Archive for the 'Art' Category

DrawBot Badge – Workshop

Woot!

I and Jason Huggins (@hugs), of Tapster Robotics, will be giving a conference at the 2018 Hackaday SuperConference. The conference will be “Getting Started in Small Scale CNC and Robotics (Build a CNC Badge)”. By the end of the workshop you will have built, programmed and learned to use the DrawBot Badge.

The badge is way more than that though. The badge PCB is a very capable general purpose CNC/Robotics controller. We considered every small scale CNC machine we could think of and made sure this badge could control it. Here is what it can control.

  • (3) Stepper Motors
  • (3) Hobby Servos
  • (3) Homing/Limit switches
  • (1) Variable Speed Spindle PWM signal
  • (1) Laser Module (Power control and Safety interlock)
  • (4) Control switch inputs
  • (1) Probe switch control
  • (1) Coolant Control
  • (1) High current (3 Amp) output for relays or solenoids (includes flyback diode)
  • (1) i2C interface (for displays or Sh**ty Add-Ons)
  • (1) SD Card socket to store and run files

You can’t use every feature at once, like the Laser PWM and Spindle PWM are the same signal, but they are broken out logically to multiple, machine specific, connectors.

It is all powered by an ESP32 running Grbl_ESP32, which provides serial, Bluetooth and WebUI interfaces.

The first half of the conference will cover tips and tricks for getting started with making and controlling small machines. We will also learn and use some basic gcode to control some motors and other items. It is a just a basic intro to get you started and discover some resources. During the second half we will build the DrawBot badge.

If you are interested, sign up for the conference and be sure to get into the workshop when that is posted. The workshop will be limited to about 20 people, but I will bring extra badges for sale and will be happy to help build and hack them all weekend. I will also bring extra motors, servos, switches, etc for hacking up simple machines.

Open Source

Within the next couple weeks, all of the documentation will be released. Badge kits will also be for sale on Tindie after the conference.

 

 

DrawBot Badge – Preview

I showed off an early version of my DrawBot Badge at the Hardware Happy Hour last night. Some tweeted pictures generated a lot of questions, so I thought I would write a quick post about it.

I have been following the #badgelife thing for a few years and felt that the mechanical and CNC world needed to be represented. The goal was to create something small, safe, fun and something anyone could learn to use. A drawing machine seemed the perfect fit.

Drawing Surface

I decided to use 3″ square Post-It notes. The main feature is that they are self stick, so I don’t need any clamps or tape. It is also cool that you can stick them to things when the drawing is done. They are cheap and easy to find. I like the kind that have the majority of the back (full stick) covered in adhesive. This means you can use a small stack of them and peel them off as they are done.

 

Drawing Mechanism

I tried to make the drawing mechanism as tiny as possible. The size is about 30mm x 70mm. It uses (3) of the smallest readily available class of hobby servos call micro servos. You can buy these from AliExpress for as low $1-$2 in low quantities.  The choice of the arm configurations was primarily based on tightly packing the the motors, but I also wanted something new and interesting.

The pen lift is simply a cam on one of the motors. The entire mechanism rotates on two 3mm bearings. In my experience with drawing machines, gravity is the best way to engage the pen to the work. The mechanism needed to work hanging from a lanyard or sitting on a table.

Electronics

There is only one electronic item right now. It is an ESP32 dev module. There are also (3) connectors for the servos and (1) for voltage monitoring. The entire back of the badge is a PCB. I made the board full size to enclose the back and the pen lift cam need to push on something. I have big plans for the rest of the area though. The ESP32 provides the Bluetooth and Wifi needed for the remote control.

Firmware

It is running my ESP32 port of Grbl with a little hacking for the servos. The ESP32 uses an RTOS, so I just created a low priority, repeating task (20Hz). The task checks the position of a virtual CNC machine, does some kinematic math and updates the servos. The software supports streaming drawing data (gcode) via serial port, bluetooth, SD card or wifi. I am using the bluetooth option to send via my phone. I will publish the firmware soon.

Crazy Math (Kinematics)

The math is actually not too hard. You know the desired pen location, the axes of the servos and the lengths of the linkages. There are two ways to do the math. The first way is using the law of cosines and the Pythagorean theorem.

