Category Archives: Gadgets

3D printed handlebar phone mount (with wireless charging)

S5Mount27

As you might know by now, I ride motorcycles. When I do, I like to use my phone as speedometer, GPS and music player. There are plenty of generic handlebar mounts out there, but they all have the same limitations;

  • Having the screen constantly on draws a lot of battery, and there is no easy way to charge the phone while riding. Sure, you could connect a power adapter and fiddle with the connector every time you place or remove your phone from the mount, but that is cumbersome – and unsafe if it’s raining.
  • Riding in direct sunlight requires setting the screen brightness to 100% to be readable. Aside from the increased power draw issue, no available products I’ve found had a visor that could increase readability on the screen.
  • Most handlebar mounts are not made for high speeds. I have previously used one advertised for “bicycles and motorbikes”, but that one came apart while riding over 100km/h on the highway. The phone was only saved by the fact that I had a wired headset plugged in, leaving it hanging until I could safely pull over.

I decided to design and 3D print my own, specifically for my phone; Samsung Galaxy S5, which is itself waterproof unless you open the plastic tab to connect a USB cable to charge it.

After a number of revisions, I had a fully working prototype that included wireless charging. After testing it out, I could refine it further, and I finally had a design I was happy with. It will probably not win any beauty contests, but it’s extremely easy to use and works just as intended. I used the previous revision for more than 10’000 km (from a single print), so it’s been extremely reliable.

I have since made additional improvements and the next version is ready.

Features

  • Wireless charging.
  • Access to all buttons, including volume. Power button requires you to flip up the visor.
  • Weatherproof.
  • Drain holes (if left outside in rain).
  • Auto locking visor.
  • Headphone access.
  • Recess for camera.
  • Robust

How to use

Flip the lid up, slide the phone in, flip the lid down and you are ready to go. Starting the bike will turn on the built-in Qi charger, which will detect if the phone is in place. If it is, the charger will engage and power the phone wirelessly using resonant inductive coupling. This allows you to have the screen on at all time and still arrive to your destination with a fully charged battery.

Material

I used PLA filament for my prints. I considered ABS, which would at first glance appear to be a better choice, were it not for it’s high sensitive to UV radiation (sunlight). PLA is on the other hand more sensitive to heat, but the temperatures in Sweden rarely go high enough to compromise the structural integrity of pieces of this size. New materials come out all the time, and I’m sure there are better options out there by now, but PLA has worked for me.

Stainless steel mounting

Mounting the holder on the handlebar requires 4 x stainless M6 40mm bolts with Allen/Hex socket heads, along with matching locking nuts. One extra bolt and nut of the same size is used as hinge for the self-locking visor.

If you can get it, use non-magnetic stainless steel – test by holding a magnet to it and see if it sticks. This is to avoid causing interference in the induction-based wireless charging, which can also cause magnetic metal in close proximity to get warm. The charger does have a shielding plate, and even without it the distance to the bolts should be big enough, but better safe than sorry.

Note: Even when specified as non-magnetic stainless steel, bolts and nuts can still have a weak reaction to a magnet. This should be just fine).

Electronics

A cheap Qi charger or DIY Qi kit is placed in the compartment directly behind the phone, which will transfer the power from the charger to the Qi receiver pad in the phone.  Both the charger and receiver pad can be found on eBay for less than 3€ each, including shipping.

These chargers/kits usually have Micro USB sockets for power input. The power socket is placed downward, at an angle that makes it impossible for rain and splashes to get to it. The charger is then fastened and waterproofed using hot glue or silicon sealant. To power the Qi charger, you have a few options:

A. Use a portable USB battery pack. There are a plethora of options out there in different shape and size. If you don’t want to make modifications on your motorcycle, or want  to use this mount on a bicycle, this is your best option.

B. Power it directly from the motorcycle. To do this, you need a 12V to USB (or Micro USB) adapter, you can find cheap waterproof variants on eBay.

Many bikes already have a relayed auxiliary 12V jack inside the headlight housing, this would be the easiest option. If not available, using a relay to only provide power when the ignition is turned on is highly recommended. Though the power draw from the Qi charger itself is minimal when no phone is detected, some power adapters can drain the battery if left connected with the bike not running for a couple of days. A simple switch can be used to prevent this, but you always run the risk of forgetting to turn it off. Using a relay completely eliminates that risk.

