Member postings for david john

On attempting to set the valve timing I found that I could not get the port openings to coincide with either the top or bottom dead centre crank positions. In fact in all cases everything seemed to be 180degrees out. The positions of the eccentrics which impart movement to the valves are governed by pins fixed to the crank webs. I have checked all the components i.e. eccentrics, crankshaft ,positions of journals and pins according to the drawing as well as dimensions and orientation and nothing seems to be amiss. I can solve the problem by moving the pins but it means fabricating another crankshaft. I would be grateful for comments as to whether I have missed something or whether the drawing is wrong.

The test pressure should have read 160psi not 180psi

I have a vertical steam copper boiler which I constructed about 20yrs ago. It was built to standard drawings and is silver soldered throughout. It was tested to 180psi which was twice the working pressure. On overhauling it recently I noticed that there were two small bulges in the inner ring around where the firehole is situated. I have used the boiler on several occasions to power a Stuart 10 vertical steam engine without any problem. I havn't noticed any leaks at all and am satisfied that it's still intact. I am wondering if I inadvertently over pressurised it when using it and if so , have I weakened it so as to be unsafe?

I forgot to mention in my last post that the resistance controller is wired in series to the field winding but I will try to re-send the wiring diag. from the article.

Many thanks to all who have replied to my query. Certainly food for thought. I have made one attempt to forward the

wiring diagram to this post but it was rejected for some reason which I will investigate.it was the Rex Nicholls tram as someone rightly suggested. I have made it to look like Toby from Thomas the Tank engine but the face is that of Thomas not Toby as that was the only mould available. I don't think my grandsons will worry about that though. The loco is powerful enough to move me along the track at a fair speed just on the on/off switch without the resistance controller in the circuit but it would be ideal to have some sort of speed control.

I have recently completed a battery loco base on the series of articles beginning in M.E. Vol 162 no 3845.The motor is a converted 12v. car dynamo and the power is supplied by a 12v car battery. Everything works fine until I wire in the speed controller. This is basically a length of resistance wire soldered to studs with a moving arm contacting the studs.This is where the problem starts.When the speed controller arm is positioned at the end where no current has to pass through the resistance wire the motor runs slower than when it has to pass through the whole length of resistance wire at the opposite setting.Please can someone explain this.My knowledge of electricity extends to O level physics and Ohms law only and this was a few years ago now.

Many thanks.