Raspberry Pi Wire Shelf Mount + Wallet & Keys Hold + Spool Hook

Here’s a video:

For a while I’ve been logging my favorite prints here but some of them are two small to warrant a post. So introducing: #goodprints! At first I’m going to shoot for monthly installments, but as I print more, I’ll post more.

This time we’ve got 3 prints in the above video. Here are the details:

Raspberry Pi Wire Shelf Mount – Everyone knows that wire shelves are the best. Now you can securely mount a Raspberry Pi to one. Thingiverse Link

Here is the drawing for mating with the shelf:

Wallet, Keys & Leatherman Wall Mount – I’m constantly loosing these things in my lab, now they’re not going anywhere. Thingiverse Link


Wall Hook – This is for mounting stuff like filament spools, wire, and tape to the wall. It accepts 3/4 inchĀ dowels. There are two version, one 85mm long and one 150mm long (designed to fit hatchbox 1kg filament spools). Thingiverse Link

THERMAL RUNAWAY Errors on Prusa i3 MK2 3D Printer

This time we’re trying to work through a hardware bug!

Without warning, my printer would stop it’s current print and display “THERMAL RUNAWAY” on the display screen:

This would happen once every couple of prints or so.

According Prusa’s Docs a common cause of this is problems with the thermistorĀ connection. They show a graph that has very erratic readings from the sensor:

Ā This seemed like a good place to start so I re-seated the connector and used octoprint to generate my own graph:

No erratic readings, the temp would drop off and then start heating back up.

The problem ended up being the connection between the terminal lug and the wire on the heater in the hotend. To fix this, I cut off the crimp lug and stripped away some insulation. I put this into the screw terminal block. I’ve done a couple of prints and had no issues after making this modification.

Singer Parts Drawer Holder

I use theseĀ Akro-Mils 10144 D sets of drawers to keep my various electronics components organized. They’re cheap, reasonable quality, but most importantly inexpensive.


drawer

 

Something that I find myself doing a lot is transferring individual drawers around. For example, I have a specific drawer that holds short jumper wires for breadboards. Sometimes I bring this drawer up to campus for working in the lab. Same goes for my misc-resistor drawer. It’s much easier to move the drawer rather than re-packing it.

The problem is that these are open drawers! They don’t have lids, so what I’ll do is put it in a ziplog bag and throw it into my backpack. This is a bad solution, I have a 3D printer, time to get CADing.

I wanted the drawer to be able to lock in place, so it wouldn’t slide out of the holder while in transit, here is a video of the locking mechanism in action:

As I iterated on this design, it became clear that I could get away with a pretty thin wall thickness, and that extending the slot cut made it much much easier to flex the locking mechanism, so the grab point on the outer surface became unnecessary.

 

Annoyingly, I couldn’t figure out a good solution to be able to use this part without having to use supports.

Here is the Thingiverse Link

If you’re interested, I’m keeping a page of all of my prints. You can find it here.

Tiny Apartment Improvement Project – Wire Shelf Keyboard Holder

I recently purchased a Prusa i3 MK2Ā and it is glorious. The price was right, the assembly was straightforward and the print quality is probably better than I will ever need. After printing the requisite amount of dogs and other figurines, it’s time to start using this tool to improve my life.

Keyboard Shelf

I store a lot of my equipment on wire shelves. They’re cheap, easy to move around, and pretty strong. They can hold a lot of stuff, which means I keep a lot on them, and space, much like in the rest of my apartment, is limited. The server that is hosting this webpage lives on one of these shelves, and sometimes I have to manually work on it with a keyboard and monitor. It is a pain to have to dig out a keyboard, but it’s also not worth it to have a keyboard permanently on the shelf taking up space. That desire to maximize space is the motivation behind this project.

Here is the thingiverse page for this project with the parts, if you end up building or modifying it, let me know!

I’ve also added a page on this blog for holding more of my work with 3D printing, this will get fleshed out more as time goes on.

UV Resin Curing Cabinet | Final Code, Schematic, Bill Of Materials and Demo

Here’s a demo of the finished system:

In the end, it all turned out really well. Painting it white and using a white print stand was a good insight, the light reflects around the box pretty well for how few LEDs are in use.

