Intro: Pointless (Button) Pumpkin - With Arduino Brains
My name is Nils. I am 20 years old, and I live in Germany. This is my first
After receiving a lot of good remarks and picture/ instructions requests from friends and neighbours about my last pumpkin, I have now decided to share my next project with the community. Thus, hopefully, this does not only help and
inspire others, but also eternalises the pumpkin, enabling people outside my
inspire others, but also eternalise the pumpkin, enabling people outside my neighbourhood to enjoy the jack-o-lantern after these past and present few days.
What is this pumpkin and what can it do?
The "Pointless (button) Pumpkin - with Arduino brains" is an Arduino UNO (or MEGA) controlled counter with homemade LED display.
Each time someone presses the button in the middle of the pumpkin, the counter increments.
Originally, my goal was to count the amount of people visiting my house on Halloween, though everyone ended up loving the pumpkin and spamming the button. Thus, the objective failed (I more or less suspected this), whereas the project stayed a lot of fun and got a lot of good feedback!
If you like this instructable, please vote for me in the halloween contests 2016 :)
Since I was a complete newcomer to building stuff with arduinos, I will try my best to make this instructables understandable to people without previous knowledge. I know that building with arduino can be complicated or even frustrating; therefore, I will try to make the electronics part as simple and as thorough as possible. That being said, I cannot cover all of the basics on arduino and electronics in general (there are lots of great stand alone instructables out there about this). What I do explain should definitely be at least enough to easily make a pointless button pumpkin.
If you are interested in electronics, Instructables just brought out new classes on Arduino programming, Led lighting, and Electronics (free at the moment!).
Step 1: Materials and Tools
- one pumpkin for the main project (with the display)
- one pumpkin for the hands
- one pumpkin for the head
- wire to attach the hands
optional materials to enhance the button:
- one small decorative gourd
- hot glue (about 1-2 sticks)
- server spoon
- bowl for the pulp of the pumpkin
- rotary tool with small milling bitsmall
- big and small kitchen knifes
- non-permanent marker
- big and small clay ribbon loop tools
- 5mm drilling bit
- 7mm drilling bit
- 25mm center bit (size depends on your button)
- hot glue gun
- 20 LEDs (color: white, yellow, or red) - you can buy a whole set with coloured ones too, since these are a good thing to start an electronics stash
- 14 100Ω resistors (resistance depends on the LEDs you use! See step 11 for more information)
- one large and one small breadbord
- jump wires or Dupont cables (to connect things on the breadbord)
- one button
- one 10kΩ resistor
- optional: a 3D printer to extend the button (not necessarily needed!!!)
Components for the Arduino UNO version (picture 3):
- one Arduino UNO
- 14 pnp-transistors (I used BC327‑40BK, but these are a bit overkill for this project)
- two 470Ω resistors
Components for the Arduino MEGA version (picture 4):
- one Arduino MEGA2560
Step 2: Hollowing the Pumpkin
In contrary to general belief, cutting the pumpkin open on the top is not the best choice. If the pumpkin should last longer it is vital to consider that the stalk can still provides nutrients to the pumpkin. So, do not cut the pumpkin open around the stalk! I find cutting the pumpkin open in the back to be both discrete and functional.
Keeping this in mind, it is probably the best idea to cut the hole on the least pleasant looking side of the pumpkin (since this part will not be visible from the front). To cut a round hole, try to gradually twist the knife while cutting, twisting with the same force all around the hole. Finally, lever out the back with your knife.
To hollow out the pumpkin you can use a server spoon. Cleaning the inside of the cut out part of the pumpkin can be done with the concave part of the spoon pointing upwards (picture 3) - how one normally eats with a spoon (from now on referred to as the eating way). Inside the pumpkin, I found it easier to use the spoon the other way around first (convex side pointing away from the pumpkin). This works best on the upper side of the Pumpkin since scraping with the spoon "the eating way" around would not work very good with this obtuse angle. Scratching out the lower parts, it is easier to turn the spoon "the eating way" again since this allows better carving with the curvature and less stabbing into the pumpkin.
In the end, once all the pulp is loose and in the way, one can easily spoon it out into a bowl or directly into the trash.
Additionally, the more soft pulp is removed here, the later the pumpkin starts to attract mould. The pumpkin also lasts longer if you store it in a cool place.
Step 3: Sketching the Pattern
After taking the guts out of your pumpkin, it is ready for preparation of the sculpting.
First, I marked in the middle (with a small x) where the button will go later. I did the sketches for the lettering by hand, but it would also be simple to print some text and trace it.
