Quad Rocker

[Foozer]

Someone queried a while ago as to a Double Rocker, so why not a Quad

Getting time to build something, so to aid in my trip to the nut house a Quad Rocker seems just the ticket for the ride. Havent a clue if the idea will even work but what the heck . . . Its a work in progress, making it up as I go along


The idea is roughly as shown, simple rotary Rocker type action.

Found a piece of stock and carved out the main body. Drilling what will be the cylinders sorta taxed my brain cell till I came up with this contraption. Only have this ol AA109 so may look a tad odd.

Once the body was centered up on the little RT the side was found using a 0.250 edge finder. Cranked it over 1/2 the dia. of the body which just happened to be the spot for the cyl centerline as its to be 0.125 off center. Used a spot drill to mark the hole then drilled it up a tad under the final size of 0.375. Used a short 0.375 reamer to bring the bore to size. This done 4 times at 90 degree intervals.


Time to work up a crankshaft and what will be the conecting rod pieces. I dont know how you all center things up, guessing the equiptment is better as I went round and round getting that piece of brass centered. Finally came to the point of tapping was moving it more than needed so resorted to just shimming one side a bit to get to a total runout of +\- 0.003. Best I could do.

Drilled the little holes that will be the crank pins. Why? What the heck its fun even if I'm clueless.

Shall see what tomorrow brings

Robert

 

[Deanofid]

Hiya, Robert;
Glad to see you making some chips!

Your Quad Rocker is an interesting concept. Not likely that you'll see one in every shop, at least, until you show us how it's done. It ought to be fun to watch run, and I'll bet it makes a neat sound, too.

You sure have found some unique ways to address your work holding situation with the R/T.
For centering one of those things quickly, I usually put a stud in the center of the R/T and locate it in the spindle bore using the table feeds, and bolt it down. Then lock the feed screws and locate the work piece using a dead center or pointed stylus in the spindle, but it has to have a center spot or a central hole for that to work. Then tighten it down on the R/T and check again.

With the chuck on the R/T, though, you should be able to get centered up just by centering the R/T with the feed screws, then screw on the chuck and be done.

Dean

 

[cfellows]

I wondered when somebody would do one of these. I bet it'll be a screamer!

Chuck

 

[Foozer]

Little more done on this Quad.

Made the crankpins out of what i had. Trying to avoid soldering so figured some tap and die work was in order. Smallest set i have is 2-56 varity, it'll work, maybe. Idea is the pins thread into the disk with just a squeak of locktite. As the 2-56 size is a tad bigger than the pin size I figured for the con rod I fabed em out of stock, threaded the end, then turned the shank down to the 0.060 size for the pistons to slip over. One of the pistons will have to be just touch soldered to make it the master.

Kinda stuck some pieces together to see what the heck I'm doing and what needs to be done for clearance. Still havent figured out how to apply the air, something to sleep on.

Posted by: Deanofid
With the chuck on the R/T, though, you should be able to get centered up just by centering the R/T with the feed screws, then screw on the chuck and be done.

The RT is one of those 3 inch HF jobs. Have a threaded stub that I attach to the RT for the chuck to spin on. Its getting that stub centered that gave me fits, if I can get it to withing 3-4 thousands I'm happy

Posted by: cfellows
I bet it'll be a screamer!

That noise is me, Pieces to small for my fat fingers. Looks good on paper but in real life,

There coming to take me away Ha Ha

Robert

 

[SBWHART]

Interesting Idea there Foozer

I guess you'll have to feed the air in from the centre by pressurizing the crank case.

Looking forward to watching progress.

Good luck

Stew

 

[Blogwitch]

I love builds where people are 'winging' it. All the little trials and tribulations laid bare.

There should be no trouble with 'feeding' it. It isn't ported or timed, so a little manifold with four pressure lines out, one to each head.

Blogs

 

[zeeprogrammer]

Nifty Robert. Glad to see you cutting.

