help for newbie with Mark 6 engine

[oregonsteam]

I finished the Mark 6 steam engine, and it will run well with my air compressor at 20 psi. When I try it with the boiler, it will run for a few seconds, then stop. The boiler seems to spit out a lot of water as well. I tested the boiler underwater and did not detect any leaks. Anyone have any advice?

Thanks

 

[rangerssteamtoys]

Are you over filling the boiler? Is the engine nice and warm when you try to run it on steam. Sometimes the boilers will prime and spit out steam and water mix, causing the engine to be filled up with water. So with some more pressure and spinning the flywheel by hand while under steam it *should* run. If you have done all of these things, then ???

 

[Bogstandard]

Hi Oregonsteam, welcome to HMEMs.

Without seeing what a Mk6 engine or boiler looks like, it is difficult to suggest a remedy.

For a general rule, until the engine gets to working temperature, you will get a lot of condensate being produced in the engine itself, maybe suggesting to you it is the boiler at fault, not so, it may take a few minutes for the engine to come up to temperature. Does the steam come off a steam collector dome on top of the boiler, or is it straight out of the top of the boiler? Are the pipes between the boiler and engine lagged with insulation? The steam might be turning back to water because the pipes are staying cool.

All these things can cause the symptoms you are experiencing. Just a little more information from yourself will help to diagnose it a lot easier.

I hope this has helped a little

John

 

[oregonsteam]

I hope this picture helps. The boiler is on a stand being heated by sterno fuel. The instructins say to put in 3 1/2 ounced of water, which fills the boiler fairly full. What comes out for the first few minutes is mostle water, it basically floods the entire stand. Thanks for any advice.

 

[kvom]

Engine image is here:

http://www.amazon.com/gp/product/images/B0006N6OQA/sr=8-1/qid=1217427661/ref=dp_image_0?

The forum software won't display is as IMG tag

 

[tmuir]

Ah the Midwest Model VI

This boiler is soft soldered.
Once you built the boiler did you wash it out to clean the flux out?
If not the flux can make the water froth up inside the boiler causing priming (splashes out hot water instead of steam).

Something else to try is put a bit less water in the boiler, you may simply be filling up the boiler too much.

Not too much that can go wrong with the boiler really, I'm guessing you have either too much water in the boiler, flux still inside the boiler or the steam pipe going down too far inside the boiler.

Hope that helps.
Tony

 

[rangerssteamtoys]

You got me confused with the "Mark 6"

I have the midwest model VI and it runs great for me, I used the original boiler at one point but it just didnt look big enough. So I upgraded to a jensen 60 boiler, it has a sight glass which is very useful.

The engine runs great on air? Right, so the problem is with the boiler.

Try all of the things suggested on this topic, I'm leaning toward the flux in the boiler though.

 

[tel]

I agree with the others, try putting less water in. The other thing to look at is the screw/spring that the cylinder oscillates on - try backing the screw off 1/8 to 1/4 turn and see if that makes a difference.

 

[oregonsteam]

Thanks for all the great advice. I cleaned the boiler, but also removed it from the insulation and brass jacket. I clamped it to a ring stand over the can of sterno. In no time at all I had good pressure and the motor was running great! I think there might not be enough air holes in the brass jacket to let the fire get hot enough. Anyone else have the midwest model 6 with similar results? This is my second model, I have the "Little Kathy" kit from Tiny Power. I felt like it was a little over my head, so I went for the model 6. I made aluminum castings of all the parts of the "Little Kathy" so if I make a mistake I will have copies. Has anyone built the "Little Kathy" engine? I am new to steam engines, but not to modelling. I used to fly model helicopters, but I want to build something from scratch. I have a tiny foundry, capable of melting 5 or 6 pounds of aluminum at a time, and a small metal lathe from Harbor Freight. I really would like to have a milling machine someday. Does anyone have a suggestion for a do it yourself motor I can make to increase my skills before I build the "Little Kathy" (It is a piston and valve motor, not a wobbler) Thanks again for all your advice and suggestions.

 

[Tin Falcon]

Here are probably two of the best links on the web for plan downloads ,enjoy browsing


http://npmccabe.tripod.com/steam.htm

http://www.john-tom.com/html/SteamPlans.html
Tin