For all these markings, it is important to use a non permanent marker (I used a board marker) to ensure that excess ink can be removed post-carving!
Drawing the segments of the digit-display by hand was a bit too tricky for me. Therefore, I created a template, which you can also see in the pictures above. For the display to have straight lines you can print and cut out the template. It is important to leave a little connection (piece of white paper) in the middle between the two digits, thus ensuring the right distance between them.
Drawing boxes in the corners of the outline (picture 4) ensures that one does not accidentally carve the digits without segments.
Step 4: Carving the Pattern
Once everything is prepared and ready to carve, it is convenient to start at the top right side if you are right-handed. This ensures the least amount of smearing of the ink with your hand or wrist. To carve the actual design, I used a rotary tool with a small milling bit (see picture 2 or Step 2).
After carving the design, the ink can be wiped off with a wet tissue/cloth.
To make lighting from the inside easier and better visible, it is possible to carve out the inside of the pumpkin a bit (at the corresponding places to the text) using a clay ribbon loop. To get a better idea on where the letters are on the outside while you look in the pumpkin, you can use a flashlight to shine through the pumpkin at the affected areas. With the newly thinned outer walls at these places, the lighting is much better better (see picture 5).
This thinning is not needed for the LED display since we will later on drill separate holes in the inside for the LEDs (step 10). It is therefore more convenient to drill deeper holes instead of thinning the outer wall. Additionally, this creates a better shield from the general lighting inside the pumpkin, leaving the display relatively dark if the digits are not lit (see the last picture above).
Step 5: Sculpting the Head
In addition to the main pumpkin, I decided to add a bit of actual sculpting to make the overall composition more aesthetically pleasing.
Pictures 1 and 2:
I took a new pumpkin and peeled off the the outer layer at the front with the big clay ribbon loop tool.
Then, I carved in the hairline with a small clay ribbon loop tool.
Afterwards, I used the big ribbon loop tool again to shape the eye-line. Since I wanted to carve a pumpkin face that is peering out behind the main pumpkin, I did not need to sculpt the entire face. As a result, I carved the eyes lower than they usually are. This results in a downwards shifted face with the mouth roughly at the bottom of the pumpkin.
Using the pointy side of the big loop tool, I sketched the nose.
Once that was done, I took a small ribbon loop tool to dig out where the eye-ducts are. You can do this to see how thick the wall of the pumpkin is. If the pumpkin flesh gets a lot softer, you have to stop digging - otherwise you will break through.
Then, you can devote yourself towards the eye-line and the forehead a bit more. Here, you can use the big ribbon loop tool again. The eye-line can be carved a bit deeper, and since the hair (carved later) should stand out a bit you can carve away some of the forehead.
To get more detail into the nose, I took away some more pumpkin under the nose and then used the small ribbon loop tool and carved out the nostrils.
Afterwards, I also elaborated the fine lines on the outside of the nose around the nostrils with the small loop tool. If you want to get even more delicate lines here, you can eventually use the scalpel to precisely trim these better.
This picture demonstrates more carving below the eyebrows, which gives the eyebrows more emphasis.
Next, you can sculpt the eyeballs. Cutting away pumpkin around them with a scalpel creates a rough shape. This can be rounded off and smoothly transitioned with the small loop tool.
Focusing on the forehead, most people have several wrinkles. I carved a large one, similarly shaped as the hairline, with the small loop tool.
Cutting inside the eyeballs, I created an almond-shaped cut to differentiate between eyelid and eyeball.
After that, I carved out the inside of the almond shape since the eyeballs are deeper than the eyelids.
Now, you can drill the pupils with the 7mm drilling bit.
The nose has some vertical wrinkles. You can cut these with the scalpel to make the face look more lifelike.
In the end, I added another wrinkle on the forehead and carved some hair with the small ribbon loop tool. I also cut little creases inside the hair curls to create the hair structure. Finally, I carved away more of the pumpkin around the face to give the face more depth.
Step 6: The Hands
The corresponding hands to the head are easier than one would think. I will walk you through the whole process:
First of all, you need a separate piece of pumpkin for the hands. Each hand needs about one third of a pumpkin - so one pumpkin for both hands should be more than enough.
I used the large kitchen knife to cut straight down the one side of the pumpkin (see picture 2).
It is best to remove the hard, outer layer of the pumpkin with a clay ribbon loop tool (the bigger one) before cutting out the rough shape.