The second method uses intersecting circles. Each linkage can sweep a circle from a axis point and radius. Any two linkage’s circles will intersect at two points. It is easy to pick one of the points as more desirable. While it is less deterministic, due to the two points thing, it appears to run about 40% faster on the ESP32.

The Z is very simple. Any Z value less than 0 is pen down and everything else is pen up.

Drawing Quality

The quality is basically “Adorably Wiggly”. I am using the cheapest analog servos. That means I might get about 200 x 200 resolution at best at the servo hubs. If you mapped that grid to the paper it would be a warped grid with dense and sparse areas of the grid due to the non-linear nature of the mechanism. Digital servos with very low deadbands (~1us) it would probably do a lot better, but I am not sure that is worth it. It would only be a little less wiggly. They cost about 4x what analog servos do (still pretty cheap).

There is a calibration feature. Each servo is a little different and it is difficult to precisely mount the arms at the right angle. The calibration adjusts the zero angle and pwm/degree of rotation.

Next Steps

This project is part of a talk proposal for Hackaday SuperCon 2018. If that gets accepted, the badge will become a full featured CNC controller capable of running a router, laser cutters, high res plotter, etc, as well as the Drawbot badge. Only the DrawBot will be populated. The rest will be modular like this board.

I may also make a simple version that is only the draw bot. The BOM cost is currently about $10-$12 (without 3D printed parts)

Regardless of what happens all source files will be publish sometime in October.

 

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Next Project – Wooden Nickel Engraver

I started working on my next backpack scale CNC project. My backpack scale projects are tiny CNC machines that I can easy carry in a backpack to tech meetups and events. This machine is going to be a wooden nickel laser engraver.

Wooden nickels are small wooden discs. You can buy blanks from various places, including Amazon. You can usually get 100 for less than $10. The goal is to create a machine that loads them from a feed tube, engraves them, then ejects them.

Mechatronics

The basic drive will be an H-Bot. It will be similar to the midTbot, but the motors are at the ends of the X axis. It will be fully enclosed, but I not started work on that part yet.

Disc Feed System

I hope to be able to use a single hobby servo to handle the loading and unloading of the blanks. The servo will control a sliding device that has three positions.

  • In the first position it acts like a support shelf for the disc. The bed slides under the feed tube and a disk drops into the pocket.
  • The next position is the clamping position. This holds the disc still while engraving.
  • The final position retracts the shelf so the disc drops through.

Electronics

The goal is to use a low cost controller like an Arduino Nano.

  • (2) Stepper motors for the X,Y motion
  • (1) Hobby servo for the disc feed system (PWM)
  • (1) Laser power control (PWM)
  • (2) homing switches
  • (1) interlock switch loop if there is a door and/or cover

Status

The major new feature of this design is the disc feed system, so I am primarily working on that right now.


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Laser Galvo Control Experiments

 

 

I recently bought some laser galvos from Aliexpress. What I got was the basic guts of a laser light show system. It came with everything I needed except the lasers. My goal is to control a laser to make a large interactive artistic display or game controlled by a micro controller with a DAC. I have a PSoC 5 and an ESP32 that have DACs, so I may use those.

Galvos work like speakers, old school analog meters or hard drive arms. They move proportional to a current. They can move extremely fast and precisely with the ability to move to 30,000 positions per second. The galvos came with drivers. This simplifies the control to a simple differential voltage. A differential voltage is used to increase noise immunity. The ILDA spec says the differencial voltage is 0 to 10V. This means at one end of travel you supply -5V and 5V and at the other end of travel you swap the voltages supply +5V and -5V.

My DACs are 0V to 5V (0r 3.3V). I need to convert this range to a 10V differential voltage. The easiest way for me to do this is to use some op amps. With what I have on hand it is easiest to get the 10V differencial using 0 to 10V and -10V to 0. I tested on the galvos by outputting a -10V to 10V sin wave from a function generator. It worked great.

Assuming I use the 0-5V DAC, I need to map that to a -10V to 10V range. That is a 20V span and requires a 4x gain. I then need to offset that by -10V. The op amp circuit I show below is what I made.

I used an LM324N because I had some. That has (4) op amps in a single package. The rails of the device need to be hooked up to a + and – supply that is greater than the range I will be using. Fortunately the galvos came with a power supply that outputs +15V and -15V. I used some potentiometers in the circuit to allow me to adjust the circuit.

