British 0-4-0 Toy Locomotive: he said

[Artie]

Hay Carl, not Hey You Carl......

I have NO experience here just running this though the grey matter... so take these musings with a grain(bucket) of salt... the air can supply PRESSURE and VOLUME.... one doesnt always equate to the other... is the safety valve now exhausting steam?

Pressure will make the wheels try to move but in doing so if this reduces the pressure significantly (as in lack of volume - low temp on boiler AND low capacity in boiler) they wont go any further. Further if the system is trying to supply low volumes, then leaks could stop any 'get up n go'. The point is these problems wont exist with air, as even at low pressures it can supply large volumes.

It may come back to getting rid of those leaks and getting more pressure up...(more heat as the guys are suggesting). I would have thought that the pressure relief valve should be blowing off merrily with the wheels stalled.... as per the real thing sitting at stations....

then again I could be entirely wrong... that would be no 'first'.... good luck mate....

 

[Maryak]

Zee,

With the boiler 2/3 full of water and the safety in place when the pistons go down operated from the wheels they are trying to pull a vacuum in the boiler and with this small air space you may be feeling the resistance of the "SUCK"

Best Regards
Bob

 

[zeeprogrammer]

Thanks Jim, Rob, and Bob.

I don't see any 'steam' leaks. But after a while I get water coming out of the port blocks and/or pistons. So I'm thinking two issues...one is not enough heat and two is that the cylinders are too leaky. But if the cylinders are too too leaky then I'm thinking it wouldn't have run as well as it did on 5 psi air. What water I'm seeing may be condensation.

Sounds like everyone is saying there's not enough heat. In support of this theory, shortly after I lit the wicks, my little butane pencil torch ran out of fuel. ;D Thus punishing me for my prior (recurrent) sins.

Thanks!

 

[Deanofid]

Zee, I don't know how many times you tried spinning the wheels, but here's something else to ponder;

Remember when we said the water from the boiler will condense in the cylinders? That will go on for some time before the cylinders get warm enough to start working on steam.

On some of my engines, when running on steam, I'll have to spin the flywheel many times to pump out
all the condensate that has formed in the cylinder. You just have to keep doing that until the cylinder(s)
get hot. If you are expecting it to start going after a couple of turns of the wheels, or a few pushes
along the track, it's probably not going to happen. Lift the whole thing off the track, and spin the wheels a bunch of times (after you know you have steam!).

Again, boiler not too full. Again, use denatured. Again, hurry up! And take off that tutu.
They're flammable.

Dean

 

[zeeprogrammer]

Thanks Dean.

I did some spinning and even more rolling. Difference?

I'll be using denatured alcohol next time and my pencil butane torch is refilled.

No worries about the tu-tu. It's protected with 'Retard-All'. ;D

Unfortunately, the first can I used was 'Repell-All' and I had it pointing in the wrong direction.
Stuff doesn't seem to come off.

 

[joe d]

Hiya Zee

A thought...(I know it's dangerous ;D) maybe hit the cylinders BRIEFLY with your pencil torch to pre-heat them a bit? Be sure to stop short of un-soldering anything.....

Keep at it, you're pretty much there!

Cheers, Joe

 

[zeeprogrammer]

Thanks Joe. I was thinking the same.

I forgot to mention that prior to steaming, I ran it on air again. Got it down to 5 psi according to the pressure gauge and so long as I gave it a spin and started it before I sat it down, it tooled along the track. So I'm thinking it's a heat issue...unless I got some of the tu-tu's 'Retard-All' on it. :big:

 

[joe d]

Zeepster

I thought the flame retardant was you clutching a pink frilly fire extinguisher..... :big: :big:

 

[bearcar1]

Retard-all ............. Rof} Rof} Rof} Rof} Rof} Rof} Rof}



Just remember Zee', Saint Peter don't count the number of times... ;D

BC1
Jim

 

[kcmillin]

Zee, when using a torch to heat the boiler you should have no safety problem. as far as the boiler goes. Just watch out for the burners filled with flamable liquid though.

There is a simple explanation why your soldered joints will hold up.

Water boils at 212 degrees F give or take. Your soldered joints melt at nearly 1000 degrees F. The water will act as a heat sink and take away heat from the joint.

Have you ever tried to soft solder a wet copper pipe. It don't work.

To prove this there is a simple science experiment you can try.

Take a 20 oz plastic pop bottle and fill it up about 1/2 inch with water. LEAVE THE CAP OFF!!!!!!!!

Then carefully take your torch to the bottom of the bottle, making sure that you are only torching it where the water is.

What will happen is the water will boil, IN A PLASTIC CONTAINER!!

This works because the bottle melts at 400 degrees and the water will not allow it to get above 212.

This can be use in a survival situation when you need to sterlize water.

Kel


EDIT: This is assuming your saftey valve works of course.

 

[SAM in LA]

Zee, when using a torch to heat the boiler you should have no safety problem. as far as the boiler goes. Just watch out for the burners filled with flamable liquid though.

There is a simple explanation why your soldered joints will hold up.

Water boils at 212 degrees F give or take. Your soldered joints melt at nearly 1000 degrees F. The water will act as a heat sink and take away heat from the joint.

Have you ever tried to soft solder a wet copper pipe. It don't work.

To prove this there is a simple science experiment you can try.

Take a 20 oz plastic pop bottle and fill it up about 1/2 inch with water. LEAVE THE CAP OFF!!!!!!!!

Then carefully take your torch to the bottom of the bottle, making sure that you are only torching it where the water is.

What will happen is the water will boil, IN A PLASTIC CONTAINER!!

This works because the bottle melts at 400 degrees and the water will not allow it to get above 212.

