Vic and Sue Thies “Too Much Fun Railroad” includes an area dedicated to the Wizard of Oz/Emerald City that includes Professor Marvel’s balloon hanging from a line. Vic asked me if I could animate the balloon to make it rise/return to earth.

“Well of course I can!” Hmmm…, Easier said than done only using what is at hand.

Without a worm drive motor on hand, I figured that the balloon would need a counterweight, otherwise when it goes up and stops, it would probably start to unspool under its own weight until the switch disengages, making it go up again, then starting to unspool again, etc., etc. etc. until it was time to reverse and come down. …And wouldn’t that be fun!

I used a piece of 2" x 4" for a chassis to contain the motor and pulleys. A pulley on either end supports the balloon and counterweight (will probably be the wicked witch and her flying monkeys, or…), and a pulley in the center shuffles the two weights back and forth. All of these pulleys are made from plastic train wheels. The center “drive” pulley has a couple USA Train traction tires on it to eliminate the slippage from the 80# test fishing line.

A donated motor drives the assembly using a belt drive and I made the driven pulley on my lathe to attain ~10:1 reduction. The motor is mounted on two vertical uprights like the spindle between equal length “A-arms” on a car allowing it to move back and forth through an arc for tension adjustment.

The lines that holds the balloon and counterweight weights pass through “trip switches” to stop the ascent. As the balloon rises, a lever pulls the switch opening the circuit until the electronics tell the balloon to decend.

I had a stroke of genius that allows instantaneous, infinite adjustment in the X, Y, and Z axis, as well as allow for rotation in the X-Y plane, all vital to having the lines centered within the levers. This also allows the switch/lever assemblies to “break away” and reposition themselves rather than breaking, if for some reason the balloon does not stop. I’ll let you guys ponder this one until I get some pics up.

The electronics consist of a 555 chip in oscillator mode running a relay to forward/reverse the drive motor for ascent/decent. A dc-dc voltage converter reduces the motor voltage to keep the balloon from becoming a rocket.

Pics in a day or two.

It’s pretty much finished with some final testing to do. It may still be a bit fast and I may need to substitute a slow motion motor. I could go to multiple pulleys, but each increases the possibility of failure due to belt slip/tension/breakage, etc.

This is set up as a typical reverser unit except that “sensor switches” take the place of the train passing the diode. The low voltage board allows control of the motor speed.

Note that the sensor switches mount to the steel plates (shims) using magnets glued to them allowing them to be positioned in any fashion. Two small magnets per switch assures that the swithes have a firm grip on the plate and don’t easily move/rotate. The “Z” axis is handle by shims behind the steel plates, but I don’t think these will be necessary. The magnets also allow the switches to reposition themselves or even “break away” and this has already saved many hours in what would have been broken parts. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

A split shot sinker attached to the line will pull the lever before the balloon reaches the board turning off the motor until it reverses.

If I say I will do something, I’m good to my word and necessity is the mother of invention. Here I give you the Balloon Lifter (sans balloons):

That is some terrific engineering.

Now let’s see it in operation.!

For now, just the included video. It will be up to Vic to install it with the balloon.

Well, there’s probably a way to view that, but until then…

Woo hoo. Got it!

OK, that looks neat!

Where’s Toto and the Ken behind the curtain? (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)

I found that as the drive wheel for the fishing line would turn, the line would “walk” across the surface from one side to the other when the unit reverses. When it would reach the end, it could work is way under the traction tires/wheel edge creating additional friction as a momentary “hangup” stalling the motor when running really slowly.

I removed the traction tires and chucked the “wheel pulley” in the lathe and spun it while applying a “ribbon of sand paper” around it. This evened out the step where the two wheels were glued together, fixed some flaws at the edges, and provided a nice surface for the fishing line to bite on removing the hang-up. I also moved one “dangle pulley” out a bit from the face so the fish line draws across the wheel pulley in a “screw fashion” rather than bunching on itself.

Go figure. Earlier when I was on the computer I could not view your video. Now, no problem.

So Todd, doesn’t the T&LB have its own balloon, hanging from that palm tree near the gate? Seems like the perfect opportunity…

Hadn’t occured to me. Actually, my balloon has a motor and propeller which make it swing which probably wouldn’t work that well with the switch levers, not that this couldn’t be overcome.

You know for me the fun is in the challange of the designing and building. I’ve never seen anyone use magnets to position switches like this, but it certainly seems to work well and now this technique is out there for all to see.

More people will enjoy its operation on Vic and Sue’s railroad. And it will be one more thing they, rather than me, can maintenance. Besides, Linda always holler’s that there’ too damn much sh-t to put out for open houses. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

Maybe I’ll come up with something a bit different for my balloon.

I’m seeing a loop of wire , hanging from some trees , with your balloon putting along in the sky …(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)

Sort of like a gondola’s

“I can’t come back, I don’t know how it works!”

Well, there is no place like home.

I got nuttin’.