Rotary valve help

[Wagon173]

Has anybody ever built a rotary valve without a rotary table? I'm going to finish the rest of the launch engine before I cut the grooves out of the rotary valve so that I can try to take the best approach I can for now. I'd rather not take a chance on a cheap rotary table as I have no experience with them and don't have the patience to park the project for a few weeks until I can afford a decent one. I was thinking about marking the degree points I need on my lathe chuck with a protractor then chucking the part, putting on my milling attachment and using a dremel with an arbor and saw. Anybody ever taken this approach? Anything I'm overlooking?

 

[te_gui]

Not exactly sure which engine you are building, but I have seen people cut the groove in the a parting tool and then use JB weld to block off the bits that affect the timing. Its a little crude, but might get you by until you get better equipment.

Brian

 

[Wagon173]

Nevermind. I looked at the saw blades and cutoff wheels I have for my dremel and none of them are thick enough. It needs to be .100. I think my plan now is to mount some round stock in the milling vice and turn a custom saw tool out of drill rod then harden it. I'll mount the tool in the mill and turn the valve on the axis of the round stock with a set of needle nose vice grips. For advertizing as a beginners first project, this kit seems to require an awful lot of special tools.

 

[Wagon173]

Te_gui, didn't see your post. I'll keep that in mind though if my new idea flops. JB is one that isn't in short supply in my shop

 

[Wagon173]

Oh, and I'm building the LMS Launch engine kit. It's the first of a series of three. I believe next is a horizontal and last is a locomotive.

 

[canadianhorsepower]

Oh, and I'm building the LMS Launch engine kit. It's the first of a series of three. I believe next is a horizontal and last is a locomotive.

HI I don't exactly understand your question according to this picture
can you show whitch one your trying to build

 

[WCPenney]

Not sure if this will help or not. The River Queen engine is very similar and has 11 pages of build notes including making the valve. I'm on my way out the door otherwise I'd find the relevant section.... http://www.john-tom.com/MyPlans/SteamPlans3/RiverQueenEngine/RiverQueenPlansInstruction.pdf

 

[Wagon173]

Canadianhorsepower, the valve I'm talking about is set between the pillow bearings with the hex screw in it. WCPenny, I appreciate the article. There was some decent info in there. It was a bit of a weird read as it seemed to jump sections everytime a column was over. They used a rotary table with indexing attachment and offered using a hacksaw and knife edge file as a substitute. I don't have the table and I'd rather use power tools lol. So here's my end result.
A piece of brass hex rod that I messed up earlier in the project used as leverage to pivot the valve.

The rod screwed into the locknut hole on the valve

A piece of .250 drill rod machined at the end to fit tightly inside of the valve

The .375 drill rod soon to be my cutting tool

Parting the drill rod to the with of my valves and to clear the top of the valve.

Ready to start putting some teeth in it.

Roughed the teeth with a 1/8 endmill

Finished the teeth with a cutoff disc and a dremel.

Hardened the teeth

Turned the valve by hand in the mill. In hind sight I should have drilled and tapped the pivot for a small bolt to provide downward force as it was a chore to keep it from jumping around, but whatever, it worked lol.

Used a needle file to clean the burrs and voila, a rotary valve!

I'm sure that most of y'all have ran into and tackled much more complex and difficult problems especially you guys that have been doing this for years. But for my second machine project, I'm quite impressed with and proud of myself Thanks for your help though!