Pulley wheel

Original situation

Pulley wheel machined from solid plastic. In an attempt to reduce costs a tool was made in South America to mould the wheel, including eccentric cable groove and removing all machining. Technical problems arose with the new injection moulding.Tools were shipped to Clamcleats Ltd for assessment.

Clamcleats Ltd Assessment

Excess flash on the moulding. The part warped after moulding. Eccenctric cable groove not within design specification limits – close tolerance required.

Clamcleats Ltd Solution

Gate size was increased by 100% allowing mould to be filled under reduced pressure. This was a quick, cost-effective tool modification. Outcome – both moulded-in stresses and split lines were reduced.

Material was changed from 15% glass fibre filled to 40% glass bead filled. Glass bead filled materials shrink in a uniform manner – reducing warping. Small tool modification made to compensate for difference in material shrinkage. Machine settings optimised. Outcome – Flat part achieved.

Eccentric cable groove – bespoke cutter made. Groove machined on a CNC mill after moulding has stabilised. Bearing pressed in when moulding is still hot, used as a location for machining. Outcome – Groove within design specification.

Present situation

We supply the completed part, moulded and machined, achieving the 30% cost reduction that our customer had originally hoped to achieve.

For further information about custom designs please contact jemery@clamcleat.com.