The lower op amp provides the gain. The gain on the positive side is 1 + 30k/10k which is 4. The negative side is used for the offset and its gain is 30k/10k which is 3. I need an offset of 10V, so 10V divided by the gain of 3 is 3.33V.  I need that value to come from the upper op amp. That op amp has a gain of 1 so I simply need to adjust the pot in front of that to output 3.33V.

 

The DAC is connected to the lower left voltage source in the schematic shown as 2.49V. The galvos would be connected to Gnd and the output of the lower op amp (green line).  The schematic is interactive. Click the link below and try adjusting the input voltage between 0V and 5V.

Click here to interact with the circuit.

I needed to create 1 circuit for each axis. Here is my breadboard.

Here are the signals on an oscilloscope. The yellow trace is the 0-5V input as a 5kHz sin wave. The blue trace is the output. Both traces use the center line as the 0V. The scale is 5V per division. The input has a low of 0V and a high of 5V. The output goes from -10v to 10v.

 

I am using the tiniest laser I could find so that I don’t have to worry about safety yet. I 3D printed a base to keep things in line.

Here is a short Instagram video of some testing.

 

Playing with my laser galvos at NERP tonight.

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The Polar Coaster – A Drink Coaster Drawing Machine

I designed this machine to draw custom, round drink coasters. I already have a laser cutter for square coasters and I wanted to try something unique for round coaster.

The Base

The base of the machine has two stacked 5mm bearings in the center for the bed to rotate on. There are (3) 3mm bearings on the bed perimeter that provide support and keep it level. They have little shafts that snap into the base.

The Bed

The bed is  a 156 tooth GT2 pulley. It has little springy fingers that grip the coaster when it is on the bed. The bed connects to the motor pulley with a closed loop belt.

The Radial Arm.

This is a belt driven, cantilevered arm that uses 6mm shafts and linear bearings. The belt is a cut pieces with the ends clamped at the carriage. It has a slotted mounting hole that lets the arm rotate. The pen must be adjustable to get to the exact center of the coaster or the drawing will be distorted. There is a limit switch on the top.  This is the only axis that needs to be homed. To setup the machine you home it and jog the pen until it is exactly over the center of the bed. You then set the work zero for X (Gcode: “G10 L20 P0 X0”). This only needs to be done once. If you use different types of pens, the center should be rechecked.

The Z Axis

The Z axis uses a micro servo and a cam to control the height of the pen. The firmware is setup to only have (2) Z positions, pen up and pen down. It uses 3mm rods and tiny little 3mm linear bearings.  There is a compression spring on one of the rods that applies a little pressure to the pen, and allows the pen to float a little on uneven coasters.

The Controller

I used my Grbl HAT controller. It is a bit overkill for this project but works perfectly.  It is attached to a Raspberry Pi in this photo, but I have not been using the Pi in this project yet. I just connect directly via USB.

Kinematics and Pre-Processin

See this blog post on how it was done. The pre-processor is written in C#, but it is rather simple and you could probably read the source file and convert if you cannot deal with C# on Windows.

Firmware

I use a modified version of Grbl 1.1f.  Grbl does not support servos, so I needed to hack that in.  I used the PWM that is normally used for the spindle speed to control the servo. I turned off the variable speed spindle option and streamlined the spindle functions to the bare minimum I thought Grbl needed.  I adjusted the PWM parameters for use with a servo and added pen_up() and pen_down() functions. I tried to put as much of the custom code into one file spindle_control.c. I had to add a few lines in stepper.c to look at the current machine Z height and apply the correct pen up/down function.

CAM

You can use anything to generate the gcode that works with Grbl. The pen will go up when the Z is above zero and down when it is below zero. Therefore, you want the Z movement as short as possible to speed up the drawing and not have the pen dwell on the material and bleed.  I make the depth of cut 1mm and the z clearance 3mm.

CAD Files.

The design was done using PTC CREO 3.0.  A STEP version of the design is linked at the end of the post.

Performance

It does a great job. Here a recent coaster. This was done from a rasterized bitmap image found online (searched: circular Celtic braid).

Here is a Fat Tire beer themed coaster.

