Has anybody built the steam engine kit : (40701) Liegende 12/36 ?

[Brian JohnParticipant @brianjohn93961]

No, I have not tried that. The other engines I have do not need it so it never occurred to me.

How hot is ''preheating'' the cylinder and how does this help ?

[MichaelRParticipant @michaelr]

Brian.

Have you given any thought to preheating the steam before it gets to your engine, you could loop your steam pipe around the boiler where it would get the heat from the boiler shell and the burner which would help to dry the steam out, also keep the steam feed pipe run as short as practicable between engine and boiler, this should help reduce the condensation

Mike.

[Brian JohnParticipant @brianjohn93961]

I still want to try to make a piston valve and a main piston when I get my lathe running well enough. From what should I make the piston rods : 2mm silver steel or stainless steel (grade 304) ? I have to cut a 2mm thread on each end of the rods. I thought stainless steel might be better but it could prove difficult cutting a thread with die.

I am thinking about your advice to preheat the steam.

Edited By Brian John on 13/09/2015 16:34:03

Edited By Brian John on 13/09/2015 16:38:40

[JasonBModerator @jasonb]

Stainless, silver steel will rust too easily. Also easier to thread stainless than silver steel

[Brian JohnParticipant @brianjohn93961]

Thank you. What is silver steel mainly used for then ?

[David Clark 13Participant @davidclark13]

Silver steel is used mainly for tools and components that require heat treating or just need to be tougher than mild steel.

[Keith LongParticipant @keithlong89920]

Brian – use 303 grade stainless NOT 304. 303 is a much freer cutting grade,

[Brian JohnParticipant @brianjohn93961]

Keith : my supplier here in Australia only has 304 grade. There is a note on the website to call first as the smaller sizes are proving difficult to get. My other main supplier does not have any 2mm stainless steel at all so I have take what I can get. There are lots of 2mm stainless steel rods available from Hong Kong and China but they do not list the grade.

[norman valentineParticipant @normanvalentine78682]

I recently dismantled a photo copier, all of the shafts were stainless steel. I have no idea what grade it was but it was so easy to machine. A lot of the shafts were rubber coated but that was easy to remove with a sharp knife.

[Brian JohnParticipant @brianjohn93961]

None of my suppliers has stainless steel rod that small. Apparently the 2mm rod was reclassified as wire a few years ago and this has caused problems for some reason. I will have to buy stainless steel from Hong Kong. One of my suppliers said that he now uses 2mm brass rod for piston rods with no problems so I will consider that too. Any thoughts on that ?

NEW STEAM TESTING : I have been running this engine on air for an hour per day for the last month. I suspect that this may have worn that Teflon seal down a bit so I tried to run it under steam today. The results were better but not outstanding. It did run at first but quickly ran out of puff. This happened with the MIDWEST wobbler engine so I then placed a piece of 1/8 tube inside the 3/16 steam outlet to restrict it. It worked with the Midwest engine but not with this one. I then installed a globe valve (not in the picture) in the steam line and opened it just a crack but with the same result. The engine runs for about one minute and then runs out of puff. I think I will need a stronger boiler to get this engine going for any length of time.

Quite strange as the PMR twin cylinder and single cylinder engines runs very fast for about 20 minutes with this boiler. But at least the Liegende engine was running on steam today so some progress has been made. I think I will still have to make proper pistons for the valve and main cylinder. I will also have to find some way to increase the heat to this boiler….gas perhaps ?

NOTE : the chimney came off the firebox towards the end of testing. I had used 243 degree soft solder so I was quite surprised. I did not expect that to melt. I will have to silver/hard solder it tomorrow but this could be tricky as the front plate of the firebox is only 0.6mm thick and could easily melt. A copper front plate may be required.

Edited By Brian John on 14/09/2015 08:03:14

Edited By Brian John on 14/09/2015 08:05:35

[Brian JohnParticipant @brianjohn93961]

Rather than cutting a new valve piston and new main piston from scratch, might it be easier to remove the Teflon wrapping and fit a brass or aluminium sleeve around them. The sleeves could be fixed in place around the existing pistons with Loctite.

 

Edited By Brian John on 18/10/2015 08:58:08

[Ian S CParticipant @iansc]

For stainless rod, how about welding wire, or even bronze brazing rod.

Ian S C

[Neil WyattModerator @neilwyatt]

Try plugging the chimney hole. That way the hot air will travel up and around the boiler and I bet you will get more puff.