This can be use in a survival situation when you need to sterlize water.

Kel


EDIT: This is assuming your saftey valve works of course.

A bit off topic, but this is something we do with new Boy Scouts.

I take a paper cup, fill it with water, put a raw egg in the cup and set it in the fire. The cup will only burn down to the water level and the egg will be boiled.

SAM

 

[mklotz]

The same thing is happening in your boiler. The metal in contact with the water can't get any hotter than the boiling temperature of the water. This temperature is strongly influenced by the pressure in the boiler. The higher the pressure, the higher the boiling temperature.

The Clausius-Clapeyron equation relates the pressure and temperature. If you want to use it, it's implemented in the STEAMT program on my site.

 

[bearcar1]

I wonder also, what the heat conductance of chrome plating is? Hmmmm.... ???

BC1
Jim

 

[shred]

If it'll run on 5 PSI air, the mechanism and fits should be ok. To me it acts like the burner isn't generating enough steam.

I would hit the bottom of the boiler with a propane torch instead of the burner as an experiment. If that does it, then all you need is more heat.

Btw, you will need to flip the wheels several times to get condensed and aspirated water out of the steam lines and cylinders, especially if you fill the boiler all the way up with water (2/3rds full is good).

Check for leaks when it's running on air by spraying soapy water around all the joints and bushings.

Of course if you rigged a pressure gauge, you'd know what pressure steam your burner was giving you...

 

[zeeprogrammer]

Thanks all.

Well, it's still a no go.

Denatured alcohol, preheated water, added a bit of butane pencil torch.
Easy to push...but just wouldn't spin...either on or off the track.

That 'Retard-All' is tough stuff.

I'm questioning the pressure gauge showing 5 psi and running on air. I'm thinking the cylinders/piston...or the interface between the cylinders and porting blocks. Not sure where to go from here...worse...I'm running out of time.

I'll probably (i.e. will) give it another go but at some point I'll have to set it aside...more projects are waiting (and not just machining).

poo :'(

 

[Kermit]

Water is a very heavy substance. Perhaps this is just a problem of insufficient horsepower. The pistons in your cylinders are quite small, and the considerable increase of weight when filled with water is probably just to much for such small pistons. It seems to run ok with air power, no?

Any chance you could make a little larger cylinder and pistons for the Loco? I think that would all you would need to get 'er steaming.




Kermit

 

[zeeprogrammer]

Thanks Kermit. If the pistons are too small, then the design is flawed and no doubt, other builders of this kit will be as disappointed as I. I may be willing to rebuild the cylinders to spec...but I won't build them to a different size/design when I don't know enough nor whether even that would work. If the design is flawed...then I'll take the success I have and go on to something else.

I ran it on air again and if the gauge is right, it's around 5 psi. Call it 6. Certainly, when I cover the air nozzle...there's not a whole lot.

But the 2nd attempt tonight at steam was still a failure. So I'm thinking something else is working against me.

One thing I noticed is that when running on air, or when I spin the wheels, they seem to turn pretty easily. But when I try to steam...it looks like they're binding.

I'm wondering if I still have an issue with the crank pins. I notice that I can pull the cylinders to an angle relative to the porting block. The springs on the pivot pins don't seem very strong. So I'm wondering if the steam is pushing the cylinders out to an angle and that's causing binding down at the crank pins. I'll take a look at that next time. Why not air? Maybe because it happens only at a certain psi?

If I start sounding like I'm grasping at straws...let me know.

Did I mention 'poo'?

 

[shred]

How loose are the springs holding the cylinders on? If you have to run them loose to get the thing to work, then the ports don't line up.

Running on steam will heat things up, which will change dimensions some, but usually towards the 'looser' fit. Slather the cylinders and pistons in oil too.

Have you ever popped the safety valve with steam? I still think you aren't making enough or it's leaking out as it's made. Anchor the loco down, disconnect the steam line to the cylinders and heat until it pops. This will scare the bejeebers out of you even if you have a pressure gauge rigged. If you don't, you should feel like a bomb disposal tech trying to see his way around an ammo dump by the light of a cigarette lighter.

Here's what it looked like for me (btw, several minutes of heating-time was edited out of the beginning of this video): http://www.homemodelenginemachinist.com/index.php?action=dlattach;topic=2049.0;attach=1603

Another thing to try-- I forget what design your safety is, but there ought to be a way for you to manually open it (grab the end of the stem with some pliers is what works on mine). Run a fire for a few minutes and then pull open the safety to see what comes out (wearing appropriate safety gear, of course). No hiss, no steam.

 

[zeeprogrammer]

Thanks shred.

That video was very interesting!

I have no adjustment on the pivot pin springs. You just tighten the pivot pins down until the end seats against the frame. Having said that...no one can accuse me of having perfectly concentric pivot pins that fit the perfectly concentric holds in the cylinders.

I can't manually open the safety valve. And I suspect it will never pop on the loco. Primarily because the cylinders will move out from the porting blocks and whatever leaks through the cylinders.

This weekend I'll take a closer look at the pivot pins and the connection to the crank pins. When I was trying to run tonight...I had the distinct feeling that it was fighting itself. And, whenever the wheels stopped (after I push the thing a bit), they stopped very suddenly...as if they suddenly bound.

 

[doubletop]

Zee

A whole heap of good advice and I know you'll do this because being in the intangible world of IT you do this every day. Stop, think analyze and be methodical. I know from my recent experience that I started chasing the next idea and had no record of how many variables I'd introduced by way of messing up a perfectly good setup. Make changes in a way that gives you a route back to where you started and take notes on the way.

It will reduce hours of frustration and you'll end up knowing what fixed it in the end.

Sucking eggs maybe...............

Pete