# Gearless Mechanism--4 stroke i.c. engine



## Brian Rupnow (Sep 2, 2015)

I have long been fascinated with the old hit and miss engines that were 4 cycle engines, but used no gear to drive the cam shaft at half the speed of the crankshaft. I have studied on this, and they break down into two main types. The kind I can not reproduce on a manual mill is the type which had cam tracks cut into the face or periphery of a disc. Chuck Fellows did a really nice job of reproducing one of those last year. The other type, which I can reproduce on my manual machinery, is the "star wheel" type. I don't want to start another engine build right now. However, I will attempt to create one of the mechanisms, post drawings of how I made it, and build the mechanism and make a video of it operating. I might fall on my face here, but follow along if you are interested. The one I make will be sized to work on a model engine.


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## jimjam66 (Sep 2, 2015)

He's baaaaaack! Thm:


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## tornitore45 (Sep 2, 2015)

Brian, I cannot see a reason why the Chuck Fellow cam type could not be made with circular arcs on a rotary table.   Granted it may be a self scalp depilatory experience, but we are not afraid to take a machining challenge, are we?


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## Brian Rupnow (Sep 2, 2015)

tornitore45 said:


> Brian, I cannot see a reason why the Chuck Fellow cam type could not be made with circular arcs on a rotary table.   Granted it may be a self scalp depilatory experience, but we are not afraid to take a machining challenge, are we?


Tornitore--if you think it can be done on a manual machine, then go for it. I don't think I could.---Brian


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## Brian Rupnow (Sep 2, 2015)

Got to have something to mount the star wheel in----


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## Herbiev (Sep 2, 2015)

Always interested in your projects Brian.


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## Swifty (Sep 2, 2015)

I can see that you are keen to use the new mill on another project. I will follow along with great interest. 

Paul.


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## Brian Rupnow (Sep 3, 2015)

These mechanisms seem to do a lot better with a roller on the end which rides on the cam. I am assuming that this is because #1--it will be moving twice as many times in a complete cycle as a lifter which runs off a camshaft---and #2---it will be moving twice as fast, and #3--it has more mass than a standard "valve pushrod".


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## BronxFigs (Sep 4, 2015)

Hello there Brian-

So happy to see that you are undertaking the challenges of redesigning, revamping, and improving,  this type of   2:1  "GEARLESS" reduction mechanism. 

Hope you also will do some work regarding the inertia governor mechanism that controls the exhaust valve events.

Good luck with this interesting project, and thanks for sharing your thoughts, renderings, and insight.


Frank


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## Brian Rupnow (Sep 4, 2015)

At this point, I have to decide whether the engine cylinder will be horizontal or vertical. The gearless mechanism will work on either, but for illustration purpose, I will use vertical. I also needed to show the exhaust valve that will be acted on (the intake valve is atmospheric)----and what better to use than the valve body/carburetor that I so recently designed for the oscillating i.c. engine.
----Now, to get into the science of how this thing works. Immediately below the stem of the exhaust valve, you will see the 4 lobed brown "star wheel". This star wheel has 4 "lobes" that will contact the bottom of the exhaust valve and lift it, if the entire gearless mechanism is lifted on a cam. It also has 4 "relieved areas" between the "lobes"  (as shown) which will NOT contact the valve stem if the star wheel gets rotated 1/8 (22.5 degrees) before it gets lifted again!! So--Stay with me--the cam is attached to the crankshaft. That means that with every single revolution of the crankshaft, that gearless mechanism will lift up on the cam lobe and then return to the "down" position--(There will be a tension spring attached to the gearless mechanism to ensure that it does return to the "down" position and stay in contact with the cam. So---as long as we are able to rotate that star wheel 1/8 of a turn every time the mechanism goes up and down then the valve will only get lifted EVERY OTHER time the gearless mechanism is lifted.--That nifty looking green ratchet wheel with 8 notches on the same shaft as the star wheel is the component which ensures this will happen.


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## Brian Rupnow (Sep 4, 2015)

BronxFigs said:


> Hello there Brian-
> 
> So happy to see that you are undertaking the challenges of redesigning, revamping, and improving,  this type of   2:1  "GEARLESS" reduction mechanism.
> 
> ...