 

[gbritnell]

Robert, now that is one unique setup!! The ingenuity on this site never fails to amaze me.
gbritnell

 

[SAM in LA]

Robert,

Looks like an interesting build.

Is the piston a narrow disk?

How do you maintain a tight clearance between the cylinder and piston?

SAM

 

[arnoldb]

Glad to see you making chips again Robert, and on a unique engine as well!

It'll be an air-hog for sure ;D

Regards, Arnold

 

[Foozer]

So did some piston work today. Simple enough, make little pieces from big pieces. Disk dia is 0.380 a tad over the 0.375 bore dia. The final task of rounding over the disk edge should get em down to size. Con rod is 0.125 in dia and for this needs a 0.062 hole drilled thru. Not a lot of room for error so to help me out I stuck a piece of AL stock into my little post mounted V-Block drill jig and drilled a 0.125 hole length wise. Rotated the jig 90 degrees and drilled a 0.062 hole 0.480 from the faced off end. If all is right I should have a drill jig that will locate the crank pin hole where I want it and centered in the con rod.

Took the clamp off for shot and one of these days Ill learn how to use the camera Just an op of sticking the piece into the hole butted up against the face and drilling the hole. The jig holds the bit in place to drill the hole clean thru the com rod

Holes in place and crank end slightly rounded over for clearance.

Posted by: SAM in LA

Is the piston a narrow disk?

How do you maintain a tight clearance between the cylinder and piston?

Yup piston is will be a disk about 0.020 thick slightly rounded over on the edge. Not exactly a tight clearance, concept is an air hog.


So far only 2 pieces made for the Wall Hanging of Educational Experience. Tomorrows another day filled with opportunity. Finish turning the pistons down to size, assemble and see if the pieces clear each other.

Will it actually run? Should know soon enough

Robert

 

[kustomkb]

Great idea!

cant wait to see the results.

 

[Deanofid]

You're moving along at a pretty good pace, Robert. It's going to be so neat!

Dean

 

[Foozer]

You're moving along at a pretty good pace, Robert. It's going to be so neat!

Dean

Still undecided as to how the air flow will go. Fix the crank steady, feed the air into the center and have the housing turn or fix the housing and have the crank turn. Dont think there is enough OOMPH for the center feed method. Crank rides in ball bearings so, guess only way to find out is the wait and see.

Itty Bitty pieces, what was I thinking But will be a cool little gizmatron

Robert

 

[Foozer]

All the Itty Bitty pieces done. Somehow I spaced it and had the bearings on one side, that not gonna work. Bit of rework and the crank bearings are as they should be, one each side of the internal rib.

Check out assembly looking for any tight spots, so far so good, it turns free enough. Next up, fab an outer ring to address the air feed and fab up a flywheel.

One thing I found out quick enough, turning small pieces, the tool bit has to be dead on center. If it actually runs Ill be doing the "Look what i can Do" dance

Robert

 

[zeeprogrammer]

Ill be doing the "Look what i can Do" dance

And we'll be watching.

You're not kidding about Itty Bitty!

 

[Foozer]

One each "Quad Rocker"

Not much to look at, but she do run , Incorporated the Blogwitch idea of an air manifold within the unit itself. Cut a 1/8 X 1/8 slot around the circumference joining the tops of the four cylinders. Shrunk fit an outer ring to seal it all up and ran the air inlet up thru the base to intersect the slot.

Didnt know if it would even work but da photo tells the tale. Not exactely a screamer, but spins at a good clip.

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Happy Dance Time

 

[Deanofid]

Looks like it gits with it to me, Robert. Really neat!
Congratulations, on the concept and the successful build. Record time, too,
from first idea to running engine.

Well done!

Dean

 

[arnoldb]

The "Weeee!" in the video says it all Robert ;D - Great job !

Regards, Arnold

 

[Blogwitch]

Wonderful work, your concept proven. :bow:

Now pat yourself on the back, sit back in your chair and allow that grin to grow.

Getting something running that came out of your own mind is a feeling to be cherished.


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