The rough shape of the hands can be easily achieved by placing a real hand (ask a friend or use your own) flat on the outside of the peeled pumpkin piece and carefully tracing around it with a small kitchen knife or the scalpel. After removing the real hand, you can cut the lines through the whole pumpkin.
Rounding off of the upper and lower edges of the shape can be done with the scalpel or a small kitchen knife.
Once the rough shape is established, you can start to sculpt the thumb with the scalpel. To do this, you can put your own thumb where the sculpted thumb should be on the Pumpkin to see where the front finger joint will go. Above and below the joint, I thinned the pumpkin by slowly cutting away pumpkin on every side of the thumb (on the top, bottom and sides).
The thicker part that was left over now is the joint which I emphasised by cutting in the small wrinkles with the scalpel (sculpting these works best when cutting out grooves with a V-shaped contour).
Once the joint is done, you can concentrate on the fingernail, which basically is a U shaped cut. The groove should also be cut with a V-shape like contour.
Then, cut down the pumpkin on top of the nail and cut away the flesh next to the nail a bit more, forming a smooth transition to the nail.
As the last step for the thumb, you need to cut the creases at the joints on the bottom of the thumb.
Continuing on to the index finger, you can use your own hand again as a contour to cut around.
After rounding off the upper and lower edges, you might assert that the pumpkin finger is too thick in comparison to your own finger. In this case, you can cut away the lower layer of the pumpkin in order to make it more realistic.
The rest of the finger will be done similar to the thumb: thinning and cutting the creases at the joints and afterwards modelling the fingernail.
To outline the knuckles, you can use the small clay ribbon loop tool carving two lines that meet at the upper main part of the hand (see marking in picture 15).
The other three Fingers are done in the same way:
- place a real hand on the pumpkin as a guide and cut around the finger
- round off of the upper and lower edges of the shape with the scalpel
- compare it to your own hand and figure out where the joints would go
- thin the pumpkin above and below the joints by cutting away pumpkin on every side of the finger
- emphasise the joints with creases
- model the fingernail
- cut the creases at the bottom of the hand where the joints are; and
- outline the knuckles with a small clay ribbon loop tool
Step 7: The Electronics
The brains of the project is an Arduino UNO. This could be replaced by an Arduino MEGA, which would simplify the electronics a lot (see step 15).
This is my first attemp at Arduino programming and building. I have had an Arduino beginners kit lying around and never had the time to play around with it. Now that I actually did, I really loved it and enjoyed it a lot. I have some very basic programming skills in Java and had made one or two electronics projects (playing around with LEDs and stuff) before, but was nowhere near knowing a lot about any of this. Therefore, I write this guide for prople whith basically no knowledge of electronics and programming. Because of this, I hope rebuilding the project is easy enough for everyone. (I will only cover the Arduino basics needed for this project, but feel free to check out the new Arduino class on Instructables - free at the moment). Ask away in the comments if you have any questions!
I only used parts I already had at home, which is why I started the project the complicated way with the Arduino UNO and a whole bunch of transistors.
The Arduino UNO is less practical for this circuit since it only has a very limited amout of digital pins, making it impossible to light up two digits of the display at the same time! Therefore, I decided to switch between the two digits very fast (using the transistors as theese switches), lighting only one digit at a time. This switch in intensity is not visible to the bare eye, since the frequency is too high to notice.
In contrast, the Arduino MEGA has about double the amout of pins, making it possible to control each Led seperately.
Thus, the easy way is the one with an Arduino Mega, though I will mainly focus on the Arduino UNO version in this instructable (since I ended up using this). The MEGA version is discribed in step 15 and should also be easy enough to replicate too.
Step 8: Wiring and Arduino Setup
Additional comments to the diagram:
I used a battery kit for the Arduino to provide more flexibility. Plugging the USB cable into a cheap phone wall charger works too.
This wiring can be broken down into three segments:
- the LED digits and their controls
- the button
- the flickering LEDs as general lighting for the pumpkin
Each of these parts will be discussed in detail in the next steps.
Most people (those a bit more advanced or not electronically interested) will only need the sketch above...
For interested beginners, I have summed up some Arduino starting steps (see Insctructables Arduino class for further information) below:
Arduinos are small microprocessor units to control electronics projects.
For them to run according to your needs, they have to run some previously programmed source code (see step 9 for mine).
To program and transfer this to the arduino, one nedes the free Arduino IDE (found here: https://www.arduino.cc/en/Main/Software). After downloading and installing the program, it is possible to open projects and transfer them to the Arduino with the small arrow in the top left corner (second button).
