Category: Projects

The Story of Frank’s Marvelous Table

As usual it was way more work than anticipated, but I’m quite pleased with the final result. I had a to build a ridiculous number of jigs and templates for this thing. –Frank

After 4 months of hard work, Frank, a new member, and carpenter completed an absolutely show-stopping dining table in the workshop and posted images of the final piece on the Ace Community Discussion Board.  

Prompted by the Ace Community, Frank also provided insight into his process and the many tools he used to design, sketch, render, and build his dream dynamic, curvy table.

I’ve only been woodworking earnest for about the past year. I dabbled with it in college as well but just a bit. Most of what I know has been from the school of YouTube or from talking with people around Ace, and being a mechanical engineer has helped with some aspects.–Frank

Check out some highlights from his build:

Frank built a “ridiculous” number of custom jigs for shaping the unique curves of his design. See how he takes his idea, renders it, builds it, and tests it below:

Image of rendered white and gray jig on a dark brown curved wooden table top
Rendered Jig
Image of a light wood jig, metal router holding a curved piece of dark brown wood on a large work table.
Testing the Jig

 

He also put together a super neat glue-up for the top of the table:

Image of several long pieces of wood held in 6 horizontal clamps on a yellow folding table
Super neat and tidy glue up

He even converted his living room into a stylish workshop and all that between his 10-month-old’s naps!

Image of a makeshift workshop with plastic sheets draped around a metal rack holding woodworking tools and a curved wooden table top.
Frank’s living room converted into a workshop

The project may have been “way more work” than Frank thought it would be but, wow! Hopefully, he’s sending out dinner invites soon!

Image of modern dark wood table set with two golden candlesticks and a white vase with a pink flower
Frank’s table is set and ready to enjoy

Coworking for Computer Vision

Hi, my name is Mark. I’ve been a member of ACE for almost 9 years. There’s been three things on my To-Do list gnawing at my psyche for some time:

  1. Learn about Raspberry Pi microprocessors through Internet of Things (IoT) applications.
  2. Get hands-on experience with Artificial Intelligence.
  3. Learn the popular Python programming language.

Why these? Because computers are getting smaller while getting more powerful; Artificial Intelligence (AI) is running on ever smaller computers; and Python is a versatile, beginner-friendly language that’s well-documented and used for both Raspberry Pi (RPi) and AI projects.

I’ve been working in computer vision, a field of AI, for several years in both business development and business operations capacities. While I don’t have a technical background, I strive to understand how the engineering of products & services of my employers works in order to facilitate communication with clients. Throughout my career I’ve asked a lot of engineers a lot of naive questions because I’m curious about how the underlying technologies come together on a fundamental level. I owe a big thanks to those engineers for their patience with me! It was time for me to learn it by doing it on my own.

Computer Vision gives machines the ability to see the world as humans do – Using methods for acquiring, processing, analyzing, and understanding digital images or spatial information.


In starting on my learning journey I began a routine of studying at our ACE Makerspace coworking space every week to be around other makers. This helped me maintain focus after the a pandemic induced a work-from-home lifestyle that left me inhibited by a serious brain fog.

My work environment at ACE Coworking

OpenCV (Open Source Computer Vision Library) is a cross-platform library of programming functions mainly aimed at real-time computer vision. AMONG MANY COMPONENTS It includes a machine learning library as a set of functions for statistical classification, regression, and clustering of data.

Fun Fact: Our ACE Makerspace Edgy Cam Photobooth seen at many ACE events uses an ‘Edge Detection’ technique also from the OpenCV Library.

A self-paced Intro to Python course came first. Then came a course on OpenCV which taught the fundamentals of image processing. Later still came tutorials on how to train a computer to recognize objects, and even faces, from a series of images.

Plotting the distribution of color intensities in the red, green, and blue color channels

 

3D scatter plot of distributions of grouped colors in images

 

A binary mask to obtain hand gesture shape, to be trained for gesture recognition

 

Notice the difference in probabilities associated with the face recognition predictions when the face is partially occluded by face mask

Eventually, I moved onto more complex projects, including programming an autonomous mini robot car that responds to commands based on what the AI algorithm infers from an attached camera’s video feed – This was real-time computer vision! There were many starter robot car kits to choose from. Some are for educational purposes, others come pre-assembled with a chassis, motor controllers, sensors, and even software. Surely, this was the best path for me to get straight into the software and image processing. But the pandemic had bogged down supply chains, and it seemed that any product with a microchip was on backorder for months.

