Tony Bird
Senior Member
Hi,
Well the first cylinder of the engine seemed to work OK, now onto the problem of the off-set cylinder engine. Quite a lot of thought had been given to how to correct the position of the ports and trunnion, from major rebuilds a completely new cylinder to what did happen; doing absolutely nothing to the cylinder itself. A number of drawings and cardboard models had been made that indicated the as the trunnion was in line with the ports the off-set should not effect a great deal of how well the cylinder of this engine performed. Just to be sure, instead of drilling the ports in the port block so there was very little or no lap, the holes were drilled 0.50mm smaller to give some lap. There was a cosmetic consideration should the trunnions be or the cylinders be in line with each other? Well, it was thought that it would be better if the cylinders lined up, so the trunnion pivot hole was not drilled in the centre of the port block. Marking out. (P.040).
The difference of alignment between the trunnion rods, with the cylinders in line. (P.041).
The position of the steam ports in the port block of the second engine. (P.042).
The wood screws that secured the engine base plate were replaced with M3 studs and nuts screwed into inserts in the wooden base. (P.043).
With the cylinder fitted to its port block the missing parts on the engine were made, first a cylinder cover. (P.044).
Then a big end for the piston rod. (P.045).
Followed by the piston itself. (P.046).
To complete the engine, a piece of the biscuit tin was screwed to its wooden base. Note biscuit tin name plate. (P.047).
The engine was put on test. (P.048).
A short video of the engine test, first the first engine completed and then the second and finally with both engines in motion.
We now have an engine that works quite well, the next exciting instalments are of what Tony did next. To be continued….
Well the first cylinder of the engine seemed to work OK, now onto the problem of the off-set cylinder engine. Quite a lot of thought had been given to how to correct the position of the ports and trunnion, from major rebuilds a completely new cylinder to what did happen; doing absolutely nothing to the cylinder itself. A number of drawings and cardboard models had been made that indicated the as the trunnion was in line with the ports the off-set should not effect a great deal of how well the cylinder of this engine performed. Just to be sure, instead of drilling the ports in the port block so there was very little or no lap, the holes were drilled 0.50mm smaller to give some lap. There was a cosmetic consideration should the trunnions be or the cylinders be in line with each other? Well, it was thought that it would be better if the cylinders lined up, so the trunnion pivot hole was not drilled in the centre of the port block. Marking out. (P.040).
The difference of alignment between the trunnion rods, with the cylinders in line. (P.041).
The position of the steam ports in the port block of the second engine. (P.042).
The wood screws that secured the engine base plate were replaced with M3 studs and nuts screwed into inserts in the wooden base. (P.043).
With the cylinder fitted to its port block the missing parts on the engine were made, first a cylinder cover. (P.044).
Then a big end for the piston rod. (P.045).
Followed by the piston itself. (P.046).
To complete the engine, a piece of the biscuit tin was screwed to its wooden base. Note biscuit tin name plate. (P.047).
The engine was put on test. (P.048).
A short video of the engine test, first the first engine completed and then the second and finally with both engines in motion.
We now have an engine that works quite well, the next exciting instalments are of what Tony did next. To be continued….