This is free

If you want to print one yourself, I’ve made the 3D model freely available on http://www.thingiverse.com/thing:911206

Shopping list

If you don’t already have it, a Qi receiver is needed. This is placed inside your phone between the battery and the back cover. It usually have 2 or 3 pins, depending on model. Additionally, you will need:

Qi charger
Qi charger
Waterproof 12V to Micro USB adapter
Waterproof 12V to Micro USB adapter
5 x Stainless steel M6x40mm hex socket bolts with locking nuts
5 x Stainless steel M6x40mm hex socket bolts with locking nuts

Assembly instructions

  1. Print all parts. Recommended layer height is 0.1mm if you want it smooth. I went with 75% infill to be on the safe side.
  2. Sand, polish, prime, paint, acetone treat or anything you like (optional). The print shown in photos here did not get any post treatment except for removing supports. This will show you the raw look pretty much straight out of the printer.
  3. Test the Qi charger – if you have still not installed the Qi receiver in your phone, see step 8 for an example. Mine shows a faint red light when power is on but no phone is detected, and a bright blue light when a phone is detected and charging. If a phone is detected but has a bad connection (coils in charger and receiver doesn’t line up), it will blink. As you can see, the lower/right side of the phone has a better connection than the upper/left:
    Red light. No receiver detected.
    Red light. No receiver detected.

    Blue light. Receiver detected., charging phone
    Blue light. Receiver detected., charging phone
  4. Place the charger in the cavity of the printed mount (body) with the port down. Plug it in and insert your phone. If it charges keeps and doesn’t lose the connection every 10 seconds or so, you can just glue the charger in place and skip ahead to step 16. If not, we need to line up the coils in the charger and receiver.
  5. Unplug the charger and pry it open:

    Look Ma', no hands!
    Look Ma’, no hands!
  6. Unscrew any tiny screws that holds the PCB to the case:

    The ancient art of balancing precision screwdrivers
    The ancient art of balancing precision screwdrivers
  7. Remove the innards of the charger and turn it over. This one has a cracked shield, but should still work:

    It's not all it's cracked up to be
    It’s not all it’s cracked up to be
  8. Next, time to have a look at the Qi receiver. Remove your phone’s rear cover and determine where in the Qi receiver pad the coil is. If not clearly marked out, you can usually feel it by pressing down on it. Here I have marked it out with a colored pen to demonstrate the next step:

    No need to be fancy, this will be covered up
    No need to be fancy, this will be covered up
  9. Now we need Line up the the printed charger cover to the center of the phone (hint: It’s at 71mm), with the opening of the cover facing towards you. Make a vertical line on the inside of the cover along the center of the receiver coil:

    Rule number one
    Rule number one
  10. Line up the printed charger cover to the top (from your POV) of the phone. Make a horizontal line on the inside of the cover along the center of the receiver coil. After this you can put the cover back on your phone.
    Rule number two: Do not talk about ruler club
    Rule number two: Do not talk about ruler club

    Read ahead a few steps, the following should be done in a fairly quick order:

     

  11. Add a few dabs of hot glue or epoxy glue to  the charger coil:

    Hot dang!
    Hot dang!
  12. Turn the coil over and place it as close to the cross marking on the cover as possible while still being able to  reach the Micro USB port through the opening of the case. Attach a cable to make it easier to see if the port can be reached and is straight:

    Work fast
    Work fast
  13. Hold the PCB straight and apply hot glue or epoxy generously to the port with the cable still attached. (Tip: If you don’t want to clean up glue from your fancy cable, use a sacrificial or already broken cable. It only needs to be attached in this step to prevent glue from entering the port.)
    Keep adding glue until it it reaches the brim of the cover, while holding the PCB steady until the glue begins to solidify. The glue will both keep the PCB in place and keep moisture out.

