ModelPlan 117


JCB 712 Articulated Dump Truck

 A 10 Set Plus Model

Designed, described and illustrated by Tony James, this model continues the JCB theme set by his earlier "Loadall 520-4", the subject of ModelPlan 95, and is built to the same 1/8th scale.

The prototype JCB 712 was a rather unusual model in the JCB range. Although no longer in production, it can be seen on many construction sites. It has a 111.5 hp engine and a gross weight of 20,670 kg with a 12,000 kg payload. The body capacity is a heaped 7.5m2 (9.4 cu.yd).

The unusual steering is arranged by pivoting the front and rear sections of the truck, and the model simulates the prototype's hydraulic ram arrangement for controlling this.

As, like ModelPlan 95, this model is fitted with heavy duty non-Meccano tyres, it is offered as a "10+" model. However, with the exception of its motor (P.D.U. or Decaperm) and two extra 3" Pulleys, it can be built with the contents of a No.10 Set.

The model has four-wheel drive using three differentials but only one universal joint. The two chassis halves are joined by a horizontal roller bearing so that any one wheel can rise up to 6" above the others on rough ground.

Fourteen pages of instructions describe the construction of the centre bearing; the axles; the differentials; steering operation; frames; gear train; clutch; gear change; tipping arrangements; bodywork; cab; and mudguards.

Illustrating the instructions are sixteen pages of diagrams, stapled separately to allow removal to allow easy reference while building. Also included are fourteen colour illustrations and a comprehensive parts list.