Frank--By "inertial governor" are you talking about the "centrifugal governor" as used on hit and miss engines?---if so, no, I am only covering the gearless mechanism in this thread. If you want to see a centrifugal governor controlling the exhaust valve events, then look at the build thread I just finished on the "oscillating i.c. engine".  It is a hit and miss with a centrifugal governor on it.---Brian


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## Brian Rupnow (Sep 4, 2015)

Toolguy raises a very good point.--What keeps the star wheel and ratchet wheel from drifting out of the proper rotational relationship to the valve stem. I have seen it done two ways, and know of a third. The third way which I know of, is a spring loaded detent ball and eight detents in either the star wheel or the ratchet wheel. This might work fine for something that only sees occasional use and slow moving components, but it wouldn't live with something like this application.  I have seen the following method used on a model---A piece of rubber or vinyl tubing is slipped over the axle  between the ratchet wheel and the blue "fork" supporting it, and is a bit longer than the actual space provided there. This acts as a friction brake to keep the star wheel from rotational drifting out of alignment. The third way, which is used by Philip Duclos on his gearless engine design, it to have a piece of spring wire laying tight against the flat face pf an 8 sided octagonal wheel which rotates with the star and ratchet wheel.  When the star wheel and ratchet wheel and octagonal wheel rotate, the spring wire is bent away from the flat it lays against and after the 22.5 degrees of rotation another flat face is presented and the spring wire snaps into place against the flat to keep it from drifting rotationally until the next cam action turns it again. I like the Philip Duclos method best, and will investigate it farther---The only thing I don't like about it is that it begins to get very "busy" around the star wheel. If anyone out there knows of a better/different way, please step forward and tell me about it.---Brian


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## Brian Rupnow (Sep 4, 2015)

I just found this video, which shows the action of the starwheel very clearly at 2:18 into the video.
[ame]https://www.youtube.com/watch?v=dneJKmdRbu8[/ame]


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## BronxFigs (Sep 5, 2015)

Hello Brian- and others....

Very interesting to see and read about this star-ratchet mechanism.  The video shows it all, including the spring loaded/adjustable, governing mechanism.  Maybe my references to "intirtal governor" was the wrong term to use for this set-up.

The Olds Vertical Gearless, I'm pretty sure, uses a a weighted, "inertial" (??)  governor that reciprocates, or "bobs" up and down, along with the star ratchet, which in turn, also  controls the latching mechanism, that allows the exhaust valve to be either be held open at higher speeds, or to close and open at lower engine speeds.  The governor, and spring combination,  can also be adjusted to kick in/latch-unlatch at different RPMs. 

Wish I was as good at giving explanations as you, and some of  the other engine builders, who post on this forum.  Also wish I could provide link ups with videos showing the Olds Vertical Gearless in action - along with its simple, easily machined, governing mechanism.

Can't wait for your next installment.  


Frank


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## Brian Rupnow (Sep 5, 2015)

The preceding video shows a couple of really top notch ideas that I have been wondering about. First, instead of a spring holding the gearless mechanism in contact with the cam, the large end of the rod which runs to the cam totally encircles the cam, similar to early steam engine valve rods. This means that no spring is needed. The revolving cam can now not only push the rod in it's upward travel. but also pull it back down again. Secondly, instead of some strange shaped cam, the cam is a perfect circle, simply offset by some calculated amount from the central axis of the crankshaft. And---(best of all) it has a true ratchet and pawl system to turn the ratchet wheel with a nice positive action, and then hold it by spring pressure to prevent rotational drift of the star wheel.


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## Brian Rupnow (Sep 5, 2015)

I have decided to use the Duclos method to keep the star and ratchet wheel from getting out of rotational position. I have machined an 8 sided shape onto the side of the ratchet wheel and used a piece of .030" diameter spring wire (in red) held in place by a washer (dark blue) and #4-40 shcs. (yellow). When the ratchet wheel is forced to rotate 45 degrees (by a mechanism not yet shown), the wire will spring away, then snap back into place against the next flat face. The light blue "fork" that supports the star and ratchet wheel has had a small "ear" added to one side to provide a place for the #4-40 shcs to thread into. It also has a very slight groove machined into it for the .030 wire to set in to keep it from moving.