A backlog of cargo ships waiting outside west coast ports as a symbol of supply chain issues

I couldn’t find a starter robot car kit for sale online that shipped within 60 days and I wasn’t willing to wait that long. And I didn’t want to skip this tutorial because it was a great exercise combined RPi, Python, and AI. ACE Makerspace facilities came to the rescue again with the electronics stations and 3D printers which opened up my options.

I learned a few things working at computer vision hardware companies: Sometimes compromises are made in hardware due to availability of components; Sometimes compromises are made in the software due to the lack of time. One thing was for sure, I had to decide on an alternative hardware solution because hardware supply was the limiting factor. On the other hand, software was rather easy to modify to work with various motor controllers. 

So after some research I decided on making my own robot car kit using the JetBot reference design. The JetBot is an open-source robot based on the Nvidia Jetson Nano, another single board computer more powerful than the RPi. Would this design work with the RPi? I ordered the components and shifted focus to 3D printing the car chassis and mounts while waiting for components from Adafruit and Amazon to arrive. ACE has (2) Prusa 3D printers on which I could run print jobs in parallel;



When the parts arrived I switched over to assembling and soldering (and in my case, de-soldering and re-soldering) the electronic components using ACE’s electronics stations equipped with many of the hand tools, soldering materials, and miscellaneous electrical components. When fully assembled, swapping in the Raspberry Pi for the Jetson Nano computer was simple and it booted up and operated as described on the JetBot site.

Soldering
It’s ALIVE! with an IP address that I use to connect remotely

The autonomous robot car starts by roaming around at a constant speed in a single direction. The Raspberry Pi drives the motor controls, operates the attached camera, and marshals the camera frames to the attached blue coprocessor, an Intel Neural Compute Stick (NCS), plugged into and powered by the Raspberry Pi USB 3.0 port. It’s this NCS that is “looking” for a type of object in each camera frame. The NCS is a coprocessor dedicated to the application-specific task of object detection using a pre-installed program called a MobileNet SSD – pre-trained to recognize a list of common objects. I chose the object type ‘bottle’.

“MobileNet” because they are designed for resource constrained devices such as your smartphone.  “SSD” stands for “Single-shot Detector” because object localization and classification are done in a single forward pass of the neural network. In general, single-stage detectors tend to be less accurate than two-stage detectors, but are significantly faster.

The Neural Compute Stick’s processor is designed to perform the AI inference – accurately detecting and correctly classifying a ‘bottle’ in the camera frame. The NCS localizes the bottle within the camera frame and determines the bounding box coordinates of where in the frame the object is located. The NCS then sends these coordinates to the RPi; The RPi reads these coordinates, determines the center of the bounding box and whether that single center point is to the Left or Right of the center of the RPi’s camera frame.

Knowing this, the RPi will steer the robot accordingly by sending separate commands to the motor controller that drives the two wheels:

  • If that Center Point is Left of Center, then the motor controller will slow down the left wheel and speed up the right wheel;
  • If that Center Point is Right of Center, then the motor controller will slow down the right wheel and speed up the left wheel;

Keeping the bottle in the center of the frame, the RPi drives the car towards the bottle. In the lower-right corner of the video below is a picture-in-picture video from the camera on the Raspberry Pi. A ‘bottle’ is correctly detected and classified in the camera frames. The software [mostly] steers the car towards the bottle.

Older USB Accelerators, such as the NCS (v1), can be slow and cause latency in the reaction time of the computer. So there’s a latency in executing motor control commands. (Not a big deal for a tabletop autonomous mini-car application, but it is a BIG deal for autonomous cars being tested in the real world on the roads today.) On the other hand, this would be difficult to perform on the RPi alone, without a coprocessor, because the Intel NCS is engineered to perform the application-specific number-crunching more efficiently and while using less power than the CPU on the Raspberry Pi.

Finally, I couldn’t help but think that there was some irony in this supply chain dilemma that I had experienced while waiting for electronics to help me learn about robots; Because maybe employing more robots in factories will be how U.S. manufacturers improve resilience of supply chains if these companies decide to “onshore” or “reshore” production back onto home turf. Just my opinion.

Since finishing this robot mini-car I’ve moved on to learn other AI frameworks and even training AI with data in the cloud. My next challenge might be to add a 3D depth sensor to the robot car and map the room in 3D while applying AI to the depth data. A little while back I picked up a used Neato XV-11 robot vacuum from an ACE member, and I might start exploring that device for its LIDAR sensor instead.

