Rotary valve help

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Wagon173

Senior Member
Joined
Dec 4, 2012
Messages
129
Reaction score
32
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?
 
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
 
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.
 
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 :p
 
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.
 
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

steam launch.JPG
 
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.
IMGP0372_zpscf72fa49.jpg


The rod screwed into the locknut hole on the valve
IMGP0373_zps3922c64c.jpg


A piece of .250 drill rod machined at the end to fit tightly inside of the valve
IMGP0364_zps219da51d.jpg


The .375 drill rod soon to be my cutting tool
IMGP0366_zps570a30fc.jpg


Parting the drill rod to the with of my valves and to clear the top of the valve.
IMGP0367_zps5c400c4b.jpg

IMGP0368_zps07a63368.jpg

IMGP0369_zpsa596ee80.jpg


Ready to start putting some teeth in it.
IMGP0370_zps388a86ca.jpg


Roughed the teeth with a 1/8 endmill
IMGP0371_zps08838298.jpg


Finished the teeth with a cutoff disc and a dremel.
IMGP0374_zps8810ef43.jpg


Hardened the teeth
IMGP0375_zps3a396761.jpg


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.
IMGP0376_zpsb36ab312.jpg


Used a needle file to clean the burrs and voila, a rotary valve!
IMGP0377_zps250e3943.jpg


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!
 

Latest posts

Back
Top