Welcome back to the Trick or Trivia Blog. In this installment, I will show off how I built the candy dispenser that will set beside the tombstone. Unfortunately this part of the project did not turn out as I had planned because I could not find the type of bowls I was looking for. I did managed to cobble something together that works, and I will be able to build a better version for next Halloween.
My original idea was to use faux concrete flower urns that typically can be found beside tombstones. I got the idea from some flower vases I saw at the local Hobby Lobby back in July, but was unable to find them again at any store I visited. So I improvised and bought two cheap Halloween Candy bowls, and hacked them into something that would work. While this is not the most refined solution, it worked well in the end.
The Hardware and Tools Needed
Below you will see a list of the hardware and tools used to build the candy dish that catches the dispensed candy.
- Two large bowls of similar size
- 15-20 Sticks of Hot Glue
- Hot Glue Gun
- 6”x6” Square of Plywood
- Knife or Scribe
- Shims Made from Scrap Cardboard.
Installing The Touchscreen
Before we get started on the candy dispenser, I wanted to quickly show you how I installed the touch screen into the Tombstone. I spent a lot of time mulling over how to mount the screen, and after several different mockups, I decided on just using hot glue to secure it. Unfortunately during the time I moved to my new home, and the time I began working on this (a week later) I found that the Raspberry Pi Screen had cracked after a heavy box had been stacked on top of the box the screen was wrapped up in. So I had to order a new screen and wait on it to arrive.
You might remember that when I carved out the tombstone, I left a square patch near the top, fairly blank. This is the place where I cutting out the recess for the screen.
To get started I transferred the screen’s metal housing dimensions to a piece of scrap cardboard. I then cut out the waste cardboard, and checked the screen for fitment.
As you can see, the screen fit perfectly inside the template.
The next step is to cover the flat part on the tombstone with painters tape. This will give us somewhere to trace out the rectangle we need to remove.
After eyeballing the placement, I traced the rectangle onto the painters tape. I tried to keep this as centered as possible, but in the end it was off a little, but no big deal as it is a 100+ year old digital tombstone!
Next I use a razor knife to trim the excess tape away. This gives me a clean line to follow when cutting out the foam.
Using a cheap box cutter I was able to remove the foam rectangle with little trouble. If I had to do this again, I would have used a jig saw to cut this out as the cut would have been easier.
Finally, a shot from the back showing how I used hot glue to secure the screen in. I am withholding the shot of the screen installed from the front until the next installment of this series.
Building the Candy Dispensing System.
The heart and soul of this project was the touch screen, but we can not forget the reward that we owe the children who visit us on Halloween night. When I originally prototyped the candy dispensing system, I had a plan in mind that would utilize a faux flower urn and smaller candle dish to hide the dispenser. The Dispenser was planned around that urn, and its dimensions. Unfortunately I was unable to find that style flower urn for sale when the time came to buy it despite several being on the shelves of Hobby lobby just days before. I would not let that stop me though, and I improvised with two large candy bowls from the dollar store.
To get started, I needed to find a suitable piece of scrap wood. Fortunately I found this piece of ⅜” thick hardboard laying around from an old cheap book shelf we had planned to throw away. I cut a suitable sized piece off and heated up my glue gun.
While the glue gun was heating, I mocked the dispenser hopper up, and found some scrap foam to use as a shim to set it at an angle. You can use cardboard or even dry hot glue to raise the back of the hopper up.
With the angle set, I used a knife to trace an outline of the foam so I could remove the paper covering. I did this because I know from past experiences that hot glue does not stick to this surface very well.
Then I simply cut through the black paper layer, and used my knife to rough it up a little for better glue adhesion.
I then added hot glue to the roughed up surface. The glue sticks I am using are considered “High Temp” meaning they melt around 350f, and honestly they were a little too hot for the foam I used, but they are all I had. In retrospect, I should have used “Low Temp” glue sticks.
I then placed the foam on top of the glue. One of the bad things about using “High Temp” glue sticks is that you will get burnt instantly if any squeezes out the sides and comes in contact with your finger. This is much less of an issue with “Low Temp” glue sticks. I buy these sticks by the 25lb box, so I have an abundance of them.
Next I glued the smaller foam strip down. This part was tricky as the high temp sticks are hot enough to melt this foam. I let the glue gun cool down some before applying any glue.
For the next part, I managed to find a low temp glue stick in my Girlfriend’s craft room. I knew I would melt the foam with the high temp sticks. I should have removed the black paper here as well but I got into a rush and forgot to cut it out until it was too late.
Finally I glued everything down and held pressure on it until the glue cooled. It looks very messy here, but I did clean it up a bit.
With the hopper secured in place, I was able to mock up the servo placement. It took a few tries, but I finally managed to get the edge of the board trimmed down enough so that the plunger was able to travel enough to eject the candy.
With the optimal placement found, I used my used my knife to carve out a hole that the servo could fit inside. Then I used hot glue to secure things.
With the candy dispenser assembly completed I moved on to modifying two bowls. Basically I cut a relief into the bottom of the black bowl, and a similar relief into a side on top of the other bowl. I then used about 20 glue sticks to secure everything together.
I am not going into much detail on this bowl design on purpose as I feel that the odds of someone finding similar bowls is slim to none, and there is surely a better way to do this. Here you can see that I have placed the glue about one inch up on the purple bowl and let it “flow” onto the black bowl about an inch as well. I did the same on the inside.
Here you can see how I layered the glue on the inside of the two bowls.
One more shot of the inside. You can almost make out the candy hopper.
And a final shot of the bowls pared together. You can see the hopper in the big bowl, and the candy feeds into the smaller bowl. Both of these will be perched on a stand beside the tombstone and the black bowl will have a jack-o-lantern cover as to hide the dispenser.
That is going to wrap this installment of Project: Trick or Trivia. Check back in a few days for the next installment, where we bring everything together, and demo the system working. Until then, remember to Hack The World, and Make Awesome!