Let me know if you’re interested in learning about AI or microprocessors, or if you’re working on similar projects. Until then, I’ll see you around ACE!

Mark Piszczor
LinkedIn

The Captain's Chair

Ted Huller: 3D Printing Master

Introduction

Ted Huller is a long-time Ace member and also Ace’s resident 3D Printing Steward. I’m Carter Jenkins, and I had the chance to talk with Ted about his history with Ace as well as some recent work he has done.

Ted’s History with Ace

ted hullarTed is a long-time friend of Ace Executive Director Rachel Crafty, but Ted’s story begins before Rachel was in that role. Ted works in a laboratory, and throughout his working process, he sometimes finds that he needs to make custom-built parts in order to fulfill certain jobs. He normally would make these parts out of wood, (Ted is a master woodworker) but one day the job required a small beaker holder that was too fine to make with wood. Hearing about Ace’s 3D printing workspace, Ted decided that he should learn some basic skills in 3D printing so that he could handle situations like these. He admits the process wasn’t very smooth, but in the end, he had a working product, and that experience made Ted very interested in 3D printing as a whole.

Fast forward a few years, and Ted became a regular Ace member. He still did woodworking at home, but the Ace makerspace had become his new home for metalwork and some 3D printing. Ted quickly got his own 3D printer at home, meaning that his interactions with Ace slowly dwindled as his needs for printing materials shrunk. One day, however, former 3D printing steward Matt stepped down, leaving the position open to anyone in the Ace community. After some deliberation, Ted decided that he should give something back to the Ace community, and with his new expertise, Ted became the printing steward.

The 3D Printing Space at Ace

The 3D printing space is shared with a multipurpose space that houses the electronics lab, a couple of workstations, and the big format paper printer. This room is known as the Clean Fabrication room. There are two Prusa-brand 3D printers, which Ted calls “the Ford F-150 of printers. There’s a lot of them, they’re not the most sophisticated, but they’re pretty darn reliable and thought out.” There’s also a nearby computer dedicated to preparing files for the printers. The printers don’t need a computer to run, but makers will often find that it helps to be able to do last-minute manipulations to the 3D object files.

The Slack community for 3D printing at Ace has members in the hundreds, and pretty much all questions and discussions happen over Slack. Ted considers it the most efficient way to ask, read, and answer questions; he encourages new members to use Slack for almost all of their communications.

An Example of Ted’s Work

Metal plating placed in the Ace metal mill
Some in-progress work being done at the Ace metal mill

Ted and his wife recently bought an old minivan so they can go camping without having to deal with tents. The Toyota they bought was almost perfect for this purpose, except for one thing. The two of them both found the minivan to be a little too small to have both front seating and bed arrangements, so they looked into having adaptable seats that could swivel and lie down to make beds. The Toyota’s seats, however, were bolted to the floor in such a way that commercial seat-adjusting kits wouldn’t work. With no other options, Ted turned to his making skills to fabricate a “captain’s chair,” similar to those found in commercial RVs.

Ted started with drilling out a swivel plate and holes in the floor of the van, making sure to line them up precisely by means of the metal mill at Ace. The actual process of making the seat swivel wasn’t that difficult, but Ted encountered another problem soon after. Modern-day seats in cars and vans have lots of electrical wiring leading into them, whether it’s for operating a heater or controlling the seat’s back-and-forth movement. Ted found that the wires in the seat were dangerously close to shearing themselves on some exposed metal left by the drill holes, which would cause all sorts of maladies if not addressed properly. To solve this problem, he 3D printed a large plastic washer that bolts onto the wire hole. This means that instead of the wires dragging on sharp metal edges, it’s protected by a layer of comparably soft plastic. There were other little 3D-printed objects that Ted made, such as protective sheaths for the wire connectors.

3D printed swivel bushing used in the seat
An example of a bushing used in the project

Interestingly, Ted’s neighbor was going through a similar process with a van of their own at around this time. They had also encountered the same wire-cutting problem, and since Ted had just fitted the washer he offered to print a duplicate for his neighbor. With about a dollar’s worth of filament, Ted solved his neighbor’s problem.

Closing

Ted will continue to make and create at Ace for a long time. There are no big projects in his immediate future, but before our talk ended Ted told me that he was looking forward to, “training some more people, getting them ready, and seeing what people are going to 3D print.” I’m Carter Jenkins and thank you for reading.

