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Re: Next overhaul project....

Posted: Sun Dec 24, 2023 10:43 am
by Scrat
We have a working water pump.

Of course, both balls were stuck in their seats.
Still waiting for good weather to have a test run.

Re: Next overhaul project....

Posted: Sun Dec 24, 2023 11:28 am
by Old Man Aaron
Always good to get another job ticked off. Hope it clears up soon. :thumbleft:

Re: Next overhaul project....

Posted: Mon Dec 25, 2023 1:32 pm
by Scrat
Today there was a gap in the rain but....also a leaky fitting which kept me from firing up.
After fixing that I will try again.

Re: Next overhaul project....

Posted: Tue Dec 26, 2023 1:16 pm
by Scrat
Got a few metres under her own steam today, but the backhead looks like a miniature version of the Niaragra Falls.

So back to the workshop.

Re: Next overhaul project....

Posted: Tue Dec 26, 2023 6:23 pm
by philipy
Slow and steady wins the race.. or something!

Re: Next overhaul project....

Posted: Tue Jan 02, 2024 12:17 pm
by Scrat
Happe new year!

December 31th she did the first lap under her own steam. This is a big step after getting just a few metres on December 26th.
Niagara falls have been removed from the backhead, other minor jobs have been completed.
(And new jobs identified of course)
Next on the list:
- engine pump is not reliable, sometimes it delivers water to the boiler, sometimes not.
- a proper blowdown valve is needed
- the blower is too weak, even at 50psi it cannot hold the fire alive.

And here´s what you might have been waiting for:

The twins:

Image

Re: Next overhaul project....

Posted: Tue Jan 02, 2024 12:22 pm
by philipy
Superb! Well done.

Re: Next overhaul project....

Posted: Tue Jan 02, 2024 2:59 pm
by ge_rik
Excellent. I'm now tempted to construct an over-type loco. One was used on the Aveling & Porter sidings on the Aldeburgh branch at Leiston so it would be nostalgic for me to see if I can find a three foot gauge version for the PLR
rlwyleiston5.jpg
rlwyleiston5.jpg (26.29 KiB) Viewed 32762 times
Rik

Re: Next overhaul project....

Posted: Tue Jan 02, 2024 3:13 pm
by Scrat
Hi Rik,

these tram locos can become addictive....
We might hold a photo cometition on that topic as well.

Re: Next overhaul project....

Posted: Thu Jan 04, 2024 6:57 am
by Old Man Aaron
:bravo :salute:

Re: Next overhaul project....

Posted: Wed Jan 17, 2024 5:20 pm
by Dr. Bond of the DVLR
Wow! Brilliant to see you bringing it into service. I really love an overtype. For many years I was invovled at the Garratt Works Museum steaming Sirapite up and down a tiny bit of track - happy days.

Looking forward to the next up dates.

Re: Next overhaul project....

Posted: Thu Jan 18, 2024 8:08 am
by Scrat
Compared to 807, Sirapite is quite huge.
I spent the last workshop sessions building the brake gear.
Image
Took a few tries to get the lever dimensions right.
The handwheel is a Wilesco spare part.

As soon as the weather gets better I will have another test run.
Hopefully I will be on board the train this time.
Draughting has been worked on. Blower power has been improved.
Last time the blower was too weak to hold the fire, even while the engine was not running.
The water pump is reliable now so I be able to get a few laps with driver.

Re: Next overhaul project....

Posted: Thu Jan 18, 2024 8:28 am
by philipy
She looks superb, Holger.
Can't wait to see a video of her running.

Re: Next overhaul project....

Posted: Thu Jan 18, 2024 9:26 am
by Scrat
philipy wrote: Thu Jan 18, 2024 8:28 am She looks superb, Holger.
Can't wait to see a video of her running.
Here you go:
https://youtu.be/qnYce0YG07A

Re: Next overhaul project....

Posted: Tue Feb 06, 2024 12:30 pm
by Scrat
Another test run last weekend showed that the water pump is reliable now.
That´s the good news.

There still is an issue with draughting. Even at standstill using the engine blower or the electric blower I cannot get the pressure above 25 psi.
As boiler and smokebox are one piece there is no leak there. The smokebox door also seals nicely.
The firedoor also seals well.
The suspect in this case is the grate. Bars are 3mm diameter with just 1.5mm gap between them.
I will make a new grate for the next test.

Re: Next overhaul project....

Posted: Wed Feb 07, 2024 10:02 am
by Old Man Aaron
Sounds frustrating. I hope it's just the grate that sorts it, that is a ridiculous bar gap - even 16mm locos have wider spacing.. :scratch:

Re: Next overhaul project....

Posted: Wed Feb 07, 2024 1:17 pm
by Scrat
Hi Aaron,

the spacing is always a bit trial and error.
I use Anthracite coal.
My LBSC Titfield Thunderbolt and my Maxitrak Swallow have had issues with clinker.
A wider spacing of the grate bars solved this problem.
I will just make another grate for 807 and try again.

it´s always a long way to get all components in this line to match.
Firehole door (top air), grate, flues, smokebox tightness, blastpipe, blower assembly.
In this case I am quite sure that the grate is to blame.

Re: Next overhaul project....

Posted: Mon Mar 04, 2024 2:19 pm
by Scrat
Had a few laps on Saturday.
The loco pulls me but needs more weight.
Traction is a real issue.
The new grate works well. When running, she can keep the steam.
However, the blower still cannot keep the fire alive at standstill, even with 75 psi on the clock.
(to be investigated).
It is fun to ride this tiny engine round the garden.
She sounds like a small lawnmower.

Re: Next overhaul project....

Posted: Fri Mar 08, 2024 8:09 am
by Scrat
Still not happy with the draughting. I am only used to 5" gauge locos having the blower and blast pipe inside the smokebox.
I would like to ask the experts here:

As the exhaust steam enters the chimney above boiler level, how should the blast pipe and blower nozzle look in order to create a good draught?
In this case the blower pipe enters the bottom of the blast pipe and uses the same nozzle.
(Pics to follow)

Re: Next overhaul project....

Posted: Sun Mar 10, 2024 1:20 pm
by Scrat
Investigated further into the draughting issue:
The exhaust steam enters a T-piece...at the bottom.
So much for not obstructing the flow of the exhaust steam.
The blower was also included in this strange contraption.
As soon as I tried to unscrew anything, the exhaust steam pipe and the blower pipe broke off and crumbled to bits.

I have now made a new exhaust steam pipe with a slightly bigger inner diameter, a good-sized bend upwards and a 2mm nozzle.
The blower pipe has received the same treatment.

Under compressed air the difference is huge.
Time to test under steam.