CLEVER IDEA

[randyc]

This morning, I had an appointment with an ophthalmologist to discuss cataract removal in my left eye.  As the doc was jotting down his notes and I was admiring the precision optical equipment, my eyes (well, one eye, ha-ha-ha) lit on this little mechanism.
 
Ever had a need for a custom pair of gears or rack/pinion ?  Maybe you could use a non-standard number of teeth or strange diameter, etcetera, for an uncritical, slow speed application.  Here’s an idea that would let you make a pair of “gears” in an hour or so:
 
   
 
(Click on the sketch to see an enlargement)

Perhaps this is a well-known method of approximating gearing but it was new to me and I’ll keep the idea in mind for possible future application !  (The only thing similar to this that I can recall is a movie projector film transport, but the projector drive wheel teeth are shaped more like a gear.)
 
The sketch shows the two parts disengaged and separated, just for clarity.  Also, I neglected to note on the sketch that the pins are tapered as well as rounded. 
 
The length of the pins and the taper are chosen to properly engage the counter-sunk holes in the mating part.  A CAD drawing would easily determine the correct configuration.
 
I thought that this was a very ingenious way of optimizing cost versus function and I hope that the designer got a raise for the idea !

[f350ca]

Really neat design. I've never seen it used before.

[randyc]

(08-30-2017, 06:33 PM)f350ca Wrote: Really neat design. I've never seen it used before.

Whew, thanks Greg !

I was starting to feel stupid, thinking that everyone in the world knew about this idea except me :o)

[Highpower]

Admit it Randy, you've been playing with your tinker toys again haven't you?

[randyc]

(08-30-2017, 08:35 PM)Highpower Wrote: Admit it Randy, you've been playing with your tinker toys again haven't you?  

My word, I think you've got it - the designer of that mechanism played with the same toys as I did !

Incidentally I wonder how many members of this forum DIDN'T own an "Erector Set" or it's British equivalent, the name of which I've forgotten, unhappily.  I'd bet that the percentage would be low.  And how many inspirational designs could have been created by six-year-old minds, LOL, with these "toys," then forgotten and subconsciously recalled thirty years later ?

My parents took the little motor from the kit away from me the day after Christmas so I spent MY erector set time shooting the little nuts from the set at my brother with a clothespin gun 

[Vinny]

I had an erector set, tinkertoys, lincoln logs and lego!

[f350ca]

REALLY hate to admit it but I was pre Lego, my kids had boxes of it though. I did have a building set that used bricks but they were polyethylene hollow things, don't recall the name. Another set that had I-beams and columns and panels that snapped onto them to make buildings, again can't recall the name. And of coarse Mechano sets (that English equivalent). Im sure all the gears and pulleys led to my demise of becoming an engineer. Can't imagine the hours I spent building things with that Mechano set.

[randyc]

(08-30-2017, 10:18 PM)f350ca Wrote: REALLY hate to admit it but I was pre Lego, my kids had boxes of it though. I did have a building set that used bricks but they were polyethylene hollow things, don't recall the name. Another set that had I-beams and columns and panels that snapped onto them to make buildings, again can't recall the name. And of coarse  Mechano sets (that English equivalent). Im sure all the gears and pulleys led to my demise of becoming an engineer. Can't imagine the hours I spent building things with that Mechano set.

Man, I was just thinking of that !!!  Pre-Lego doesn't EVEN describe my toy history, I'm WAY earlier than that (and "Mechano" is the name that I was attempting to recall).

BTW, has no one questioned this or has everyone built a clothespin gun and shot nuts with it 

"........so I spent MY erector set time shooting the little nuts from the set at my brother with a clothespin gun......"

[Pete O]

I still have my Meccano set from 45 years ago. I used to kid myself that my kids would love it- four daughters and none were the slightest bit interested. Now I kid myself that my grandchildren will love it.

[f350ca]

Lets really date ourselves, Match Box cars and Dinky Toys that both came from England in cardboard boxes especially made to fit each toy.
How times and manufacturing have changed, when I was a kid if it came from Japan it was junk, now I only wish I could afford more Japanese tooling.