Coasters are made to be super absorbent, so larger tipped felt pens tend to bleed a little too much. I like to sketch with Micron pens and the thinner ones really work well on this machine.

Build You Own?

The build is not difficult, but covers a lot of areas. You should know how to work with STEP files and compile firmware.

The design is open source with no commercial restrictions, so feel free to use any part of my work. I found most of the parts on Amazon and eBay. I bought the belt from Stock Drive Products. The polar motor pulley is 36 tooth and the arm pulley is 20 tooth.  Cutting the shafts requires an abrasive cutoff wheel.

Please post any questions in the comments section and I will try to address them.

Links

 

I sell on Tindie

 

 

 

Lost PLA Casting

cast2

We recently did some aluminum casting at the Inventables Beer and Making night. The primary mission was to do some lost foam casting, but I wanted to try lost PLA.

Beer and Making is typically a gonzo/hackathon type event, so we deliberately try to use materials on hand and try to learn for ourselves. We used pink insulation foam because it could be easily hand carved during the event. This was the first time for everyone, so I was quite happy with our success.  I’ll point out some areas where we probably could have done better.

The furnace

One of the perks of working at Inventables is our personal Exploration and Project budgets.  We all get a budget for personal exploration and making things. The furnace was recently purchased by Jon, one of the fulfillment team members, with some of his budget. This furnace runs off standard 110V and can heat the material up to 1150°C.  We set it for about 1000°C for the aluminum.

furnace

 

The Model

sprues

 

The model I used is the unofficial mascot for the CNC build Club, the CNC Ninja Squirrel.  I tried to use as little PLA as possible.  I used 2 perimeters and 5% infill.  There are a few steep overhangs, so I typically need at least 2 perimeters for success with this model. I didn’t use any special filament, just the PLA was in the printer at the time.

The model will be buried in the sand.  You need to create a couple of channels (sprues) to reach the surface for the casting process.  The channels have several functions.

  • Provide a place to pour the aluminum.
  • Provided an escape path for the air and other gasses created when the material is burned out.
  • Provide a a source of aluminum for the part to draw from when it shrinks.

I created the channels from pink foam and hot glued them onto the PLA model.

The Sand

We used what we could find quickly.  We used about 9 parts of a play sand and pool sand mixture and 1 part of bentonite power (the Tait mix).  We added just enough water to make it clump a little.

The Setup

cast1

We got a large metal metal tray and put some dry sand on top.  This was a bit of a fire pit in case of any spills or fires.  You can see the size of the crucible in the foreground and the tongs that came with it.

We made a small enclosure out of MDF.  We filled it half way with the sand mix. We placed 3 items to cast in it.  We then covered the items in sand.  We added the sand slowly and packed it down with a rod at several levels.  We poured each of the 3 items with separate pours.  We wanted to make sure each item got a lot of aluminum.

We used scraps of MakerSlide as the aluminum to melt.  We cut the pieces to the length of the crucible.  We would add a piece at a time as they melted.  It took about 30 minutes for the first batch and about 10 minutes for the other batches.

Pouring

IMG_1722

The pouring was pretty exciting.  Some of the aluminum ran to the MDF sides and started a little fire.  We had a fire extinguisher ready, but simply put a cover over the box to kill the flames. Most of the flames you see in the image are the foam being burned away.

Results

We did three separate parts.  2 were foam and 1 was PLA.  The PLA probably had the best quality finish, but the part came out noticeably darker.  It was easy to clean up with a stiff wire brush.

Next Time

  • The first change I would make is to use something non flammable for to hold the sand.  I think a ceramic flower pot might be good.
  • Build up the sand around the sprues to keep the aluminum from spreading.
  • Cover the part in dry wall paste.  This creates a thin shell between the part and sand to get a better finish.
  • Get some better sand and a little fire clay to make a better sand mix.
  • I might try to model the sprues onto the part in PLA
  • Mark the in and out sprues, so you know what side to pour into.
  • The smoke and fumes were pretty nasty, especially the MDF.  Do this outside!

 

 

Line-us Clone Controlled by Easel and Grbl

Last week I made a Line-us drawing robot clone.  Unfortunately I had no good way to make it draw easily.  I thought I would give the CNC toolpath a shot.  My goal is to have a super portable thing to generate conversation at meetups. If I used Easel it would allow anyone with a web connection to easily make something.

