# For inquiring minds



## Gaffboat (Mar 11, 2012)

I'm working on another automaton project and thought some of you might be interested in the design process and how some of the parts work. For the new project I need to move a piece 70 mm (~ 2.75 in) in one direction and then back to the starting position with one revolution of the shaft. This was my test mechanism for converting a constant rotary motion into a reciprocating linear motion that moves the needed distance. Nothing special here, but it won't be seen when the project is finished.


----------



## TwoSkies57 (Feb 23, 2009)

This outta be interesting


----------



## Mike (Nov 22, 2004)

Oliver, all that work to make the cow swish her tail? :haha:


----------



## old55 (Aug 11, 2013)

TwoSkies57 said:


> This outta be interesting


+1 what Bill said.


----------



## jw2170 (Jan 24, 2008)

Boy, another lesson in mechanics.

Can't wait...


----------



## JOAT (Apr 9, 2010)

Mike said:


> Oliver, all that work to make the cow swish her tail? :haha:


Ah, that's probably a better guess then mine. All I could come up was something obscene. :yes2:


----------



## MarcNThyme (May 13, 2012)

This type of rotary to linear motion conversion was used extensively on machines such a metal working shaper. The speed of the stroke in one direction is greater than the stroke in the opposite direction. This allowed the shaper tool to be set for a given feed rate for the forward stroke followed by a rapid retraction on the return stroke.


----------



## TenGees (Sep 12, 2012)

*Very interesting*

Very nice, Oliver. Maybe you could incorporate that into your mouse in the cheese. Then again, I'm sure you'll come up with something amusing.

Interesting observation, Ron, about the differing speeds. I wouldn't have noticed that, had you not mentioned it. Now you have me wondering about the speeds of different rotary to linear devices.


----------



## tooler2 (Aug 11, 2012)

VaughnRonald said:


> This type of rotary to linear motion conversion was used extensively on machines such a metal working shaper. The speed of the stroke in one direction is greater than the stroke in the opposite direction. This allowed the shaper tool to be set for a given feed rate for the forward stroke followed by a rapid retraction on the return stroke.


Now I am intrigued, I will have to open up my shaper to check it out. As a farmer I am very familiar with pitman arms but not this principle. What is it called? I would think it would be applicable for a pump jack.
Rob


----------



## david_de (Jun 3, 2013)

I suspect he is inventing the steam engine. But then I see no spark plug so I could be wrong?


----------



## Wood Chip (Apr 10, 2011)

Oliver: is the second hole:
a) to balance the wheel;
b) to provide an optional speed and/or stroke distance;
or
c) a mistake that you left in because no one will see this mechanism anyway?

This works like a steam locomotive but backwards. 

Are you familiar with the book, "507 Mechanical Movements" by Henry T. Brown? It's one of my favorite reads! Having admired your posts for a long time, I suspect you already have a worn copy in your shop.


----------



## tooler2 (Aug 11, 2012)

Wood Chip said:


> Oliver: is the second hole:
> a) to balance the wheel;
> b) to provide an optional speed and/or stroke distance;
> or
> ...


AFAIK a locomotive used a pitman arm. It is fixed to the wheel and the wheels turn the same speed in relation to the piston stroke for their entire rotation.
Rob


----------



## rwl7532 (Sep 8, 2011)

I saw the animation in my email with no signature.
Immediately I thought "Gaffboat".

regarding the device: I'm "pumped".

(avatar needs a curly light bulb update by the way)


----------



## Gaffboat (Mar 11, 2012)

Mike said:


> Oliver, all that work to make the cow swish her tail? :haha:


Mike: No cows involved (although I do have a cow idea percolating in the sketchbook). You'll have to wait a while while I figure out how to move some other parts. I will say this much, alligators are involved in the new project. :yes4:

Gary: The second hole was not a mistake it was an ... ummm ... unintended feature that failed to meet design specifications. Yeah, that's my story. Yes, I do have "507 Mechanical Movements" by Henry T. Brown which is very helpful when you need ideas for movement.

Ron: Yes, the speed of the return stroke faster which will actually work well in this project.


----------



## rwbaker (Feb 25, 2010)

Looks like a elevator door opener - circa 1970

What are the guaranteed number of cycles?

Baker


----------



## DaninVan (Jan 1, 2012)

'Different strokes for different folks'?


----------