The software flow chart has changed slightly. I removed the speaker as it wasn’t loud enough and added software debouching for the pushbutton interrupt service routine. Here’s that most recent version:

 

The interesting parts of the code are the cookResin function as well as the main loop of the Arduino:

Again, this all should all be explained by the flow chart. The full source can be found at the bottom of this post.

The circuit schematic hasn’t changed at all since this post, here’s a fritzing of what’s going on:

Super simple, basically a screen and a button. The parts to make this are here:

Assembly is super straight forward, if you’re trying to build one and have any questions, let me know!

Thanks for reading!

UV Resin Curing Cabinet | CAD Modeling And Physical Build and Installation

This past school year I too several classes related to 3D modeling. One class in particular, a class based aroundĀ SolidWorks. I hadn’t really been able to use the software again, not having the tools to actually execute. MADE@MassChallenge really has the whole kit, 3D Printers, a 40W Laser Cutter etc. All the tools of a hackerspace as a part of my job. Here’s a “finished” model of the system:

Cure Cab Models

The frame is built out of:

  • .22in thick masonite painted black on one side
  • The frame is held together with a series of L brackets and machine screws from home depot
  • The front opening is secured with two metal hinges from home depot

There were a couple 3D modeled components as well:

  • The four feet

I ended up gluing these down with hot glue even though they have cuts for screws. In the end, it wasn’t worth it to use more screws and add more complexity.

  • The electronics enclosure

View post on imgur.com

There is a frosted acrylic sheet inserted in the top. One of the goals of this project was to show off the tech, and I think this does that quite nicely.

  • The knob assembly

View post on imgur.com

The knob has a stem that comes of the back and forces the hinge back, keeping the door closed. I wanted to try and keep things as simple as possible. The threads I modeled weren’t within tolerance. So I just glued the nut in place so the knob could rotate freely.

  • The print stand, for holding up the prints so they cure evenly

View post on imgur.com

It doesn’t make sense to have the prints just sit on the bottom of the frame. I also cut inserts that fit the inside of the print stand. This is so resin doesn’t cure to the print stand so it can be used many times while only needing to change the cardstock inserts.

Here are some more photos of the build process:

Cure Cab Build Photos

I’ll include the plans to build this whole assembly in the final post for this project once it’s all finalized.

UV Resin Curing Cabinet | Declaration and Software Flow

This project is the first of what I hope to be many in collaboration with the MADE@MassChallenge Hardware lab. The primary goal of this project is to speed up the time to delivery on prints coming out of the Formlabs Form 1+ SLA 3D printer using UV LEDS. Here’s a proof of concept of my circuit:

One of my tasks during my internship at MassChallenge was managing the queue of incoming models to be 3D printed on our 3D printers. Turnaround is often a pressing issue when doing this. It was often the case that teams had a deadlines or presentations that they needed parts for. Shaving even minutes off of the time from submission to receiving a fully processed part mattered quite a bit.

The Form 1+ is an amazing printer. If used correctly, the print quality can be much higher than the other 3D printer in MADE, a uPrint SE Plus by Stratysis; a printer almost 5 times the cost.

The post processing involved with the Formlabs has a steeper of a learning curve and leaves a lot of room for possibly destroying a part in the process.

The problem is not a fault of Formlabs, but rather a problem in the chemistry behind the resins used to create the parts. They are photopolymers, and need UV light to be cured. It is suggested that this be done through exposure to sunlight, but that takes quite a long time. I also have a sneaking suspicion that there are adverse effects of doing this, but I canā€™t prove any of that as of now but hopefully more on that later.

As this is a project that will be used by people other than myself, it is worth it to commit time and effort into the user experience. Atheistic should also be taken into account as this has to stand up next to the beautiful design of the Form1+. In short, a UV LED strand, a 3A switch, a power supply and a Light tight box could functionally do the trick, but in this case a polished design is as important as the functionality.

At this point, a push button switch, a rocker switch and a 16×2 Character LCD will be the UI. The software flow is as follows:

I’ll post the final code when I finish, but this chart is basically what the code running in the above video looks like.

Thanks for reading, more on the physical construction in the next post.