MEMSyard Wars - Blast Finger Engine Competition

[Bogstandard]

EVERYONE - STOP BUILDING

I am now officially ending this week long competition.

You can add to this post either comments or new builds, but it won't be counted.

I personally, am astounded at the results.

If we had another global catastrophe, I am sure I know who I would seek out to help. We could have finger engines for everyone in a matter of days.

Every one of the entries was way out of the thinking box, from edible to self destruct.

With nearly 1500 reads in just over a week, I think the general membership have enjoyed it immensely.

Well done to everyone who participated. A big thank you for your efforts.


VOTE HERE

http://www.homemodelenginemachinist.com/index.php?topic=2119.msg17265;topicseen#new

Overwhelmed Bogs

 

[dsquire]

Hi All

Just bumping this topic to the top. Does anybody new want to take up the challenge?

Cheers

Don

(5175)

 

[Blogwitch]

There must be thousands of new members now since this post was run, and I am sure a lot of new ideas could be brought out into the open.

This was all done as a bit of wacky fun way back when, and it sure got the site members working together and following the posts.

Maybe someone could raise a new post with a bit of a different set of rules.


John

 

[Captain Jerry]

OK, I'll jump in. How about a challenge to build a finger engine with a shop built clutch or other means of de-coupling the finger pad from the flywheel such that the flywheel spins and finger pad does not continue to oscillate. I'm thinking a one week (month?) time frame. If anyone else is interested, I will try to refine the rules but there shouldn't be too many except that the clutch mechanism not be purchased as a unit from an outside source. Purchased components for the clutch may be allowed.

I think it is do-able. Anyone else?

Jerry

 

[Captain Jerry]

OK, I guess not. How about some other ideas?

Jerry

 

[arnoldb]

Well, I'm game for a bit of fun; there's already a thought for a shop-made clutch floating around my noggin, but it'll have to wait for the weekend...
I think I can scrounge together a couple of hours on Saturday or Sunday - it will make a nice diversion from another project I'm working on, and I could use a new "executive toy" on my office desk ;D

Anybody else ?

Regards, Arnold

 

[Captain Jerry]

Good on ya, Arnold! I have a couple of ideas floating around too. But I'm so slow it will be at least a week before I have anything to show. Bill Riechart's engine uses gears to get some speed which Is critical to good performance according to Bogs but I'm going to try it with less than two full gears.

There should be more than just two ways to do this. If anyone else has an idea but doesn't want to take the time to build it, throw the idea on the table and maybe someone else will be inspired.

Jerry

 

[Captain Jerry]

Hear is my "less than 2 gears" idea. It is only a very rough arrangement but it uses a section of a gear to drive the pinion. At the end of the stroke, the quadrant is retracted from the pinion by a small spring (not shown) so that it clears the pinion on the way back letting the flywheel freewheel.

When the lever is pressed again, the cam at the end forces the segment into mesh with the pinion for the power stroke. Style and arrangement of all components has not been decided. I believe that a normal gear tooth form will work but a ratchet style might be needed.

Jerry

 

[arnoldb]

;D You're not slow Cap - at least you already have halve a drawing!

I want to cut some metal tomorrow and don't even have a plan yet, so it'll be scribbles & seat of the pants work - most likely coupled with some egg on the face...

Regards, Arnold

 

[Captain Jerry]

A drawing is a way to postpone real progress. I hope to make some parts tomorrow too but the drawing may be discarded before I finish. New designs don't always pan out, or as they say "back to the drawing board". I have the arrangement sorted ot but no dimensions. I will let the contents of the scrap bin contents dictate.

Jerry

 

[Ken I]

Jerry, Arnold, I was thinking maybe a roller clutch (too complicated) but how about a spring clutch - the drive is via a close wound spring which just snugs onto the driven shaft - when torque is applied it tightens - in overrun it loosens.

I've seen outboard drives use this "clutch" but using a ground square section spring coil running with clearance - a solenoid coil causes it to be attracet to the hub and it engages - good for plenty horsepower so it should work small scale.

Ken

 

[Captain Jerry]

Ken

That's a good idea. I have never seen a coil spring clutch but the concept is easy to understand. I wonder if it could be made to work on the low torque required for a finger engine. I don't have to drive in city rush hour traffic any more so my finger doesn't get as much exercise as it used to.

I do remember seeing something like that on a wood lathe at an early-American crafts fair. It had a leather strap wrapped once around the work piece. The power was supplied by a foot pedal at one end of the strap and the return spring was a bent sapling. I don't remember how the centers were worked out.


Jerry

 

[Noitoen]

Photocopy machines have a few of those spring one way clutches. The slip in the wrong direction but tighten in the other. There is still a little friction which might slow down the flywheel.

 

[Captain Jerry]

I'm going to start a new thread for the rest of this discussion. I hate to detract from all of the really creative finger engines that Bog's challenge generated. I wasn't on board at the time of that exersize but it looks like it was a lot of fun and got a lot of participation.

The current discussion has turned to a slightly different topic and so I'm going to start a new thread. For lack of a better name it will simply be titled "Finger Engine Clutch" in the Break Room.

http://www.homemodelenginemachinist.com/index.php?topic=15389.msg158205;topicseen

Jerry

 

[shred]

I think one of the fun things about the blast-build was the simple design and short short timeframe to build in (though we had a few days to contemplate designs IIRC). A clutch thing would be cool to build, but might take away some of the rush-to-make-anything-work of the original.