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## Brian Rupnow (Sep 5, 2015)

To give some idea of scale, here are the parts we have been looking at with a "to scale" model of my hand.


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## Brian Rupnow (Sep 5, 2015)

I'm getting to the "hinky" part of this design now. Assume for a moment, that the gearless mechanism has not yet stopped moving down---The star wheel is clear of the bottom of the valve-stem so it can rotate, but it hasn't rotated yet. The spring loaded pivoting "pawl arm" is swung in by the spring pushing on the back of it and you can see that the bent end of it is going to catch the tip of the ratchet wheel below the centerline of the ratchet wheel. If my downward travel is calculated correctly, then when the gearless mechanism continues it's downward travel and is fully bottomed out, the ratchet wheel and consequently the star wheel is going to be rotated by an amount equal to 45 degrees of rotation. --When that happens, then the gearless mechanism will move upwards due to influence from the cam, and since it has rotated 45 degrees, one of the lobes on the star wheel is going to contact the stem of the valve and lift it.---Clear so far??


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## idahoan (Sep 5, 2015)

BronxFigs said:


> Hello Brian- and others....
> 
> Very interesting to see and read about this star-ratchet mechanism.  The video shows it all, including the spring loaded/adjustable, governing mechanism.  Maybe my references to "intirtal governor" was the wrong term to use for this set-up.
> 
> ...



Frank you were correct; what you are referring to is an inertia governor, or what us old engine guys commonly refer to as a pendulum governor.

Seems that it was used on some of the better quality engines of the day; like Deutz, Olds and lots of others.


Dave


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## Brian Rupnow (Sep 5, 2015)

Thank you Dave. I had not previously heard of an "inertial governor."---Brian


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## Brian Rupnow (Sep 6, 2015)

I have absolutely no intention of building an engine for this gearless mechanism to go on. That being said, it is such an interesting mechanical device that I'm sure someone will want to build an engine to try it on. BE WARNED---This is not for any kind of high speed engine. This type of device was used on either hit and miss engines or old stationary thumpers that sat all day running about 600 to 750 rpm. I am going to do a "quick and dirty" design of a 1" bore x 1.5" stroke engine to mount it on. This will purely be a "guide" for anybody who may decide to take the design and run with it, and to give me some frame of reference for placement of parts.---Brian


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## BronxFigs (Sep 6, 2015)

Dave-

Thanks for giving me/us the correct term, i.e. "pendulum governor"....  Sorry for the confused terminology. 

Frank


Frank


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## Brian Rupnow (Sep 6, 2015)

I suppose if it was easy, everybody'd be doing it!!! This is getting complicated----and no, I haven't shown any fins on that engine. That's why it looks so skinny.--and the head isn't on it yet.


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## Brian Rupnow (Sep 6, 2015)

So----There we have it at about 99%. It ends up at about 10" tall, overall. The more I modeled, the more it began to look like the Philip Duclos engine. There is a good reason for that. Distance from underside of base up to center of crank has to be tall enough to allow for a flywheel. Overall cylinder length is determined by length of piston and stroke.  The carburetor/valve body has to be positioned so that it can feed directly into the cylinder head, and the length of the 4 round pillars supporting the cylinder is determined by the minimum amount of room required to fit something like the gearless mechanism into the space between the crankshaft and the stem of the exhaust valve.


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## Brian Rupnow (Sep 7, 2015)

So, here we have it. a single cylinder four stroke engine 1" bore x 1.5" stroke, air cooled, large enough to accommodate the gearless mechanism. Again, as I said, I don't plan on building the engine, only the gearless mechanism. However, I wanted to ascertain that if someone ever actually did want to use it on an engine, it would be possible. It makes a good looking model.


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## Brian Rupnow (Sep 7, 2015)

Someone has asked for everything I have done on this project as .stl files. You will need 3D cad software to do anything with these, and remember that nothing is proven here--it is all a "work in progress". I am confident about the gearless mechanism. The engine itself, is as I have said "Quick and dirty" but is sized to work with the gearless mechanism.---Brian
http://www.mediafire.com/download/o1x03gjh59119ak/OVERALL_GEARLESS_ON_ENGINE-X_-1.zip


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## Brian Rupnow (Sep 7, 2015)

Not exactly huge, is it!! I wanted to make the star wheel, but didn't have any material the right size. I was able to cut this ratchet wheel from a short length of 1" diameter cold rolled.