    Don't be afraid of using too much glue. It is non-conductive, will not short anything out and will not damage the PCB .
    Don’t be afraid of using too much glue. It is non-conductive, will not short anything out and will not damage the PCB.
  14. After a minute or two, before the glue (or epoxy) is fully hardened, unplug the cable while holding the PCB secure. We only want the cable loose, not all the glue.

    Will be cleaned up
    Will be cleaned up
  15. Let it solidify completely, then trim the excess glue along the port edge. The entrance to the cover should now be completely sealed, while allowing a Micro USB cable to be connected.

    It's functional
    It’s functional
  16. Time for the next chapter. We will now attach the charger/cover to the main body of the mount, then seal the edges.
    Start by masking the body (cavity side) with masking tape, then trimming the edges with a scalpel or craft knife, This will help us get a nice sharp edge for the sealant.
  17. Place the charger/cover in the cavity with the port facing the bottom hole of the body.
  18. Apply a sealant as hot glue, epoxy glue or silicon along the edges of the cover. If you don’t want it all over the cover, you can place something round in the middle, such as the bottom of the original Qi charger case:

    Bottom of original Qi charge case is used to create a nice edge for the hot glue
    Bottom of original Qi charge case is used to create a nice edge for the hot glue
  19. Before hardening completely, remove the center object (if used):

    Scalpel used to make sharp edge
    Scalpel used to make sharp edge
  20. Trim sealant with something sharp:

    Excess sealant trimmed with scalpel. Qi case bottom used as center sealant blocker removed.
    Excess sealant trimmed with scalpel. Qi case bottom used as center sealant blocker removed.
  21. Remove masking tape:

    All cleaned up
    All cleaned up
  22. Place phone in the mount to make sure the sealant is not protruding so much as to block it:

    It fits!
    It fits!
  23. Place two nuts in the upper holes as in the photo. Nylon lock (if used) should point up:

    Lock it up
    Lock it up
  24. Place the visor so that if blocks the nuts. Fasten it with a bolt and nut:

    Holding the nut with pliers might help while tightening the bolt.
    Holding the nut with pliers might help while tightening the bolt.
  25. You should now have something that resembles an angry pig:

    Angry pigs are angry
    Angry pigs are angry
  26. Place the phone in the mount and make sure that you can close the visor:

    Almost done!
    Almost done!
  27. Connect a Micro USB cable to a charger and verify that the phone is charging:

    It's alive!
    It’s alive!
  28. Insert the remaining two nuts. You can now attach it to your handlebar using the clamps and bolts:

    Everything in place
    Everything in place
  29. Connect the 12V to Micro USB cable. You’re all done!
    S5Mount27

Enjoy your new mount! Now you never have to worry about getting lost or your phone running out of battery while riding again. Just remember to keep your eyes on the road!

Frosty, the 3D printed Mini-ITX case

I made another computer case.

Frosty - fully assembled case
Frosty – fully assembled case

Our home server/HTPC broke down after close to 6 years, and it was time to replace it. Being me, I didn’t want to just buy an off-the shelf machine – where’s the charm in that?

This one is a little different than my previous builds. I didn’t modify an existing enclosures this time, but instead created one completely from scratch. 3D modeled and 3D printed based on nothing more than my own ideas and my own measurements.

I do like reusing and repurposing existing things, and I try to not get stuck in a throw-away mentality. This new case is however entirely made from renewable or recycled materials. The main body is printed using biodegradable PLA plastic (made from corn starch or cane sugar). The only other parts of the case consist of a power switch and an LED, both taken from the failing computer it was meant to replace.

I had an idea of a completely smooth case without any visible corners, with a single air inlet on the top connected to the CPU fan. A number of smaller air outlets near the bottom would force the airflow to spread out around the motherboard and the rest of the components. The shape would initially resemble a simplified cloud, but that quickly changed.

I was impressed with the layout, performance and tweakability of the Asus H81T Mini-ITX motherboard that I used for the 1-Up NES case mod, and decided to use another one for the new case. Most important was the fact that the H81 has a rear power jack that fits standard laptop power bricks, and I could pick up a used one from Dell on eBay that worked right away, no modifications needed.

