Elmers Beam Engine No.24

[Wannabe2]

Hi,
I'm a newbie and have been lurking around in here for a while. I find the information very relevant and helpful in here.

I'm in the process of having a go at building Elmers Beam Engine No.24 and have a question about the cylinder ports. I suppose this relates to all cylinder construction.

In Elmers plan it calls for two #60 inlet/outlet steam ports and a couple of other holes which go through the steam chest and some also through into the cylinder. The #60 holes are then plugged on the outside edge of the steam chest.
In a cylinder construction should these holes be done before or after boring the cylinder and steam chest? I can see positives for each way. Doing it before is likely to cause the drill to wander. Doing it after it's likely to burr the bores, break drills and the posibility of solder weeping into the steam chest bore.

 

[hitandmissman]

I would do the holes first and than bore the cyclinder. Before filling the holes, I would use a aluminum tube in the valve chest(solder won't stick to it very good, than pull it out and finish the chest). I am going to build this one myself.

 

[rake60]

Welcome to HMEM Wannabe2

When I built that engine I did drill and ream the cylinder bore before drilling the .040"
cross holes. It did indeed raise a burr in both the cylinder bore and valve bore.
Soldering the outside of those ports shut did also result in high spots of solder in
the valve bore in my cylinder.

Turning the respective reamers into the bores gently by hand removed both the
solder weep and burrs.

If you drill the port holes first, they will most likely close up when the cylinder and
valve hole are machined. To open them back up you'd need to run the #60 bit back
through. That will raise a burr in the cylinder that will have to be removed.

Kind of a Catch 22 thing I suppose.
Either way, deburring the bores is a requirement.

Rick

 

[Wannabe2]

Thanks Guys. I decided to go with boring the cylinder and valve first. As rake60 said 'you are going to have to debur either way' and I was worried about drill wander if the ports were done first.
I like hitandmissman's idea of plugging the valve bore with aluminium before soldering and will go that way when I get to there.
Hitandmissman: I unintentionally started this engine after I built a small adapter plate for the rotary table loosely based on an article Harold Hall had in a copy of Model Engineer Workshop recently. I wanted to try the new adapter plate out on something and decided to try making the flywheel. Took ages to do but looked so good after it was finished that I had to do something with it so started into the rest of the engine. A lot of very small parts in there to make.
Have a look at Marv's flywheel program. I found out about it after I did the flywheel the hard way.