Step 9: The Code
Very detailed comments to each part of the program are added into the Arduino code (.ino file below).
Similar to the wiring, the code can also be broken down into three subparts (digits, button, and flickering LEDs).
Each of these parts has a seperate method (subprogram inside the code) with the exception of the digits control, which is split into two methods to simplify the code. These methods are called upon from the main code inside the loop()method. The loop () method is the main part of the program, which is run over and over until the Arduino is disconnected from the power.
This means that basically the Arduino runs the following steps over and over again:
- check if button is pushed
- change the light of the flickering LEDs in intervals
- display the number of pushes on the LED-Digit-Display
Step 10: Preparing the Pumpkin for LEDs
Behind every stripe of the 7-Segment displays there has to be one LED. To know where to drill the hole from the inside, you can take a thin but long needle and poke through the middle of the stripe (from the outside). The needle has to be thin (so the hole it creates wont be noticeable later on) and long enough to go through the entire pumpkin wall. You have to be careful to stick the needle into the pumpkin perpendicular to the surface.
To see the needle on the inside you can create some contrast with a bright flashlight from the outside, thus lighting through the wall of the pumpkin. While pulling the needle out again you can either mark the spot with the marker or place your rotary tool/ drill bit there. After marking (placing your drill bit) and removing the needle, you can create a hole deep enough for the LED. I made a bigger hole with the rotary tool, continuing on with a 5mm drill bit (since I use 5mm LEDs) by hand.
While creating these holes, it is a good idea to check with the needle whether you are drilling straight or if you have to adjust your angle. If any of the holes end up completely in the wrong place (three of mine did), you can stuff some leftover pumpkin into the wrong hole and start over a bit to the side. This will be slightly visible in the end, but not very much.
The depth of the hole depends on the thickness of the pumpkin. I left about 5mm of the wall standing, giving a good bright stripe instead of a dot or lighting the neighbouring stripes. You can notice the wall becoming very thin if some water leaks out of the needle-holes in the front (using the drill bit by hand).
I started off creating a hole as deep as the LED at first and then gradually thinning while sticking a lit LED inside in intervals. Instead of shining with the LED itself, you can also use the flashlight which is less accurate but more convenient.
After drilling all holes, you can compare their depth which is related to the intensity transmitted while shining a flashlight from the inside.
Step 11: The 7-Segment LED Displays
My LED-Digit-Display consists of two digits. Each digit contains 7 LEDs arranged in an 8-shape. Each line of the actual Display on the pumpkin is lit by a separate LED. These LEDs are turned on or off individually to form the wanted number.
Switching between digits with transistors:
As mentioned in step 7, the Arduino UNO has too few pins to attach all of the 14 LEDs (two 7-segment digits) separately. To solve this problem, I used transistors to switch very fast between the single digits, thus only needing 9 pins for the two 7-segment digits (7 LED control cables and one cable each to control the transistors). The corresponding LEDs of the two digits are connected (top most LEDs, etc.) and the bases of the transistors associated with the same digit are also connected. The transistors I used are BC327‑40BK pnp-transistors (they are too powerful, but I had some of them lying around).
If this is your first electronics project, you will probably be wondering what transistors are:
A transistors is an electronic component which has three wires (collector, base, and emitter). In general, there are two types of transistors. The npn-transistor lets current pass from the emitter (+) to the collector (-) if the base has a voltage 0.7V higher than the emitter. The pnp-transistor lets current pass from the collector (+) to the emitter (-) if the base has a voltage 0.7V lower than the emitter. Therefore it functions as an electronic switch, being triggered with specific voltages at the base. (There is a lot more information about them in the internet!)
Keeping this application in mind, it is possible to switch between the digits of the display by applying a high voltage at the base of the one set of transistors and a low voltage at the base of the other set of transistors (I used a 470Ω resistor here to be on the safe side of restricting current/voltage). Reversing this polarity switches between the two digits. Changing the specific LEDs lit between each polarity-switch gives you the possibility to display different numbers on the two separate digits, while having the same wire attached to both upper LEDs. Once this switching reaches a frequency higher than about 60 switches per minute (30 times LED on), the human eye cannot see a flickering anymore.
Getting the Voltage for the LED right:
LEDs need a specific voltage. This voltage depends on the color of the LED and the manufacturer. You should be able to find out which voltage your LEDs need by looking through the manual or online description (I used the 5mm white LEDs with a voltage of 3.2-3.4V). While providing a higher voltage to the LEDs may harm them, providing a lower voltage will only darken them until they completely turn off at a specific voltage.