2dbenchy

Grbl

Grbl Logo 250px

The most compact machine controller is Grbl and I have a lot of experience with it.  Grbl is designed to send step and direction signals to stepper motors.  The draw ‘bot uses hobby servos.  The nice thing about hobby servos is they don’t need to be homed.  They have feedback to tell them where they are. They also don’t care about speed, acceleration or steps/mm.  They just go wherever you tell them as fast as they can go. It occurred to me, the easiest way to hack this into Grbl was to not modify the Grbl code at all.  I would let Grbl think it is using stepper motors.  I would just add some extra code that runs on regular interval to tell the hobby servos where the stepper motors are in 3D space and they would be told to go there.  I played around with some intervals and 8 times per second (8Hz) seemed to work pretty well.  The ‘bot uses machine coordinates. The work coordinates are offset to the left because the ‘bot cannot draw at 0,0.  The pen would crash into the frame.

PSoC

I recently port Grbl to PSoC. I used (3) 16bit PWM components to control the hobby servos.  See this blog post on how I did that.  I then attached a 8Hz clock signal to an interrupt.  The interrupt sets a flag when it is time to update the servos.  When the main code sees this flag it does the calculations and and sets the PWM values.  Keeping the code out of the interrupts gets Grbl happier.

servospwms

Easel

Easel is already setup to use Grbl.  You can either import gcode or create a design right in Easel.  I started out with importing gcode because the Benchy design was not in a format I could import. I created a template that shows the allowable work area. This will allow anyone to quickly create a drawing.

easel_template

2D Benchy

I wanted to have a little fun with the first print.  “Hello World” was not good enough.  3D printers use benchmark prints, so I thought I would do a 2D version of the classic 3DBenchy.  To get a 2D drawing of 3DBenchy, I traced over an image with the line tool in CorelDRAW.  I then exported a DXF of that.

trace

Skate-oko-asaurus: The self replicating skateboard

We build a lot of skateboards for fun at Inventables.  Some of the guys even sell them at local craft fairs.  They thought it would be cool to have a CNC router optimized for skateboards that was easily portable.  I first thought about putting wheels at one end, then realized the machine itself could be a skateboard.  We thought it would make a perfect Gonzo Build.

2014-10-26 11.00.15

A Gonzo Build is something we came up with at Pumping Station One CNC Build club.  The concept is that we try to build an original, “one off”, CNC machine in one evening.  They also tend to have a whimsical aspect to them, so we don’t take ourselves too seriously.  We usually get about 8-12 people to help build.  If parts need to be fabricated, they must be done that night on -site.

2014-10-26 11.00.50

Building a stock Shapeoko 2 in one night is a challenge in itself, but we decided to up the challenge by totally tricking this out with every feature we could think of.  We did have a few master CNC building ringers in the group, like Tait Leswing and David Ditzler.

Here are the stats of the machine.

  • 1200mm x  250mm work area
  • Skateboard specific wasteboard supported by additional extrusions.  It is narrower than a stock Shapeoko 2 and about 3 times as long.
  • Drag Chain
  • gRAMPS Controller running grbl 0.9.
  • Quiet DC spindle with full speed control.
  • Feed hold / Resume / Reset buttons
  • Homing switches on all axes
  • Auto Z zero with Z probe
  • Trucks and wheels
  • NEMA 17 motors with dual Y stepper drivers.
  • Portable dual 24V/48V power supplies with master power switch.

2014-10-26 11.18.20

 

soa_controller

Most of the Shapeoko parts came from reject area at Inventables, so there are a few dings and scratches.

The wasteboard was cut from 5/8″ particle board on the PS1 Shobot.  It has a grid v carved into the work area.  There are threaded inserts for clamps, primarily around the perimeter, but there is a truck bolt pattern strategically placed so a cut out board can be flipped or remounted accurately . It is supported below by 2 additional MakerSlide pieces and tied to the MakerSlide rails above.  It is the bed turned out very rigid.  It does deflect a little with heavy rider but pops right back.  After the build, I added several coats of spar varnish to ward off the dusty footprints.  Biggest guy to ride it so far tips in at about 230lbs.

soa_bottom

We set our selves a goal of completing before midnight.  Done or not, I was going to ride it at midnight.  We thought we were finished about 20 minutes early.  Everything worked fine except the Z axis was not moving correctly.  It had the classic stutter and random motion of one coil wire not connected.  We tried to find the problem, but over 2 meters of drag chain slowed us down.  Midnight came some we dropped it to the floor and I rode it across the shop.

