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The Coin Slide Operated Jelly Bean Machine

3D model description

This started out as a simple project to test out printing some worm gears. I started designing a simple base to hold the gears so I could test them and I just happened to be snacking on jelly beans and thought "I should make a jelly bean dispenser out of these."... then about halfway into it I thought "man this should be coin operated like some of those other 3D printed candy machines".... then "Maybe it should be different though" so I decided to design and incorporate a coin slide operated mechanism... well after all that this snowballed into the "The Coin Slide Operated Jelly Bean Machine."

I designed this and printed this over two years ago so I don't exactly remember much of my thought process while designing it I just know I kept adding to the design as I went so I'm sure there was much easier ways to accomplish things. (there are some design flaws.)

Anyway.... This probably isn't for the faint of heart and I doubt anyone is crazy enough to try printing this but I still thought I'd post it because someone might be able to use parts of it (the coin slide mechanism?) or maybe at least get ideas from it.

The whole thing was designed to work with a 40 oz jar from Gimbals Fine Candies Gourmet Jelly Beans. that I found on Amazon.

If your crazy enough to try printing one of these there are some more diagrams here and I tried to do some quick assembly instructions below but your going to have to figure out somethings on your own especially things like sourcing the correct springs. You will have to rotate some of the STL's for printing too I forgot to orientate them before uploading them and I'm sure some parts will need fitting before assembly. Like I said I designed this a few years ago so details are fuzzy but if you have questions I will try to answer them.

Assembly of the Base
Start by inserting the Worm_Gear into the Base.
Slide the Shaft_Plug onto the Worm_Gear_Shaft then Slide on the Shaft_Plug and then the Handle.
Screw on the Handle to the Shaft_Plug with a 4-40 x 3/8" Button Head Screw.
Drop the Spring and Ratchet_Stop into the square hole in the Base. (make sure the spring you use will stand upright.) The tallest point of the Ratchet_Stop should be toward the front of the Base.
Insert the Handle assembly into the hole aligning it into the Worm_Gear. Using a 4-40 x 1/2" socket head screw attach the Shaft Plug to the Base through the hole in the bottom of the Base.
Turn the handle clockwise (away from you) to check for Proper operation. (You may have to hold the Main_Gear down with your finger.)
Slide the Dispenser_Disk under the tab on the Cover and then place the Dispenser_Disk onto the shaft of the Main_Gear.
Attach the Cover to the Base with (4) 2-56 x 1/4" flat head screws. (you will have to move the Dispenser_Disk around to screw in the screws.
Next attach the Dispenser_Disk to the Main_Shaft with a 8-32 x 2 1/4" long flat head screw.
Once again turn the handle clockwise (away from you) to check for Proper operation. The Dispenser_Disk should turn counter clockwise.
Assembly of the Coin Slide
Insert the Coin_Slide into the Slide_Block
Screw in a 2-56 x 3/8" button head screw into the single larger hole in the bottom of the Slide_Block. (Only tighten the screw enough so the Coin_Slide can not be removed from the Sidle_Block but is still free to move in and out.
Screw a 6-32" x 3/8" socket head cap screw into the Gear_Stop (it doesn't need to go in all the way and will be adjusted later.)
With the Coin_Slide pulled all the way out drop your Spring into the rear square hole. (the spring you use must stand up.)
Next a smaller spring is inserted into the hole that is inside the rear of that square hole in the Slide_Block.
This spring must be compressed while inserting in the Gear_Stop. You also have to make sure the bottom spring stays upright. (yes this can be a pain in the a$$)
After inserting the Gear_Stop secure it with a 4-40 x 1/2" flat head screw though the side of the Slide_Block.
Check the the Gear_Stop moves up and down while still wiggling front to back.
The other square hole in the top of the Slide_Block is for the Gear_Teeth_Stop. This is suppose to use a 2/56 socket head cap screw to keep the Main_Gear from turning until you pull the Coin_slide back out but is a design flaw and it tends to jam everything up so I do not use it.
Next insert the Lock_Block and secure with a 4-40 x 5/8" socket head screw.
Test the operation with and without a quarter. With a quarter in the Coin_Slide the screw in the top of the Gear_Stop should fully retract and be just below the top of the Slide_Block when the Coin_Slide is fully pressed in. (You still may need to adjust the later for proper fit with the Main_Gear.)
Final Assembly and Adjustment
Place a quarter int he Coin slide and push it all the way forward to retract the Gear Stop.
Insert the Coin Slide Assembly into the Base and align the holes and secure with (2) 6-32 x 1/2" flat head screws.
Pull the Coil Slide out then turn the Handle until in Locks in place. If it does not Lock place you need to remove the Coin Slide Assembly and adjust the screw in the top of the Gear Stop. Repeat the process until you find the sweet spot that will lock the handle. NEVER FORCE THE HANDLE ONCE IT LOCKS.
Retest the operation a few times to make sure everything is working correctly. Keep in mind without the Gear_Teeth_Stop you can continue to turn the handle as long as you want if the Coin Slide is left pressed in.
The Door_Hinge can be super glued to the base and the Door_Flap attached with a pin made out of something like a sewing pin.
Turn the Base upside down to screw on the Jar full of delicious jelly beans.
To keep people honest.... The Coin_Box can be secured with a 4-40 x 1/4" Flat head screw and the Jar Lock and be secured with a 4-40 x 1/2" button head screw and nut.
Enjoy...... and reap the profits.

  • 3D model format: STL





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