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## Brian Rupnow (Sep 8, 2015)

It's a cute little devil, so far.


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## Brian Rupnow (Sep 9, 2015)

Okay kids and turtles!!! Some folks are asking me (I post on three different forums) why I don't build the complete engine.---I don't want to build another engine right now. There is plenty of work involved in building the demonstration model---trust me. The demonstration model will be hand cranked, but it will most definitely show the complete operation of the gearless mechanism. Note that in this model, I haven't shown the springs which hold the gearless mechanism in contact with the cam.---Brian


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## Brian Rupnow (Sep 9, 2015)

Following my policy of "Never throw anything away---ever!!" I hunted around in a box of junk and recovered a one piece crankshaft I made a few years ago that turned out too crooked to work in an engine----But---it will work fine for a hand cranked demo model. You can see the big strange looking cam setting on one end of the crankshaft.


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## Brian Rupnow (Sep 9, 2015)

Progress was made today. I don't think the crankshaft idea is going to work out, but it's not a big deal. The stand is almost finished, the cam is made, and the guide and capture plate are finished.


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## Brian Rupnow (Sep 10, 2015)

I just had my first "test drive" of this mechanism, and it's awesome!! Even though I know how it works, even through I have watched the video 25 times, it is just "awesome" when it comes to life from parts you have made yourself, from drawings you have made yourself. What a great thrill that even after having done this kind of thing for 50 years, I still get excited when I see one of my creations run. It is not my invention, it is not my intellectual property, and it's all been done before many times by many people---but I still get excited!! Video tomorrow, maybe.


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## Swifty (Sep 10, 2015)

That mechanism brought back memories of a press tool that was made years ago, as parts were formed and finished, they remained tagged together until the correct number was reached and the "cam" allowed the crop punch to chop the strip off.

Paul.


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## Brian Rupnow (Sep 10, 2015)

Tomorrow I will make a "valve" to fit into the top plate, complete with valve spring and spring retainer to hold the valve closed. I have arranged things so that I can crank the mechanism by hand, or drive the mechanism very slowly with a belt drive from a power source. I will have to see what works best before I make the video.


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## Brian Rupnow (Sep 11, 2015)

Here ya go fellows!! Hope you enjoy. If you want a set of drawings to build your ow mechanism, email me at [email protected] ----Brian
[ame]https://www.youtube.com/watch?v=HuwlBj3YZMQ[/ame]


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## Barnbikes (Sep 11, 2015)

What do you think the max rpm would be?


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## Brian Rupnow (Sep 11, 2015)

Barnbikes said:


> What do you think the max rpm would be?


That is kind of like asking me "How high is up!!!" I think probably 500 to 600 RPM but that is only a guess. The type I built depends on a pair of tension springs to hold the gearless mechanism against the cam.--I can visualize a tendency to "float" the entire mechanism if the speed gets too high. The link I posted earlier in this thread shows a video where the mechanism is firmly connected to the cam with a link not unlike a connecting rod. That solves the "float" problem, but makes the engine a lot taller.


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## Jyman (Sep 11, 2015)

Very nice work Brian. Barnbikes you beat me to that question. I would think the rpm would depend on the spring holding the arm for the star wheel and the spring pulling it back down. But I could just see it running in a IC engine. I would be interested also in know how high of RPM's it could run at.


Sent from my iPhone using Model Engines


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## BronxFigs (Sep 12, 2015)

Ingenious mechanism built by very clever machinists who love to share with other model makers, and hobbyists.  

I too, share your excitement Brian when I view these mechanisms, levers, bell-cranks, etc, all working their individual magic, in perfect concert, doing what they were designed to do.  This star-ratchet indexer, the Chuck Fellows two-track cam, and the Wright Bros. gearless mechanism all share that special, "wow factor".  Watching them working, never gets old.  I guess I still have some kid in me left.

Thanks for another interesting build from the land of Brian R.


Frank


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