2014-10-26 11.03.30

As a skateboard, it is pretty much a joke.  On the first ride, we didn’t even have long board trucks, so the turning radius was huge and you can easily scrap an edge.  The front has a handle cut into the nose of the bed.  The ideal way to move it around is to lift the front and drag it on the back wheels.

 

 

 

Intro to V Carving

In a couple weeks we are going to do a CNC V Carving night at Pumping Station One.  We hope to fabricate a number of designs on the CNC router.  This blog post will serve as a basic introduction to the concept and will help people get artwork ready.

What Can V Carving Do?

V Carving uses a V shaped bit to to “carve” a design into the material.  Because the bit has a v shape, you can cut narrow shapes with the tip or wider shapes near the bottom.

You can even cut shapes wider than the widest part of the bit by doing multiple passes of the bit.  The depth of the cut is proportional to width of the cut, so you need to make sure your material is thick enough.  If you have very wide areas, you can set a depth limit and you can make that area have a flat bottom with a second flat bit.

Normally routers cannot cut square inside corners because you are cutting with a round bit.  V Carving can get around this limitation because the bit can rise up into the corners until it gets to the zero radius tip.

Finishing Tricks

V Carvings can look great simply cut in the natural material, but they can really pop when you put a contrasting finish in the carved areas.  This is a time consuming process and can be difficult to do well.

You can often shortcut this process by using masking materials.  You start by applying a background finish to the work piece.  This is then masked with tape or specialized masking material.  The router then cuts through that as it is cutting the design.  Now, only the cut area is exposed and you can simply spray paint the exposed area.  If the design has multiple colors you can cut one color, paint, remask and repeat the process.

The files should in in DXf, DWG, AI, EPS or PDF  format.  Many programs like InkScape and CorelDRAW can output these formats.  If you have hi resolution bitmap, some of these programs can convert to a vector format.  Feel free to try that, but help with that will be beyond the scope of the session.

The quality of the masking material comes into play with very fine details.  If your design will leave tiny isolated dots of masking, some materials may not stick well enough and break free during cutting.  If that happens, you can manually touch up those areas later.  I like to use Avery Paint Mask, but plain masking tape, adhesive shelving paper and materials for vinyl cutters also work.

What is good artwork to start with

  • Avoid very thin lines lines.  The  material needs to be needs to be perfectly flat and consistently thick for this.
  • Very large areas to cut will take a long time, so avoid them for this session.
  • Multiple colors.  Multiple colors is OK, be each color needs to be separated from the other color so there is masked uncut area between them.

This logo would work.  The red would be the base material and all other colors would be cut and colored.

This one would be very hard to do because of the adjacent colors.

How to bring the artwork to the session.

To save time, the artwork should be as ready to import as possible.  Problem artworks will be pushed to the back of the queue and might not get cut.

The artwork needs to be in a digital, vector format.  By digital I mean you can sent the file electronically.  Vector files are created with actual geometry.  Lines are lines and not a string of pixels.  Scans and photographs are not usable.  If you zoom in and the image gets pixelated, it is not ready to use.  The shapes also need to be closed.  If you have a square, for example, all the corners need to meet or the software cannot determine inside from outside.  Tiny gaps can be closed in the CAM software, but if you can see them, close them.

Try not to be too complex or have large cut areas.  These will take a long time and will limit how many people we can accommodate in one session.  We can still create G-Code, but you many need to cut it at a later date.

If there is time I my cut small PS:One snowflakes for the people who did not bring any artwork.

Material

The idea material is a smooth, pre-finished piece of wood.  It needs to be as least as deep as 1/2 the width of your widest feature if you are not planning a flat bottom.  The material should be as flat and consistently thick as possible or the results can be distorted, because the depth of the cut is so critical.  Avoid oily or wet finishes because the mask material may not stick well.  Plywood does not look well and often interior layers have voids.

