The Unofficial Mamod and Other Steam Forum

Spule 4

All:

So now the loco has:

IP bits are: Cylinders, Boiler(/w regulator, improved saftey valve and injector), Spacer and Bufferplates

Sidestreet Banerworks: Burner

PPS: Wheels, Cylinder Gaskets and.....something else?

Roundhouse: lubricator

Mamod (mechanical) bits are: reverser and con rods. Frames and body are also Mamod. I think now it is actually a Jan-mod!

With the Roundhouse lubricator, the footplate is much cleaner, I will take a photo here in a day or so.

It runs great on the bench on both compressed air and steam. Uses a good amount of steam oil, and a decent amount of condensation and a slight bit of remaining oil came out of the lubricator.

.....but still (as before last spring) it can hardly move itself on the rails, nevermind pull or push anything. As it ran VERY well back in the camel dung and Mamod safety valve days, and the same in the Sidestreet upgrades I gave it in the 1980s, this is perplexing.

Inspection after things cooled down shows there are a few things left to do:

1. There is a kink in the exhaust line where it bends up to leave the reverser and up into the smokebox, need to get that. I noticed wiggling the exhaust line impacted the running of the loco, so I bet this is the main problem?

2. I do need to pack the cylinder nuts.

3. I did check the chassis for binds (there are not any) but apparently the front bearings and mounting nuts spin freely on the frame. I could never get them where they would tighten against the frame. I guess I need to cram a couple spacers in there.

4. Re-pack the wicks (the one at the front of the loco will go out from time to time). More reading to do here: http://www.roundhouse-eng.com/spirit.htm

Any other ideas of things to check...other than sanity?

_________________
Garrett

Les · Posted: Sun Feb 10, 2008 10:23 pm Post subject:

So it's a Frankenloco then.

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Graham-Jilly

Spule 4

DLR · Full member Joined: 13 Nov 2007 Posts: 552 Location: Blyth

its the "O"ring cylinders. it might pull something on the track when its cold and on air but when it heats up the glands are machined to such fine tolerances they clamp on to the piston rod. This is what happened with mine and a few other 16millers on their locos.

Graham-Jilly · Posted: Mon Feb 11, 2008 10:20 am Post subject:

well I found with the O ringed pistons they need a small amout of backpressure and they run great am very happy with them
just view some of my vids
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Spule 4 · Posted: Mon Feb 11, 2008 12:05 pm Post subject:

Spule 4 · Posted: Mon Feb 11, 2008 12:06 pm Post subject:

DLR · Full member Joined: 13 Nov 2007 Posts: 552 Location: Blyth

I didn't fix it. I sent them back and bought the standard MSS cylinders which can be run on lower pressure ( with the O ring ones fitted, the boiler was at 50psi)

Titan · Full member Joined: 19 Jul 2006 Posts: 721 Location: Derby

Hmm, O ringed cylinders should work at the same pressure as normal ones. Whilst there is more friction from the O rings, this is more than compensated for by the efficiency gains through reduction in leakage.

Indeed that is the key to good running - minimising the leaks and unfortunately it is the most difficult thing to achieve. Often leaks are difficult to spot! I still have not got Titan up to the standard it was at before it was worn out ten years ago, but it is slowly getting there!

The second thing is having a good fire, if you are making lots of steam in the first place you can get away with quite a number of leaks before performance turns bad. make sure that the wicks are trimmed right and all are producing a good flame and it will help a lot.
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It's a Mamod Jim, but not as we know it!

Graham-Jilly · Posted: Tue Feb 12, 2008 9:46 pm Post subject:

I totaly agree with Titan.
Ive just built and tested my own wick burner for my loco and its delivering great heat and the loco ran very well last night and virtualy flew up the gradient that is on my line. and also i found that the o ringed pistons need a lot of running in for best performance as well
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Spule 4 · Posted: Tue Feb 12, 2008 10:54 pm Post subject:

Thanks for the replies!

From my reading here (and a lot of other areas) I think I have a few things nailed down.

I am guessing that the O ring pistons are going to need more running in.

At least I am getting steam oil, a LOT of steam oil now through the beast. The previous deadleg lubricator was not as good for this.
_________________
Garrett