What i've done today

[johnd]

Jun 10, 2024 21:27:52 GMT GWR 101 said:

Hi, I found it necessary to slightly reduce the height of the frames towards the rear and also chamfer the tops slightly. I also found that the access holes in the frames for the blow down valves had to be elongated. Fortunately I realised and was able to elongate the holes into slots on the miller. Good luck. Paul

Belive it or not eventually when i managed to get the boiler. Down in the frames both blow down valves were misaligned. As you found they had to be elongated by about 1/4”(6mm). Unfortunately my frames are complete and assembled so I had to resort to hand modification.

[johan]

Finished the 3D drawing of a part of the engine of the locomotive. For giggles I send it to a 3D printing service to have it 3D printed in 316L stainless. Let us say I'm not giggling at the moment.

[GWR 101]

I must be honest when I encountered the problem I didn't investigate what was the cause of the issue (very remiss of me).
Being an old guy I don't have the resilience to file the holes into slots. But I do like a challenge so mounting the "assembled frames" on the miller suitably fixed to enable them to be machined I saw as a challenge I had to take up. Each to their own, your method was probably quicker, good luck with the rest of your build. Paul

[steamer5]

Not long got home from a night run, given that it was a nice clear night & the temperature dropped to 9C with a sneaky breeze, starting at 5:30 pm finished at 8:30 pm, carried just short of 1200 passengers, with wait time which got to a hour & 20 minutes a great night was had by all!

Cheers Kerrin

[suctionhose]

When building an engine, there are occasions when one needs extended periods of intense concentration OR if not…

Coupling Rods:
1. Wrong offset – not enough material for the larger end – added some
2. Overall height under size – change drawing
3. Drilled hole too big to ream ¾”- deal with later
4. Use wrong radius cutter – try to fudge it
5. Drill strap bolts 3mm out of position – how the hell?
6. Used wrong material – not thick enough – added some on
7. Drank some wine – didn’t help
8. Mixed up left and right hand (again)
9. Drill oil holes on the bottom…
10. Plug and redrill oil holes on top – in the wrong place!
11. Just caught it in time…
12. Somehow, still looks ok after all that!

[JonL]

There are some times when there faults have accrued to such a depth where a deep breath and a fresh piece of metal is the best answer...

[johnd]

Jul 16, 2024 9:20:10 GMT suctionhose said:

When building an engine, there are occasions when one needs extended periods of intense concentration OR if not…

Coupling Rods:
1. Wrong offset – not enough material for the larger end – added some
2. Overall height under size – change drawing
3. Drilled hole too big to ream ¾”- deal with later
4. Use wrong radius cutter – try to fudge it
5. Drill strap bolts 3mm out of position – how the hell?
6. Used wrong material – not thick enough – added some on
7. Drank some wine – didn’t help
8. Mixed up left and right hand (again)
9. Drill oil holes on the bottom…
10. Plug and redrill oil holes on top – in the wrong place!
11. Just caught it in time…
12. Somehow, still looks ok after all that!

Just came in from the workshop and read this post. Think I recognised most of the above, today’s deliberate mistake was making two left hand brackets. Just put primer coat on when the fault was noticed. Happy Days.

[suctionhose]

Jul 16, 2024 16:04:33 GMT JonL said:

There are some times when there faults have accrued to such a depth where a deep breath and a fresh piece of metal is the best answer...

Yes, agreed. But to quote the lyrics of Kenny Rogers' "The Gambler":

"You've got to know when to hold 'em
Know when to fold 'em
Know when to walk away
And know when to run..." (Running Day Saturday)

[dhamblin]

After further work to improve piston packing and general sealing on both of Britannia's cylinders, I sprayed the primer on them this afternoon.

Race is on to get everything reassembled and tested with three track runs coming up in August.

Regards,

Dan

[johan]

I had designed the base of my engine as a 3D print. But after getting a quote I decided that making it as a brazed construction would be a possible cheaper, less intimidating to finish alternative. So today I finished drawing out that. And compromising 17 sub-parts is it a complicated affair... I really have no idea if I will be able to make that. So I guess that it will have to be the first part of the loc that gets constructed. Just to check feasibility. I doubt it but we'll have to see.

Now first making getting the electric loc ready for the open door days, then a holiday, some modifications to the lathe and needed tools and then starting this project.

[chris vine]

Hi Johan,
For soldering big fabrications you will need a lot of heat to get it up to temperature quickly. Too slow and the flux will be exhausted before the solder flows.
It might be worth a few practice joints on similar size bits of scrap?..
Chris

[johan]

Chris, it is a fabrication around a half pipe of 101.6mm diameter, 3.65mm wall thickness, 125mm long and almost 1.2kg. So it is rather large. I do have a couple of propane burners and oxy-acetylene at my disposition. Biggest handicap is that I have to do this alone. I could do it in 3 steps but I can not decide if that would be simpler or not.

