Self-Propelling Gear

[Ken I]

When I built the inside out radial "improbability drive" it was for puzzle value (to tease friends, family and aquaintances) - unfortunately the nett result was pug ugly (I have a pug).

The local expression is "skreeulelik" which roughly translates into "screaming ugly".

So its not going on display as such - but it got me to thinking if I could come up with a more elegant inside out version.

This is it :-

A self propelling gear

I've just finished building it and its running itself in (or to destruction - whichever comes first) out in the shop.

The gear is simply bling - or if you like the raw material for the flywheel.

If I design something I don't post on it until it at least looks like its going to work - so my work in progress posts are often a bit ass-backwards.

I will post a video and some progress photos shortly.

Any bright ideas on what to call it ?

Ken

 

[steamer]

Ken,

That's beautiful! I haven't noodled out completely yet, but I think I get it.
Four pulses per rev?



Dave

 

[cfellows]

Actually, I count 4 pulses per opposite pair of pistons which would be 12 pulses per rev??? Nice looking engine. Would love to see a video of it.

Chuck

 

[steamer]

yeah yeah yeah....I meant per piston...that's really cool!

Dave

 

[Ken I]

Dave, Chuck - yes that's 4 pulses per piston x 6 pistons working in opposite pairs

Here's the vid....

[ame=http://www.youtube.com/watch?v=C1oe3oULlD0]http://www.youtube.com/watch?v=C1oe3oULlD0[/ame]

I designed it as an 8 cylinder but then realised with 4 up and 4 down it would not be self starting - back to the drawing board -changed it to 6 cylinders (a curious case of less being better) - I deleted the timing hub before I realised that that would remain the same - too many saves between error and the penny dropping to recover - colourful language.

Since there are two rotating shaft sealing points there is a fair amount of leakage to the exhaust. Could use closer fits or seals to improve.

Motor reverses by swopping inlet / exhaust or by rotating the timing hub 45° (has an extra set of holes).

This motor is not going to win any prizes for efficiency but it does run and looks interesting.

Ken

 

[bearcar1]

Ken, yet another fascinating engine you've built. Excellent! Would there be any notions of releasing drawings for such? stickpoke :hDe: I'm still getting my head around your "Improbability Drive" and you come along with this, yet another fine example of engineering. BRAVO! :bow:

BC1
Jim

 

[ttrikalin]

fantastic!
really enjoyable engine!


take care
tom in MA

 

[arnoldb]

;D I was wondering why you were so quiet Ken...

That's a real beauty :bow: :bow: - and very very well built as well :bow: :bow:

: Remember to put some pin stripes low down on the glass sliding doors next time you get a puppy; prevents them from flattening their faces ;D
Anyway, I disagree; your "improbability drive" engine is not "skreeulelik" - it is "mooi van lelikgeid" - just like a pug ;D

Vriendelike Groete

Arnold

 

[AussieJimG]

I thought your Improbability Drive was a great device. This one is even better. And beautiful as well.

Thanks for sharing. It has made my day.

Jim

 

[ShedBoy]

Well it certainly isn't pug ugly now. My mate has a pug too at his farm, lovely personality. Great looking engine.

Brock

 

[Ken I]

Thanks guys - here's some work in progress pictures :-

Bearcar - yes I will post the drawings in due course.

All the bits :-

This motor has a small parts count and (I think) is relatively easy to make.

I was going to bore out the corners and machine the square (its an aproximation of the true sinusoidal path - but not far out) - but I "cheated" and machined it on a friend's NC - just a lot easier that way.

I was originally going to make the cylinder of cast iron - but then I felt it would just look like a round blob and instead chose perspex for asthetic reasons rather than durability.

I machined the pistons in pairs, either end of a piece of aluminium - note the "floating" pin chuck for tapping the M2 threads - using finger power.

Machining the valve distributor hub on the RT.

Ken

 

[bronson]

That's a very good looking engine and sounds pretty neat. Nice machining on the parts.

 

[Smifffy]

Awesome!

 

[Ken I]

While mulling this over further, I realised you can have more or less lobes - with 4 lobes the pistons have to cycle 4 times per revolution and seems to limit the speed.
Then I thought maybe eliptical - and then it struck me - a single eccentric is going to be the easiest by far.

The ballancing holes (which have been calculated to give an exact ballance) add some eye appeal to boot.

Photobucket logon is down (again) so I've attached the concept.

When I post the drawings, I will post that as an option.

Ken

 

[steamer]

Thats cool Ken! I cant help but envision something geared to the OD of her!

Dave

 

[Ken I]

For anyone who's interested, I've posted a *.zip file under downloads - it contains the 2D drawings in *.dwg, *.dxf & *.pdf format plus an MSWord *.doc file of build notes.

The plans contain the 4 lobe version above as well as the single eccentric option which will be easier to make.

Ken

 

[Noitoen]

Thats cool Ken! I cant help but envision something geared to the OD of her!
Dave

Now he's going to build a ferris wheel to go with it .

The more lobes you put into it, the slower it runs but with more torque.

 

[bearcar1]

Say, thanks a million for posting up your drawings for us to pour over,Ken. This one has so many potential live-display applications, not to mention just down right fun to watch. A 'kp' is the very least I do to show appreciation of your work. :bow:

BC1
Jim

 

[mu38&Bg#]

That's fun. Good Job!

 

[ChrisB]

It seems everytime you post I get more amazed

Another truly wonderful engine, and another one for the ever growing to-do list. I seem to learn by just reading your posts, I can only imagine what I would get out of actually getting round to building something.