The molten solder proves how much heat is being wasted up the chimney.

Neil

[Brian JohnParticipant @brianjohn93961]

Ian : I managed to get plenty of stainless steel rod from Hobby Mechanics. I cleaned him out of all he had left ; He will not be getting more. Some of it is bent but most of it is useable. There is plenty available on ebay as it is used for model helicopters.

Neil : yes, good point but the Teflon has to be replaced eventually. It is only designed to last about 200 hours. I suspect it is already starting to wear.

It will be a shame to do without my chimney

Edited By Brian John on 18/10/2015 11:54:49

[Neil WyattModerator @neilwyatt]

Posted by Brian John on 18/10/2015 11:54:15:

It will be a shame to do without my chimney

Don't get rid of it, just plug it, and if I am wrong you can take the plug back out. Give it a try before changing the pistons, 200 hours is a hell of a long time to run a small engine, four years at two half-hour runs every week.

Neil

[Brian JohnParticipant @brianjohn93961]

I have been running it on air for 30 minutes per day ever since I built it. It needed running in. There was some stiffness concerning the eccentrics which seems to have gone now.

[Ian S CParticipant @iansc]

I used graphite impregnated Teflon for the bush through the piston of my second hot air engine, a BETA type, after 1000 hours of running I stripped it, and overhauled it. I had to ream out the Teflon bush, as it had got some oil on it and it swelled, It has done a hundred or so hours since overhaul, still no wear. It has a 1/4" stainless rod running through it, and generally runs at 600 to 1000 rpm.

You may have trouble with hard soldering the chimney after it having been soft soldered, my little engine has it's chimney held on with a couple of 1/8" Whitworth bolts.

Ian S C

[Brian JohnParticipant @brianjohn93961]

I rebuilt the whole section that was previously soft soldered as I could not save it…too messy trying to clean it all up. I hard soldered a new L piece to a copper plate which was then bolted on to the brass plate. All good now even if a bit pointless

The Teflon that is on the main piston is a type of flexible cloth. The Teflon on the valve piston is firmer….more of a solid sleeve.

I will try this engine with one of my vertical boilers. The firebox is hard soldered to the base of the boiler so no heat is lost there. It may produce more steam than the horizontal boiler.

Edited By Brian John on 19/10/2015 14:14:05

Edited By Brian John on 19/10/2015 14:15:45

[Brian JohnParticipant @brianjohn93961]

Some success today steaming this engine. I plugged the chimney as advised and the engine ran well for over an hour before it started to jam up. I suspect that eventually some water formed in the cylinder. It even ran badly on air for about 15 minutes before it settled down. I always run the engines on air after steaming.

I will have to get back to building the triple meths burner as originally planned. This engine runs better with lots of steam ; the double burners are not quite enough.

Edited By Brian John on 26/10/2015 06:25:01

[Brian JohnParticipant @brianjohn93961]

Today I have tested the new triple burner and another double burner ; it ran well but not much better than the double burner. I was expecting a big improvement but did not get the result I wanted. I may need a gas ceramic burner for this engine. There is still a lot of water going through to the engine but it is not causing the problems that it used to. I am yet to try running the steam pipe through the firebox.

Edited By Brian John on 09/11/2015 05:56:34

[Ian S CParticipant @iansc]

If you look in your burner thread, I put a bit there about how I use camp stove burners in some of my hot air engines.

Ian S C

[Brian JohnParticipant @brianjohn93961]

I ran this engine for over an hour today using the double flame burner. It ran well without any problems. Have you ever had an engine ''come good'' all by itself ?

[Ian S CParticipant @iansc]

Yes Brian, most of my hot air engines improve after an hour or two, some quite a bit.

Ian S C

[Brian JohnParticipant @brianjohn93961]

I made a brass adaptor today (5mm fine scale to 3/16-40) so that I could fit a displacement lubricator. Because the pistons on this engine are wrapped in Teflon I was not expecting much of an improvement but I was very wrong…there is a dramatic improvement. It requires much less steam to get it going and the engine changes direction easily with the reversing lever. I do not even need the larger double burner I made especially for this engine. It will now run using my standard size burners. I was thinking of fitting a ceramic burner to this boiler but that will now not be necessary.

**LINK**

How far should a displacement lubricator be opened ie. how many turns of the dial ?

Edited By Brian John on 18/04/2016 09:03:39

[Brian JohnParticipant @brianjohn93961]

Is this the smallest drain cock available ? Does anybody know of anything smaller ?

**LINK**

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