For a while I’ve been watching PET bottles filament maker projects on YouTube.
There are a lot of them, and I have to say, it is a very interesting project and I wanted
to make one as well.
So, following the same steps and ideas, I’ve made the design, made a schematic for a PCB,
3D printed some parts, made some tests and slowly made my own bottle to filament machine.
Right now is not perfect, but at least, does it work?
Well, stick till the end of the video to find out.
I’ve made a PCB to go with this project and order it from PCBWAY, and basically, together
with an Arduino, it should control the heating block temperature, the feeding speed, maybe
a fan, it could also have a display and a control encoder and so on.
So guys, let’s see how to make a bottle to filament maker and then try to print something
with that filament.
So, let’s get started.
What’s up my friends, welcome back.
The part list for such a project has 3D printed parts, screws and nuts, bearings, also a PCB,
electronics such as Arduinos, drivers, mosfets and so on.
We also need a wood board, a 3D printer heating block, a stepper motor and much more.
If you search on youtube, you can find all sorts of bottle to filament makers and I’ll
put some other links below for other videos.
The idea is to cut the bottle into long srips and we will see how to make that later in
the video.
Then we pass that strtip through the heated block with a nozzle output close to 1.75mm.
That will give it the cylindrical shape.
To pull the filament we use a motor, gears and a spool.
This is the 3D design I have so far, so let’s begin and see if we need to change something.
First I’ve made the filament puller.
For that We have these 3D printed parts.
Two big gears and a cylinder in between.
All these parts were printed with PLA filament, 0.2mm layer height, 2 perimeters, 20% infill
and 0.4mm nozzle.
To increase torque, I’ve made another small gear and this gear will be rotating with another
smaller gear connected to a stepper motor.
I’ve made two support sides to keep the gears in place.
This motor will be controlled with a stepper driver that goes on the PCB, right here.
If you want to try this same project, you can download my PCB for free and then order
it to PCBWAY as well.
For that download the GERBER files and go to PCBWAY.com.
Here click the quote now button and select the PCB size, the amount of PCB and the solder
mask color.
Then click save to cart and on the next page click the upload button.
Here upload the GERBER file you’ve downloaded from my website.
Wait a few moments for a PCBWAY engineer to confirm your files and then make the payment
and receive the PCBs in a few days.
The finish quality is great as always.
I never had problems with my prototyping PCBs and for only 5 dollars I can test my projects
over and over again till I have a final version that I like.
Anyway, once you have the PCB you can try this same project, so let’s continue.
I’ll make this project on the go and then, if needed, I’ll make a second version and
improve the parts that might go wrong with this one.
We need some sort of wood board to screw all the parts on it.
I’ll use this one and first I mark where I want the filament puller to go.
Then I make the holes.
For the gears you’ll need 2 bearings on each side.
These are 608ZZ bearings.
You also need an M8 threaded rod, nuts and washers.
Now I use some M3 screws and fix the entire support in place like this.
Actually I first placed it backwards so I had to make other holes and fix it in place
the correct way and also leave some space for the stepper motor.
Once the puller is in place I mark the holes for the stepper motor support and make sure
that the small gear will be in touch with the big gear.
Then I use the drill again to make the holes.
Then I use some short M3 screws and a NEMA 17 stepper motor and screw it in place on
the 3D printed support.
Then I screw the support in place next to the other gears.
Basically, the puller system is now ready.
The next part we have to solve is the heating block.
For that I’ve ordered all sorts of aluminum blocks of different sizes.
I even ordered some aluminum bars so I could maybe try making my own block.
But finally I’ve ended up using this stock one from a 3D printer and it has a 12V heater
inside and a thermistor so we could measure the temperature.
My PCB already has a voltage divider and a thermistor connector so we could later measure
the temperature with the Arduino.
I first enlarged the input and removed the thread of the aluminum block with a 6mm drill.
Then I make the input angle of the hoel a bit bigger.
Then I added the brass nozzle and enlarged the hole using a 1.8mm drill.
The standard filament size is 1.75mm but by pulling harder on the filament, even with
a 2mm hole for example, we can make it close to 1.75.
We should try different hole sizes and see the results.
Anyway, now using this metal bracket used with stepper motors, and also this piece of
an old PCB, I secure the heating block in place.
Is important to use metal parts because this will get quite hot, the melting temperature
of PET is above 200 degrees.
Now we have the heating block with a support, wires for the heating element and the thermistor.
I don’t screw it in place just yet.
Next I’ve made this small spool to keep the bottle PET strip.
This will be screwed in place on the other side of the board but a little bit to the
side, and this is why.
In order to make sure the plastic strip wont rotate and will always be horizontal, we have
this other part that will keep the strip straight and point it towards the heating block.
So I screw in place this part as well.
And next I decide where to place the heating block and using two more screws, I fix it
in place as well.
When I have everything where I wanted, more or less, I make some holes for the wires so
they could go below the wood board.
I want to keep the electronics below.
I’ve also printed this legs and this will give us some space from the ground so the
electronics could fit below.