Mauricio’s Big Build

Overview

Mauricio Salmerón has been working on a project recently. What started as a joke request to a friend has now spanned into a multi-month project that is now nearing completion. I got a chance to speak with Mauricio over a weekend and he shed some light on what other workshop members saw as two large pieces of wood glued together.

Mauricio has been an off-and-on member of the Ace Makerspace for a few years now. He used to own a furniture-making shop called “The Furniture Space,” where he did woodworking to create all kinds of custom furniture such as tables and sideboards. After that, Mauricio found Ace to be the best place to continue honing his craft.

A while back, Mauricio was talking with June, a friend of his. The conversation eventually drifted to June’s need for a new bed. After discussing how June’s search hadn’t been successful, Mauricio jokingly offered to build her a bed frame. The two laughed, and the conversation moved on. However, a month or two later June took Mauricio up on his half-serious request.

A half completed bed frame
The bed frame, later in its construction phase

Mauricio worked on the project on and off, but many months later it’s nearly complete. Throughout his build process, Mauricio used many workshop tools to complete the project. The table saw, chop saw, router, drill, and planer to name a few. He estimates “another 10 hours of work and headboard assembly” and the new frame will be ready to send to June. The entire assembly consists of 5 main parts that can be put together to complete the full platform-style bed. June, of course, will have to provide the mattress, but it seems that the bulk of the work has been completed.

Process

  • Early pieces
    • Oak boards were surfaced through the joiner and planer, then dimensioned with the table saw
    • The boards were clamped together and glued to make the large sides of the bed, the tops to the sides with pocket screws
    • The three main pieces were completed by now, each with its own plywood support frame
  • Later pieces
    • The surfaced boards were put together with pocket screws and clamps to create the headboard
    • The last piece, the middle mattress support, was made with plywood, glue, and pocket screws
  • Final assembly
    • The three large oak pieces were attached with latches, the headboard had cleats and bolts to attach to the side pieces, and the middle mattress support piece

Tools and materials

  • Tools
    • Table saw
    • Chop saw
    • Router
    • Circular saw
    • Drill
    • Planer
    • Joiner
  • Materials
    • Titebond III wood glue
    • Pocket screws
    • Plywood and Oakwood
    • Cleats
    • Bolts
    • Latches

Making an Alder Shoe Rack/Side Table

My 23 year old son told me he’d love a shoe rack in his new home that doubled as a side table for his sofa.  He’d been unable to find anything to buy that fit the dimensions, so I decided to build him one.

There were a few specifics that needed to be accounted for — the dimensions of the space, the color of wood that would complement his room, and the fact that they hang coats against the wall that the rack/table would abut…

He loves mid-century modern furniture — so I found and modified a style online to be able to hold 5 pairs of shoes, be the right height for the sofa table, and allow for the coats to co-exist.

I recently made a different shoe rack with mitered corners on the plywood sides — and was pretty unhappy with the results.  Solid wood is so much more forgiving for the occasional minor gap in the joint — because you can sand it down to make the flaw less visible.  I found plywood, however, having such a thin veneer, too easy to oversand and ended up with areas where the veneer was gone and the underlying ply exposed.

But I knew a plain butt joint wouldn’t provide enough stability.  I decided instead to do two things to strengthen the joints in the plywood pieces:  I created a hidden spline joint, and I added a 2″ back strip to each shelf to support the entire structure.

 

That left all the plywood edges exposed, which I’d planned to cover with iron-on edge veneer.  In my cabinet-making days (decades ago!) I’d regularly made plywood shelves with edge veneer without problem.  But in this project, this is where the headaches got the worst!

I ironed the edge veneer on each board before assembling the piece.  The edge tape is 7/8″ wide, so there’s a good amount to remove till it’s the proper width for the plywood.  I sanded each piece down, only to discover that I’d inadvertently sanded through the plywood veneer in places.

Additionally, once I put the pieces together, additional sanding went through parts of the edge veneer AND the plywood veneer!  I cannot even count how many re-dos I did of the edge veneer — which was far more challenging now that the piece was assembled and everything had to fit exactly.

I finished the piece in oil based varathane to warm up the color a bit.   In the end it came out okay.  Most of the flaws were in the back, which won’t show being against the sofa. (My son was pleased, most importantly)

I’ve thought about how I’d do it differently next time.  I don’t know how easily I could find a thicker veneered plywood, but I’d swear the veneer was thicker in the old days…!