Examples

Image From http://www.routercut.com/

 

Image from: http://www.makecnc.com

PS:One Longboard

The subject of skateboards came up about 2 weeks ago at meeting of local makers.  One of the PS:One Hackerspace guys confessed he wanted to buy a longboard for getting around town.  Longboards are more about basic transportation and carving smooth turns than doing tricks.  The large size also encourages design and graphical creativity.  I thought it was the perfect opportunity to get the creative juices flowing.  It was a fun project that cost less than $50 to complete.

Once I get these ideas in my head I am totally obsessed with them.  The only way to clear my brain is to actually build the thing whether I need it or not.  I finally got some time between 2.x Lasers and ORD Bots orders on the CNC router last Sunday night.

Design:

  • 3/4″ baltic birch deck.
  • Logo inlay on top near the front in a contrasting wood type.
  • The inly would be 1/4″ thick so minor dings and chips would not wreck the inlay.
  • Pockets cuts on the back to look cool, reduce the weight and give the board a little flex.
  • Miter the edges of the pockets for a cool look, make it more comfortable to carry and make it less prone to chipping.
  • Round the perimeter edges.
  • I really like the drop style truck mounting, but I would stick with a conventional bottom mount to start with.

Drop through mounting – Image from Moose

I found a whole bunch of longboard PDF templates here at Silverfish Longboarding.  I started with the ST11 version.  I felt the exposed wheels would allow more wheel, truck and mounting options without the wheels “biting” the board.  The outline had a few sharp corners that I smoothed out.  I didn’t want the line that is produced when you round the edge with the sharp corner.  I imported an SVG of the snowflake logo from the PS:One wiki and sketched in some pockets on the back that looked cool, but still preserved the strength off the board with hope for a little flex.
I bought a truck and wheel kit off eBay for about $35 (free shipping). I only did basic research into what made a good choice.  I just bought something that fit the basic requirements and looked cool (wide, reverse kingpost, big red wheels).
The basic deck is 3/4″ thick Baltic birch plywood..  The local high end lumber yard, Owl Hardwood, had some really nice 13 ply material.  The top side is perfect.  The back side is really good with only a few small blemishes and all the inner layers are high quality with no voids.  Most plywood has knots and voids on the inner layers.  The exposed edge and the pockets would show the inner layers so I wanted them to look good.

Fabrication Process.

  • Cut the inlay piece out of  1/4″ thick oak.
  • Mount the Baltic birch on the router and check for Z flatness in the inlay area.  I mounted it on a sacrificial particle board.  This board was clamped by itself, so unclamping the plywood would not affect the position of the sacrificial board.
  • Cut the pocket for the inlay slightly under sized.  I then continued to profile the edges larger until it fit tightly.
  • Glued the inlay in place.
  • Cut the bolt holes for the trucks.
  • Cut the deck outline.  I purposely cut extra deep into my sacrificial base so that I would have a clear outline of the board.  This would allow me to flip it squarely to do the back side.
  • Cut the back pockets 1/4″ deep.
  • At the last minute I decided to add the the PS:One logo to the back as a 1/8″ deep pocket.  It turned out to be my favorite detail.
  • Used a 1/2″ 90 Deg V bit to miter the edges of the pockets.  I did a profile pass on the pocket lines set inside the line 0.02″ to make sure the tip was always inside the edge for a clean cut.  The depth was set to leave 1/16″ of the original pocket wall.
  • Unclamp the deck.
  • I used a 3/8″ 1/4 round bit with guide bearing on the router table to round the edges.
  • Sanded.
  • Stained using Minwax Golden Oak stain.  It is a light colored stain that varies quite a bit with the wood type.
  • Sealed.  Minwax Satin Poly Urethane.

Time:

  • Design, research, ordering parts…about 1 hour.
  • Total time on the router…about 1 hour.
  • Sanding and Finishing…about 1.5 hours.

Cost:

  • $10 worth of baltic birch
  • $5 1/4″ x 8″ oak for inlay
  • $35 trucks and wheels.
  • Already had all bits, stain and varnish

TO DO:

  • I want to laser cut a bunch of little PS:One snowflakes out of grip tape and sprinkle them on the deck.
Hind Sight:
  • I am not super happy with the way the baltic birch stained.  Woods like that can look blotchy due to varying wood density.  I might have done better pre treating with a wood conditioner the birch or going without stain.