I used a modeling tool that I already knew; Tinkercad – a free, browser-based online CAD tool from AutoDesk. It has limited functionality and performance, and I’m planning on learning a “real” CAD program soon (Fusion 360?), but I was eager to get started right away. After a number of versions and revisions, I had a rough printed version (5) up and running 24/7 for about a month. After a lot of checks, changes and tweaks, I finally printed the final version (8) on my heavily modified RigidBot 3D printer. By now the initial project name Fluffy had changed to Frosty, and the design would now look more like snow than a cloud. I made a snowflake design for the air inlet, which also serves as a fan guard.

After sanding I applied a few layers of acrylic clear coating to get more of a snow crust look. PLA is notoriously hard to sand as it melts and clumps up if you go too fast due to the friction. I only went up to 240 grit, which is why the surface isn’t perfect. If this was a job for someone else I would go to at least 800 grit, but as it will only be used at home this is good enough.

Bottom and top parts after sanding and clear coating
Bottom and top parts after sanding and clear coating
Insides before assembly
Insides before assembly

When assembling the computer, pretty much everything fit perfectly. I only had to drill the hole for the LED a tiny bin larger and use a scalpel to shave off about 0.2mm for the power switch.
Unless you have your ear right next to the computer, you can’t hear it running. Since I use an SSD, the only moving part in the computer is the CPU fan, and Intel did a fantastic job with making it whisper quiet – at least when enabling the Q-Fan control in the UEFI bios.
With the CPU on full load on all cores at 3.2Ghz, the computer is still almost dead silent and the CPU temperature is usually around 30°C.

All in all, I’m happy with the results. I’ve learned a lot and had fun doing so.

If you want to print your own, I’ve made the .stl files freely available at http://www.thingiverse.com/thing:1241259

Outline of case functionality
Outline of case functionality
Power LED inserted
Power LED inserted
Power switch inserted
Power switch inserted
Empty case, seen from rear
Empty case, seen from rear
Fully assembled case, seen from rear
Fully assembled case, seen from rear
Everything in place except top cover
Everything in place except top cover
Everything in place including top cover
Everything in place including top cover
At it's current home, next to external HDD. Previous computer occupied entire shelf, hence the extra space.
At it’s current home, next to external HDD. Previous computer occupied entire shelf, hence the extra space.

The Volume Pill

The volume control on my guitar amp does not behave as I want it to.

Today it is like this:
Amp volume at 0 = (silence)
Amp volume at 1 = LOUD
Amp volume at 2-10 = LOUDER

This is a problem when using a distortion pedal without a dedicated volume control, as our very easily disturbed neighbors starts banging the wall at volume 1, and I sometimes want to play without headphones.

For the distortion to really kick in I can’t lower the volume knob(s) on my guitar too much either, so I had to introduce an additional volume control to take effect after the pedal.

In short, I needed to go from here:

[Amp]<--[Pedal]<--[Guitar]
to here:

[Amp]<--[Volume]<--[Pedal]<--[Guitar]

So I made a small volume controler using a 500k potentiometer and two 1/4″ jacks. I didn’t have a good enclosure at hand so I simply used an old plastic medicine jar.

The Volume Pill
The Volume Pill

It’s not pretty, but it works!

The Pedalboard Project

About two months ago I bought an electric guitar after a 17-18 year long hiatus. A cheap Les Paul copy that looks good but plays bad. 😉 I also bought a few effect pedals such as Overdrive, Distortion and Echo/Delay. And then a few more. I realized that I needed a pedalboard to avoid having to patch in everything and getting wires all across the floor whenever I wanted to play. I was looking at a number of the pre-made solutions and also a few custom ones before deciding to build one myself. Wanting to add some additional functions and a semi-retro style, I decided to go with wood as my material of choice. After measuring, sketching, drawing and calculating about two weeks I had a finished design. I bought two pine planks and began by drawing up lines for everything that were to be cut and drilled. I wanted an empty place on the right side where I could add additional pedals such as Wah, or as in the pictures below, a multi-effect pedal. After producing the rough pieces, I began sanding everything by hand. Since this is not going to be displayed on a pedestal in an art museum, I only went with 120 grain paper. The top parts were first glued, then drilled and screwed for additional stability. After a single layer of wood stain, I assembled the pieces using a piano hinge for opening the lid and a pair of chest clasps for fastening the lid when closed. Wanting something to carry the pedalboard with, I opted for IKEA ULVSBO drawer handles. While at IKEA, I also picked up the laptop support BRÄDA, which after cutting out a piece from a lower corner and flipping upside down was a perfect fit for the dashboard. Filing the corners and sanding it in a single direction made it look a bit like ebony. Adding all jacks, switches and panels, next up was the soldering. No biggie. Aside from power, I wanted 4 jacks on the pedalboard:

