Scott Vacuum Engine rebuilt

[deverett]

Some time ago I built a Scott vacuum engine from Polly Models castings. I put car antifreeze in the hopper thinking it would prevent corrosion of the cast iron cylinder in the gunmetal hopper. How wrong I was. See my tale of woe in http://www.homemodelenginemachinist.com/index.php?topic=18246.0

I stripped the engine down, cleaned everything and re-assembled it. Here are a couple of pics of how it looks now. Even the poor in sight will notice I haven't changed the springs. They will be replaced in due course.




I've had it running and thought I'd got the video on camera, but video has vanished into cyber space. Better try again.

I have also finished making my version of the Root square piston engine based on Ernie Weinberg's drawings. This was another part built project some years ago, but there were many machining errors and it went into a dark corner. Recently in my effort to clear up part done projects, it was resurrected and finished off but it refuses to run and I have spent far too long trying to find the cause, so it has gone on the shelf until I get more enthusiasm. I suspect I will have to remake the valve cover.

Dave
The Emerald Isle

 

[Blogwitch]

Dave,

Very nice rescue and clean up. Who would have thought anti freeze would have done so much damage.

Later in the year I will be posting about my build and finishing it off, and looking at yours has made me come to a decision, I will be leaving my water hopper as bare metal. Nothing against yours at all, but I don't like too much paint at all.

Hope to see yours running sooner rather than later.


John

 

[deverett]

John

I look forward to seeing your version up and running. With the work you put into the hopper, I'm not surprised you will leave it polished. In my case, after a bit of machining on the hopper, I decided to add body filler to the hollows and equalise the side slope angles and get the ends vertical. Hence the paint - it hides a multitude of errors!

One thing I have noticed is that it doesn't run as easily or well as before the strip down. there must be something very slightly out of alignment compared to its previous set up, although it does spin freely enough.

Dave
The Emerald Isle

 

[Blogwitch]

It isn't just for the looks Dave, I am worried about the paint not being able to withstand the heat.
I will be using Japlac, a sort of deepish blue, bought specially for the looks I want to give my engine, and I don't think it will take a coat of heat resistant laquer over the top. The heat resisting laquer I have is a heavy spirit based type, similar to cellulose, and I think it will bubble the low spirit Japlac. I suppose the only way would be to try it out on a sample plate.

That's the problem with these low output engines, even a slight shift can knock their speed for six. That's why I always try to build in a bit of hidden adjustment here and there, even a few thou is usually enough.

Maybe another stripdown and reassemble will cure yours.


John