The output of the Arduino (HIGH) in general is 5V, which means that you have to use a resistor in front of every LED. The magnitude of the resistor depends on the parameters of your LEDs. To calculate this, one can use online LED Resistor Calculators (for example: http://www.hebeiltd.com.cn/?p=zz.led.resistor.calculator). If the calculated resistance is not available, always use the next highest one. The general formula is: Resistance [Ω] = Voltage [V] / Current [A] , where Voltage is the difference in voltage of your power supply (here 5V) and your LED. For this, you also need to know what Current your LED needs. In general, "normal", modern LEDs use about 20-30mA (0.02-0.03A). If you are not sure, a lower current is safer and only results in a darker LED. I used 100Ω resistors since my LED was about 35mA and 3.3V (3.4V/0.035A=97Ω)).
While adding the flickering LEDs to my project, I found out that you can control the output voltage of the digital pins of your Arduino by replacing the HIGH with a number between 0 and 255 (equivalent to 0 and 5V). The equation to calculate this number is: number = 255 / 5 * voltage. A bit more detailed description can be found in the code (above the setup() method).
You have to be careful though, since only the PWM (marked with ~) pins on the Arduinos seem to have this capability.
Step 12: Preparing the Pumpkin for the Button
To mount the button on the front of the main pumpkin you need to drill a hole with the same diameter as the button (or the created button mount) into the front of the pumpkin.
Here, you need to pre-drill the hole with a smaller drilling bit (I used a 5mm one) at the marked spot.
Then, you drill the actual, bigger hole on top of the smaller one with the corresponding center bit (I used a 25mm center bit since my 3d printed mount is roughly this diameter).
Step 13: The Button
For this project you need a push button switch, which connects the two wires when pushed.
Connecting the button is straight forward (similar to the StateChangeDetection Arduino example: https://www.arduino.cc/en/Tutorial/StateChangeDet...). Therefore, I will not elaborate on this. The wiring can be found in step 8.
I used the biggest button I could find around my place.
Since this was still too small for me, I got the idea of attaching a smaller pumpkin to the button. I know that the plain button would have worked too and that there are bigger and nicer buttons out there, so this is a purely optional part.
OPTIONAL pumpkin button with 3D printed parts:
I used a 3D printer since I have access to one, but this could also been done by gluing tubes into each other at the right spaces.
The parts I printed can be found below.
- The main part to stick the button in (picture 1 - one top left)
- The tube to secure the button and secure the pressing pin onto it (picture 1 - second from the bottom on the left)
- The pressing pin (picture 1 - one bottom left)
- The part to go over the pressing pin to make it more stable and have a bigger space to glue to (picture 6)
- The part to secure the button holder to the wall of the Pumpkin (picture 1 - second from the top on the left)
As a button, I used a smaller hard-shell pumpkin, which makes cutting the pumpkin open way more difficult than I thought. I ended up drilling holes around a circular line and cutting the rest out with a sharp knife.
Hollowing it out was very easy since it had a hard shell. I could just scrape everything soft out with a small spoon
For the glue to stick, I needed to dry the inside of the pumpkin. I used a conventional hair dryer to accomplish this. Alternatively, you can just let the hollowed out decorative gourd air-dry for a couple of days (starting this before the rest of the project is a good idea then).
Before gluing, I ended up shortening the pressing pin to the right length. I assembled the whole button and 3D printed parts and secured it to the pumpkin. To assemble the parts, you first have to put the button into the main part (part 1). Most bigger (built in) buttons have a threading and a screwing cap, which can be secured next. Afterwards, you put the pressing pin (part 3) onto it and secure both with part 2. Next, you can stick the cylindrical reinforcement for the pressing pin (part 4) onto the pressing pin and secure the whole construction in the pumpkin, sliding part 5 onto the back from inside the pumpkin (picture 4).
Pressing the button, you need to measured how much longer the pressing pin is than the pumpkin is high/deep. This is the amount you have to shorten your pressing pin.
To glue the pumpkin to the pressing pin, I used hot glue (a lot) - see picture 9.
Step 14: The Flickering LEDs
After the rest of the project was done, I realized neither a flashlight (too directional), nor a candle (too dangerous) would be convinient as inner lighting. Nonetheless, I wanted to also light the other writing on the pumpkin (besides the display).
Therefore, I added six extra LEDs (same as the ones used for the digits) as ambient light.
