Looking forwards to seeing if this resolves the issueScrat wrote: ↑Sun Mar 10, 2024 1:20 pm 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.
Next overhaul project....
- -steves-
- Administrator
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- Joined: Thu Jul 28, 2011 1:50 pm
- Location: Cambridge & Peterborough
Re: Next overhaul project....
The buck stops here .......
Ditton Meadow Light Railway (DMLR)
Member of Peterborough and District Association
http://peterborough.16mm.org.uk/
Ditton Meadow Light Railway (DMLR)
Member of Peterborough and District Association
http://peterborough.16mm.org.uk/
- Old Man Aaron
- Trainee Driver
- Posts: 816
- Joined: Wed Oct 19, 2016 11:08 am
- Location: Sunshine Coast QLD, Australia
Re: Next overhaul project....
Hoping it does, sounds like you've found the culprit..
Regards,
Aaron - Scum Class Works
Aaron - Scum Class Works
Re: Next overhaul project....
Goes better than before, but still not as I want it to.
Blower kan keep the fire alive now st 50 to 75 psi and even raise the pressure.
Blastpipe still needs some tuning.
As usual with traction engines the blastpipe is in the chimney, so there is less area for the exhaust steam to mix with the hot gases.
I will now put it in "locomotive position" about half height of the smokebox.
The block of lead (2.2 kgs, hidden between the frames) really makes a difference in traction.
Blower kan keep the fire alive now st 50 to 75 psi and even raise the pressure.
Blastpipe still needs some tuning.
As usual with traction engines the blastpipe is in the chimney, so there is less area for the exhaust steam to mix with the hot gases.
I will now put it in "locomotive position" about half height of the smokebox.
The block of lead (2.2 kgs, hidden between the frames) really makes a difference in traction.
Re: Next overhaul project....
Yesterday we hat a meeting at a firend´s track.
There is a long uphill section.
While firing up I heard comments like "that thing is never giong to pull anything" and "just put it on the mantelpiece".
Jokes aside, the loco is running.
I made it up the long incline, the pressure gauge was at maximum during the whole trip, even though I had left the ashpan in place and the damper closed. So the new blastpipe is doing its job.
With the old arangement I had to take the ashpan off to get any draught at all.
Downside:
The blower needs more work.
As soon as the loco is stopped, the blower does not hold the fire alive.
A new nozzle is required.
Back to the drawing-board lathe...
There is a long uphill section.
While firing up I heard comments like "that thing is never giong to pull anything" and "just put it on the mantelpiece".
Jokes aside, the loco is running.
I made it up the long incline, the pressure gauge was at maximum during the whole trip, even though I had left the ashpan in place and the damper closed. So the new blastpipe is doing its job.
With the old arangement I had to take the ashpan off to get any draught at all.
Downside:
The blower needs more work.
As soon as the loco is stopped, the blower does not hold the fire alive.
A new nozzle is required.
Back to the drawing-board lathe...
Re: Next overhaul project....
More work has been done.
I added some more hidden lead and replaced the 0.8mm internal diameter pipe between the banjo bolts with 2mm internal diameter pipe.
I now have to re-set the valves when the engine is hot.
Never thought that expansion would have a noticeable effect in 5" gauge but it does.
The effect on the valve timing is there and needs to be taken into account.
Let´s see what the next steam test will show.
I added some more hidden lead and replaced the 0.8mm internal diameter pipe between the banjo bolts with 2mm internal diameter pipe.
I now have to re-set the valves when the engine is hot.
Never thought that expansion would have a noticeable effect in 5" gauge but it does.
The effect on the valve timing is there and needs to be taken into account.
Let´s see what the next steam test will show.
Re: Next overhaul project....
Today, 807 received a proper baptism.
The Steel turtle had just received a new set of batteries and a light overhaul.
She weighs about 40kgs, the body is made of 3mm steel plates.
Turret can be turned endlessly (10core twist connection), water gun has a range of 5 to 6 m.
Barrel can be moved up and down for proper aim.
2.7 l water tank, 4 led gel batteries with 7Ah each.
Red and blue underfloor lights.
The Steel turtle had just received a new set of batteries and a light overhaul.
She weighs about 40kgs, the body is made of 3mm steel plates.
Turret can be turned endlessly (10core twist connection), water gun has a range of 5 to 6 m.
Barrel can be moved up and down for proper aim.
2.7 l water tank, 4 led gel batteries with 7Ah each.
Red and blue underfloor lights.
- Old Man Aaron
- Trainee Driver
- Posts: 816
- Joined: Wed Oct 19, 2016 11:08 am
- Location: Sunshine Coast QLD, Australia
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