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[xrad]

Hello All,
while 1/24 tug is on hold, I am building a live steam 1/24ish puffer. Orion mouldings 36" puffer hull. VERY NICE with all rivet detail. got mine in dark red gel coat. Bought a twin steam engine off ebay. Got a laser cutter. 5.5watt...cut well for a few days...seems not so good now. but , might be my svg files.
waiting on vertical boiler too. want this to be close to original style.


edit: fixed the laser cutter...focus was out of alignment

[rhavrane]

Bonjour,If your steam machine is the M29, good choice, it runs quite well even at low pressure, I have one  https://youtu.be/TO16806-3pM

[ooyah/2]

Hi X-Rad


Some years ago I scratch built a Clyde puffer at 1ft to the inch giving a 33"long puffer.
These boats were built normally to 66ft long to fit into the locks of The Forth &Clyde Canal.
You may have some trouble fitting the engine and a vertical boiler, so here are all of the picks that I have of Skylight which may be of some use to you .
 I look forward to your build


George

[Geoff]

What was the actual engine you purchased as it looks quite nice and I may be interested in getting one.


Thanks


Geoff

[rhavrane]

Bonjour,

Funny George, I have the twin of your puffer : https://youtu.be/X8Km9Zgmw98                                                                                  Geoff, I would kindly suggest you to have a glance to this site if you didn't know it yet  http://www.microcosm-engine.com/ as I imagine I have recognized the M29 steam machine.

[1967Brutus]

Looks like an M29 to me as well...

Strong advise: install as a minimum wick feed lubricators on the crossheads, and if possible on the excenters.

If you don't, expect high piston wear.

What happens is: the M29 by design has fairly loose fitting piston/cylinder clearance, and no piston rings (it relies on a labyrinth seal of sorts), and a not 100% sealing throttle valve. This is done intentionally, so the engine remains on temperature better even when stopped, as there is a continuous puff of steam flowing through the engine.
These loose fitting pistons, in combination with crossheads and stuffing box basically ensure that the pistons do not really touch the cylinder walls, and if they do, they just slide along without any contact pressure.

Now the crossheads as well as the guides (like pistons and cylinders) are made out of brass, and especially with an enclosed installation, it is near impossible to keep the crossheads adequately lubricated manually: they do not need much oil, but they absolutely need a constant supply of it, because brass is not the most wear resistant material. So without a constant feed, you need to bring the boat back in every 10minutes at the latest.
Lack of lubrication here over time this will result in lateral wear of the crossheads.
The stuffing box of the pistonrod consists of an O-ring for seal, and this stuffing box will function as a fulcrum point of sorts. If the crossheads wear and get an increasing clearance, the pistons will start slapping around in the cylinders, rubbing against the cylinder walls, resulting in oval pistons and oval cylinder bores.

And when you're at it, the extra effort to also hook up the crank bearings and excenters to a wick feed is negligable. Your engine will thank you for it.

All I can say is that it has served my M29 very well, allready 56 running hours and zero detectable wear or deterioration of performance.
It also is WAY less fuss operating the engine, as 5 ml of oil will keep the engine lubricated all day long, literally all day long.
When I still manually lubricated mine, I used that much during a 20 minute bench run.