I know this is new to me and I'm prepared to start all over again. If it doesn't work out I can still try to TIG weld it. With 3mm steel to work from that could be an option. But I fear for distortion going that way. A combination of TIG and brazing might be an option as well.

[kipford]

If you have Oxy-Acetylene, you can tack it together then finish braze it all with silicone bronze rods. You can do this on your own without background heat just make sure you use a big enough nozzle. You will still have to watch for distortion though. I have brazed up a few racing car space frame chassis in the same way but using nickel-bronze rods which require more heat than silicone.

[johan]

Jul 30, 2024 12:11:43 GMT kipford said:

If you have Oxy-Acetylene, you can tack it together then finish braze it all with silicone bronze rods. You can do this on your own without background heat just make sure you use a big enough nozzle. You will still have to watch for distortion though. I have brazed up a few racing car space frame chassis in the same way but using nickel-bronze rods which require more heat than silicone.

Do you mean that "CuSi3" material? When I went to the shop to buy some TIG welding rods they offered me some of these to try. It are "copper-silicon" rods for TIG. I got plain and flux coated ones. They told me it was for thin sheet material and used lower temperature than welding. We tried at the evening classes to use them but we failed to make it work, didn't flow out or the base metal melted and it made a mess.

Or should I use these with oxy-acetylene? I do have a "heating head" Gloor 3952A that I used to braze my boiler. It gives a more spread out flame. Worked well to fix the last leaks.

As for distortion, I have included 0.5mm on all important edges/planes for machining afterwards. So with a bit of luck that should take care of distortion if it is not too extreme.

I know: too much stuff, no knowledge and even less experience

[kipford]

Johan
These are the rods I use or an equivalent for model engineering applications with the appropriate flux. They are brazing rods not welding ones and consequently melt at a lower temperature. Although they need more heat than silver solder the flux does not get exhausted so quickly so heating up larger sections for brazing is much easier. I use them on all types of section from thin section to large diameter bar. I now use Oxy-Propane as the heat source so your oxy-acetylene will be more than adequate. Main problem with distortion is if the part twists due to uneven heating. So tack it together then complete each joint working from the corners inwards, much like you would torque tighten a bolt pattern.


www.weldequip.com/sifbronze-brazing-rods.htm

[mbrown]

Today was the annual 2.5" Association Rally at The Sutton Coldfield Club track at Little Hay. This year I decided to give my old Bagnall 0-4-2T, "Darent" a run for the first time in over 25 years. She was built from a small drawing of the prototype in the history of the Cliffe Hill Mineral Railway where the big engine ran, being scrapped in the 1950s. I started her on a tiny Centrix lathe in a spare bedroom and later upgraded to an EW lathe which enabled me to finish her in 1983. During the 1980s she was frequent performer at 2.5" rallies, but although her most recent boiler certificate was granted in 1998, I don't think she had run since about 1995 until today.


20240804_145219 by malcolm brown, on Flickr


I checked her over a few days ago and found that the O rings in the gauge glass seals had hardened completely to the extent that I had to machine them out. But with new O rings, the gauge glass sealed perfectly and the only other essential job was to replace a stripped union nut on the inlet to the crosshead feed pump and pickle the injector in a weak citric acid solution for 20 mins or so. Today, she passed her new boiler inspection without difficulty.


20240804_145238 by malcolm brown, on Flickr

I had forgotten the joys of running a simple and straightforward loco without too many blobs and gadgets! Darent (named after the river running through the village where she was built) has a perfectly proportioned boiler with a deep square firebox and fairly short tubes. As a result, she can sit quietly with the fire banked up, simmering gently if held by a red signal, but a touch of blower brings the fire around and she's always ready to go on the green. You can run the fire right down, but a few shovels full of coal and the pressure is back to blowing off after a few yards. Altogether a very pleasant few hours running, terminated only by the stiffness in my knees - I am not as young as I was when she last ran at Little Hay in the 1980s!

Here's a short video of her running - although I had left the injector on too long and she was priming - hence the bubbles in the gauge glass and the fountain of water from the whistle valve! (and apologies for the intrusive finger at the beginning!)


20240804_121916 by malcolm brown, on Flickr


Best wishes

Malcolm

[VGC]

I did not write about it here when I did it, but some weegs ago I made a second valve gear running demo for a steam loco website.

You can see a similar configuration here:

www.constructor.valvegear.de/xtern/userfiles/uk_ChrisV_petersrailway.php?lang=en&autorun&link=vgc

The demo consists of an overlay window which controls the basic design program window. Editing is deactivated there. Only reversing and running is working.

[johnd]

Just heard from a friend that after 88 years Mamod steam models is closing down. Great shame as i had many happy hours running a Mamod stationary engine when i was a young lad.

[suctionhose]

My life has been divided into 3 parts: 1/3 working, 1/3 sleeping and 1/3 looking for small parts on the floor!

Spot the spring washer:

[johan]

Aug 9, 2024 5:00:02 GMT suctionhose said:

Spot the spring washer:

That's easy! But then, I have a lot of practice in that....