I make holes and add a leg on each corner.
Now the pulling and heating system is ready.
Is time to prepare the PCB.
Order my design from PCBWAY.com.
As you can see the board has a space for an Arduino, a stepper driver, connector for the
main input supply, connector for the heater and a fan, more connectors for the termistor,
a rotary encoder, a display and some other inputs and outputs.
It also has spaces for two MOSFETs that would control the power applied to the heating element
and the power for a possible cooling fan.
I solder female pins for the Arduino and stepper driver.
THen I add the MSOFETs.
Finally I add all the capacitors and resistors.
I also add the input and output screw terminals.
This is the schematic for this PCB and you could download it from below this video.
As you can see, the board works at 12V, so we need a 12V supply.
Now the PCB is ready.
As you can see it has 3mm holes so we could screw it in place below the wood board.
But first let’s test it.
First I connect an i2c display and the thermistor to the PCB.
I want to see if we can read the temperature.
I upload the first code that will only read the thermistor temperature and print it on
the screen.
It looks that it works ok.
Next we need to control the stepper motor.
Connect the motor to the driver output.
To test this, I have this other code that is using the aaccel_stepper library to change
the speed of the motor according to the potentiometer value.
I upload it and as you can see, I can activate the rotation with a push button.
Then using a potentiometer I can change the speed.
So this also works ok.
Last part is to control the power applied to the heater with the MOSFET and also read
the temperature and control the setpoint at a certain value, let’s say 200 degrees.
I’ve made this code with a PID control that will change the PWM value applied to the MOSFET
and keep a steady value.
I’ve uploaded the code to the arduino and connected the heater and the thermistor to
the PCB together with the LCD screen once again.
As you can see the PID value gets lower as the temperature reaches the setpoint of 200
degrees and then the temperature will stay more or less on that point, so the temperature
PID control also works.
Everything works, so I’ve connected everything below the wood board and fixed the PCB with
screws.
For now I’ve glued the screen and the controls here on the board as well.
Then we create a final code that will heat up the block, read the temperature and control
the speed of the step motor, all at the same time.
This is the final code that you could download from below.
Upload it and let’s give it a test.
The temperature stays around 200 degrees, the values are printed on the screen and I
can control the motor speed using the potentiometer.
Is time to create some filament.
For that we first have to make some bottle plastic tape strips.
First we need to make the bottle smoother.
As you can see, this bottle is not smooth, it has all sorts of shapes on it, and we don't
want that.
The best way to make that is to place some water inside the bottle.
Then put some water to boil in a cooking pot.
Place the bottle inside the cooking pot and let it boil so the water inside will vaporize
and increase the pressure.
At the same time you could make the plastic softer by heating it up with a heat gun.
As you can see, the bottle is now smooth.
We can cut it.
I’ve tried different methods for the stripes cutter.
The one with the bearing should be better but I wasn’t able to make the bearings perfectly
flat.
Anyway, I’ver just printed this support and placed a cutter knife.
The 3D printed part should give the maximum width of the plastic tape.
Cut the bottom of the bottle.
Cut a small part and insert it into the cutter.
Pull and you will see how the tape is created.
You can make a few meters out of each bottle.
It depends on the bottle size.
I wind the plastic tape on the spool holder.
Heat up the machine.
Cut a very thin part on the tip of the plastic tape.
Insert it into the extruder and pull it using some pliers.
Pull till you have enough length.
Insert the plastic filament into the pulling spool.
Increase the speed and adjust it to have more or less a 1.75mm filament.
You might need to change the speed, the width of the plastic tape or the nozzle hole diameter.
Try till you get good results.
Also, the more you inflate the bottles, the thinner will the plastic wall be so the filament
will be smaller later.
Have that in mind.
So, just like that in a few minutes, I have my first filament made out of a PET bottle
and looks promising.
And using the same method I’ve tried different colors.
All is left to do is to try the new filament with a 3D printer.
I place the filament over an old empty spool I had laying around.
I preheat the printer at 260 degrees.
Insert the filament till you can see some plastic coming out of the nozzle.
I print an example file of a cube.
We start and it seems to go ok but the printer is having problems staying at 260 degrees,
I never printed at that value.
The test cube was turning out more or less.
As you can see, after a few layers I’ve decreased the speed and increased the flow
rate and you can see the difference.
Also, after a while, the filament got stucked for a moment so a few layers weren’t printed.
Then the print continue without any problems.
So I guess, the material is ok but you have to make more tests till you get the good configuration
for the speed, temperature, flow rate and so on.
but hey, I was able to print something using plastic from a PET bottle.
That’s pretty cool, right?
Obviously, there are a lot of parts that could improve with this project but that’s for
a future update video since I was working on this one for more than a month.
But feel free to improve it yourself.
So guys, that’s how you could make filament out of PET bottles.
You have my PCB below for download, get it and order it at PCBWAY.
Get my schematic, my code and everything you need for this project form electronoobs.com
and try your own filament puller machine.
I hope that you like this project and if so, consider giving me a like or comment below.
Thanks again and see you alter guys.