  1. Guitar in. Also used if you want to add additional pedals first in the pedal chain.
  2. Aux in. Will be sent directly to the output(s) so that you can attach your phone or audio player for jamming without it being affected by the pedals. I might add a separate booster/volume control to this later.
  3. Amp out. Also used if you want to add additional pedals last in the pedal chain.
  4. Headphones out. I might add a separate booster/volume control to this later.

The control panel has the following functions

  1. Main power. Powers the whole pedalboard on/off
  2. AC/DC. There is a 2x9v battery compartment (connected in parallel)  under the lid for powering the pedals with batteries instead of using an AC/DC adapter. This switch allows you to change power source on the fly.
  3. Pedals/Bypass. Allows you to send the Guitar in signal directly to the outputs, bypassing all pedals.
  4. Voltmeter. Very useful when running on DC power to see how much is left.

All power cables are detachable and reroutable. This gives you the option to power only one or a few pedals with battery power and the remaining pedals with the transformer. This includes the main power switch, voltmeter and LED strips. If running everything on batteries, it eats batteries fast – especially the Korg RP50 multi-effect – but it works! After adding some industrial-strength Velcro, it was only a matter of arranging the pedals how I wanted them, patching the audio signal and routing the power cables. I also added TDK ferrite cores around all patch/power cables to minimize electrical interference. Being only the second wood-based project I’ve done since I was 15, I’m quite happy with the results. What would you have done different? I am already thinking about version 2. 🙂

The Chest Case Mod Project – Part III

The Chest Case mod project has been moving forward! If all goes as planned (which it rarely does), the final assembly will be tomorrow!

First off, I made two errors while making the design:

  1. I forgot to take the cables into account
  2. I forgot to take the cables into account
To start, the HDD/SSD cage will have to be moved from behind the PSU. Since the PSU is modular, meaning you can attach and remove the power cables, the removable cables are taking slightly more vertical space due to the connectors to the PSU. This means I’m about 1 cm short of fitting the drive cage in the planned space. I will therefore relocate it higher up, elevated partly inside the chest lid. It will still not be visible when the lid is closed, but will be the first thing you see if you open it.
Secondly, I did not study the physical component design of the motherboard before starting this project. All the motherboards I have ever used in the past when building computers have had their HDD (ATA/SATA) sockets flat on the top of the motherboard. This one has it on the side, on the opposite side of the rear panel where the USB, audio etc. ports are. That means that the SATA cables won’t fit unless I open a hole in the front of the chest for this very purpose. All angled SATA connectors are angled the wrong way, pointing down to the bottom of the chest. Or so I thought, after trying the three different kinds I had at home. After some scouting I did however find SATA cables with inverted angles, meaning the actual cable would point straight up. The space for the connector was still too tight though, only leaving a few millimeters to the edge, where it would be impossible to fit any connectors at all.  However, carefully grinding down part of the front board of the chest from the inside proved to give just enough space to fit the cables. I did have to be very careful when grinding though, as the front board is only about 4 mm thick. When done, the board was only about 1 mm thick in the area where the SATA ports are.
Other than that, I have drilled, filed, grinded, polished and cut the case to have all the openings it needs to have, from air vents for the fans to a large opening for the PSU and motherboard rear panel.
Today I did some last revisions to fit the video card that was slightly to high when fitting it, and finished off with staining all the cuts and holes (“Dark Oak” dye), and also applying it to the surrounding chest panels for it to blend in better.
Tomorrow I will pick up the inverted SATA cables and a proper version of Windows 7, and I’m hoping to have the entire computer up and running tomorrow or the day after that.

Edit: All done!