EASTON & ANDERSON

GRASSHOPPER ENGINE BUILD

Part ten by Jason Ballamy

Fabricating con and eccentric rods

Next on the list was the conrod, this is made from a 9" length of 5/8 x 1 1/4 flat steel. When this was cut I thought that while I was setting up the machines for the conrod that I may as well do all the other similar rods in one go so also cut some steel for the two eccentric rods, pump rod and two tie rods

After squaring off the ends to length each bar was held on end and the two bolt clearance holes drilled together with a small centre hole formed with a BS 0 centre drill
Each bar in turn was then held in the 4-jaw with tailstock support to reduce the majority to a cylinder followed by adding a slight taper to each end for about 1/3 of the length
The tapers were then blended by hand to give the traditional fish bellied shape
I then set the rods to one side and cut some bronze and steel for the bearings and end caps
The bronze was then machined to thickness with a flycutter
Before being tinned with soft solder prior to being sweated together
The bearings were then flycut down to the finished sizes
Then set up a stop on the mill vice so the bearings and plates can be drilled for the bolts
And here they all are ready for assembly
Well actually the bearings were bored first and the widths reduced to leave a raised section around the bore
With then now assembled the narrow edges could be turned and recessed
And them all completed