A bell positioning apparatus for a glass tubing manufacturing apparatus comprising: a bell configured for a glass tube to be drawn over; a support connected to the bell ; a frame with at least one frame leg , a platform supported by the at least one frame leg and a support arm attached to the platform and the support , the support arm configured to move the support with at least two degrees of freedom; a frame leg dimensional stability apparatus operatively coupled to the at least one frame leg, comprising a temperature control component configured to maintain a temperature in the at least one frame leg and configured to maintain a deflection δ of the bell to less than 200 microns over a time period of 4 hours, wherein: δ = Δ T * L * CTE L * h / W , where: ΔT is a temperature variation across a width of the at least one frame leg over a time period of 4 hours when the at least one frame leg is a single frame leg or a temperature variation between two frame legs over a time period of 4 hours when the at least one frame leg is more than one frame leg; L is a length of the at least one frame leg; CTE L is the coefficient of thermal expansion of the at least one frame leg; h is a length of the support from a top of the platform to a bottom edge of the bell; and W is the width of the at least one frame leg when the at least one frame leg is a single frame leg or a distance between two frame legs when the at least one frame leg is more than one frame leg. a bell configured for a glass tube to be drawn over; a support connected to the bell ; a frame with at least one frame leg , a platform supported by the at least one frame leg and a support arm attached to the platform and the support , the support arm configured to move the support with at least two degrees of freedom; a frame leg dimensional stability apparatus operatively coupled to the at least one frame leg, comprising a temperature control component configured to maintain a temperature in the at least one frame leg and configured to maintain a deflection δ of the bell to less than 200 microns over a time period of 4 hours, wherein: δ = Δ T * L * CTE L * h / W , where: ΔT is a temperature variation across a width of the at least one frame leg over a time period of 4 hours when the at least one frame leg is a single frame leg or a temperature variation between two frame legs over a time period of 4 hours when the at least one frame leg is more than one frame leg; L is a length of the at least one frame leg; CTE L is the coefficient of thermal expansion of the at least one frame leg; h is a length of the support from a top of the platform to a bottom edge of the bell; and W is the width of the at least one frame leg when the at least one frame leg is a single frame leg or a distance between two frame legs when the at least one frame leg is more than one frame leg. ΔT is a temperature variation across a width of the at least one frame leg over a time period of 4 hours when the at least one frame leg is a single frame leg or a temperature variation between two frame legs over a time period of 4 hours when the at least one frame leg is more than one frame leg; L is a length of the at least one frame leg; CTE L is the coefficient of thermal expansion of the at least one frame leg; h is a length of the support from a top of the platform to a bottom edge of the bell; and W is the width of the at least one frame leg when the at least one frame leg is a single frame leg or a distance between two frame legs when the at least one frame leg is more than one frame leg. <EOS>