Project Information
I made a direct drive version of this and it was ok except you can dispense all 6 marbles in less than 6 seconds…..which is very fast.
If I use a worm gear drive, I can slow it down so it takes longer to dispense all 6 marbles. About 4 seconds per marble would be about right, which is 15 RPM. Since kids can crank up to 100 RPM, the worm gear needs a speed reduction ration of 100/15 of 6.7.
Since the worm gear speed reduction ratio is determined by the number of teeth on the worm gear, using 7 or 8 teeth should be ok….....I chose to go with 8 teeth on the spur gear. It takes about 29 sec on the actual model, cranking it at 100 RPM, to dispense all 6 marbles.
The model is made of maple parts, except the worm gear and crank handle are made from a 1.25" diameter birch dowel. I used water based red dye on the worm gear and crank handle.
You can use this link to watch a Youtube video of this model in action.
For more details, see my woodworking web site.
I think the grand-kids will have fun with this one.
If I use a worm gear drive, I can slow it down so it takes longer to dispense all 6 marbles. About 4 seconds per marble would be about right, which is 15 RPM. Since kids can crank up to 100 RPM, the worm gear needs a speed reduction ration of 100/15 of 6.7.
Since the worm gear speed reduction ratio is determined by the number of teeth on the worm gear, using 7 or 8 teeth should be ok….....I chose to go with 8 teeth on the spur gear. It takes about 29 sec on the actual model, cranking it at 100 RPM, to dispense all 6 marbles.
The model is made of maple parts, except the worm gear and crank handle are made from a 1.25" diameter birch dowel. I used water based red dye on the worm gear and crank handle.
You can use this link to watch a Youtube video of this model in action.
For more details, see my woodworking web site.
I think the grand-kids will have fun with this one.