once the ball chain is in place crimp the slot together to prevent the ball chain coming out again.
Never attach wick heads or handles directly to the "A" coupling as this will cause undue side pressure on the first connecting rod resulting in shorter life of the product.
Use quick links shown below or other suitable connector.
Dangerous use of Mild steel key/split rings : Continuous heating and reheating of these rings with any centrifugal forces causes the ring to open up. Standard cheap low carbon key rings will weaken at 260 Deg C. within 2 minutes!
Even small stainless steel splitrings will open. Remove risk, increase product safety and product life by using stainless steel quicklinks.
Use a quick link at the fire end and tighten the quick link with pliers to prevent it coming undone once the head is attached.
How do I check my ball chain for wear and tear?
Referring to the diagram above.
If you have nickel plated steel ball chain look for signs of rust and wear marks at point A and signs of the ball opening too much at point B.
If you are using Stainless steel ball chain look for signs of the hole at point A getting larger and again the ball opening at point B.
Depending on your style of spinning you could see signs of wear at any point along the chain length.
No matter what you decide to use, always check your equipment before using it.
Caution: Only soak the wick in the fuel container as the hollow balls will soak up the fuel and can cause the chain to catch on fire whilst spinning.