Garden Railway Forum

As the test pressure gauge was still attached to the boiler I thought I'd make the safety valve next.  It's the ball bearing type, but not a pop-valve.


This is the top of the safety valve, the holes were marked out and centre punched under my bench mounted illuminated magnifying glass, and drilled in the bench drill.  The holes are 1.3 mm dia.




Testing the safety valve, using the small Sievert cyclone burner

I have been slowly plodding along with the construction, it's been a lot of fun though. At the moment I'm pushing for a steam test soon. The chassis is on the workbench, I'm getting it all set right, I love all the fitting. There was too much sideways play in the axles so I added grubscrews to the spacers that sit between the wheels and axle bushes, these allowed me to adjust their position to reduce play. Then I had the bright idea of oil blackening these parts. They came out a lovely shiny black.



This is the part being blackened in the video


Axle spacer fitted with grub screws


Happy New Year

Hi Dave, Happy New year to you too.
Your blackening process is one I've used for things, but never found it very durable. Some actually chipped off. Have you any experience of this?
Grant.

Have you tried chemically blackening metal Grant?

LNR wrote: ↑Tue Jan 02, 2018 12:01 pm Hi Dave, Happy New year to you too.
Your blackening process is one I've used for things, but never found it very durable. Some actually chipped off. Have you any experience of this?
Grant.

Hi Grant, I've used it a bit. Look at this image, I made these die holders for my Unimat 3 lathe in about 1990, not sure when I blackened them but maybe when I restarted the hobby in 2005. The smaller has worn because I hand thread with it often. I'd say it was an ideal finish for loco parts with no great thickness and no chipping.

A while ago I tested the chassis on air power, the first from a football pump, and then from my car tyre. I was so happy with the slow running on the tyre compressed air that I'm speeding towards a steam test





This project is two years old now

Great slow running Dave, a credit to your fitting work. Bet your dying to get on with the project now.
Re the metal blackening, and not wishing to hijack the thread, but when you used the word blackening
that put me on a different track. As an antique clock collector, I have cause to "blue" many steel items and the colour is really long lasting. Seeing you quench in sump(?) oil I thought you were looking for something different.
Grant.

LNR wrote: ↑Wed Jan 03, 2018 3:20 am Re the metal blackening, and not wishing to hijack the thread, but when you used the word blackening
that put me on a different track. As an antique clock collector, I have cause to "blue" many steel items and the colour is really long lasting. Seeing you quench in sump(?) oil I thought you were looking for something different.
Grant.

It's really dirty 4-stroke lawnmower sump oil, plenty of missed oil changes, so plenty of carbon.

Here's a summary of photos filling the gap from Feb '17 until now.

Safety valve with new whistle valve


Whistle valve, and turret for pressure gauge, plus one accessory


Instead of brazing, I Loctited the nipple to the blower pipe


Smokebox sealed


The loco prior to my April UK trip


Smokebox door locking bar


Machining the chassis mounted port blocks


Cylinders and port blocks


Smokebox with mounted reversing block


Machining the reversing valve


Piston assembly


Prototypical openings in buffer beam; I passed the pistons through them


Setting the port openings


Complete reversing valve assembly with steam inlet and exhaust, plus big bucket dead leg lubricator


O-rings in port blocks, small port is steam, large is exhaust, optimized for forward running; we'll see if it makes a difference in real life


Regulator body


Outside on the line with the large regulator handle


Halfway into the blower pipe elbow


Elbow with fittings and blower pipe


Blower pipe fitted to smokebox


Merry Christmas!

Great little engine. I like the unusual way the cylinders are coupled to the driverods. Looks a bit like a rack railway locomotive.

Prototypical openings in buffer beam, so that's why there are big holes!

I never knew why, yeah laugh it up.

This engine is lovely and a joy to read about it's creation.

Wow! That's so good. I do admire your engineering skills - and envy them.

Rik

daan wrote: ↑Fri Jan 05, 2018 10:57 am Great little engine. I like the unusual way the cylinders are coupled to the driverods. Looks a bit like a rack railway locomotive.

Thank you. It would have complicated things angling the cylinders and all downwards. It's a bit of an oversight too. I was going for attachment at the rear crank pin, but was concerned that I wouldn't get enough "waggle'. Let's see how it looks when I make the footplate.

tom_tom_go wrote: ↑Fri Jan 05, 2018 12:32 pm Prototypical openings in buffer beam, so that's why there are big holes!

I never knew why, yeah laugh it up.

This engine is lovely and a joy to read about it's creation.

Thank you Tom. It's just my guess, but the holes are in the right place

It's getting really close to a steam test, with a blowtorch in the firebox!

ge_rik wrote: ↑Fri Jan 05, 2018 1:30 pm Wow! That's so good. I do admire your engineering skills - and envy them.

Rik

Thank you Rik. I really enjoy it. I just don't seem to lose interest anymore, unlike when I was young. I admire your work too. And, (fingers crossed) I hope this loco gives the slow/smooth performance that you have found lacking in comercial live steam locos

Today was the day! Steam test time. Two runs on the workbench in the garage this afternoon, without the chimney extension or the smokebox door so it could be fired by the blowtorch.

1st run with half a gauge glass of water seemed very brief until the water was out of sight, but the 2nd run with a full glass of water lasted about 30 minutes of gentle ticking over. First impressions, it runs wet.

The lubricator worked well on the 2nd run, I started it off without the lid, trickling steam over the cold oil, then put the lid on. It's connected to the reverser by a silicone tube, I could see the different flow when slowing or stopping the engine compared to the running, there's a reverberation when running. After the run there were plenty of oil splatters on the boiler shell and a fair amount inside the smokebox.

There was a gentle leak from the blower valve throughout, which will not be a problem when the blower is connected.

Very nice Dave, bet you can’t wait to get it on the track.

When you say it runs wet is this just exhaust condensate?

It's lovely and I really like the big oscillating engines. I like running live steam trains - they don't have to be exact scale models to float my boat.

That really doesn't dissapoint me for an oscillating engine, or any live steam engine actually. It runs really slow and smooth as silk. Good job!