2½" Gauge LNER P1
It's been a long time since I wrote anything about the P1! Things have moved ahead though but unfortunately I didn't take any photos whilst the work was being done.
I made new shorter connecting rods to move them to the second axle. I didn't flute them at the time but will probably do so when the loco is stripped for a repaint. Rather than make new eccentric rods I just cut a piece out of the old ones and silver soldered the two bits together. This is only temporary and I will make new ones at a later date.
I took the opportunity to make new crankpins rather than reuse the old ones as they were quite worn and also fitted all new bushes to the coupling rods.
My fears that the new shorter connecting rods would foul the slide bars proved unfounded and when everything was reassembled there was plenty of clearance.
New connecting rod
I also decided to tackle the problem of the over oiling of the lubricator. Rather than make a completely new one, I got rid of one of the cylinders and sleeved the other one down from 1/8" diameter to 3/32" diameter. I also machined away as much of the upstand as possible to increase the oil capacity of the tank.
The first few test runs proved that the loco still ran well but recent runs showed that the lubricator didn't seem to want to work properly. I took the loco to the 2½" day at my home club in July and it seemed to run ok but I noticed at the end of the run that the lubricator was full of water. Both of the check valves (one in the lubricator itself and one in the feed line) were obviously leaking. There was no sign of oil on the chimney either so the cylinders were getting little, if any, oil.
I took all the check valves to pices, cleaned them, and reseated the balls ready for the next rally at Little Hay at the beginning of August. The loco really struggled to get around the track and I suspected my driving trolley was dragging for some reason. Trying someone elses did improve matters slightly but not a lot. Again there was no sign of oil on the chimney but the oil in the lubricator had gone down to about half.
The next day I had a look under the front of the loco and there was steam oil everywhere so something must have been leaking and the oil was not getting to the cylinders. I took the lubricator off and immediately found that the connection for the oil feed pipe was very loose on the lubricator. No wonder it was leaking! The problem turned out to be that the union nut was too long and tightened down before clamping the pipe. I just shortened the nut a little and problem solved.
I tried pushing the loco up and down to check that the ratchet drive to the lubricator spindle was working ok and it was really stiff to move. Thinking about it, I remembered that I had fitted O rings to the pistons and I guessed that it was these making the loco so stiff to move, I took the cylinder front covers off and the cylinder bores were bone dry with no sign of oil. No wonder the O rings were sticking! I reckon this was why the loco was struggling at Little Hay and it probably wasn't anything to do with the driving truck after all. I put a bit of steam oil in the cylinders and everything immediately freed up and the loco became very free running again.
The next rally is at Stockport this coming Sunday and I decided to give the loco a run at home tonight to make sure the lubricator was working now. I didn't want to take the loco all that way only to find it still had problems.
The test proved ok and plenty of oil was now getting to the cylinders as shown by a generous coating on the top of the chimney. The lubricator is still giving too much oil but I'm leaving it as it is for now. At least it's working! Roll on Sunday!
The problem now with the lubricator is that the teeth on the ratchet wheel are much too coarse and it really needs a finer toothed wheel fitting. A job for the future though.
PS I'll add some photos when I get my camera back off my brother - he's borrowed it again!
Well, I had a good day at the Stockport rally. The weather was better than forecast and I had a good long run with the P1. The lubricator worked faultlessly but I had to stop to refill the tank every 5 or 6 laps. Not too bad I suppose but will look to fit a finer tooth ratchet wheel before the next run.
The loco still seems a bit lacking in power and the valve timing goes out when you notch up the reverser (I always notch up as far as possible when I'm driving). A couple of things to look at sometime in the future.