I’d definitely invest in an edge veneer trimmer to lessen the sanding I was doing.

And I’ll likely lean more towards using solid wood vs plywood in future projects!

laser etched rubber stamps

Adventure in Rubber Stamp Making

So Ace is working on a holiday card and we need rubber stamps for some of the art. This is the tale of making rubbers stamps including all the mistakes on our 100w CO2 Laser.

Materials used

  • Scrap wood
  • Gorilla Spray Glue
  • Craft Foam
  • Art Ink pads
  • Laser Engravable Rubber Polymer, low odor, from rubber-stamp.com

The artwork

The artwork… that is the first place things went wonky but I didn’t realize it until I cut. I had forgotten that engraving needed an outer boundary in order to drop out the right stuff. Check out these screenshots. Everything black in these images will be burned away.

The thing to remember with vector laser files, LaserSoft, and rubber stamps is:

  • Mirror the art
  • Set an outer boundary for the etching
  • The outer boundary is the same as the cut line so you will need one object to be the boundary and one object on another layer to be the cut line.
laser art
In this file, I forgot to put an outer boundary for the vector etching and that means all the white bits between the pink cut line and the inner art is what will print when I stamp it. Not ideal.
Laser art
In this one most of the art is correct and all the inner graphics that are white will print. The only thing that is wonk is the white gap between the pink cut line and the etching. That is easily solved though post-laser with a pair of scissors.
bad rubber stamp
Opps… etched away the thing I wanted to stamp.
laser etched rubber stamps
The actual art I wanted to stamp.

 

 

 

 

 

 

 

 

 

Here are the results from the two files. As you can see the art in the first file didn’t match the intention.

Testing and getting the right settings down

The laser polymer comes with some settings but they are for much lower wattage lasers than ours.

settings from laser package

It took a bunch of test etching to get to settings that worked. I used a focus range for etching. These are the settings we finally settled on:

  • Cutting: 15/90/87
  • Etching: 150/80/78 (make sure to turn on grade engrave)

Putting it together and what I learned about glue

So I cut the outlines out of some scrap wood and used e6000 glue to attach the rubber bit. The results were… bad.

rubber-bad-glue
Hard curled up crumbling stamps.

The final product did work out well with a layer of craft foam and using gorilla spray glue.

The post-laser etching finishing and clean up

Laser etching rubber polymer is dirty. Really dirty. When the stamps come off the laser they should be soaked in the water right away for about 10 – 15 min. then scrubbed with a soft brush.

This is what a brand new filter looked like after 8.1min. of cutting and etching laser.

Dirt filter after cutting laser polymer next to new filter material.
festival mask

Hack your mask with valves

The “dirt-bike” or sports dust masks are really popular. A lot of folks know them from using them at events like Burning Man and Coachella. The issue with a lot of “dirt bike” style masks is the exhalation valves which are totally unfiltered. This makes these masks pretty useless for COVID-19 safety. You can read more about what the CDC says about masks with valves.

Everything I used for this 2-min hack:

  • CLUX Mesh Black Face Mask with Black Carbon Filter by Continental Luxury (amazon)
  • small (not tiny) rubber bands – one for each valve
  • Scissors
  • Non-Woven Polypropylene Fabric (woven fabric will work too)

I assembled the mask according to manufacturers’ directions. I cut the filter fabric to go over the valve with a very generous overlap – you can always cut off the excess. Then I slipped the rubber band over 2 layers of filter fabric to secure it to the Valve. This covers the valve and any leaky spots around the opening.

sport mask disassembled
Sport mask as it comes all disassembled. Most of these require assembly.
value hole on mesh part of the mask
The valve hole in the mask without the “hardware”
fabric, mask, and rubber band
Assembled mask with quick filter materials
filtered valve
the filter “value-cover” takes about 3 seconds to put on.
filtered valve close up
the “valve-cover” close up
respirator and tools

Respirator Hack for Covid

So the issue with a lot of respirators and dust masks is the exhalation valve which is totally unfiltered. This makes them pretty useless for COVID-19 safety. You can read more about what the CDC says about masks with valves.

Everything I used for this 5-min hack:

  • 3M Rugged Comfort Half Facepiece Reusable Respirator 6502QL (Medium)
  • Electrical tape
  • Scissors
  • Non-Woven Polypropylene Fabric (woven fabric will work too)

Check out the gallery below to see how I added a filter to my valve. I specifically added it to the outside so it would last longer before getting moist and so others could see it. I used two layers of material for the filter.