To still convey a candle-like effect, I programmed the Arduino to periodically change its output voltage of the LEDs. For this, I used the built in random() method, which can return a random number in a user-specified interval. For preciser information, see my comments in the code or the documentation on this method. (Which interval is needed depends on the Leds you use).
Each Arduino pin outputs about 60mA current. Since I wanted to supply my LEDs with roughly 20mA (mine are still almost as bright as with 35mA), I ended up connecting two times three LEDs parallel. This way the voltage for each stays the same and the current is the sum of all currents needed (here about 60mA).
You can play around with this though! Unlike voltage, excess current is not a bad thing. While the Arduino might provide more, the LEDs only draw as much as they can/want. You will notice a drop in intensity once the LEDs don’t get as much as they want anymore though. This is also not bad (in principle) but we want the most light we can get. Therefore, finding a good balance of number of LEDs and their intensity is best here.
I used six LEDs (two rows/pins of 3 LEDs each) since this was enough for my purpose (see videos/pictures for an idea on intensity). You can add as many LEDs as you have Arduino pins to spare!
In the end, I left the LEDs on a separate breadboard and didn't build a nice stand or hold for them. You can simply bend them a little towards the direction you want them pointing to get your writing to glow nice and evenly.
As some of you may have noticed, only one LED-row will flicker if you connect the LEDs the way I did. At first, I did not even notice. The one row is constantly lit due to the fact that it is not connected to a PWM pin on the Arduino. Switching this pin with one of the display pins (with PWM) solves the issue (e.g. switching pins 13 and 10).
For me, the flickering effect seemed natural even with one row not flickering!
Step 15: Arduino Mega Version
As mentioned before, using an Arduino MEGA2560 would simplify this project a bit.
Even though I did not use the Arduino MEGA for my actual project, I still want to share the idea behind it. Additionally, I will also comment on some of the differences between the UNO and the MEGA version.
The main difference between the UNO and the MEGA board is the amount of pins. Since the MEGA has sufficient pins, it is possible to control each LED separately, through its own pin (rendering the transistors obsolete). This also simplifies the schematics (see above)!
The essential change in the code lies in the display section. Aside from the pin definitions and their initialisation, one does not have to change anything else than the lightDisplay() method since this assesses which LEDs have to be lit. Here, I removed the switching between digits because both LEDs can be lit at the same time
Make sure to connect the flickering LEDs to PWM pins (one the Arduino MEGA the 2-13 pins) since only these are able to change the output voltage!
Step 16: Putting the Pieces Together
Placing the electronics:
To place the electronics inside the Pumpkin it is best to cover the bottom with a plastic bag. This prevents moisture, dirt, and pumpkin to ruin the electronics and also shields the components from mould after a few days (I am glad I thought about this!).
Since the button is already assembled, only the the LEDs and the wiring is missing. Here, we need to put the Arduino, the breadboards, and the already connected LEDs inside the pumpkin. It is easier to connect the Button wires now while the wiring of the LEDs does not obstruct the breadboard. The wires can be connected where the red and the black wires in the schematics of step 8 are.
Afterwards, you can stick the LEDs in the predrilled holes. Finding the right LED for each hole is easier if you label the wires with a bit of adhesive tape and a permanent marker while the breadboard is still outside the pumpkin.
Attaching the hands:
To assemble the hands, you hold them in position on the pumpkin and sketch around the wrist with the non-permanent marker (picture 3 and 4).
With the scalpel you carefully remove the skin inside the marked area. On the side without the marking of the wrist, you can just create a rounded cut (see pictures 5).
Then, carve in the pumpkin as deep as the hand is with the kitchen knife at the side of the wrist (pictures 5 and 6). Holding the hand to the pumpkin in this step helps creating a snug fit.
To attach the hands, first cut a wire which is about 20cm/ 8 inches long. This can be stuck into the hand at the wrist. Afterwards, stick the other side of the wire through the cut out area on the big pumpkin. Here, you have to make sure that the wrist of the hand and the cut out shape match and the transition looks natural. To absolutely secure the hand on the pumpkin, you can jam the end of the wire somewhere into the inside wall of the pumpkin (picture 8). This prevents a twisting of the hand due to its weight. Be sure to use wire thick and stable enough to hold the weight.
Step 17: Final Beauty
After following all the above steps, you should have your very own pointless button pumpkin.
I hope the instructable is understandable and you had as much fun with this project as I had.
If you have any questions, be sure to leave a comment below and I will get back to you as soon as possible.
If you liked this instructable, please vote for me in the halloween contests 2016 :)