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Applications and Implications

This week it is time to look inward and start asking the big questions.

WHO ARE YOU? AND WHAT DO YOU WANT!?

Avatar references aside, there are actual questions about my final project that need to be answered, so let’s get to it.

Questions

What will it do?

My final project is going to measure the diameter and roundness of 3D printing filament to let the user know if it is usable or not.

Who has done what beforehand?

The main inspiration for this project came from using an ARTME3D filament extruder and stumbling across the InFiDEL, a low cost inline filament diameter estimator originally created by Thomas Sanladerer a.k.a. MadeWithLayers.

What will you design?

I will design a main PCB and multiple connected sensor boards as well as an enclosure to house all of the electronics and mechanisms.

What materials and components will be used?

Since most of the parts are 3D printed, the main material is PLA filament.

I use multiple colors from PolyMaker and Bambu Lab but you can stick to your favorite one.

Other key materials include:

  • 1x double sided FR4 PCB sheet

  • 1x SEEED Studio XIAO RP2040

  • 3x ATTiny412 (SOIC-8)

  • 3x Honeywell SS59ET hall effect sensor

  • 1x Rotary encoder with switch

  • 1x 1,3” OLED Display

  • An assortment of miscellaneous electronics

  • An assortment of M3 and M2 screws

  • 1x Angled USB-C to USB-A cable

  • ~40cm 28AWG 4 wire ribbon cable

  • 4x Amphenol IDC connectors

You can find a complete bill of materials on my final project page.

Where will they come from?

Sources are listed in the BOM mentioned above.

How much will they cost?

Here is a rough breakdown of what building this project is going to cost.

Amount Material Cost
500g Filament 15€
1 FR4 Sheet 10€
Electronics 20€
1 USB power supply 10€
1 USB cable 4€
1 IDC cable 12€
4 IDC connectors 3€
TOTAL 74€

Of course you also need a few crucial tools, but those should be available in any FabLab.

For a more detailed look at the cost, check the aforementioned BOM.

What parts and systems will be made?

  • A mainboard based on the XIAO RP2040

  • Three sensor boards with an ATTiny412 and SS59ET hall effect sensor

  • 3D printed sensor modules

  • 3D printed case

  • lasercut cable clips

  • vinyl cut sticker labels for the UPDI pins

What processes will be used?

  • 3D printing

  • PCB milling

  • Soldering (SMD and THT)

  • Lasercutting

  • Vinylcutting

What questions need to be answered?

  • What are the minimum and maximum values to determine whether a piece of filament is usable or not?

  • How can the sensors be calibrated in a consistent way?

  • How will the user be notified about a bad piece of filament?

  • What would actually working with this “product” look like?

How will it be evaluated?

  • Does the system reliably measure the diameter and roundness of a given piece of filament?

  • Does the system reliably notify the user of potentially bad filament?

  • Does the system keep working for long periods of time?

  • Is the system easy to use?

  • Does the system interfere with the usual operation of a 3D printer?

What tasks have been completed?

  • Design, manufacture and program main PCB

  • Design, manufacture and program three sensor PCBs

  • Design an enclosure

  • Plan out internal wiring and system integration

  • Create a wiring harness

What tasks remain?

  • Manufacture cable clips via Lasercutting

  • Manufacture UPDI pin stickers via Vinylcutting

  • 3D print all remaining parts

  • Assemble everything

  • Perform shake test

  • Perform function tests

What has worked? What hasn’t?

I am pretty sure that by saying this I am going to jinx it but so far it is amazing how smoothly manufacturing the parts has gone.

Whether it was PCB milling, lasercutting or 3D printing, not a single buildjob has failed.

It really goes to show how things can just work if you take care of your machines and design for the respectiv process.

Another thing that went off without a hitch was the whole I2C and programming stuff.

I mean there were some design errors in my early boards that prevented it from working but those errors were pretty easy to fix.

One last positive thing before I highlight the things that didn’t work out: Ribbon cables and IDC connectors.

They are so simple, elegant and easy to use. Love it!

Flipping over the coin, a thing that didn’t work out and really annoyed me is that I couldn’t stick to my initial design.

Having the sensors at different angles has limited my freedom in design so much, that I wish I had considered this earlier and built around it from the beginning.

Also over the weeks it has always annoyed me when I was not able to combine the weekly assignment with the current state of my final project.

I did learn a lot of things that I implemented later, but combining it would have cut down on a lot of frustration and worrying about time.

The last complaint that I have is probably the biggest, the initial idea of having my system influence a running print job just was not feasible to implement anymore at some point.

It is the feature that would have set this project apart from any other filament sensor out there and while this definitely leaves room for improvement in the futer, it just really sucks that in the end of the Fab Academy I had to stick to the minimum viable product.

What will happen when?

I would be lying if I said I had a proper plan for this.

I am already behind schedule with writing this, so I’m not going to pretend that I have the situation under control when it comes to time management.

All I have is a list of ToDos and the drive to finish what I started, we’ll see where this takes me.

What have you learned?

The amount of stuff I have learned is too much to write here, so you should definitely check out all of my weekly assignments.

I think I am going to write a neat little reflection paragraph over on my final project page to properly answer this question.

Thank you for reading my self-interview, no downloads this week but remember to stay hydrated!