Jacobs Ladder---

[Brian Rupnow]

I went over to Barrie's hobby shop on Saturday morning, hoping to find a small roller chain and sprocket set-up. Sadly, they don't have anything like that. I know from when I built the pile-driver, that the only sprockets available to me in town are small bicycle sprockets, and thats just too big for this project. I'm not sure what to do now. This would have made a nice small project with a lot of eye appeal and not too many parts, but as of now I'm kind of stuck!!!

 

[Brian Rupnow]

The model engine Gods have smiled on me once again!!! A gentleman known as Duffy out of Quebec has offered to send me a pair of sprockets and some chain out of a 1950's era printer. So---The project still lives, and will be christened "THE DUFFY" in his honour.

 

[Brian Rupnow]

This gets more and more interesting as I dig my way into the design. I realized last night that I didn't need to have the center flight of stairs extend down below the two outer staircases. I can achieve the same "orbiting" by moving the axis of the pivot arms up and into the position shown. This makes a much more compact assembly, easier to fabricate and much more eye appealing. The pivot arms clear the spacers between the two outer flights, and the bearing support off to one side clears everything. Now with sprockets to tie the two shafts together, and a pulley on the end of the highest shaft we are starting to get somewhere.

 

[Brian Rupnow]

Thank you everyone for the great suggestions. I really like Evans cam concept. I'm not going to use it, but it is a really great idea. I have rethought the big "windows" in the sides of the outer staircases, in favour of two 2" dia holes in the near side staircase only for the "arms". I have added in a 4 1/4" dia pulley, which is as large as I can go without hiding some of the stair treads with it. I have added a 2 1/2" x 1/2" x 10" baseplate. I have to sneak Duffys sprockets and chain in behind that pulley yet. I also have to figure out some way to make a track for the wooden balls to follow around from the top discharge point to the bottom step to let them recirculate. My current thinking is two bent 3/16" rods running side by side to form a "ball track".

 

[lee9966]

That's really cool!

The balls can do some roller coaster action on the way back, gravity defying curves, or a loop.

Lee

 

[mklotz]

The balls can do some roller coaster action on the way back, gravity defying curves, or a loop.

Better yet, the balls can roll down a ramp and activate the lever arm on Brian's previously built escapement device, thereby producing a totally useless, albeit entertaining, bit of chewing gum for the eyes.

 

[Brian Rupnow]

The ball return has me somewhat concerned. I don't want the model to take up a lot of real estate, so big sweeping curves of parallel round rod is not a particularly great option. Although the total drop is not dimensioned on the drawing, its only about a 4 1/2" total drop from the top step to the bottom step. I would like the balls to fall off the end of the top step, circle around a full 360 degrees and enter at the front of the bottom step. The best alternate I can think of at the moment is to have a short vertical section of 1" thinwall tube about 2 1/2" long on the left-hand side of the stairs, which the ball falls straight down through, but then I'm not sure what to do with it after it falls down thru the tube. I can't afford to have any level spots in the return system---it must all slope downhill. This kind of thing does not lend itself to a "machining" solution. Its a problem.---I can get my balls up, but I' not sure how to get them down!!! ;D ;D ;D

 

[bearcar1]

Hi Brian, a great number of ways for the ball to be returned to the bottom of the chute can be imagined of course. It occurred to me, in a Rube Goldberg style, that a set of stair steps that have treads tilted in opposite directions could be utilized. The ball, after its initial lift would exit out onto the top step of the stairway and would then be forced to roll to the other end of the step where it would then would have to travel back the opposite direction until it met the end of that step and so on and so forth until it reached the bottom step and would again begin its journey back up Duffy's lift. The board game "Mousetrap" has such a contraption built into its action if you have ever seen it in action.

BC1
Jim

 

[Brian Rupnow]

Bearcar---Thats a great idea!! It just entails far more work than I wanted to get into. I'm liking the idea of a vertical tube as stated earlier, then a parallel track made of round rods with only a slight downhill slope and a 180 degree turn at the discharge end. I have to be carefull that the balls don't bounce off the track or roll so fast that centifugal force causes them to jump off the rails. Thats why I was thinking of dropping them down a section of tube, to get rid of most of the vertical difference. A peice of 1" clear rigid plexi tube would be great for that.

 

[Brian Rupnow]

And where, short of making them myself, do I get a dozen 3/4" dia. wooden balls?????????

 

[Brian Rupnow]

Nevermind---I did a quick online search and found all kinds of sources. now what do I do with the other 88 wooden balls????
http://www.woodparts.ca/WOODTURNINGS-BALL.HTML

 

[Brian Rupnow]

I may have part of the answer. Like many men my age I take a plethora of age related medications. Nothing serious, just old man stuff, arthritis etc. Anyways---the pill bottles are a clear plastic 1" in diameter x 3" long.--Might make the perfect vertical tube for the returning balls. As it is I currently use them to hold a wide assortment of small taps, dies, set screws, etc. in my little machine shop. Might as well use them on my toys too!!!

 

[Brian Rupnow]

Better yet, the balls can roll down a ramp and activate the lever arm on Brian's previously built escapement device, thereby producing a totally useless, albeit entertaining, bit of chewing gum for the eyes.

Marv---I truly hope that wan't a shot. None of this hobby stuff I build is truly usefull. Its all eye candy. Of course, I will agree, some of it is more "eye candy" than others. ;D ;D

 

[mklotz]

Not a shot at all, Brian. I like your mechanisms and was just trying to puzzle out a way to tie the ladder together with your recent escapement device. Like so many others, I'm fascinated with devices that do nothing except show off the ingenuity of mechanical design.

 

[tel]

... and somewhere in the cycle it would be good to see the ball trip a single cycle of the slinky machines as it goes past. ;D

 

[bearcar1]

I can see it all now 8)

[ame=http://www.youtube.com/watch?v=k1sP_bRheP8&feature=related]http://www.youtube.com/watch?v=k1sP_bRheP8&feature=related[/ame]

Ones imagination is boundless

BC1
Jim

 

[Blogwitch]

Two parallel wire rods are perfectly good enough for balls to roll down, say 1/8" copper coated gas welding rod. Dirt cheap, and you will have enough to play around with for ages.

If you have them feeding into a plastic cereal bowl at the bottom, you could have a never ending supply of balls.

John

 

[agmachado]

Hi Brian,

I was reading the comments of this topic and I immediately thought of a soundtrack for this project...

[ame=http://www.youtube.com/watch?v=LHSaK78d9b8]Rush - Jacbos Ladder[/ame]

I do not know if you like this style of music ... but that's okay!

I like your projects and again thanks for sharing them with us.

:bow:

Best Regards,

Alexandre

 

[Brian Rupnow]

I can see it all now 8)

http://www.youtube.com/watch?v=k1sP_bRheP8&feature=related

Ones imagination is boundless

BC1
Jim

Just watched the vido----HOLY COW!!!

 

[Brian Rupnow]

Waiting for wife to get home from work, so figured I could fill in some time---