Gearless hit and miss engine of my own design

[xander janssen]

Hi,

Very nice engine, especially the gear-less part.

In this month's issue of the German magazine "maschinen-im-modellbau" there is nice rotary vane pump (30 mm) in diameter.

www.vth.de/maschinen-im-modellbau/1...us-wenigen-teilen-gebaut-mit-bauplan-im-heft/

The plans are in the magazine, but they are under copyright so I won't post them here.

Xander

 

[BronxFigs]

Very interesting. Through my amateur eyes it reminds me of the Olds Vertical Gearless that DeBolt Machine Inc. sold as a casting kit. This engine is horizontal, but the valve mechanism looks similar to the Olds concept.

It would be nice to see some measured drawings for just the gearless valve control mechanism.

Frank

 

[BronxFigs]

Can anyone explain the gearless/ratchet mechanism that works the valve timing on this engine. The video shows a horizontal engine with a 10 tooth ratchet and a 5-lobe "cam" The drawing of the ratchet shows 8 teeth, and a 4-lobe "cam" that's used with the engine mentioned in this thread. I believe that the Olds Vertical gearless uses a very similar mechanism.

I would like to use this indexing mechanism on a future engine build, but I am not that clever...I need some measured drawings, or detailed photos, or sketches, or explanations of how this all works. Drawings always help me envision how things go together.

Anybody? Help!

Frank

 

[xander janssen]

Hi Frank,

The absolute number of lobs and ratchet theet does not matter as long as the number of lobs is half the number of theet (4/8 or 5/10 or ... or N/2*N)

This means that the ratchet needs 2*N "actutations" by the cam on the crankshaft for the ratchet to make one full rotation. In the same rotation of the ratchet, the lobs actuates the outlet valve N times i.e. half the number of crankshaft rotations as necessary for the 4 stroke engine.

In non-gearless engine, this factor 1/2 is reached by using gears with N and 2*N number of teeth between the crankshaft and the camshaft.

In these you-tube movie you see a close-up of the principle including the hit and miss action.

[ame]http://www.youtube.com/watch?v=Z73pewvI4vg[/ame]
[ame]http://www.youtube.com/watch?v=yyFFyTHYdZs[/ame]
Hope this will help you understanding,

Xander

 

[BronxFigs]

Thanks for the videos. The ratchet mechanism is very easy to see working its magic.

Probably can be adapted to many scratch-built engines.

Frank

 

[Chicken]

Hi!

A small update from my side! The engine setup is now 100 % complete. A belt driven rotary vane pump of my own design was added for the cooling water. The engine will now just sit there and run for hours. Although it is a fairly large engine with 100 ccm, it only consumes about 30 mL of fuel per hour when running without load.
I won't paint the engine as I really like the looks of the bare metal and the rusty look of the cast iron parts. I'll keep it covered with some WD40 to avoid corrosion of the steel parts.

Please enjoy the final video. It includes the engine startup so maybe you get a feeling for the size!

[ame]http://www.youtube.com/watch?v=gP1yfUAUezI[/ame]

best regards,
Alex

 

[Lawijt]

Great & beautifull engine.

 

[OregonBill]

Alex, what a wonderful creation you have given birth to. It must be very satisfying to have so much talent. Can I borrow some?

 

[dalem9]

That is so cool. Great job. Dale

 

[BronxFigs]

Hello members...

This original thread posted by Alex, shows videos of the gearless, star-ratchet mechanism that Brian Rupnow is using on his vertical engine design. In concept, I believe these two mechanisms are very similar.

I enjoyed reading through both threads and builds. Thanks, gents, for the interesting information.

Frank

 

[Brian Rupnow]

This engine and it's star wheel mechanism provided a lot of the information for the thread I am currently posting. I also gained a lot of information from the Philip Duclos gearless engine. However, seeing them work and designing your own working mechanism are not quite the same thing, as I am sure many of you have discovered.--As a matter of interest, Frank, what have you built lately??-Brian Rupnow

 

[gus]

Brian.
Congrats.Another Great Engine. Its the General Election now and distracted from real engine work. Distracted by the forums.

 

[Eoin]

I've followed this thread with much interest and, may I add, great work.

Eoin.