The Dale Maley Family Web Site

Subtitle

Wood Auger Marble Lift

I got the idea to build another marble game with the following attributes:

-hand-cranked

-wood auger to lift 1" diameter marbles

-several, maybe up to 4 bowls where marbles get transferred bowl to bowl

-about same footprint as wood-link marble lifting game already built

-3" diameter auger about 16" high to give same lift as wood-link marble mechanism already built

-will need some method of transferring hand crank power 90 degrees to auger. 
-maybe use wood bevel gears, or old grist mill method, I made on another project



Concept #1

I like the grist mill concept, but I need to get the gears as low as possible, to keep the over-all height down to reasonable limits.


Too much work to make worm gear

After further thinking about it, it would take many man-hours to make this big worm gear by hand.  It has a 3" OD with about 11 teeth.  Boy, that is a lot of material to remove with a Dremel carving tool plus 1/2" drum sander !!!


Is there another option for lifting the marbles?


I searched Youtube and found a Marble Pump on a video by Matthias Wandel. You can see the video using this link.


He sells plans to build the marble pump for $14, so I bought the plans and downloaded them.



How does the marble pump work?

One weakness I have discovered about myself is that I am not really good at visualizing 3D items.  I did not understand how the marble pump works, even though I saw the Youtube videos and downloaded a Sketchup file of the model.


You have 2 sets of motion happening at the same time:  The crank moves the block right to left........and at the same time the marble lifting piston is moving up and down.


  Using Sketchup, I made 4 views of the marble pump, with the crankshaft at 0, 90, 180, and 270 degrees. Once I did this, I now think I  understand how it works.


Crankshaft at 4 positions

Crankshaft at zero degrees

 

Crankshaft at 180 degrees

Crankshaft at 270 Degrees

Scaling marble pump from 5/8" marbles to 1" diameter marbles

As best as I can tell from the Sketchup plan I purchased for the marble pump, it is designed for 5/8" diameter marbles.   I want my machine to use 1" diameter marbles.  Rather than "reinvent the wheel", I decided to try simply scaling me marble pump by the ratio of the marbles sizes. 

Original model sized for 5/16" radius, I want 1/2 of 1-1/16" for 1" marbles, so ratio of 17/32 to 5/16 = 1.70.


I scaled the model up by 1.7, then made some slight adjustments to get standard 3/4" thick wood pieces.



Next step

I am going to build the marble pump scaled up for 1" diameter marbles, and see if it works ok or not.
I have some 1/8" diameter brass rods, so I might try a piece for the crank.
I will use cheap pine for the wood pieces and see how they work, I may have to go to some hardwoods if the pine does not work.
An interesting question is whether the 1/8" brass crank can pump marbles or lift a stack of 12 to 16 One-Inch marbles, since that is roughly how high I want to go.

Another thing to think about:  Kids can crank up to 100 RPM, which means 100 marbles per 60 seconds, or over 1 marble per second. That seems way too fast for my model.  I may still need to use a worm gear to slow down the machine?