please help fab slide valve(no machine tools)

[DaveHughes]

Hey folks:

Anyone have ideas on building a simple slide valve, I have no machine tools as of yet. I do have files, hand saw, vice, stick and tig welding gear and oxy actelynene equipment.
Thanks
Dave

[Al_Messer]

Do you mean the valve itself, or a simple slide valve design of an entire engine?

[DaveHughes]

Hi Al:

I need some help on fabing up a slide valve (only) with only the tools mentioned.
Coincedently I received some info on a compressor engine conversion some time ago that you built. I happen to be bulding such an engine for a boat.
Anywho that's the long and short of it. Any help would be appreciated.
Thanks
Dave

[UnkaJesse]

Dave,
About that valve, do you mean the seat on the cylinder AND the "D" valve or just the D valve? Also, how large is this valve?? If it is small, you might hack saw out the parts from brass and then file them so they fit together like a 3-D jigsaw puzzle and then silver solder everything at one time while it is clamped together.

Unka Jesse

[DaveHughes]

Unka J:

Just the valve Jess. It will be used for a double single acting engine with bores of 2.25 and a stroke of 2 inches.
Thanks
Dave

[Allen_from_CHT]

an awful lot can be done from billet with a coping saw, a hand grinder, a drill, and hand files to finish.

There are reprints available (through lindsay and others) of model engineering books from the 30's where they start off saying "You don't need to buy all this fancy expensive machine stuff."

It just takes a LOT longer.

[UnkaJesse]

Dave, Send me a sketch of the valve off board to fernj1@earthlink.com and maybe I can give you some pointers. I still suspect that the best way is to saw and file out a bunch of brass parts and using a good high silver content (not Silfos) silver solder, just sweat it all together. You can fabricate most any thing about a model steam engine that way and it works as well on larger stuff.

Unka Jesse

[Al_Messer]

Get a copy of "High Speed MarineSteam Engine" by A. A. Rayman. He described filing and drilling and chiseling out a "D" valve. Use a good grade of cast iron and make sure your cold chisels are SHARP. Drill a row oof holes around the perimeter inside a scribed line for the cavity, carefully chisel out cavity to the line,then dress surface by rubbing on very fine emery cloth laid of a true flat surface. When this is done, carve out the top side of the valve with various files, round and half-round,to provide a place for the valve nut to ride and you will be almost ready to run.

[DaveHughes]

I was wondering if it was possable to use cardon steel for construction? Or is steel a poor performer for this application?
Thanks
Dave

[Allen_from_CHT]

Will it work? Yes. Has it been done? Yes. Is it "recommended practice"? No.

Residual moisture and lubrication is a bit more of an issue with mild steel, but if it is what you HAVE, and you don't have cast iron (or bronze) then, yes, it can be done

[pattiandruss]

Works well to just hacksaw and file a piece of brass. A Dremmel tool with a small burr does a fine job of hollowing out the cavity. I have made several of these and after you put the steam chest cover on, you can't see it anyhow. Russell

[Bob_Starr]

I really don't see that making a slide valve would be too hard using a minimum of tools. Essentially a rectangular shape that is internal so your boo boos are not seen! Much of the top side could be done with a 4" grinder and as Al mentioned a series of holes for the cavity would outline that area. I think, tho, that I would opt for a small grinder either in a dremel or even a drill motor to finish it off. Something that I did not see mentioned in this thread is in the final finish. You will need to put it on a piece of glass and sand it very flat and very smooth. It is best to use dissimalar metals in these applications.